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Diffstat (limited to 'tk8.6/generic/tkTextBTree.c')
| -rw-r--r-- | tk8.6/generic/tkTextBTree.c | 4895 |
1 files changed, 4895 insertions, 0 deletions
diff --git a/tk8.6/generic/tkTextBTree.c b/tk8.6/generic/tkTextBTree.c new file mode 100644 index 0000000..81e31dc --- /dev/null +++ b/tk8.6/generic/tkTextBTree.c @@ -0,0 +1,4895 @@ +/* + * tkTextBTree.c -- + * + * This file contains code that manages the B-tree representation of text + * for Tk's text widget and implements character and toggle segment + * types. + * + * Copyright (c) 1992-1994 The Regents of the University of California. + * Copyright (c) 1994-1995 Sun Microsystems, Inc. + * + * See the file "license.terms" for information on usage and redistribution of + * this file, and for a DISCLAIMER OF ALL WARRANTIES. + */ + +#include "tkInt.h" +#include "tkText.h" + +/* + * Implementation notes: + * + * Most of this file is independent of the text widget implementation and + * representation now. Without much effort this could be developed further + * into a new Tcl object type of which the Tk text widget is one example of a + * client. + * + * The B-tree is set up with a dummy last line of text which must not be + * displayed, and must _never_ have a non-zero pixel count. This dummy line is + * a historical convenience to avoid other code having to deal with NULL + * TkTextLines. Since Tk 8.5, with pixel line height calculations and peer + * widgets, this dummy line is becoming somewhat of a liability, and special + * case code has been required to deal with it. It is probably a good idea to + * investigate removing the dummy line completely. This could result in an + * overall simplification (although it would require new special case code to + * deal with the fact that '.text index end' would then not really point to a + * valid line, rather it would point to the beginning of a non-existent line + * one beyond all current lines - we could perhaps define that as a + * TkTextIndex with a NULL TkTextLine ptr). + */ + +/* + * The data structure below keeps summary information about one tag as part of + * the tag information in a node. + */ + +typedef struct Summary { + TkTextTag *tagPtr; /* Handle for tag. */ + int toggleCount; /* Number of transitions into or out of this + * tag that occur in the subtree rooted at + * this node. */ + struct Summary *nextPtr; /* Next in list of all tags for same node, or + * NULL if at end of list. */ +} Summary; + +/* + * The data structure below defines a node in the B-tree. + */ + +typedef struct Node { + struct Node *parentPtr; /* Pointer to parent node, or NULL if this is + * the root. */ + struct Node *nextPtr; /* Next in list of siblings with the same + * parent node, or NULL for end of list. */ + Summary *summaryPtr; /* First in malloc-ed list of info about tags + * in this subtree (NULL if no tag info in the + * subtree). */ + int level; /* Level of this node in the B-tree. 0 refers + * to the bottom of the tree (children are + * lines, not nodes). */ + union { /* First in linked list of children. */ + struct Node *nodePtr; /* Used if level > 0. */ + TkTextLine *linePtr; /* Used if level == 0. */ + } children; + int numChildren; /* Number of children of this node. */ + int numLines; /* Total number of lines (leaves) in the + * subtree rooted here. */ + int *numPixels; /* Array containing total number of vertical + * display pixels in the subtree rooted here, + * one entry for each peer widget. */ +} Node; + +/* + * Used to avoid having to allocate and deallocate arrays on the fly for + * commonly used functions. Must be > 0. + */ + +#define PIXEL_CLIENTS 5 + +/* + * Upper and lower bounds on how many children a node may have: rebalance when + * either of these limits is exceeded. MAX_CHILDREN should be twice + * MIN_CHILDREN and MIN_CHILDREN must be >= 2. + */ + +#define MAX_CHILDREN 12 +#define MIN_CHILDREN 6 + +/* + * The data structure below defines an entire B-tree. Since text widgets are + * the only current B-tree clients, 'clients' and 'pixelReferences' are + * identical. + */ + +typedef struct BTree { + Node *rootPtr; /* Pointer to root of B-tree. */ + int clients; /* Number of clients of this B-tree. */ + int pixelReferences; /* Number of clients of this B-tree which care + * about pixel heights. */ + int stateEpoch; /* Updated each time any aspect of the B-tree + * changes. */ + TkSharedText *sharedTextPtr;/* Used to find tagTable in consistency + * checking code, and to access list of all + * B-tree clients. */ + int startEndCount; + TkTextLine **startEnd; + TkText **startEndRef; +} BTree; + +/* + * The structure below is used to pass information between + * TkBTreeGetTags and IncCount: + */ + +typedef struct TagInfo { + int numTags; /* Number of tags for which there is currently + * information in tags and counts. */ + int arraySize; /* Number of entries allocated for tags and + * counts. */ + TkTextTag **tagPtrs; /* Array of tags seen so far. Malloc-ed. */ + int *counts; /* Toggle count (so far) for each entry in + * tags. Malloc-ed. */ +} TagInfo; + +/* + * Variable that indicates whether to enable consistency checks for debugging. + */ + +int tkBTreeDebug = 0; + +/* + * Macros that determine how much space to allocate for new segments: + */ + +#define CSEG_SIZE(chars) ((unsigned) (Tk_Offset(TkTextSegment, body) \ + + 1 + (chars))) +#define TSEG_SIZE ((unsigned) (Tk_Offset(TkTextSegment, body) \ + + sizeof(TkTextToggle))) + +/* + * Forward declarations for functions defined in this file: + */ + +static int AdjustPixelClient(BTree *treePtr, int defaultHeight, + Node *nodePtr, TkTextLine *start, TkTextLine *end, + int useReference, int newPixelReferences, + int *counting); +static void ChangeNodeToggleCount(Node *nodePtr, + TkTextTag *tagPtr, int delta); +static void CharCheckProc(TkTextSegment *segPtr, + TkTextLine *linePtr); +static int CharDeleteProc(TkTextSegment *segPtr, + TkTextLine *linePtr, int treeGone); +static TkTextSegment * CharCleanupProc(TkTextSegment *segPtr, + TkTextLine *linePtr); +static TkTextSegment * CharSplitProc(TkTextSegment *segPtr, int index); +static void CheckNodeConsistency(Node *nodePtr, int references); +static void CleanupLine(TkTextLine *linePtr); +static void DeleteSummaries(Summary *tagPtr); +static void DestroyNode(Node *nodePtr); +static TkTextSegment * FindTagEnd(TkTextBTree tree, TkTextTag *tagPtr, + TkTextIndex *indexPtr); +static void IncCount(TkTextTag *tagPtr, int inc, + TagInfo *tagInfoPtr); +static void Rebalance(BTree *treePtr, Node *nodePtr); +static void RecomputeNodeCounts(BTree *treePtr, Node *nodePtr); +static void RemovePixelClient(BTree *treePtr, Node *nodePtr, + int overwriteWithLast); +static TkTextSegment * SplitSeg(TkTextIndex *indexPtr); +static void ToggleCheckProc(TkTextSegment *segPtr, + TkTextLine *linePtr); +static TkTextSegment * ToggleCleanupProc(TkTextSegment *segPtr, + TkTextLine *linePtr); +static int ToggleDeleteProc(TkTextSegment *segPtr, + TkTextLine *linePtr, int treeGone); +static void ToggleLineChangeProc(TkTextSegment *segPtr, + TkTextLine *linePtr); +static TkTextSegment * FindTagStart(TkTextBTree tree, TkTextTag *tagPtr, + TkTextIndex *indexPtr); +static void AdjustStartEndRefs(BTree *treePtr, TkText *textPtr, + int action); + +/* + * Actions for use by AdjustStartEndRefs + */ + +#define TEXT_ADD_REFS 1 +#define TEXT_REMOVE_REFS 2 + +/* + * Type record for character segments: + */ + +const Tk_SegType tkTextCharType = { + "character", /* name */ + 0, /* leftGravity */ + CharSplitProc, /* splitProc */ + CharDeleteProc, /* deleteProc */ + CharCleanupProc, /* cleanupProc */ + NULL, /* lineChangeProc */ + TkTextCharLayoutProc, /* layoutProc */ + CharCheckProc /* checkProc */ +}; + +/* + * Type record for segments marking the beginning of a tagged range: + */ + +const Tk_SegType tkTextToggleOnType = { + "toggleOn", /* name */ + 0, /* leftGravity */ + NULL, /* splitProc */ + ToggleDeleteProc, /* deleteProc */ + ToggleCleanupProc, /* cleanupProc */ + ToggleLineChangeProc, /* lineChangeProc */ + NULL, /* layoutProc */ + ToggleCheckProc /* checkProc */ +}; + +/* + * Type record for segments marking the end of a tagged range: + */ + +const Tk_SegType tkTextToggleOffType = { + "toggleOff", /* name */ + 1, /* leftGravity */ + NULL, /* splitProc */ + ToggleDeleteProc, /* deleteProc */ + ToggleCleanupProc, /* cleanupProc */ + ToggleLineChangeProc, /* lineChangeProc */ + NULL, /* layoutProc */ + ToggleCheckProc /* checkProc */ +}; + +/* + *---------------------------------------------------------------------- + * + * TkBTreeCreate -- + * + * This function is called to create a new text B-tree. + * + * Results: + * The return value is a pointer to a new B-tree containing one line with + * nothing but a newline character. + * + * Side effects: + * Memory is allocated and initialized. + * + *---------------------------------------------------------------------- + */ + +TkTextBTree +TkBTreeCreate( + TkSharedText *sharedTextPtr) +{ + register BTree *treePtr; + register Node *rootPtr; + register TkTextLine *linePtr, *linePtr2; + register TkTextSegment *segPtr; + + /* + * The tree will initially have two empty lines. The second line isn't + * actually part of the tree's contents, but its presence makes several + * operations easier. The tree will have one node, which is also the root + * of the tree. + */ + + rootPtr = ckalloc(sizeof(Node)); + linePtr = ckalloc(sizeof(TkTextLine)); + linePtr2 = ckalloc(sizeof(TkTextLine)); + + rootPtr->parentPtr = NULL; + rootPtr->nextPtr = NULL; + rootPtr->summaryPtr = NULL; + rootPtr->level = 0; + rootPtr->children.linePtr = linePtr; + rootPtr->numChildren = 2; + rootPtr->numLines = 2; + + /* + * The tree currently has no registered clients, so all pixel count + * pointers are simply NULL. + */ + + rootPtr->numPixels = NULL; + linePtr->pixels = NULL; + linePtr2->pixels = NULL; + + linePtr->parentPtr = rootPtr; + linePtr->nextPtr = linePtr2; + segPtr = ckalloc(CSEG_SIZE(1)); + linePtr->segPtr = segPtr; + segPtr->typePtr = &tkTextCharType; + segPtr->nextPtr = NULL; + segPtr->size = 1; + segPtr->body.chars[0] = '\n'; + segPtr->body.chars[1] = 0; + + linePtr2->parentPtr = rootPtr; + linePtr2->nextPtr = NULL; + segPtr = ckalloc(CSEG_SIZE(1)); + linePtr2->segPtr = segPtr; + segPtr->typePtr = &tkTextCharType; + segPtr->nextPtr = NULL; + segPtr->size = 1; + segPtr->body.chars[0] = '\n'; + segPtr->body.chars[1] = 0; + + treePtr = ckalloc(sizeof(BTree)); + treePtr->sharedTextPtr = sharedTextPtr; + treePtr->rootPtr = rootPtr; + treePtr->clients = 0; + treePtr->stateEpoch = 0; + treePtr->pixelReferences = 0; + treePtr->startEndCount = 0; + treePtr->startEnd = NULL; + treePtr->startEndRef = NULL; + + return (TkTextBTree) treePtr; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeAddClient -- + * + * This function is called to provide a client with access to a given + * B-tree. If the client wishes to make use of the B-tree's pixel height + * storage, caching and calculation mechanisms, then a non-negative + * 'defaultHeight' must be provided. In this case the return value is a + * pixel tree reference which must be provided in all of the B-tree API + * which refers to or modifies pixel heights: + * + * TkBTreeAdjustPixelHeight, + * TkBTreeFindPixelLine, + * TkBTreeNumPixels, + * TkBTreePixelsTo, + * (and two private functions AdjustPixelClient, RemovePixelClient). + * + * If this is not provided, then the above functions must never be called + * for this client. + * + * Results: + * The return value is the pixelReference used by the B-tree to refer to + * pixel counts for the new client. It should be stored by the caller. If + * defaultHeight was negative, then the return value will be -1. + * + * Side effects: + * Memory may be allocated and initialized. + * + *---------------------------------------------------------------------- + */ + +void +TkBTreeAddClient( + TkTextBTree tree, /* B-tree to add a client to. */ + TkText *textPtr, /* Client to add. */ + int defaultHeight) /* Default line height for the new client, or + * -1 if no pixel heights are to be kept. */ +{ + register BTree *treePtr = (BTree *) tree; + + if (treePtr == NULL) { + Tcl_Panic("NULL treePtr in TkBTreeAddClient"); + } + + if (textPtr->start != NULL || textPtr->end != NULL) { + AdjustStartEndRefs(treePtr, textPtr, TEXT_ADD_REFS); + } + + if (defaultHeight >= 0) { + TkTextLine *end; + int counting = (textPtr->start == NULL ? 1 : 0); + int useReference = treePtr->pixelReferences; + + /* + * We must set the 'end' value in AdjustPixelClient so that the last + * dummy line in the B-tree doesn't contain a pixel height. + */ + + end = textPtr->end; + if (end == NULL) { + end = TkBTreeFindLine(tree, NULL, TkBTreeNumLines(tree, NULL)); + } + AdjustPixelClient(treePtr, defaultHeight, treePtr->rootPtr, + textPtr->start, end, useReference, useReference+1, &counting); + + textPtr->pixelReference = useReference; + treePtr->pixelReferences++; + } else { + textPtr->pixelReference = -1; + } + treePtr->clients++; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeClientRangeChanged -- + * + * Called when the -startline or -endline options of a text widget client + * of the B-tree have changed. + * + * Results: + * None. + * + * Side effects: + * Lots of processing of the B-tree is done, with potential for memory to + * be allocated and initialized for the pixel heights of the widget. + * + *---------------------------------------------------------------------- + */ + +void +TkBTreeClientRangeChanged( + TkText *textPtr, /* Client whose start, end have changed. */ + int defaultHeight) /* Default line height for the new client, or + * -1 if no pixel heights are to be kept. */ +{ + TkTextLine *end; + BTree *treePtr = (BTree *) textPtr->sharedTextPtr->tree; + + int counting = (textPtr->start == NULL ? 1 : 0); + int useReference = textPtr->pixelReference; + + AdjustStartEndRefs(treePtr, textPtr, TEXT_ADD_REFS | TEXT_REMOVE_REFS); + + /* + * We must set the 'end' value in AdjustPixelClient so that the last dummy + * line in the B-tree doesn't contain a pixel height. + */ + + end = textPtr->end; + if (end == NULL) { + end = TkBTreeFindLine(textPtr->sharedTextPtr->tree, + NULL, TkBTreeNumLines(textPtr->sharedTextPtr->tree, NULL)); + } + AdjustPixelClient(treePtr, defaultHeight, treePtr->rootPtr, + textPtr->start, end, useReference, treePtr->pixelReferences, + &counting); +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeDestroy -- + * + * Delete a B-tree, recycling all of the storage it contains. + * + * Results: + * The tree is deleted, so 'tree' should never again be used. + * + * Side effects: + * Memory is freed. + * + *---------------------------------------------------------------------- + */ + +void +TkBTreeDestroy( + TkTextBTree tree) /* Tree to clean up. */ +{ + BTree *treePtr = (BTree *) tree; + + /* + * There's no need to loop over each client of the tree, calling + * 'TkBTreeRemoveClient', since the 'DestroyNode' will clean everything up + * itself. + */ + + DestroyNode(treePtr->rootPtr); + if (treePtr->startEnd != NULL) { + ckfree(treePtr->startEnd); + ckfree(treePtr->startEndRef); + } + ckfree(treePtr); +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeEpoch -- + * + * Return the epoch for the B-tree. This number is incremented any time + * anything changes in the tree. + * + * Results: + * The epoch number. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +int +TkBTreeEpoch( + TkTextBTree tree) /* Tree to get epoch for. */ +{ + BTree *treePtr = (BTree *) tree; + return treePtr->stateEpoch; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeRemoveClient -- + * + * Remove a client widget from its B-tree, cleaning up the pixel arrays + * which it uses if necessary. If this is the last such widget, we also + * destroy the whole tree. + * + * Results: + * All tree-specific aspects of the given client are deleted. If no more + * references exist, then the given tree is also deleted (in which case + * 'tree' must not be used again). + * + * Side effects: + * Memory may be freed. + * + *---------------------------------------------------------------------- + */ + +void +TkBTreeRemoveClient( + TkTextBTree tree, /* Tree to remove client from. */ + TkText *textPtr) /* Client to remove. */ +{ + BTree *treePtr = (BTree *) tree; + int pixelReference = textPtr->pixelReference; + + if (treePtr->clients == 1) { + /* + * The last reference to the tree. + */ + + DestroyNode(treePtr->rootPtr); + ckfree(treePtr); + return; + } else if (pixelReference == -1) { + /* + * A client which doesn't care about pixels. + */ + + treePtr->clients--; + } else { + /* + * Clean up pixel data for the given reference. + */ + + if (pixelReference == (treePtr->pixelReferences-1)) { + /* + * The widget we're removing has the last index, so deletion is + * easier. + */ + + RemovePixelClient(treePtr, treePtr->rootPtr, -1); + } else { + TkText *adjustPtr; + + RemovePixelClient(treePtr, treePtr->rootPtr, pixelReference); + + /* + * Now we need to adjust the 'pixelReference' of the peer widget + * whose storage we've just moved. + */ + + adjustPtr = treePtr->sharedTextPtr->peers; + while (adjustPtr != NULL) { + if (adjustPtr->pixelReference == treePtr->pixelReferences-1) { + adjustPtr->pixelReference = pixelReference; + break; + } + adjustPtr = adjustPtr->next; + } + if (adjustPtr == NULL) { + Tcl_Panic("Couldn't find text widget with correct reference"); + } + } + treePtr->pixelReferences--; + treePtr->clients--; + } + + if (textPtr->start != NULL || textPtr->end != NULL) { + AdjustStartEndRefs(treePtr, textPtr, TEXT_REMOVE_REFS); + } +} + +/* + *---------------------------------------------------------------------- + * + * AdjustStartEndRefs -- + * + * Modify B-tree's cache of start, end lines for the given text widget. + * + * Results: + * None. + * + * Side effects: + * The number of cached items may change (treePtr->startEndCount). + * + *---------------------------------------------------------------------- + */ + +static void +AdjustStartEndRefs( + BTree *treePtr, /* The entire B-tree. */ + TkText *textPtr, /* The text widget for which we want to adjust + * it's start and end cache. */ + int action) /* Action to perform. */ +{ + if (action & TEXT_REMOVE_REFS) { + int i = 0; + int count = 0; + + while (i < treePtr->startEndCount) { + if (i != count) { + treePtr->startEnd[count] = treePtr->startEnd[i]; + treePtr->startEndRef[count] = treePtr->startEndRef[i]; + } + if (treePtr->startEndRef[i] != textPtr) { + count++; + } + i++; + } + treePtr->startEndCount = count; + treePtr->startEnd = ckrealloc(treePtr->startEnd, + sizeof(TkTextLine *) * count); + treePtr->startEndRef = ckrealloc(treePtr->startEndRef, + sizeof(TkText *) * count); + } + if ((action & TEXT_ADD_REFS) + && (textPtr->start != NULL || textPtr->end != NULL)) { + int count; + + if (textPtr->start != NULL) { + treePtr->startEndCount++; + } + if (textPtr->end != NULL) { + treePtr->startEndCount++; + } + + count = treePtr->startEndCount; + + treePtr->startEnd = ckrealloc(treePtr->startEnd, + sizeof(TkTextLine *) * count); + treePtr->startEndRef = ckrealloc(treePtr->startEndRef, + sizeof(TkText *) * count); + + if (textPtr->start != NULL) { + count--; + treePtr->startEnd[count] = textPtr->start; + treePtr->startEndRef[count] = textPtr; + } + if (textPtr->end != NULL) { + count--; + treePtr->startEnd[count] = textPtr->end; + treePtr->startEndRef[count] = textPtr; + } + } +} + +/* + *---------------------------------------------------------------------- + * + * AdjustPixelClient -- + * + * Utility function used to update all data structures for the existence + * of a new peer widget based on this B-tree, or for the modification of + * the start, end lines of an existing peer widget. + * + * Immediately _after_ calling this, treePtr->pixelReferences and + * treePtr->clients should be adjusted if needed (i.e. if this is a new + * peer). + * + * Results: + * None. + * + * Side effects: + * All the storage for Nodes and TkTextLines in the tree may be adjusted. + * + *---------------------------------------------------------------------- + */ + +static int +AdjustPixelClient( + BTree *treePtr, /* Pointer to tree. */ + int defaultHeight, /* Default pixel line height, which can be + * zero. */ + Node *nodePtr, /* Adjust from this node downwards. */ + TkTextLine *start, /* First line for this pixel client. */ + TkTextLine *end, /* Last line for this pixel client. */ + int useReference, /* pixel reference for the client we are + * adding or changing. */ + int newPixelReferences, /* New number of pixel references to this + * B-tree. */ + int *counting) /* References an integer which is zero if + * we're outside the relevant range for this + * client, and 1 if we're inside. */ +{ + int pixelCount = 0; + + /* + * Traverse entire tree down from nodePtr, reallocating pixel structures + * for each Node and TkTextLine, adding room for the new peer's pixel + * information (1 extra int per Node, 2 extra ints per TkTextLine). Also + * copy the information from the last peer into the new space (so it + * contains something sensible). + */ + + if (nodePtr->level != 0) { + Node *loopPtr = nodePtr->children.nodePtr; + + while (loopPtr != NULL) { + pixelCount += AdjustPixelClient(treePtr, defaultHeight, loopPtr, + start, end, useReference, newPixelReferences, counting); + loopPtr = loopPtr->nextPtr; + } + } else { + register TkTextLine *linePtr = nodePtr->children.linePtr; + + while (linePtr != NULL) { + if (!*counting && (linePtr == start)) { + *counting = 1; + } + if (*counting && (linePtr == end)) { + *counting = 0; + } + if (newPixelReferences != treePtr->pixelReferences) { + linePtr->pixels = ckrealloc(linePtr->pixels, + sizeof(int) * 2 * newPixelReferences); + } + + /* + * Notice that for the very last line, we are never counting and + * therefore this always has a height of 0 and an epoch of 1. + */ + + linePtr->pixels[2*useReference] = (*counting ? defaultHeight : 0); + linePtr->pixels[2*useReference+1] = (*counting ? 0 : 1); + pixelCount += linePtr->pixels[2*useReference]; + + linePtr = linePtr->nextPtr; + } + } + if (newPixelReferences != treePtr->pixelReferences) { + nodePtr->numPixels = ckrealloc(nodePtr->numPixels, + sizeof(int) * newPixelReferences); + } + nodePtr->numPixels[useReference] = pixelCount; + return pixelCount; +} + +/* + *---------------------------------------------------------------------- + * + * RemovePixelClient -- + * + * Utility function used to update all data structures for the removal of + * a peer widget which used to be based on this B-tree. + * + * Immediately _after_ calling this, treePtr->clients should be + * decremented. + * + * Results: + * None. + * + * Side effects: + * All the storage for Nodes and TkTextLines in the tree may be adjusted. + * + *---------------------------------------------------------------------- + */ + +static void +RemovePixelClient( + BTree *treePtr, /* Pointer to tree. */ + Node *nodePtr, /* Adjust from this node downwards. */ + int overwriteWithLast) /* Over-write this peer widget's information + * with the last one. */ +{ + /* + * Traverse entire tree down from nodePtr, reallocating pixel structures + * for each Node and TkTextLine, removing space allocated for one peer. If + * 'overwriteWithLast' is not -1, then copy the information which was in + * the last slot on top of one of the others (i.e. it's not the last one + * we're deleting). + */ + + if (overwriteWithLast != -1) { + nodePtr->numPixels[overwriteWithLast] = + nodePtr->numPixels[treePtr->pixelReferences-1]; + } + if (treePtr->pixelReferences == 1) { + ckfree(nodePtr->numPixels); + nodePtr->numPixels = NULL; + } else { + nodePtr->numPixels = ckrealloc(nodePtr->numPixels, + sizeof(int) * (treePtr->pixelReferences - 1)); + } + if (nodePtr->level != 0) { + nodePtr = nodePtr->children.nodePtr; + while (nodePtr != NULL) { + RemovePixelClient(treePtr, nodePtr, overwriteWithLast); + nodePtr = nodePtr->nextPtr; + } + } else { + register TkTextLine *linePtr = nodePtr->children.linePtr; + while (linePtr != NULL) { + if (overwriteWithLast != -1) { + linePtr->pixels[2*overwriteWithLast] = + linePtr->pixels[2*(treePtr->pixelReferences-1)]; + linePtr->pixels[1+2*overwriteWithLast] = + linePtr->pixels[1+2*(treePtr->pixelReferences-1)]; + } + if (treePtr->pixelReferences == 1) { + linePtr->pixels = NULL; + } else { + linePtr->pixels = ckrealloc(linePtr->pixels, + sizeof(int) * 2 * (treePtr->pixelReferences-1)); + } + linePtr = linePtr->nextPtr; + } + } +} + +/* + *---------------------------------------------------------------------- + * + * DestroyNode -- + * + * This is a recursive utility function used during the deletion of a + * B-tree. + * + * Results: + * None. + * + * Side effects: + * All the storage for nodePtr and its descendants is freed. + * + *---------------------------------------------------------------------- + */ + +static void +DestroyNode( + register Node *nodePtr) /* Destroy from this node downwards. */ +{ + if (nodePtr->level == 0) { + TkTextLine *linePtr; + TkTextSegment *segPtr; + + while (nodePtr->children.linePtr != NULL) { + linePtr = nodePtr->children.linePtr; + nodePtr->children.linePtr = linePtr->nextPtr; + while (linePtr->segPtr != NULL) { + segPtr = linePtr->segPtr; + linePtr->segPtr = segPtr->nextPtr; + segPtr->typePtr->deleteProc(segPtr, linePtr, 1); + } + ckfree(linePtr->pixels); + ckfree(linePtr); + } + } else { + register Node *childPtr; + + while (nodePtr->children.nodePtr != NULL) { + childPtr = nodePtr->children.nodePtr; + nodePtr->children.nodePtr = childPtr->nextPtr; + DestroyNode(childPtr); + } + } + DeleteSummaries(nodePtr->summaryPtr); + ckfree(nodePtr->numPixels); + ckfree(nodePtr); +} + +/* + *---------------------------------------------------------------------- + * + * DeleteSummaries -- + * + * Free up all of the memory in a list of tag summaries associated with a + * node. + * + * Results: + * None. + * + * Side effects: + * Storage is released. + * + *---------------------------------------------------------------------- + */ + +static void +DeleteSummaries( + register Summary *summaryPtr) + /* First in list of node's tag summaries. */ +{ + register Summary *nextPtr; + + while (summaryPtr != NULL) { + nextPtr = summaryPtr->nextPtr; + ckfree(summaryPtr); + summaryPtr = nextPtr; + } +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeAdjustPixelHeight -- + * + * Adjust the pixel height of a given logical line to the specified + * value. + * + * Results: + * Total number of valid pixels currently known in the tree. + * + * Side effects: + * Updates overall data structures so pixel height count is consistent. + * + *---------------------------------------------------------------------- + */ + +int +TkBTreeAdjustPixelHeight( + const TkText *textPtr, /* Client of the B-tree. */ + register TkTextLine *linePtr, + /* The logical line to update. */ + int newPixelHeight, /* The line's known height in pixels. */ + int mergedLogicalLines) /* The number of extra logical lines which + * have been merged with this one (due to + * elided eols). They will have their pixel + * height set to zero, and the total pixel + * height associated with the given + * linePtr. */ +{ + register Node *nodePtr; + int changeToPixelCount; /* Counts change to total number of pixels in + * file. */ + int pixelReference = textPtr->pixelReference; + + changeToPixelCount = newPixelHeight - linePtr->pixels[2 * pixelReference]; + + /* + * Increment the pixel counts in all the parent nodes of the current line, + * then rebalance the tree if necessary. + */ + + nodePtr = linePtr->parentPtr; + nodePtr->numPixels[pixelReference] += changeToPixelCount; + + while (nodePtr->parentPtr != NULL) { + nodePtr = nodePtr->parentPtr; + nodePtr->numPixels[pixelReference] += changeToPixelCount; + } + + linePtr->pixels[2 * pixelReference] = newPixelHeight; + + /* + * Any merged logical lines must have their height set to zero. + */ + + while (mergedLogicalLines-- > 0) { + linePtr = TkBTreeNextLine(textPtr, linePtr); + TkBTreeAdjustPixelHeight(textPtr, linePtr, 0, 0); + } + + /* + * Return total number of pixels in the tree. + */ + + return nodePtr->numPixels[pixelReference]; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeInsertChars -- + * + * Insert characters at a given position in a B-tree. + * + * Results: + * None. + * + * Side effects: + * Characters are added to the B-tree at the given position. If the + * string contains newlines, new lines will be added, which could cause + * the structure of the B-tree to change. + * + *---------------------------------------------------------------------- + */ + +void +TkBTreeInsertChars( + TkTextBTree tree, /* Tree to insert into. */ + register TkTextIndex *indexPtr, + /* Indicates where to insert text. When the + * function returns, this index is no longer + * valid because of changes to the segment + * structure. */ + const char *string) /* Pointer to bytes to insert (may contain + * newlines, must be null-terminated). */ +{ + register Node *nodePtr; + register TkTextSegment *prevPtr; + /* The segment just before the first new + * segment (NULL means new segment is at + * beginning of line). */ + TkTextSegment *curPtr; /* Current segment; new characters are + * inserted just after this one. NULL means + * insert at beginning of line. */ + TkTextLine *linePtr; /* Current line (new segments are added to + * this line). */ + register TkTextSegment *segPtr; + TkTextLine *newLinePtr; + int chunkSize; /* # characters in current chunk. */ + register const char *eol; /* Pointer to character just after last one in + * current chunk. */ + int changeToLineCount; /* Counts change to total number of lines in + * file. */ + int *changeToPixelCount; /* Counts change to total number of pixels in + * file. */ + int ref; + int pixels[PIXEL_CLIENTS]; + + BTree *treePtr = (BTree *) tree; + treePtr->stateEpoch++; + prevPtr = SplitSeg(indexPtr); + linePtr = indexPtr->linePtr; + curPtr = prevPtr; + + /* + * Chop the string up into lines and create a new segment for each line, + * plus a new line for the leftovers from the previous line. + */ + + changeToLineCount = 0; + if (treePtr->pixelReferences > PIXEL_CLIENTS) { + changeToPixelCount = ckalloc(sizeof(int) * treePtr->pixelReferences); + } else { + changeToPixelCount = pixels; + } + for (ref = 0; ref < treePtr->pixelReferences; ref++) { + changeToPixelCount[ref] = 0; + } + + while (*string != 0) { + for (eol = string; *eol != 0; eol++) { + if (*eol == '\n') { + eol++; + break; + } + } + chunkSize = eol-string; + segPtr = ckalloc(CSEG_SIZE(chunkSize)); + segPtr->typePtr = &tkTextCharType; + if (curPtr == NULL) { + segPtr->nextPtr = linePtr->segPtr; + linePtr->segPtr = segPtr; + } else { + segPtr->nextPtr = curPtr->nextPtr; + curPtr->nextPtr = segPtr; + } + segPtr->size = chunkSize; + memcpy(segPtr->body.chars, string, (size_t) chunkSize); + segPtr->body.chars[chunkSize] = 0; + + if (eol[-1] != '\n') { + break; + } + + /* + * The chunk ended with a newline, so create a new TkTextLine and move + * the remainder of the old line to it. + */ + + newLinePtr = ckalloc(sizeof(TkTextLine)); + newLinePtr->pixels = + ckalloc(sizeof(int) * 2 * treePtr->pixelReferences); + + newLinePtr->parentPtr = linePtr->parentPtr; + newLinePtr->nextPtr = linePtr->nextPtr; + linePtr->nextPtr = newLinePtr; + newLinePtr->segPtr = segPtr->nextPtr; + + /* + * Set up a starting default height, which will be re-adjusted later. + * We need to do this for each referenced widget. + */ + + for (ref = 0; ref < treePtr->pixelReferences; ref++) { + newLinePtr->pixels[2 * ref] = linePtr->pixels[2 * ref]; + newLinePtr->pixels[2 * ref + 1] = 0; + changeToPixelCount[ref] += newLinePtr->pixels[2 * ref]; + } + + segPtr->nextPtr = NULL; + linePtr = newLinePtr; + curPtr = NULL; + changeToLineCount++; + + string = eol; + } + + /* + * I don't believe it's possible for either of the two lines passed to + * this function to be the last line of text, but the function is robust + * to that case anyway. (We must never re-calculate the line height of + * the last line). + */ + + TkTextInvalidateLineMetrics(treePtr->sharedTextPtr, NULL, + indexPtr->linePtr, changeToLineCount, TK_TEXT_INVALIDATE_INSERT); + + /* + * Cleanup the starting line for the insertion, plus the ending line if + * it's different. + */ + + CleanupLine(indexPtr->linePtr); + if (linePtr != indexPtr->linePtr) { + CleanupLine(linePtr); + } + + /* + * Increment the line and pixel counts in all the parent nodes of the + * insertion point, then rebalance the tree if necessary. + */ + + for (nodePtr = linePtr->parentPtr ; nodePtr != NULL; + nodePtr = nodePtr->parentPtr) { + nodePtr->numLines += changeToLineCount; + for (ref = 0; ref < treePtr->pixelReferences; ref++) { + nodePtr->numPixels[ref] += changeToPixelCount[ref]; + } + } + if (treePtr->pixelReferences > PIXEL_CLIENTS) { + ckfree(changeToPixelCount); + } + + nodePtr = linePtr->parentPtr; + nodePtr->numChildren += changeToLineCount; + if (nodePtr->numChildren > MAX_CHILDREN) { + Rebalance(treePtr, nodePtr); + } + + if (tkBTreeDebug) { + TkBTreeCheck(indexPtr->tree); + } +} + +/* + *-------------------------------------------------------------- + * + * SplitSeg -- + * + * This function is called before adding or deleting segments. It does + * three things: (a) it finds the segment containing indexPtr; (b) if + * there are several such segments (because some segments have zero + * length) then it picks the first segment that does not have left + * gravity; (c) if the index refers to the middle of a segment then it + * splits the segment so that the index now refers to the beginning of a + * segment. + * + * Results: + * The return value is a pointer to the segment just before the segment + * corresponding to indexPtr (as described above). If the segment + * corresponding to indexPtr is the first in its line then the return + * value is NULL. + * + * Side effects: + * The segment referred to by indexPtr is split unless indexPtr refers to + * its first character. + * + *-------------------------------------------------------------- + */ + +static TkTextSegment * +SplitSeg( + TkTextIndex *indexPtr) /* Index identifying position at which to + * split a segment. */ +{ + TkTextSegment *prevPtr, *segPtr; + TkTextLine *linePtr; + int count = indexPtr->byteIndex; + + linePtr = indexPtr->linePtr; + prevPtr = NULL; + segPtr = linePtr->segPtr; + + while (segPtr != NULL) { + if (segPtr->size > count) { + if (count == 0) { + return prevPtr; + } + segPtr = segPtr->typePtr->splitProc(segPtr, count); + if (prevPtr == NULL) { + indexPtr->linePtr->segPtr = segPtr; + } else { + prevPtr->nextPtr = segPtr; + } + return segPtr; + } else if ((segPtr->size == 0) && (count == 0) + && !segPtr->typePtr->leftGravity) { + return prevPtr; + } + + count -= segPtr->size; + prevPtr = segPtr; + segPtr = segPtr->nextPtr; + if (segPtr == NULL) { + /* + * Two logical lines merged into one display line through eliding + * of a newline. + */ + + linePtr = TkBTreeNextLine(NULL, linePtr); + if (linePtr == NULL) { + /* + * Reached end of the text. + */ + } else { + segPtr = linePtr->segPtr; + } + } + } + Tcl_Panic("SplitSeg reached end of line!"); + return NULL; +} + +/* + *-------------------------------------------------------------- + * + * CleanupLine -- + * + * This function is called after modifications have been made to a line. + * It scans over all of the segments in the line, giving each a chance to + * clean itself up, e.g. by merging with the following segments, updating + * internal information, etc. + * + * Results: + * None. + * + * Side effects: + * Depends on what the segment-specific cleanup functions do. + * + *-------------------------------------------------------------- + */ + +static void +CleanupLine( + TkTextLine *linePtr) /* Line to be cleaned up. */ +{ + TkTextSegment *segPtr, **prevPtrPtr; + int anyChanges; + + /* + * Make a pass over all of the segments in the line, giving each a chance + * to clean itself up. This could potentially change the structure of the + * line, e.g. by merging two segments together or having two segments + * cancel themselves; if so, then repeat the whole process again, since + * the first structure change might make other structure changes possible. + * Repeat until eventually there are no changes. + */ + + while (1) { + anyChanges = 0; + for (prevPtrPtr = &linePtr->segPtr, segPtr = *prevPtrPtr; + segPtr != NULL; + prevPtrPtr = &(*prevPtrPtr)->nextPtr, segPtr = *prevPtrPtr) { + if (segPtr->typePtr->cleanupProc != NULL) { + *prevPtrPtr = segPtr->typePtr->cleanupProc(segPtr, linePtr); + if (segPtr != *prevPtrPtr) { + anyChanges = 1; + } + } + } + if (!anyChanges) { + break; + } + } +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeDeleteIndexRange -- + * + * Delete a range of characters from a B-tree. The caller must make sure + * that the final newline of the B-tree is never deleted. + * + * Results: + * None. + * + * Side effects: + * Information is deleted from the B-tree. This can cause the internal + * structure of the B-tree to change. Note: because of changes to the + * B-tree structure, the indices pointed to by index1Ptr and index2Ptr + * should not be used after this function returns. + * + *---------------------------------------------------------------------- + */ + +void +TkBTreeDeleteIndexRange( + TkTextBTree tree, /* Tree to delete from. */ + register TkTextIndex *index1Ptr, + /* Indicates first character that is to be + * deleted. */ + register TkTextIndex *index2Ptr) + /* Indicates character just after the last one + * that is to be deleted. */ +{ + TkTextSegment *prevPtr; /* The segment just before the start of the + * deletion range. */ + TkTextSegment *lastPtr; /* The segment just after the end of the + * deletion range. */ + TkTextSegment *segPtr, *nextPtr; + TkTextLine *curLinePtr; + Node *curNodePtr, *nodePtr; + int changeToLineCount = 0; + int ref; + BTree *treePtr = (BTree *) tree; + + treePtr->stateEpoch++; + + /* + * Tricky point: split at index2Ptr first; otherwise the split at + * index2Ptr may invalidate segPtr and/or prevPtr. + */ + + lastPtr = SplitSeg(index2Ptr); + if (lastPtr != NULL) { + lastPtr = lastPtr->nextPtr; + } else { + lastPtr = index2Ptr->linePtr->segPtr; + } + prevPtr = SplitSeg(index1Ptr); + if (prevPtr != NULL) { + segPtr = prevPtr->nextPtr; + prevPtr->nextPtr = lastPtr; + } else { + segPtr = index1Ptr->linePtr->segPtr; + index1Ptr->linePtr->segPtr = lastPtr; + } + + /* + * Delete all of the segments between prevPtr and lastPtr. + */ + + curLinePtr = index1Ptr->linePtr; + + curNodePtr = curLinePtr->parentPtr; + while (segPtr != lastPtr) { + if (segPtr == NULL) { + TkTextLine *nextLinePtr; + + /* + * We just ran off the end of a line. First find the next line, + * then go back to the old line and delete it (unless it's the + * starting line for the range). + */ + + nextLinePtr = TkBTreeNextLine(NULL, curLinePtr); + if (curLinePtr != index1Ptr->linePtr) { + if (curNodePtr == index1Ptr->linePtr->parentPtr) { + index1Ptr->linePtr->nextPtr = curLinePtr->nextPtr; + } else { + curNodePtr->children.linePtr = curLinePtr->nextPtr; + } + for (nodePtr = curNodePtr; nodePtr != NULL; + nodePtr = nodePtr->parentPtr) { + nodePtr->numLines--; + for (ref = 0; ref < treePtr->pixelReferences; ref++) { + nodePtr->numPixels[ref] -= curLinePtr->pixels[2*ref]; + } + } + changeToLineCount++; + CLANG_ASSERT(curNodePtr); + curNodePtr->numChildren--; + + /* + * Check if we need to adjust any partial clients. + */ + + if (treePtr->startEnd != NULL) { + int checkCount = 0; + + while (checkCount < treePtr->startEndCount) { + if (treePtr->startEnd[checkCount] == curLinePtr) { + TkText *peer = treePtr->startEndRef[checkCount]; + + /* + * We're deleting a line which is the start or end + * of a current client. This means we need to + * adjust that client. + */ + + treePtr->startEnd[checkCount] = nextLinePtr; + if (peer->start == curLinePtr) { + peer->start = nextLinePtr; + } + if (peer->end == curLinePtr) { + peer->end = nextLinePtr; + } + } + checkCount++; + } + } + ckfree(curLinePtr->pixels); + ckfree(curLinePtr); + } + curLinePtr = nextLinePtr; + segPtr = curLinePtr->segPtr; + + /* + * If the node is empty then delete it and its parents recursively + * upwards until a non-empty node is found. + */ + + while (curNodePtr->numChildren == 0) { + Node *parentPtr; + + parentPtr = curNodePtr->parentPtr; + if (parentPtr->children.nodePtr == curNodePtr) { + parentPtr->children.nodePtr = curNodePtr->nextPtr; + } else { + Node *prevNodePtr = parentPtr->children.nodePtr; + while (prevNodePtr->nextPtr != curNodePtr) { + prevNodePtr = prevNodePtr->nextPtr; + } + prevNodePtr->nextPtr = curNodePtr->nextPtr; + } + parentPtr->numChildren--; + DeleteSummaries(curNodePtr->summaryPtr); + ckfree(curNodePtr->numPixels); + ckfree(curNodePtr); + curNodePtr = parentPtr; + } + curNodePtr = curLinePtr->parentPtr; + continue; + } + + nextPtr = segPtr->nextPtr; + if (segPtr->typePtr->deleteProc(segPtr, curLinePtr, 0) != 0) { + /* + * This segment refuses to die. Move it to prevPtr and advance + * prevPtr if the segment has left gravity. + */ + + if (prevPtr == NULL) { + segPtr->nextPtr = index1Ptr->linePtr->segPtr; + index1Ptr->linePtr->segPtr = segPtr; + } else { + segPtr->nextPtr = prevPtr->nextPtr; + prevPtr->nextPtr = segPtr; + } + if (segPtr->typePtr->leftGravity) { + prevPtr = segPtr; + } + } + segPtr = nextPtr; + } + + /* + * If the beginning and end of the deletion range are in different lines, + * join the two lines together and discard the ending line. + */ + + if (index1Ptr->linePtr != index2Ptr->linePtr) { + TkTextLine *prevLinePtr; + + for (segPtr = lastPtr; segPtr != NULL; + segPtr = segPtr->nextPtr) { + if (segPtr->typePtr->lineChangeProc != NULL) { + segPtr->typePtr->lineChangeProc(segPtr, index2Ptr->linePtr); + } + } + curNodePtr = index2Ptr->linePtr->parentPtr; + for (nodePtr = curNodePtr; nodePtr != NULL; + nodePtr = nodePtr->parentPtr) { + nodePtr->numLines--; + for (ref = 0; ref < treePtr->pixelReferences; ref++) { + nodePtr->numPixels[ref] -= index2Ptr->linePtr->pixels[2*ref]; + } + } + changeToLineCount++; + curNodePtr->numChildren--; + prevLinePtr = curNodePtr->children.linePtr; + if (prevLinePtr == index2Ptr->linePtr) { + curNodePtr->children.linePtr = index2Ptr->linePtr->nextPtr; + } else { + while (prevLinePtr->nextPtr != index2Ptr->linePtr) { + prevLinePtr = prevLinePtr->nextPtr; + } + prevLinePtr->nextPtr = index2Ptr->linePtr->nextPtr; + } + + /* + * Check if we need to adjust any partial clients. In this case if + * we're deleting the line, we actually move back to the previous line + * for our (start,end) storage. We do this because we still want the + * portion of the second line that still exists to be in the start,end + * range. + */ + + if (treePtr->startEnd != NULL) { + int checkCount = 0; + + while (checkCount < treePtr->startEndCount && + treePtr->startEnd[checkCount] != NULL) { + if (treePtr->startEnd[checkCount] == index2Ptr->linePtr) { + TkText *peer = treePtr->startEndRef[checkCount]; + + /* + * We're deleting a line which is the start or end of a + * current client. This means we need to adjust that + * client. + */ + + treePtr->startEnd[checkCount] = index1Ptr->linePtr; + if (peer->start == index2Ptr->linePtr) { + peer->start = index1Ptr->linePtr; + } + if (peer->end == index2Ptr->linePtr) { + peer->end = index1Ptr->linePtr; + } + } + checkCount++; + } + } + ckfree(index2Ptr->linePtr->pixels); + ckfree(index2Ptr->linePtr); + + Rebalance((BTree *) index2Ptr->tree, curNodePtr); + } + + /* + * Cleanup the segments in the new line. + */ + + CleanupLine(index1Ptr->linePtr); + + /* + * This line now needs to have its height recalculated. For safety, ensure + * we don't call this function with the last artificial line of text. I + * _believe_ that it isn't possible to get this far with the last line, + * but it is good to be safe. + */ + + if (TkBTreeNextLine(NULL, index1Ptr->linePtr) != NULL) { + TkTextInvalidateLineMetrics(treePtr->sharedTextPtr, NULL, + index1Ptr->linePtr, changeToLineCount, + TK_TEXT_INVALIDATE_DELETE); + } + + /* + * Lastly, rebalance the first node of the range. + */ + + Rebalance((BTree *) index1Ptr->tree, index1Ptr->linePtr->parentPtr); + if (tkBTreeDebug) { + TkBTreeCheck(index1Ptr->tree); + } +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeFindLine -- + * + * Find a particular line in a B-tree based on its line number. + * + * Results: + * The return value is a pointer to the line structure for the line whose + * index is "line", or NULL if no such line exists. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +TkTextLine * +TkBTreeFindLine( + TkTextBTree tree, /* B-tree in which to find line. */ + const TkText *textPtr, /* Relative to this client of the B-tree. */ + int line) /* Index of desired line. */ +{ + BTree *treePtr = (BTree *) tree; + register Node *nodePtr; + register TkTextLine *linePtr; + + if (treePtr == NULL) { + treePtr = (BTree *) textPtr->sharedTextPtr->tree; + } + + nodePtr = treePtr->rootPtr; + if ((line < 0) || (line >= nodePtr->numLines)) { + return NULL; + } + + /* + * Check for any start/end offset for this text widget. + */ + + if (textPtr != NULL) { + if (textPtr->start != NULL) { + line += TkBTreeLinesTo(NULL, textPtr->start); + if (line >= nodePtr->numLines) { + return NULL; + } + } + if (textPtr->end != NULL) { + if (line > TkBTreeLinesTo(NULL, textPtr->end)) { + return NULL; + } + } + } + + /* + * Work down through levels of the tree until a node is found at level 0. + */ + + while (nodePtr->level != 0) { + for (nodePtr = nodePtr->children.nodePtr; + nodePtr->numLines <= line; + nodePtr = nodePtr->nextPtr) { + if (nodePtr == NULL) { + Tcl_Panic("TkBTreeFindLine ran out of nodes"); + } + line -= nodePtr->numLines; + } + } + + /* + * Work through the lines attached to the level-0 node. + */ + + for (linePtr = nodePtr->children.linePtr; line > 0; + linePtr = linePtr->nextPtr) { + if (linePtr == NULL) { + Tcl_Panic("TkBTreeFindLine ran out of lines"); + } + line -= 1; + } + return linePtr; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeFindPixelLine -- + * + * Find a particular line in a B-tree based on its pixel count. + * + * Results: + * The return value is a pointer to the line structure for the line which + * contains the pixel "pixels", or NULL if no such line exists. If the + * first line is of height 20, then pixels 0-19 will return it, and + * pixels = 20 will return the next line. + * + * If pixelOffset is non-NULL, it is set to the amount by which 'pixels' + * exceeds the first pixel located on the returned line. This should + * always be non-negative. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +TkTextLine * +TkBTreeFindPixelLine( + TkTextBTree tree, /* B-tree to use. */ + const TkText *textPtr, /* Relative to this client of the B-tree. */ + int pixels, /* Pixel index of desired line. */ + int *pixelOffset) /* Used to return offset. */ +{ + BTree *treePtr = (BTree *) tree; + register Node *nodePtr; + register TkTextLine *linePtr; + int pixelReference = textPtr->pixelReference; + + nodePtr = treePtr->rootPtr; + + if ((pixels < 0) || (pixels > nodePtr->numPixels[pixelReference])) { + return NULL; + } + + if (nodePtr->numPixels[pixelReference] == 0) { + Tcl_Panic("TkBTreeFindPixelLine called with empty window"); + } + + /* + * Work down through levels of the tree until a node is found at level 0. + */ + + while (nodePtr->level != 0) { + for (nodePtr = nodePtr->children.nodePtr; + nodePtr->numPixels[pixelReference] <= pixels; + nodePtr = nodePtr->nextPtr) { + if (nodePtr == NULL) { + Tcl_Panic("TkBTreeFindPixelLine ran out of nodes"); + } + pixels -= nodePtr->numPixels[pixelReference]; + } + } + + /* + * Work through the lines attached to the level-0 node. + */ + + for (linePtr = nodePtr->children.linePtr; + linePtr->pixels[2 * pixelReference] < pixels; + linePtr = linePtr->nextPtr) { + if (linePtr == NULL) { + Tcl_Panic("TkBTreeFindPixelLine ran out of lines"); + } + pixels -= linePtr->pixels[2 * pixelReference]; + } + if (pixelOffset != NULL && linePtr != NULL) { + *pixelOffset = pixels; + } + return linePtr; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeNextLine -- + * + * Given an existing line in a B-tree, this function locates the next + * line in the B-tree. This function is used for scanning through the + * B-tree. + * + * Results: + * The return value is a pointer to the line that immediately follows + * linePtr, or NULL if there is no such line. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +TkTextLine * +TkBTreeNextLine( + const TkText *textPtr, /* Next line in the context of this client. */ + register TkTextLine *linePtr) + /* Pointer to existing line in B-tree. */ +{ + register Node *nodePtr; + + if (linePtr->nextPtr != NULL) { + if (textPtr != NULL && (linePtr == textPtr->end)) { + return NULL; + } else { + return linePtr->nextPtr; + } + } + + /* + * This was the last line associated with the particular parent node. + * Search up the tree for the next node, then search down from that node + * to find the first line. + */ + + for (nodePtr = linePtr->parentPtr; ; nodePtr = nodePtr->parentPtr) { + if (nodePtr->nextPtr != NULL) { + nodePtr = nodePtr->nextPtr; + break; + } + if (nodePtr->parentPtr == NULL) { + return NULL; + } + } + while (nodePtr->level > 0) { + nodePtr = nodePtr->children.nodePtr; + } + return nodePtr->children.linePtr; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreePreviousLine -- + * + * Given an existing line in a B-tree, this function locates the previous + * line in the B-tree. This function is used for scanning through the + * B-tree in the reverse direction. + * + * Results: + * The return value is a pointer to the line that immediately preceeds + * linePtr, or NULL if there is no such line. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +TkTextLine * +TkBTreePreviousLine( + TkText *textPtr, /* Relative to this client of the B-tree. */ + register TkTextLine *linePtr) + /* Pointer to existing line in B-tree. */ +{ + register Node *nodePtr; + register Node *node2Ptr; + register TkTextLine *prevPtr; + + if (textPtr != NULL && textPtr->start == linePtr) { + return NULL; + } + + /* + * Find the line under this node just before the starting line. + */ + + prevPtr = linePtr->parentPtr->children.linePtr; /* First line at leaf. */ + while (prevPtr != linePtr) { + if (prevPtr->nextPtr == linePtr) { + return prevPtr; + } + prevPtr = prevPtr->nextPtr; + if (prevPtr == NULL) { + Tcl_Panic("TkBTreePreviousLine ran out of lines"); + } + } + + /* + * This was the first line associated with the particular parent node. + * Search up the tree for the previous node, then search down from that + * node to find its last line. + */ + + for (nodePtr = linePtr->parentPtr; ; nodePtr = nodePtr->parentPtr) { + if (nodePtr == NULL || nodePtr->parentPtr == NULL) { + return NULL; + } + if (nodePtr != nodePtr->parentPtr->children.nodePtr) { + break; + } + } + for (node2Ptr = nodePtr->parentPtr->children.nodePtr; ; + node2Ptr = node2Ptr->children.nodePtr) { + while (node2Ptr->nextPtr != nodePtr) { + node2Ptr = node2Ptr->nextPtr; + } + if (node2Ptr->level == 0) { + break; + } + nodePtr = NULL; + } + for (prevPtr = node2Ptr->children.linePtr ; ; prevPtr = prevPtr->nextPtr) { + if (prevPtr->nextPtr == NULL) { + return prevPtr; + } + } +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreePixelsTo -- + * + * Given a pointer to a line in a B-tree, return the numerical pixel + * index of the top of that line (i.e. the result does not include the + * height of the given line). + * + * Since the last line of text (the artificial one) has zero height by + * defintion, calling this with the last line will return the total + * number of pixels in the widget. + * + * Results: + * The result is the pixel height of the top of the given line. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +int +TkBTreePixelsTo( + const TkText *textPtr, /* Relative to this client of the B-tree. */ + TkTextLine *linePtr) /* Pointer to existing line in B-tree. */ +{ + register TkTextLine *linePtr2; + register Node *nodePtr, *parentPtr; + int index; + int pixelReference = textPtr->pixelReference; + + /* + * First count how many pixels precede this line in its level-0 node. + */ + + nodePtr = linePtr->parentPtr; + index = 0; + for (linePtr2 = nodePtr->children.linePtr; linePtr2 != linePtr; + linePtr2 = linePtr2->nextPtr) { + if (linePtr2 == NULL) { + Tcl_Panic("TkBTreePixelsTo couldn't find line"); + } + index += linePtr2->pixels[2 * pixelReference]; + } + + /* + * Now work up through the levels of the tree one at a time, counting how + * many pixels are in nodes preceding the current node. + */ + + for (parentPtr = nodePtr->parentPtr ; parentPtr != NULL; + nodePtr = parentPtr, parentPtr = parentPtr->parentPtr) { + register Node *nodePtr2; + + for (nodePtr2 = parentPtr->children.nodePtr; nodePtr2 != nodePtr; + nodePtr2 = nodePtr2->nextPtr) { + if (nodePtr2 == NULL) { + Tcl_Panic("TkBTreePixelsTo couldn't find node"); + } + index += nodePtr2->numPixels[pixelReference]; + } + } + return index; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeLinesTo -- + * + * Given a pointer to a line in a B-tree, return the numerical index of + * that line. + * + * Results: + * The result is the index of linePtr within the tree, where 0 + * corresponds to the first line in the tree. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +int +TkBTreeLinesTo( + const TkText *textPtr, /* Relative to this client of the B-tree. */ + TkTextLine *linePtr) /* Pointer to existing line in B-tree. */ +{ + register TkTextLine *linePtr2; + register Node *nodePtr, *parentPtr, *nodePtr2; + int index; + + /* + * First count how many lines precede this one in its level-0 node. + */ + + nodePtr = linePtr->parentPtr; + index = 0; + for (linePtr2 = nodePtr->children.linePtr; linePtr2 != linePtr; + linePtr2 = linePtr2->nextPtr) { + if (linePtr2 == NULL) { + Tcl_Panic("TkBTreeLinesTo couldn't find line"); + } + index += 1; + } + + /* + * Now work up through the levels of the tree one at a time, counting how + * many lines are in nodes preceding the current node. + */ + + for (parentPtr = nodePtr->parentPtr ; parentPtr != NULL; + nodePtr = parentPtr, parentPtr = parentPtr->parentPtr) { + for (nodePtr2 = parentPtr->children.nodePtr; nodePtr2 != nodePtr; + nodePtr2 = nodePtr2->nextPtr) { + if (nodePtr2 == NULL) { + Tcl_Panic("TkBTreeLinesTo couldn't find node"); + } + index += nodePtr2->numLines; + } + } + if (textPtr != NULL) { + /* + * The index to return must be relative to textPtr, not to the entire + * tree. Take care to never return a negative index when linePtr + * denotes a line before -startline, or an index larger than the + * number of lines in textPtr when linePtr is a line past -endline. + */ + + int indexStart, indexEnd; + + if (textPtr->start != NULL) { + indexStart = TkBTreeLinesTo(NULL, textPtr->start); + } else { + indexStart = 0; + } + if (textPtr->end != NULL) { + indexEnd = TkBTreeLinesTo(NULL, textPtr->end); + } else { + indexEnd = TkBTreeNumLines(textPtr->sharedTextPtr->tree, NULL); + } + if (index < indexStart) { + index = 0; + } else if (index > indexEnd) { + index = TkBTreeNumLines(textPtr->sharedTextPtr->tree, textPtr); + } else { + index -= indexStart; + } + } + return index; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeLinkSegment -- + * + * This function adds a new segment to a B-tree at a given location. + * + * Results: + * None. + * + * Side effects: + * SegPtr will be linked into its tree. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +void +TkBTreeLinkSegment( + TkTextSegment *segPtr, /* Pointer to new segment to be added to + * B-tree. Should be completely initialized by + * caller except for nextPtr field. */ + TkTextIndex *indexPtr) /* Where to add segment: it gets linked in + * just before the segment indicated here. */ +{ + register TkTextSegment *prevPtr; + + prevPtr = SplitSeg(indexPtr); + if (prevPtr == NULL) { + segPtr->nextPtr = indexPtr->linePtr->segPtr; + indexPtr->linePtr->segPtr = segPtr; + } else { + segPtr->nextPtr = prevPtr->nextPtr; + prevPtr->nextPtr = segPtr; + } + CleanupLine(indexPtr->linePtr); + if (tkBTreeDebug) { + TkBTreeCheck(indexPtr->tree); + } + ((BTree *)indexPtr->tree)->stateEpoch++; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeUnlinkSegment -- + * + * This function unlinks a segment from its line in a B-tree. + * + * Results: + * None. + * + * Side effects: + * SegPtr will be unlinked from linePtr. The segment itself isn't + * modified by this function. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +void +TkBTreeUnlinkSegment( + TkTextSegment *segPtr, /* Segment to be unlinked. */ + TkTextLine *linePtr) /* Line that currently contains segment. */ +{ + register TkTextSegment *prevPtr; + + if (linePtr->segPtr == segPtr) { + linePtr->segPtr = segPtr->nextPtr; + } else { + prevPtr = linePtr->segPtr; + while (prevPtr->nextPtr != segPtr) { + prevPtr = prevPtr->nextPtr; + + if (prevPtr == NULL) { + /* + * Two logical lines merged into one display line through + * eliding of a newline. + */ + + linePtr = TkBTreeNextLine(NULL, linePtr); + prevPtr = linePtr->segPtr; + } + } + prevPtr->nextPtr = segPtr->nextPtr; + } + CleanupLine(linePtr); +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeTag -- + * + * Turn a given tag on or off for a given range of characters in a B-tree + * of text. + * + * Results: + * 1 if the tags on any characters in the range were changed, and zero + * otherwise (i.e. if the tag was already absent (add = 0) or present + * (add = 1) on the index range in question). + * + * Side effects: + * The given tag is added to the given range of characters in the tree or + * removed from all those characters, depending on the "add" argument. + * The structure of the btree is modified enough that index1Ptr and + * index2Ptr are no longer valid after this function returns, and the + * indexes may be modified by this function. + * + *---------------------------------------------------------------------- + */ + +int +TkBTreeTag( + register TkTextIndex *index1Ptr, + /* Indicates first character in range. */ + register TkTextIndex *index2Ptr, + /* Indicates character just after the last one + * in range. */ + TkTextTag *tagPtr, /* Tag to add or remove. */ + int add) /* One means add tag to the given range of + * characters; zero means remove the tag from + * the range. */ +{ + TkTextSegment *segPtr, *prevPtr; + TkTextSearch search; + TkTextLine *cleanupLinePtr; + int oldState, changed, anyChanges = 0; + + /* + * See whether the tag is present at the start of the range. If the state + * doesn't already match what we want then add a toggle there. + */ + + oldState = TkBTreeCharTagged(index1Ptr, tagPtr); + if ((add != 0) ^ oldState) { + segPtr = ckalloc(TSEG_SIZE); + segPtr->typePtr = (add) ? &tkTextToggleOnType : &tkTextToggleOffType; + prevPtr = SplitSeg(index1Ptr); + if (prevPtr == NULL) { + segPtr->nextPtr = index1Ptr->linePtr->segPtr; + index1Ptr->linePtr->segPtr = segPtr; + } else { + segPtr->nextPtr = prevPtr->nextPtr; + prevPtr->nextPtr = segPtr; + } + segPtr->size = 0; + segPtr->body.toggle.tagPtr = tagPtr; + segPtr->body.toggle.inNodeCounts = 0; + anyChanges = 1; + } + + /* + * Scan the range of characters and delete any internal tag transitions. + * Keep track of what the old state was at the end of the range, and add a + * toggle there if it's needed. + */ + + TkBTreeStartSearch(index1Ptr, index2Ptr, tagPtr, &search); + cleanupLinePtr = index1Ptr->linePtr; + while (TkBTreeNextTag(&search)) { + anyChanges = 1; + oldState ^= 1; + segPtr = search.segPtr; + prevPtr = search.curIndex.linePtr->segPtr; + if (prevPtr == segPtr) { + search.curIndex.linePtr->segPtr = segPtr->nextPtr; + } else { + while (prevPtr->nextPtr != segPtr) { + prevPtr = prevPtr->nextPtr; + } + prevPtr->nextPtr = segPtr->nextPtr; + } + if (segPtr->body.toggle.inNodeCounts) { + ChangeNodeToggleCount(search.curIndex.linePtr->parentPtr, + segPtr->body.toggle.tagPtr, -1); + segPtr->body.toggle.inNodeCounts = 0; + changed = 1; + } else { + changed = 0; + } + ckfree(segPtr); + + /* + * The code below is a bit tricky. After deleting a toggle we + * eventually have to call CleanupLine, in order to allow character + * segments to be merged together. To do this, we remember in + * cleanupLinePtr a line that needs to be cleaned up, but we don't + * clean it up until we've moved on to a different line. That way the + * cleanup process won't goof up segPtr. + */ + + if (cleanupLinePtr != search.curIndex.linePtr) { + CleanupLine(cleanupLinePtr); + cleanupLinePtr = search.curIndex.linePtr; + } + + /* + * Quick hack. ChangeNodeToggleCount may move the tag's root location + * around and leave the search in the void. This resets the search. + */ + + if (changed) { + TkBTreeStartSearch(index1Ptr, index2Ptr, tagPtr, &search); + } + } + if ((add != 0) ^ oldState) { + segPtr = ckalloc(TSEG_SIZE); + segPtr->typePtr = (add) ? &tkTextToggleOffType : &tkTextToggleOnType; + prevPtr = SplitSeg(index2Ptr); + if (prevPtr == NULL) { + segPtr->nextPtr = index2Ptr->linePtr->segPtr; + index2Ptr->linePtr->segPtr = segPtr; + } else { + segPtr->nextPtr = prevPtr->nextPtr; + prevPtr->nextPtr = segPtr; + } + segPtr->size = 0; + segPtr->body.toggle.tagPtr = tagPtr; + segPtr->body.toggle.inNodeCounts = 0; + anyChanges = 1; + } + + /* + * Cleanup cleanupLinePtr and the last line of the range, if these are + * different. + */ + + if (anyChanges) { + CleanupLine(cleanupLinePtr); + if (cleanupLinePtr != index2Ptr->linePtr) { + CleanupLine(index2Ptr->linePtr); + } + ((BTree *)index1Ptr->tree)->stateEpoch++; + } + + if (tkBTreeDebug) { + TkBTreeCheck(index1Ptr->tree); + } + return anyChanges; +} + +/* + *---------------------------------------------------------------------- + * + * ChangeNodeToggleCount -- + * + * This function increments or decrements the toggle count for a + * particular tag in a particular node and all its ancestors up to the + * per-tag root node. + * + * Results: + * None. + * + * Side effects: + * The toggle count for tag is adjusted up or down by "delta" in nodePtr. + * This routine maintains the tagRootPtr that identifies the root node + * for the tag, moving it up or down the tree as needed. + * + *---------------------------------------------------------------------- + */ + +static void +ChangeNodeToggleCount( + register Node *nodePtr, /* Node whose toggle count for a tag must be + * changed. */ + TkTextTag *tagPtr, /* Information about tag. */ + int delta) /* Amount to add to current toggle count for + * tag (may be negative). */ +{ + register Summary *summaryPtr, *prevPtr; + register Node *node2Ptr; + int rootLevel; /* Level of original tag root. */ + + tagPtr->toggleCount += delta; + if (tagPtr->tagRootPtr == NULL) { + tagPtr->tagRootPtr = nodePtr; + return; + } + + /* + * Note the level of the existing root for the tag so we can detect if it + * needs to be moved because of the toggle count change. + */ + + rootLevel = tagPtr->tagRootPtr->level; + + /* + * Iterate over the node and its ancestors up to the tag root, adjusting + * summary counts at each node and moving the tag's root upwards if + * necessary. + */ + + for ( ; nodePtr != tagPtr->tagRootPtr; nodePtr = nodePtr->parentPtr) { + /* + * See if there's already an entry for this tag for this node. If so, + * perhaps all we have to do is adjust its count. + */ + + for (prevPtr = NULL, summaryPtr = nodePtr->summaryPtr; + summaryPtr != NULL; + prevPtr = summaryPtr, summaryPtr = summaryPtr->nextPtr) { + if (summaryPtr->tagPtr == tagPtr) { + break; + } + } + if (summaryPtr != NULL) { + summaryPtr->toggleCount += delta; + if (summaryPtr->toggleCount > 0 && + summaryPtr->toggleCount < tagPtr->toggleCount) { + continue; + } + if (summaryPtr->toggleCount != 0) { + /* + * Should never find a node with max toggle count at this + * point (there shouldn't have been a summary entry in the + * first place). + */ + + Tcl_Panic("ChangeNodeToggleCount: bad toggle count (%d) max (%d)", + summaryPtr->toggleCount, tagPtr->toggleCount); + } + + /* + * Zero toggle count; must remove this tag from the list. + */ + + if (prevPtr == NULL) { + nodePtr->summaryPtr = summaryPtr->nextPtr; + } else { + prevPtr->nextPtr = summaryPtr->nextPtr; + } + ckfree(summaryPtr); + } else { + /* + * This tag isn't currently in the summary information list. + */ + + if (rootLevel == nodePtr->level) { + /* + * The old tag root is at the same level in the tree as this + * node, but it isn't at this node. Move the tag root up a + * level, in the hopes that it will now cover this node as + * well as the old root (if not, we'll move it up again the + * next time through the loop). To push it up one level we + * copy the original toggle count into the summary information + * at the old root and change the root to its parent node. + */ + + Node *rootNodePtr = tagPtr->tagRootPtr; + + summaryPtr = ckalloc(sizeof(Summary)); + summaryPtr->tagPtr = tagPtr; + summaryPtr->toggleCount = tagPtr->toggleCount - delta; + summaryPtr->nextPtr = rootNodePtr->summaryPtr; + rootNodePtr->summaryPtr = summaryPtr; + rootNodePtr = rootNodePtr->parentPtr; + rootLevel = rootNodePtr->level; + tagPtr->tagRootPtr = rootNodePtr; + } + summaryPtr = ckalloc(sizeof(Summary)); + summaryPtr->tagPtr = tagPtr; + summaryPtr->toggleCount = delta; + summaryPtr->nextPtr = nodePtr->summaryPtr; + nodePtr->summaryPtr = summaryPtr; + } + } + + /* + * If we've decremented the toggle count, then it may be necessary to push + * the tag root down one or more levels. + */ + + if (delta >= 0) { + return; + } + if (tagPtr->toggleCount == 0) { + tagPtr->tagRootPtr = NULL; + return; + } + nodePtr = tagPtr->tagRootPtr; + while (nodePtr->level > 0) { + /* + * See if a single child node accounts for all of the tag's toggles. + * If so, push the root down one level. + */ + + for (node2Ptr = nodePtr->children.nodePtr; + node2Ptr != NULL ; + node2Ptr = node2Ptr->nextPtr) { + for (prevPtr = NULL, summaryPtr = node2Ptr->summaryPtr; + summaryPtr != NULL; + prevPtr = summaryPtr, summaryPtr = summaryPtr->nextPtr) { + if (summaryPtr->tagPtr == tagPtr) { + break; + } + } + if (summaryPtr == NULL) { + continue; + } + if (summaryPtr->toggleCount != tagPtr->toggleCount) { + /* + * No node has all toggles, so the root is still valid. + */ + + return; + } + + /* + * This node has all the toggles, so push down the root. + */ + + if (prevPtr == NULL) { + node2Ptr->summaryPtr = summaryPtr->nextPtr; + } else { + prevPtr->nextPtr = summaryPtr->nextPtr; + } + ckfree(summaryPtr); + tagPtr->tagRootPtr = node2Ptr; + break; + } + nodePtr = tagPtr->tagRootPtr; + } +} + +/* + *---------------------------------------------------------------------- + * + * FindTagStart -- + * + * Find the start of the first range of a tag. + * + * Results: + * The return value is a pointer to the first tag toggle segment for the + * tag. This can be either a tagon or tagoff segments because of the way + * TkBTreeAdd removes a tag. Sets *indexPtr to be the index of the tag + * toggle. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static TkTextSegment * +FindTagStart( + TkTextBTree tree, /* Tree to search within. */ + TkTextTag *tagPtr, /* Tag to search for. */ + TkTextIndex *indexPtr) /* Return - index information. */ +{ + register Node *nodePtr; + register TkTextLine *linePtr; + register TkTextSegment *segPtr; + register Summary *summaryPtr; + int offset; + + nodePtr = tagPtr->tagRootPtr; + if (nodePtr == NULL) { + return NULL; + } + + /* + * Search from the root of the subtree that contains the tag down to the + * level 0 node. + */ + + while (nodePtr && nodePtr->level > 0) { + for (nodePtr = nodePtr->children.nodePtr ; nodePtr != NULL; + nodePtr = nodePtr->nextPtr) { + for (summaryPtr = nodePtr->summaryPtr ; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + if (summaryPtr->tagPtr == tagPtr) { + goto gotNodeWithTag; + } + } + } + gotNodeWithTag: + continue; + } + + if (nodePtr == NULL) { + return NULL; + } + + /* + * Work through the lines attached to the level-0 node. + */ + + for (linePtr = nodePtr->children.linePtr; linePtr != NULL; + linePtr = linePtr->nextPtr) { + for (offset = 0, segPtr = linePtr->segPtr ; segPtr != NULL; + offset += segPtr->size, segPtr = segPtr->nextPtr) { + if (((segPtr->typePtr == &tkTextToggleOnType) + || (segPtr->typePtr == &tkTextToggleOffType)) + && (segPtr->body.toggle.tagPtr == tagPtr)) { + /* + * It is possible that this is a tagoff tag, but that gets + * cleaned up later. + */ + + indexPtr->tree = tree; + indexPtr->linePtr = linePtr; + indexPtr->byteIndex = offset; + return segPtr; + } + } + } + return NULL; +} + +/* + *---------------------------------------------------------------------- + * + * FindTagEnd -- + * + * Find the end of the last range of a tag. + * + * Results: + * The return value is a pointer to the last tag toggle segment for the + * tag. This can be either a tagon or tagoff segments because of the way + * TkBTreeAdd removes a tag. Sets *indexPtr to be the index of the tag + * toggle. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static TkTextSegment * +FindTagEnd( + TkTextBTree tree, /* Tree to search within. */ + TkTextTag *tagPtr, /* Tag to search for. */ + TkTextIndex *indexPtr) /* Return - index information. */ +{ + register Node *nodePtr, *lastNodePtr; + register TkTextLine *linePtr ,*lastLinePtr; + register TkTextSegment *segPtr, *lastSegPtr, *last2SegPtr; + register Summary *summaryPtr; + int lastoffset, lastoffset2, offset; + + nodePtr = tagPtr->tagRootPtr; + if (nodePtr == NULL) { + return NULL; + } + + /* + * Search from the root of the subtree that contains the tag down to the + * level 0 node. + */ + + while (nodePtr && nodePtr->level > 0) { + for (lastNodePtr = NULL, nodePtr = nodePtr->children.nodePtr ; + nodePtr != NULL; nodePtr = nodePtr->nextPtr) { + for (summaryPtr = nodePtr->summaryPtr ; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + if (summaryPtr->tagPtr == tagPtr) { + lastNodePtr = nodePtr; + break; + } + } + } + nodePtr = lastNodePtr; + } + + if (nodePtr == NULL) { + return NULL; + } + + /* + * Work through the lines attached to the level-0 node. + */ + + last2SegPtr = NULL; + lastoffset2 = 0; + lastoffset = 0; + for (lastLinePtr = NULL, linePtr = nodePtr->children.linePtr; + linePtr != NULL; linePtr = linePtr->nextPtr) { + for (offset = 0, lastSegPtr = NULL, segPtr = linePtr->segPtr ; + segPtr != NULL; + offset += segPtr->size, segPtr = segPtr->nextPtr) { + if (((segPtr->typePtr == &tkTextToggleOnType) + || (segPtr->typePtr == &tkTextToggleOffType)) + && (segPtr->body.toggle.tagPtr == tagPtr)) { + lastSegPtr = segPtr; + lastoffset = offset; + } + } + if (lastSegPtr != NULL) { + lastLinePtr = linePtr; + last2SegPtr = lastSegPtr; + lastoffset2 = lastoffset; + } + } + indexPtr->tree = tree; + indexPtr->linePtr = lastLinePtr; + indexPtr->byteIndex = lastoffset2; + return last2SegPtr; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeStartSearch -- + * + * This function sets up a search for tag transitions involving a given + * tag (or all tags) in a given range of the text. + * + * Results: + * None. + * + * Side effects: + * The information at *searchPtr is set up so that subsequent calls to + * TkBTreeNextTag or TkBTreePrevTag will return information about the + * locations of tag transitions. Note that TkBTreeNextTag or + * TkBTreePrevTag must be called to get the first transition. Note: + * unlike TkBTreeNextTag and TkBTreePrevTag, this routine does not + * guarantee that searchPtr->curIndex is equal to *index1Ptr. It may be + * greater than that if *index1Ptr is less than the first tag transition. + * + *---------------------------------------------------------------------- + */ + +void +TkBTreeStartSearch( + TkTextIndex *index1Ptr, /* Search starts here. Tag toggles at this + * position will not be returned. */ + TkTextIndex *index2Ptr, /* Search stops here. Tag toggles at this + * position *will* be returned. */ + TkTextTag *tagPtr, /* Tag to search for. NULL means search for + * any tag. */ + register TkTextSearch *searchPtr) + /* Where to store information about search's + * progress. */ +{ + int offset; + TkTextIndex index0; /* First index of the tag. */ + TkTextSegment *seg0Ptr; /* First segment of the tag. */ + + /* + * Find the segment that contains the first toggle for the tag. This may + * become the starting point in the search. + */ + + seg0Ptr = FindTagStart(index1Ptr->tree, tagPtr, &index0); + if (seg0Ptr == NULL) { + /* + * Even though there are no toggles, the display code still uses the + * search curIndex, so initialize that anyway. + */ + + searchPtr->linesLeft = 0; + searchPtr->curIndex = *index1Ptr; + searchPtr->segPtr = NULL; + searchPtr->nextPtr = NULL; + return; + } + if (TkTextIndexCmp(index1Ptr, &index0) < 0) { + /* + * Adjust start of search up to the first range of the tag. + */ + + searchPtr->curIndex = index0; + searchPtr->segPtr = NULL; + searchPtr->nextPtr = seg0Ptr; /* Will be returned by NextTag. */ + index1Ptr = &index0; + } else { + searchPtr->curIndex = *index1Ptr; + searchPtr->segPtr = NULL; + searchPtr->nextPtr = TkTextIndexToSeg(index1Ptr, &offset); + searchPtr->curIndex.byteIndex -= offset; + } + searchPtr->lastPtr = TkTextIndexToSeg(index2Ptr, NULL); + searchPtr->tagPtr = tagPtr; + searchPtr->linesLeft = TkBTreeLinesTo(NULL, index2Ptr->linePtr) + 1 + - TkBTreeLinesTo(NULL, index1Ptr->linePtr); + searchPtr->allTags = (tagPtr == NULL); + if (searchPtr->linesLeft == 1) { + /* + * Starting and stopping segments are in the same line; mark the + * search as over immediately if the second segment is before the + * first. A search does not return a toggle at the very start of the + * range, unless the range is artificially moved up to index0. + */ + + if (((index1Ptr == &index0) && + (index1Ptr->byteIndex > index2Ptr->byteIndex)) || + ((index1Ptr != &index0) && + (index1Ptr->byteIndex >= index2Ptr->byteIndex))) { + searchPtr->linesLeft = 0; + } + } +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeStartSearchBack -- + * + * This function sets up a search backwards for tag transitions involving + * a given tag (or all tags) in a given range of the text. In the normal + * case the first index (*index1Ptr) is beyond the second index + * (*index2Ptr). + * + * Results: + * None. + * + * Side effects: + * The information at *searchPtr is set up so that subsequent calls to + * TkBTreePrevTag will return information about the locations of tag + * transitions. Note that TkBTreePrevTag must be called to get the first + * transition. Note: unlike TkBTreeNextTag and TkBTreePrevTag, this + * routine does not guarantee that searchPtr->curIndex is equal to + * *index1Ptr. It may be less than that if *index1Ptr is greater than the + * last tag transition. + * + *---------------------------------------------------------------------- + */ + +void +TkBTreeStartSearchBack( + TkTextIndex *index1Ptr, /* Search starts here. Tag toggles at this + * position will not be returned. */ + TkTextIndex *index2Ptr, /* Search stops here. Tag toggles at this + * position *will* be returned. */ + TkTextTag *tagPtr, /* Tag to search for. NULL means search for + * any tag. */ + register TkTextSearch *searchPtr) + /* Where to store information about search's + * progress. */ +{ + int offset; + TkTextIndex index0; /* Last index of the tag. */ + TkTextIndex backOne; /* One character before starting index. */ + TkTextSegment *seg0Ptr; /* Last segment of the tag. */ + + /* + * Find the segment that contains the last toggle for the tag. This may + * become the starting point in the search. + */ + + seg0Ptr = FindTagEnd(index1Ptr->tree, tagPtr, &index0); + if (seg0Ptr == NULL) { + /* + * Even though there are no toggles, the display code still uses the + * search curIndex, so initialize that anyway. + */ + + searchPtr->linesLeft = 0; + searchPtr->curIndex = *index1Ptr; + searchPtr->segPtr = NULL; + searchPtr->nextPtr = NULL; + return; + } + + /* + * Adjust the start of the search so it doesn't find any tag toggles + * that are right at the index specified by the user. + */ + + if (TkTextIndexCmp(index1Ptr, &index0) > 0) { + searchPtr->curIndex = index0; + index1Ptr = &index0; + } else { + TkTextIndexBackChars(NULL, index1Ptr, 1, &searchPtr->curIndex, + COUNT_INDICES); + } + searchPtr->segPtr = NULL; + searchPtr->nextPtr = TkTextIndexToSeg(&searchPtr->curIndex, &offset); + searchPtr->curIndex.byteIndex -= offset; + + /* + * Adjust the end of the search so it does find toggles that are right at + * the second index specified by the user. + */ + + if ((TkBTreeLinesTo(NULL, index2Ptr->linePtr) == 0) && + (index2Ptr->byteIndex == 0)) { + backOne = *index2Ptr; + searchPtr->lastPtr = NULL; /* Signals special case for 1.0. */ + } else { + TkTextIndexBackChars(NULL, index2Ptr, 1, &backOne, COUNT_INDICES); + searchPtr->lastPtr = TkTextIndexToSeg(&backOne, NULL); + } + searchPtr->tagPtr = tagPtr; + searchPtr->linesLeft = TkBTreeLinesTo(NULL, index1Ptr->linePtr) + 1 + - TkBTreeLinesTo(NULL, backOne.linePtr); + searchPtr->allTags = (tagPtr == NULL); + if (searchPtr->linesLeft == 1) { + /* + * Starting and stopping segments are in the same line; mark the + * search as over immediately if the second segment is after the + * first. + */ + + if (index1Ptr->byteIndex <= backOne.byteIndex) { + searchPtr->linesLeft = 0; + } + } +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeNextTag -- + * + * Once a tag search has begun, successive calls to this function return + * successive tag toggles. Note: it is NOT SAFE to call this function if + * characters have been inserted into or deleted from the B-tree since + * the call to TkBTreeStartSearch. + * + * Results: + * The return value is 1 if another toggle was found that met the + * criteria specified in the call to TkBTreeStartSearch; in this case + * searchPtr->curIndex gives the toggle's position and + * searchPtr->curTagPtr points to its segment. 0 is returned if no more + * matching tag transitions were found; in this case searchPtr->curIndex + * is the same as searchPtr->stopIndex. + * + * Side effects: + * Information in *searchPtr is modified to update the state of the + * search and indicate where the next tag toggle is located. + * + *---------------------------------------------------------------------- + */ + +int +TkBTreeNextTag( + register TkTextSearch *searchPtr) + /* Information about search in progress; must + * have been set up by call to + * TkBTreeStartSearch. */ +{ + register TkTextSegment *segPtr; + register Node *nodePtr; + register Summary *summaryPtr; + + if (searchPtr->linesLeft <= 0) { + goto searchOver; + } + + /* + * The outermost loop iterates over lines that may potentially contain a + * relevant tag transition, starting from the current segment in the + * current line. + */ + + segPtr = searchPtr->nextPtr; + while (1) { + /* + * Check for more tags on the current line. + */ + + for ( ; segPtr != NULL; segPtr = segPtr->nextPtr) { + if (segPtr == searchPtr->lastPtr) { + goto searchOver; + } + if (((segPtr->typePtr == &tkTextToggleOnType) + || (segPtr->typePtr == &tkTextToggleOffType)) + && (searchPtr->allTags + || (segPtr->body.toggle.tagPtr == searchPtr->tagPtr))) { + searchPtr->segPtr = segPtr; + searchPtr->nextPtr = segPtr->nextPtr; + searchPtr->tagPtr = segPtr->body.toggle.tagPtr; + return 1; + } + searchPtr->curIndex.byteIndex += segPtr->size; + } + + /* + * See if there are more lines associated with the current parent + * node. If so, go back to the top of the loop to search the next one. + */ + + nodePtr = searchPtr->curIndex.linePtr->parentPtr; + searchPtr->curIndex.linePtr = searchPtr->curIndex.linePtr->nextPtr; + searchPtr->linesLeft--; + if (searchPtr->linesLeft <= 0) { + goto searchOver; + } + if (searchPtr->curIndex.linePtr != NULL) { + segPtr = searchPtr->curIndex.linePtr->segPtr; + searchPtr->curIndex.byteIndex = 0; + continue; + } + if (nodePtr == searchPtr->tagPtr->tagRootPtr) { + goto searchOver; + } + + /* + * Search across and up through the B-tree's node hierarchy looking + * for the next node that has a relevant tag transition somewhere in + * its subtree. Be sure to update linesLeft as we skip over large + * chunks of lines. + */ + + while (1) { + while (nodePtr->nextPtr == NULL) { + if (nodePtr->parentPtr == NULL || + nodePtr->parentPtr == searchPtr->tagPtr->tagRootPtr) { + goto searchOver; + } + nodePtr = nodePtr->parentPtr; + } + nodePtr = nodePtr->nextPtr; + for (summaryPtr = nodePtr->summaryPtr; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + if ((searchPtr->allTags) || + (summaryPtr->tagPtr == searchPtr->tagPtr)) { + goto gotNodeWithTag; + } + } + searchPtr->linesLeft -= nodePtr->numLines; + } + + /* + * At this point we've found a subtree that has a relevant tag + * transition. Now search down (and across) through that subtree to + * find the first level-0 node that has a relevant tag transition. + */ + + gotNodeWithTag: + while (nodePtr->level > 0) { + for (nodePtr = nodePtr->children.nodePtr; ; + nodePtr = nodePtr->nextPtr) { + for (summaryPtr = nodePtr->summaryPtr; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + if ((searchPtr->allTags) + || (summaryPtr->tagPtr == searchPtr->tagPtr)) { + /* + * Would really like a multi-level continue here... + */ + + goto nextChild; + } + } + searchPtr->linesLeft -= nodePtr->numLines; + if (nodePtr->nextPtr == NULL) { + Tcl_Panic("TkBTreeNextTag found incorrect tag summary info"); + } + } + nextChild: + continue; + } + + /* + * Now we're down to a level-0 node that contains a line that contains + * a relevant tag transition. Set up line information and go back to + * the beginning of the loop to search through lines. + */ + + searchPtr->curIndex.linePtr = nodePtr->children.linePtr; + searchPtr->curIndex.byteIndex = 0; + segPtr = searchPtr->curIndex.linePtr->segPtr; + if (searchPtr->linesLeft <= 0) { + goto searchOver; + } + continue; + } + + searchOver: + searchPtr->linesLeft = 0; + searchPtr->segPtr = NULL; + return 0; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreePrevTag -- + * + * Once a tag search has begun, successive calls to this function return + * successive tag toggles in the reverse direction. Note: it is NOT SAFE + * to call this function if characters have been inserted into or deleted + * from the B-tree since the call to TkBTreeStartSearch. + * + * Results: + * The return value is 1 if another toggle was found that met the + * criteria specified in the call to TkBTreeStartSearch; in this case + * searchPtr->curIndex gives the toggle's position and + * searchPtr->curTagPtr points to its segment. 0 is returned if no more + * matching tag transitions were found; in this case searchPtr->curIndex + * is the same as searchPtr->stopIndex. + * + * Side effects: + * Information in *searchPtr is modified to update the state of the + * search and indicate where the next tag toggle is located. + * + *---------------------------------------------------------------------- + */ + +int +TkBTreePrevTag( + register TkTextSearch *searchPtr) + /* Information about search in progress; must + * have been set up by call to + * TkBTreeStartSearch. */ +{ + register TkTextSegment *segPtr, *prevPtr; + register TkTextLine *linePtr, *prevLinePtr; + register Node *nodePtr, *node2Ptr, *prevNodePtr; + register Summary *summaryPtr; + int byteIndex, linesSkipped; + int pastLast; /* Saw last marker during scan. */ + + if (searchPtr->linesLeft <= 0) { + goto searchOver; + } + + /* + * The outermost loop iterates over lines that may potentially contain a + * relevant tag transition, starting from the current segment in the + * current line. "nextPtr" is maintained as the last segment in a line + * that we can look at. + */ + + while (1) { + /* + * Check for the last toggle before the current segment on this line. + */ + + byteIndex = 0; + if (searchPtr->lastPtr == NULL) { + /* + * Search back to the very beginning, so pastLast is irrelevent. + */ + + pastLast = 1; + } else { + pastLast = 0; + } + + for (prevPtr = NULL, segPtr = searchPtr->curIndex.linePtr->segPtr ; + segPtr != NULL && segPtr != searchPtr->nextPtr; + segPtr = segPtr->nextPtr) { + if (((segPtr->typePtr == &tkTextToggleOnType) + || (segPtr->typePtr == &tkTextToggleOffType)) + && (searchPtr->allTags + || (segPtr->body.toggle.tagPtr == searchPtr->tagPtr))) { + prevPtr = segPtr; + searchPtr->curIndex.byteIndex = byteIndex; + } + if (segPtr == searchPtr->lastPtr) { + prevPtr = NULL; /* Segments earlier than last don't + * count. */ + pastLast = 1; + } + byteIndex += segPtr->size; + } + if (prevPtr != NULL) { + if (searchPtr->linesLeft == 1 && !pastLast) { + /* + * We found a segment that is before the stopping index. Note + * that it is OK if prevPtr == lastPtr. + */ + + goto searchOver; + } + searchPtr->segPtr = prevPtr; + searchPtr->nextPtr = prevPtr; + searchPtr->tagPtr = prevPtr->body.toggle.tagPtr; + return 1; + } + + searchPtr->linesLeft--; + if (searchPtr->linesLeft <= 0) { + goto searchOver; + } + + /* + * See if there are more lines associated with the current parent + * node. If so, go back to the top of the loop to search the previous + * one. + */ + + nodePtr = searchPtr->curIndex.linePtr->parentPtr; + for (prevLinePtr = NULL, linePtr = nodePtr->children.linePtr; + linePtr != NULL && linePtr != searchPtr->curIndex.linePtr; + prevLinePtr = linePtr, linePtr = linePtr->nextPtr) { + /* empty loop body */ ; + } + if (prevLinePtr != NULL) { + searchPtr->curIndex.linePtr = prevLinePtr; + searchPtr->nextPtr = NULL; + continue; + } + if (nodePtr == searchPtr->tagPtr->tagRootPtr) { + goto searchOver; + } + + /* + * Search across and up through the B-tree's node hierarchy looking + * for the previous node that has a relevant tag transition somewhere + * in its subtree. The search and line counting is trickier with/out + * back pointers. We'll scan all the nodes under a parent up to the + * current node, searching all of them for tag state. The last one we + * find, if any, is recorded in prevNodePtr, and any nodes past + * prevNodePtr that don't have tag state increment linesSkipped. + */ + + while (1) { + for (prevNodePtr = NULL, linesSkipped = 0, + node2Ptr = nodePtr->parentPtr->children.nodePtr ; + node2Ptr != nodePtr; node2Ptr = node2Ptr->nextPtr) { + for (summaryPtr = node2Ptr->summaryPtr; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + if ((searchPtr->allTags) || + (summaryPtr->tagPtr == searchPtr->tagPtr)) { + prevNodePtr = node2Ptr; + linesSkipped = 0; + goto keepLooking; + } + } + linesSkipped += node2Ptr->numLines; + + keepLooking: + continue; + } + if (prevNodePtr != NULL) { + nodePtr = prevNodePtr; + searchPtr->linesLeft -= linesSkipped; + goto gotNodeWithTag; + } + nodePtr = nodePtr->parentPtr; + if (nodePtr->parentPtr == NULL || + nodePtr == searchPtr->tagPtr->tagRootPtr) { + goto searchOver; + } + } + + /* + * At this point we've found a subtree that has a relevant tag + * transition. Now search down (and across) through that subtree to + * find the last level-0 node that has a relevant tag transition. + */ + + gotNodeWithTag: + while (nodePtr->level > 0) { + for (linesSkipped = 0, prevNodePtr = NULL, + nodePtr = nodePtr->children.nodePtr; nodePtr != NULL ; + nodePtr = nodePtr->nextPtr) { + for (summaryPtr = nodePtr->summaryPtr; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + if ((searchPtr->allTags) + || (summaryPtr->tagPtr == searchPtr->tagPtr)) { + prevNodePtr = nodePtr; + linesSkipped = 0; + goto keepLooking2; + } + } + linesSkipped += nodePtr->numLines; + + keepLooking2: + continue; + } + if (prevNodePtr == NULL) { + Tcl_Panic("TkBTreePrevTag found incorrect tag summary info"); + } + searchPtr->linesLeft -= linesSkipped; + nodePtr = prevNodePtr; + } + + /* + * Now we're down to a level-0 node that contains a line that contains + * a relevant tag transition. Set up line information and go back to + * the beginning of the loop to search through lines. We start with + * the last line below the node. + */ + + for (prevLinePtr = NULL, linePtr = nodePtr->children.linePtr; + linePtr != NULL ; + prevLinePtr = linePtr, linePtr = linePtr->nextPtr) { + /* empty loop body */ ; + } + searchPtr->curIndex.linePtr = prevLinePtr; + searchPtr->curIndex.byteIndex = 0; + if (searchPtr->linesLeft <= 0) { + goto searchOver; + } + continue; + } + + searchOver: + searchPtr->linesLeft = 0; + searchPtr->segPtr = NULL; + return 0; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeCharTagged -- + * + * Determine whether a particular character has a particular tag. + * + * Results: + * The return value is 1 if the given tag is in effect at the character + * given by linePtr and ch, and 0 otherwise. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +int +TkBTreeCharTagged( + const TkTextIndex *indexPtr,/* Indicates a character position at which to + * check for a tag. */ + TkTextTag *tagPtr) /* Tag of interest. */ +{ + register Node *nodePtr; + register TkTextLine *siblingLinePtr; + register TkTextSegment *segPtr; + TkTextSegment *toggleSegPtr; + int toggles, index; + + /* + * Check for toggles for the tag in indexPtr's line but before indexPtr. + * If there is one, its type indicates whether or not the character is + * tagged. + */ + + toggleSegPtr = NULL; + for (index = 0, segPtr = indexPtr->linePtr->segPtr; + (index + segPtr->size) <= indexPtr->byteIndex; + index += segPtr->size, segPtr = segPtr->nextPtr) { + if (((segPtr->typePtr == &tkTextToggleOnType) + || (segPtr->typePtr == &tkTextToggleOffType)) + && (segPtr->body.toggle.tagPtr == tagPtr)) { + toggleSegPtr = segPtr; + } + } + if (toggleSegPtr != NULL) { + return (toggleSegPtr->typePtr == &tkTextToggleOnType); + } + + /* + * No toggle in this line. Look for toggles for the tag in lines that are + * predecessors of indexPtr->linePtr but under the same level-0 node. + */ + + for (siblingLinePtr = indexPtr->linePtr->parentPtr->children.linePtr; + siblingLinePtr != indexPtr->linePtr; + siblingLinePtr = siblingLinePtr->nextPtr) { + for (segPtr = siblingLinePtr->segPtr; segPtr != NULL; + segPtr = segPtr->nextPtr) { + if (((segPtr->typePtr == &tkTextToggleOnType) + || (segPtr->typePtr == &tkTextToggleOffType)) + && (segPtr->body.toggle.tagPtr == tagPtr)) { + toggleSegPtr = segPtr; + } + } + } + if (toggleSegPtr != NULL) { + return (toggleSegPtr->typePtr == &tkTextToggleOnType); + } + + /* + * No toggle in this node. Scan upwards through the ancestors of this + * node, counting the number of toggles of the given tag in siblings that + * precede that node. + */ + + toggles = 0; + for (nodePtr = indexPtr->linePtr->parentPtr; nodePtr->parentPtr != NULL; + nodePtr = nodePtr->parentPtr) { + register Node *siblingPtr; + register Summary *summaryPtr; + + for (siblingPtr = nodePtr->parentPtr->children.nodePtr; + siblingPtr != nodePtr; siblingPtr = siblingPtr->nextPtr) { + for (summaryPtr = siblingPtr->summaryPtr; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + if (summaryPtr->tagPtr == tagPtr) { + toggles += summaryPtr->toggleCount; + } + } + } + if (nodePtr == tagPtr->tagRootPtr) { + break; + } + } + + /* + * An odd number of toggles means that the tag is present at the given + * point. + */ + + return toggles & 1; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeGetTags -- + * + * Return information about all of the tags that are associated with a + * particular character in a B-tree of text. + * + * Results: + * The return value is a malloc-ed array containing pointers to + * information for each of the tags that is associated with the character + * at the position given by linePtr and ch. The word at *numTagsPtr is + * filled in with the number of pointers in the array. It is up to the + * caller to free the array by passing it to free. If there are no tags + * at the given character then a NULL pointer is returned and *numTagsPtr + * will be set to 0. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +TkTextTag ** +TkBTreeGetTags( + const TkTextIndex *indexPtr,/* Indicates a particular position in the + * B-tree. */ + const TkText *textPtr, /* If non-NULL, then only return tags for this + * text widget (when there are peer + * widgets). */ + int *numTagsPtr) /* Store number of tags found at this + * location. */ +{ + register Node *nodePtr; + register TkTextLine *siblingLinePtr; + register TkTextSegment *segPtr; + TkTextLine *linePtr; + int src, dst, index; + TagInfo tagInfo; +#define NUM_TAG_INFOS 10 + + tagInfo.numTags = 0; + tagInfo.arraySize = NUM_TAG_INFOS; + tagInfo.tagPtrs = ckalloc(NUM_TAG_INFOS * sizeof(TkTextTag *)); + tagInfo.counts = ckalloc(NUM_TAG_INFOS * sizeof(int)); + + /* + * Record tag toggles within the line of indexPtr but preceding indexPtr. + */ + + linePtr = indexPtr->linePtr; + index = 0; + segPtr = linePtr->segPtr; + while ((index + segPtr->size) <= indexPtr->byteIndex) { + if ((segPtr->typePtr == &tkTextToggleOnType) + || (segPtr->typePtr == &tkTextToggleOffType)) { + IncCount(segPtr->body.toggle.tagPtr, 1, &tagInfo); + } + index += segPtr->size; + segPtr = segPtr->nextPtr; + + if (segPtr == NULL) { + /* + * Two logical lines merged into one display line through eliding + * of a newline. + */ + + linePtr = TkBTreeNextLine(NULL, linePtr); + segPtr = linePtr->segPtr; + } + } + + /* + * Record toggles for tags in lines that are predecessors of + * indexPtr->linePtr but under the same level-0 node. + */ + + for (siblingLinePtr = indexPtr->linePtr->parentPtr->children.linePtr; + siblingLinePtr != indexPtr->linePtr; + siblingLinePtr = siblingLinePtr->nextPtr) { + for (segPtr = siblingLinePtr->segPtr; segPtr != NULL; + segPtr = segPtr->nextPtr) { + if ((segPtr->typePtr == &tkTextToggleOnType) + || (segPtr->typePtr == &tkTextToggleOffType)) { + IncCount(segPtr->body.toggle.tagPtr, 1, &tagInfo); + } + } + } + + /* + * For each node in the ancestry of this line, record tag toggles for all + * siblings that precede that node. + */ + + for (nodePtr = indexPtr->linePtr->parentPtr; nodePtr->parentPtr != NULL; + nodePtr = nodePtr->parentPtr) { + register Node *siblingPtr; + register Summary *summaryPtr; + + for (siblingPtr = nodePtr->parentPtr->children.nodePtr; + siblingPtr != nodePtr; siblingPtr = siblingPtr->nextPtr) { + for (summaryPtr = siblingPtr->summaryPtr; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + if (summaryPtr->toggleCount & 1) { + IncCount(summaryPtr->tagPtr, summaryPtr->toggleCount, + &tagInfo); + } + } + } + } + + /* + * Go through the tag information and squash out all of the tags that have + * even toggle counts (these tags exist before the point of interest, but + * not at the desired character itself). Also squash out all tags that + * don't belong to the requested widget. + */ + + for (src = 0, dst = 0; src < tagInfo.numTags; src++) { + if (tagInfo.counts[src] & 1) { + const TkText *tagTextPtr = tagInfo.tagPtrs[src]->textPtr; + + if (tagTextPtr==NULL || textPtr==NULL || tagTextPtr==textPtr) { + tagInfo.tagPtrs[dst] = tagInfo.tagPtrs[src]; + dst++; + } + } + } + *numTagsPtr = dst; + ckfree(tagInfo.counts); + if (dst == 0) { + ckfree(tagInfo.tagPtrs); + return NULL; + } + return tagInfo.tagPtrs; +} + +/* + *---------------------------------------------------------------------- + * + * TkTextIsElided -- + * + * Special case to just return information about elided attribute. + * Specialized from TkBTreeGetTags(indexPtr, textPtr, numTagsPtr) and + * GetStyle(textPtr, indexPtr). Just need to keep track of invisibility + * settings for each priority, pick highest one active at end. + * + * Note that this returns all elide information up to and including the + * given index (quite obviously). However, this does mean that if + * indexPtr is a line-start and one then iterates from the beginning of + * that line forwards, one will actually revisit the segPtrs of size zero + * (for tag toggling, for example) which have already been seen here. + * + * For this reason we fill in the fields 'segPtr' and 'segOffset' of + * elideInfo, enabling our caller easily to calculate incremental changes + * from where we left off. + * + * Results: + * Returns whether this text should be elided or not. + * + * Optionally returns more detailed information in elideInfo. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +int +TkTextIsElided( + const TkText *textPtr, /* Overall information about text widget. */ + const TkTextIndex *indexPtr,/* The character in the text for which display + * information is wanted. */ + TkTextElideInfo *elideInfo) /* NULL or a pointer to a structure in which + * indexPtr's elide state will be stored and + * returned. */ +{ + register Node *nodePtr; + register TkTextLine *siblingLinePtr; + register TkTextSegment *segPtr; + register TkTextTag *tagPtr = NULL; + register int i, index; + register TkTextElideInfo *infoPtr; + TkTextLine *linePtr; + int elide; + + if (elideInfo == NULL) { + infoPtr = ckalloc(sizeof(TkTextElideInfo)); + } else { + infoPtr = elideInfo; + } + + infoPtr->elide = 0; /* If nobody says otherwise, it's visible. */ + infoPtr->tagCnts = infoPtr->deftagCnts; + infoPtr->tagPtrs = infoPtr->deftagPtrs; + infoPtr->numTags = textPtr->sharedTextPtr->numTags; + + /* + * Almost always avoid malloc, so stay out of system calls. + */ + + if (LOTSA_TAGS < infoPtr->numTags) { + infoPtr->tagCnts = ckalloc(sizeof(int) * infoPtr->numTags); + infoPtr->tagPtrs = ckalloc(sizeof(TkTextTag *) * infoPtr->numTags); + } + + for (i=0; i<infoPtr->numTags; i++) { + infoPtr->tagCnts[i] = 0; + } + + /* + * Record tag toggles within the line of indexPtr but preceding indexPtr. + */ + + index = 0; + linePtr = indexPtr->linePtr; + segPtr = linePtr->segPtr; + while ((index + segPtr->size) <= indexPtr->byteIndex) { + if ((segPtr->typePtr == &tkTextToggleOnType) + || (segPtr->typePtr == &tkTextToggleOffType)) { + tagPtr = segPtr->body.toggle.tagPtr; + if (tagPtr->elideString != NULL) { + infoPtr->tagPtrs[tagPtr->priority] = tagPtr; + infoPtr->tagCnts[tagPtr->priority]++; + } + } + + index += segPtr->size; + segPtr = segPtr->nextPtr; + if (segPtr == NULL) { + /* + * Two logical lines merged into one display line through eliding + * of a newline. + */ + + linePtr = TkBTreeNextLine(NULL, linePtr); + segPtr = linePtr->segPtr; + } + } + + /* + * Store the first segPtr we haven't examined completely so that our + * caller knows where to start. + */ + + infoPtr->segPtr = segPtr; + infoPtr->segOffset = index; + + /* + * Record toggles for tags in lines that are predecessors of + * indexPtr->linePtr but under the same level-0 node. + */ + + for (siblingLinePtr = indexPtr->linePtr->parentPtr->children.linePtr; + siblingLinePtr != indexPtr->linePtr; + siblingLinePtr = siblingLinePtr->nextPtr) { + for (segPtr = siblingLinePtr->segPtr; segPtr != NULL; + segPtr = segPtr->nextPtr) { + if ((segPtr->typePtr == &tkTextToggleOnType) + || (segPtr->typePtr == &tkTextToggleOffType)) { + tagPtr = segPtr->body.toggle.tagPtr; + if (tagPtr->elideString != NULL) { + infoPtr->tagPtrs[tagPtr->priority] = tagPtr; + infoPtr->tagCnts[tagPtr->priority]++; + } + } + } + } + + /* + * For each node in the ancestry of this line, record tag toggles for all + * siblings that precede that node. + */ + + for (nodePtr = indexPtr->linePtr->parentPtr; nodePtr->parentPtr != NULL; + nodePtr = nodePtr->parentPtr) { + register Node *siblingPtr; + register Summary *summaryPtr; + + for (siblingPtr = nodePtr->parentPtr->children.nodePtr; + siblingPtr != nodePtr; siblingPtr = siblingPtr->nextPtr) { + for (summaryPtr = siblingPtr->summaryPtr; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + if (summaryPtr->toggleCount & 1) { + tagPtr = summaryPtr->tagPtr; + if (tagPtr->elideString != NULL) { + infoPtr->tagPtrs[tagPtr->priority] = tagPtr; + infoPtr->tagCnts[tagPtr->priority] += + summaryPtr->toggleCount; + } + } + } + } + } + + /* + * Now traverse from highest priority to lowest, take elided value from + * first odd count (= on). + */ + + infoPtr->elidePriority = -1; + for (i = infoPtr->numTags-1; i >=0; i--) { + if (infoPtr->tagCnts[i] & 1) { + infoPtr->elide = infoPtr->tagPtrs[i]->elide; + + /* + * Note: i == infoPtr->tagPtrs[i]->priority + */ + + infoPtr->elidePriority = i; + break; + } + } + + elide = infoPtr->elide; + + if (elideInfo == NULL) { + if (LOTSA_TAGS < infoPtr->numTags) { + ckfree(infoPtr->tagCnts); + ckfree(infoPtr->tagPtrs); + } + + ckfree(infoPtr); + } + + return elide; +} + +/* + *---------------------------------------------------------------------- + * + * TkTextFreeElideInfo -- + * + * This is a utility function used to free up any memory allocated by the + * TkTextIsElided function above. + * + * Results: + * None. + * + * Side effects: + * Memory may be freed. + * + *---------------------------------------------------------------------- + */ + +void +TkTextFreeElideInfo( + TkTextElideInfo *elideInfo) /* Free any allocated memory in this + * structure. */ +{ + if (LOTSA_TAGS < elideInfo->numTags) { + ckfree(elideInfo->tagCnts); + ckfree(elideInfo->tagPtrs); + } +} + +/* + *---------------------------------------------------------------------- + * + * IncCount -- + * + * This is a utility function used by TkBTreeGetTags. It increments the + * count for a particular tag, adding a new entry for that tag if there + * wasn't one previously. + * + * Results: + * None. + * + * Side effects: + * The information at *tagInfoPtr may be modified, and the arrays may be + * reallocated to make them larger. + * + *---------------------------------------------------------------------- + */ + +static void +IncCount( + TkTextTag *tagPtr, /* Handle for tag. */ + int inc, /* Amount by which to increment tag count. */ + TagInfo *tagInfoPtr) /* Holds cumulative information about tags; + * increment count here. */ +{ + register TkTextTag **tagPtrPtr; + int count; + + for (tagPtrPtr = tagInfoPtr->tagPtrs, count = tagInfoPtr->numTags; + count > 0; tagPtrPtr++, count--) { + if (*tagPtrPtr == tagPtr) { + tagInfoPtr->counts[tagInfoPtr->numTags-count] += inc; + return; + } + } + + /* + * There isn't currently an entry for this tag, so we have to make a new + * one. If the arrays are full, then enlarge the arrays first. + */ + + if (tagInfoPtr->numTags == tagInfoPtr->arraySize) { + TkTextTag **newTags; + int *newCounts, newSize; + + newSize = 2 * tagInfoPtr->arraySize; + newTags = ckalloc(newSize * sizeof(TkTextTag *)); + memcpy(newTags, tagInfoPtr->tagPtrs, + tagInfoPtr->arraySize * sizeof(TkTextTag *)); + ckfree(tagInfoPtr->tagPtrs); + tagInfoPtr->tagPtrs = newTags; + newCounts = ckalloc(newSize * sizeof(int)); + memcpy(newCounts, tagInfoPtr->counts, + tagInfoPtr->arraySize * sizeof(int)); + ckfree(tagInfoPtr->counts); + tagInfoPtr->counts = newCounts; + tagInfoPtr->arraySize = newSize; + } + + tagInfoPtr->tagPtrs[tagInfoPtr->numTags] = tagPtr; + tagInfoPtr->counts[tagInfoPtr->numTags] = inc; + tagInfoPtr->numTags++; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeCheck -- + * + * This function runs a set of consistency checks over a B-tree and + * panics if any inconsistencies are found. + * + * Results: + * None. + * + * Side effects: + * If a structural defect is found, the function panics with an error + * message. + * + *---------------------------------------------------------------------- + */ + +void +TkBTreeCheck( + TkTextBTree tree) /* Tree to check. */ +{ + BTree *treePtr = (BTree *) tree; + register Summary *summaryPtr; + register Node *nodePtr; + register TkTextLine *linePtr; + register TkTextSegment *segPtr; + register TkTextTag *tagPtr; + Tcl_HashEntry *entryPtr; + Tcl_HashSearch search; + int count; + + /* + * Make sure that the tag toggle counts and the tag root pointers are OK. + */ + + for (entryPtr=Tcl_FirstHashEntry(&treePtr->sharedTextPtr->tagTable,&search); + entryPtr != NULL ; entryPtr = Tcl_NextHashEntry(&search)) { + tagPtr = Tcl_GetHashValue(entryPtr); + nodePtr = tagPtr->tagRootPtr; + if (nodePtr == NULL) { + if (tagPtr->toggleCount != 0) { + Tcl_Panic("TkBTreeCheck found \"%s\" with toggles (%d) but no root", + tagPtr->name, tagPtr->toggleCount); + } + continue; /* No ranges for the tag. */ + } else if (tagPtr->toggleCount == 0) { + Tcl_Panic("TkBTreeCheck found root for \"%s\" with no toggles", + tagPtr->name); + } else if (tagPtr->toggleCount & 1) { + Tcl_Panic("TkBTreeCheck found odd toggle count for \"%s\" (%d)", + tagPtr->name, tagPtr->toggleCount); + } + for (summaryPtr = nodePtr->summaryPtr; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + if (summaryPtr->tagPtr == tagPtr) { + Tcl_Panic("TkBTreeCheck found root node with summary info"); + } + } + count = 0; + if (nodePtr->level > 0) { + for (nodePtr = nodePtr->children.nodePtr ; nodePtr != NULL ; + nodePtr = nodePtr->nextPtr) { + for (summaryPtr = nodePtr->summaryPtr; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + if (summaryPtr->tagPtr == tagPtr) { + count += summaryPtr->toggleCount; + } + } + } + } else { + for (linePtr = nodePtr->children.linePtr ; linePtr != NULL ; + linePtr = linePtr->nextPtr) { + for (segPtr = linePtr->segPtr; segPtr != NULL; + segPtr = segPtr->nextPtr) { + if ((segPtr->typePtr == &tkTextToggleOnType || + segPtr->typePtr == &tkTextToggleOffType) && + segPtr->body.toggle.tagPtr == tagPtr) { + count++; + } + } + } + } + if (count != tagPtr->toggleCount) { + Tcl_Panic("TkBTreeCheck toggleCount (%d) wrong for \"%s\" should be (%d)", + tagPtr->toggleCount, tagPtr->name, count); + } + } + + /* + * Call a recursive function to do the main body of checks. + */ + + nodePtr = treePtr->rootPtr; + CheckNodeConsistency(treePtr->rootPtr, treePtr->pixelReferences); + + /* + * Make sure that there are at least two lines in the text and that the + * last line has no characters except a newline. + */ + + if (nodePtr->numLines < 2) { + Tcl_Panic("TkBTreeCheck: less than 2 lines in tree"); + } + while (nodePtr->level > 0) { + nodePtr = nodePtr->children.nodePtr; + while (nodePtr->nextPtr != NULL) { + nodePtr = nodePtr->nextPtr; + } + } + linePtr = nodePtr->children.linePtr; + while (linePtr->nextPtr != NULL) { + linePtr = linePtr->nextPtr; + } + segPtr = linePtr->segPtr; + while ((segPtr->typePtr == &tkTextToggleOffType) + || (segPtr->typePtr == &tkTextRightMarkType) + || (segPtr->typePtr == &tkTextLeftMarkType)) { + /* + * It's OK to toggle a tag off in the last line, but not to start a + * new range. It's also OK to have marks in the last line. + */ + + segPtr = segPtr->nextPtr; + } + if (segPtr->typePtr != &tkTextCharType) { + Tcl_Panic("TkBTreeCheck: last line has bogus segment type"); + } + if (segPtr->nextPtr != NULL) { + Tcl_Panic("TkBTreeCheck: last line has too many segments"); + } + if (segPtr->size != 1) { + Tcl_Panic("TkBTreeCheck: last line has wrong # characters: %d", + segPtr->size); + } + if ((segPtr->body.chars[0] != '\n') || (segPtr->body.chars[1] != 0)) { + Tcl_Panic("TkBTreeCheck: last line had bad value: %s", + segPtr->body.chars); + } +} + +/* + *---------------------------------------------------------------------- + * + * CheckNodeConsistency -- + * + * This function is called as part of consistency checking for B-trees: + * it checks several aspects of a node and also runs checks recursively + * on the node's children. + * + * Results: + * None. + * + * Side effects: + * If anything suspicious is found in the tree structure, the function + * panics. + * + *---------------------------------------------------------------------- + */ + +static void +CheckNodeConsistency( + register Node *nodePtr, /* Node whose subtree should be checked. */ + int references) /* Number of referring widgets which have + * pixel counts. */ +{ + register Node *childNodePtr; + register Summary *summaryPtr, *summaryPtr2; + register TkTextLine *linePtr; + register TkTextSegment *segPtr; + int numChildren, numLines, toggleCount, minChildren, i; + int *numPixels; + int pixels[PIXEL_CLIENTS]; + + if (nodePtr->parentPtr != NULL) { + minChildren = MIN_CHILDREN; + } else if (nodePtr->level > 0) { + minChildren = 2; + } else { + minChildren = 1; + } + if ((nodePtr->numChildren < minChildren) + || (nodePtr->numChildren > MAX_CHILDREN)) { + Tcl_Panic("CheckNodeConsistency: bad child count (%d)", + nodePtr->numChildren); + } + + numChildren = 0; + numLines = 0; + if (references > PIXEL_CLIENTS) { + numPixels = ckalloc(sizeof(int) * references); + } else { + numPixels = pixels; + } + for (i = 0; i<references; i++) { + numPixels[i] = 0; + } + + if (nodePtr->level == 0) { + for (linePtr = nodePtr->children.linePtr; linePtr != NULL; + linePtr = linePtr->nextPtr) { + if (linePtr->parentPtr != nodePtr) { + Tcl_Panic("CheckNodeConsistency: line doesn't point to parent"); + } + if (linePtr->segPtr == NULL) { + Tcl_Panic("CheckNodeConsistency: line has no segments"); + } + for (segPtr = linePtr->segPtr; segPtr != NULL; + segPtr = segPtr->nextPtr) { + if (segPtr->typePtr->checkProc != NULL) { + segPtr->typePtr->checkProc(segPtr, linePtr); + } + if ((segPtr->size == 0) && (!segPtr->typePtr->leftGravity) + && (segPtr->nextPtr != NULL) + && (segPtr->nextPtr->size == 0) + && (segPtr->nextPtr->typePtr->leftGravity)) { + Tcl_Panic("CheckNodeConsistency: wrong segment order for gravity"); + } + if ((segPtr->nextPtr == NULL) + && (segPtr->typePtr != &tkTextCharType)) { + Tcl_Panic("CheckNodeConsistency: line ended with wrong type"); + } + } + numChildren++; + numLines++; + for (i = 0; i<references; i++) { + numPixels[i] += linePtr->pixels[2 * i]; + } + } + } else { + for (childNodePtr = nodePtr->children.nodePtr; childNodePtr != NULL; + childNodePtr = childNodePtr->nextPtr) { + if (childNodePtr->parentPtr != nodePtr) { + Tcl_Panic("CheckNodeConsistency: node doesn't point to parent"); + } + if (childNodePtr->level != (nodePtr->level-1)) { + Tcl_Panic("CheckNodeConsistency: level mismatch (%d %d)", + nodePtr->level, childNodePtr->level); + } + CheckNodeConsistency(childNodePtr, references); + for (summaryPtr = childNodePtr->summaryPtr; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + for (summaryPtr2 = nodePtr->summaryPtr; ; + summaryPtr2 = summaryPtr2->nextPtr) { + if (summaryPtr2 == NULL) { + if (summaryPtr->tagPtr->tagRootPtr == nodePtr) { + break; + } + Tcl_Panic("CheckNodeConsistency: node tag \"%s\" not %s", + summaryPtr->tagPtr->name, + "present in parent summaries"); + } + if (summaryPtr->tagPtr == summaryPtr2->tagPtr) { + break; + } + } + } + numChildren++; + numLines += childNodePtr->numLines; + for (i = 0; i<references; i++) { + numPixels[i] += childNodePtr->numPixels[i]; + } + } + } + if (numChildren != nodePtr->numChildren) { + Tcl_Panic("CheckNodeConsistency: mismatch in numChildren (%d %d)", + numChildren, nodePtr->numChildren); + } + if (numLines != nodePtr->numLines) { + Tcl_Panic("CheckNodeConsistency: mismatch in numLines (%d %d)", + numLines, nodePtr->numLines); + } + for (i = 0; i<references; i++) { + if (numPixels[i] != nodePtr->numPixels[i]) { + Tcl_Panic("CheckNodeConsistency: mismatch in numPixels (%d %d) for widget (%d)", + numPixels[i], nodePtr->numPixels[i], i); + } + } + if (references > PIXEL_CLIENTS) { + ckfree(numPixels); + } + + for (summaryPtr = nodePtr->summaryPtr; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + if (summaryPtr->tagPtr->toggleCount == summaryPtr->toggleCount) { + Tcl_Panic("CheckNodeConsistency: found unpruned root for \"%s\"", + summaryPtr->tagPtr->name); + } + toggleCount = 0; + if (nodePtr->level == 0) { + for (linePtr = nodePtr->children.linePtr; linePtr != NULL; + linePtr = linePtr->nextPtr) { + for (segPtr = linePtr->segPtr; segPtr != NULL; + segPtr = segPtr->nextPtr) { + if ((segPtr->typePtr != &tkTextToggleOnType) + && (segPtr->typePtr != &tkTextToggleOffType)) { + continue; + } + if (segPtr->body.toggle.tagPtr == summaryPtr->tagPtr) { + toggleCount++; + } + } + } + } else { + for (childNodePtr = nodePtr->children.nodePtr; + childNodePtr != NULL; + childNodePtr = childNodePtr->nextPtr) { + for (summaryPtr2 = childNodePtr->summaryPtr; + summaryPtr2 != NULL; + summaryPtr2 = summaryPtr2->nextPtr) { + if (summaryPtr2->tagPtr == summaryPtr->tagPtr) { + toggleCount += summaryPtr2->toggleCount; + } + } + } + } + if (toggleCount != summaryPtr->toggleCount) { + Tcl_Panic("CheckNodeConsistency: mismatch in toggleCount (%d %d)", + toggleCount, summaryPtr->toggleCount); + } + for (summaryPtr2 = summaryPtr->nextPtr; summaryPtr2 != NULL; + summaryPtr2 = summaryPtr2->nextPtr) { + if (summaryPtr2->tagPtr == summaryPtr->tagPtr) { + Tcl_Panic("CheckNodeConsistency: duplicated node tag: %s", + summaryPtr->tagPtr->name); + } + } + } +} + +/* + *---------------------------------------------------------------------- + * + * Rebalance -- + * + * This function is called when a node of a B-tree appears to be out of + * balance (too many children, or too few). It rebalances that node and + * all of its ancestors in the tree. + * + * Results: + * None. + * + * Side effects: + * The internal structure of treePtr may change. + * + *---------------------------------------------------------------------- + */ + +static void +Rebalance( + BTree *treePtr, /* Tree that is being rebalanced. */ + register Node *nodePtr) /* Node that may be out of balance. */ +{ + /* + * Loop over the entire ancestral chain of the node, working up through + * the tree one node at a time until the root node has been processed. + */ + + for ( ; nodePtr != NULL; nodePtr = nodePtr->parentPtr) { + register Node *newPtr, *childPtr; + register TkTextLine *linePtr; + int i; + + /* + * Check to see if the node has too many children. If it does, then + * split off all but the first MIN_CHILDREN into a separate node + * following the original one. Then repeat until the node has a decent + * size. + */ + + if (nodePtr->numChildren > MAX_CHILDREN) { + while (1) { + /* + * If the node being split is the root node, then make a new + * root node above it first. + */ + + if (nodePtr->parentPtr == NULL) { + newPtr = ckalloc(sizeof(Node)); + newPtr->parentPtr = NULL; + newPtr->nextPtr = NULL; + newPtr->summaryPtr = NULL; + newPtr->level = nodePtr->level + 1; + newPtr->children.nodePtr = nodePtr; + newPtr->numChildren = 1; + newPtr->numLines = nodePtr->numLines; + newPtr->numPixels = + ckalloc(sizeof(int) * treePtr->pixelReferences); + for (i=0; i<treePtr->pixelReferences; i++) { + newPtr->numPixels[i] = nodePtr->numPixels[i]; + } + RecomputeNodeCounts(treePtr, newPtr); + treePtr->rootPtr = newPtr; + } + newPtr = ckalloc(sizeof(Node)); + newPtr->numPixels = + ckalloc(sizeof(int) * treePtr->pixelReferences); + for (i=0; i<treePtr->pixelReferences; i++) { + newPtr->numPixels[i] = 0; + } + newPtr->parentPtr = nodePtr->parentPtr; + newPtr->nextPtr = nodePtr->nextPtr; + nodePtr->nextPtr = newPtr; + newPtr->summaryPtr = NULL; + newPtr->level = nodePtr->level; + newPtr->numChildren = nodePtr->numChildren - MIN_CHILDREN; + if (nodePtr->level == 0) { + for (i = MIN_CHILDREN-1, + linePtr = nodePtr->children.linePtr; + i > 0; i--, linePtr = linePtr->nextPtr) { + /* Empty loop body. */ + } + newPtr->children.linePtr = linePtr->nextPtr; + linePtr->nextPtr = NULL; + } else { + for (i = MIN_CHILDREN-1, + childPtr = nodePtr->children.nodePtr; + i > 0; i--, childPtr = childPtr->nextPtr) { + /* Empty loop body. */ + } + newPtr->children.nodePtr = childPtr->nextPtr; + childPtr->nextPtr = NULL; + } + RecomputeNodeCounts(treePtr, nodePtr); + nodePtr->parentPtr->numChildren++; + nodePtr = newPtr; + if (nodePtr->numChildren <= MAX_CHILDREN) { + RecomputeNodeCounts(treePtr, nodePtr); + break; + } + } + } + + while (nodePtr->numChildren < MIN_CHILDREN) { + register Node *otherPtr; + Node *halfwayNodePtr = NULL; /* Initialization needed only */ + TkTextLine *halfwayLinePtr = NULL; /* to prevent cc warnings. */ + int totalChildren, firstChildren, i; + + /* + * Too few children for this node. If this is the root then, it's + * OK for it to have less than MIN_CHILDREN children as long as + * it's got at least two. If it has only one (and isn't at level + * 0), then chop the root node out of the tree and use its child + * as the new root. + */ + + if (nodePtr->parentPtr == NULL) { + if ((nodePtr->numChildren == 1) && (nodePtr->level > 0)) { + treePtr->rootPtr = nodePtr->children.nodePtr; + treePtr->rootPtr->parentPtr = NULL; + DeleteSummaries(nodePtr->summaryPtr); + ckfree(nodePtr->numPixels); + ckfree(nodePtr); + } + return; + } + + /* + * Not the root. Make sure that there are siblings to balance + * with. + */ + + if (nodePtr->parentPtr->numChildren < 2) { + Rebalance(treePtr, nodePtr->parentPtr); + continue; + } + + /* + * Find a sibling neighbor to borrow from, and arrange for nodePtr + * to be the earlier of the pair. + */ + + if (nodePtr->nextPtr == NULL) { + for (otherPtr = nodePtr->parentPtr->children.nodePtr; + otherPtr->nextPtr != nodePtr; + otherPtr = otherPtr->nextPtr) { + /* Empty loop body. */ + } + nodePtr = otherPtr; + } + otherPtr = nodePtr->nextPtr; + + /* + * We're going to either merge the two siblings together into one + * node or redivide the children among them to balance their + * loads. As preparation, join their two child lists into a single + * list and remember the half-way point in the list. + */ + + totalChildren = nodePtr->numChildren + otherPtr->numChildren; + firstChildren = totalChildren/2; + if (nodePtr->children.nodePtr == NULL) { + nodePtr->children = otherPtr->children; + otherPtr->children.nodePtr = NULL; + otherPtr->children.linePtr = NULL; + } + if (nodePtr->level == 0) { + register TkTextLine *linePtr; + + for (linePtr = nodePtr->children.linePtr, i = 1; + linePtr->nextPtr != NULL; + linePtr = linePtr->nextPtr, i++) { + if (i == firstChildren) { + halfwayLinePtr = linePtr; + } + } + linePtr->nextPtr = otherPtr->children.linePtr; + while (i <= firstChildren) { + halfwayLinePtr = linePtr; + linePtr = linePtr->nextPtr; + i++; + } + } else { + register Node *childPtr; + + for (childPtr = nodePtr->children.nodePtr, i = 1; + childPtr->nextPtr != NULL; + childPtr = childPtr->nextPtr, i++) { + if (i <= firstChildren) { + if (i == firstChildren) { + halfwayNodePtr = childPtr; + } + } + } + childPtr->nextPtr = otherPtr->children.nodePtr; + while (i <= firstChildren) { + halfwayNodePtr = childPtr; + childPtr = childPtr->nextPtr; + i++; + } + } + + /* + * If the two siblings can simply be merged together, do it. + */ + + if (totalChildren <= MAX_CHILDREN) { + RecomputeNodeCounts(treePtr, nodePtr); + nodePtr->nextPtr = otherPtr->nextPtr; + nodePtr->parentPtr->numChildren--; + DeleteSummaries(otherPtr->summaryPtr); + ckfree(otherPtr->numPixels); + ckfree(otherPtr); + continue; + } + + /* + * The siblings can't be merged, so just divide their children + * evenly between them. + */ + + if (nodePtr->level == 0) { + CLANG_ASSERT(halfwayLinePtr); + otherPtr->children.linePtr = halfwayLinePtr->nextPtr; + halfwayLinePtr->nextPtr = NULL; + } else { + CLANG_ASSERT(halfwayNodePtr); + otherPtr->children.nodePtr = halfwayNodePtr->nextPtr; + halfwayNodePtr->nextPtr = NULL; + } + RecomputeNodeCounts(treePtr, nodePtr); + RecomputeNodeCounts(treePtr, otherPtr); + } + } +} + +/* + *---------------------------------------------------------------------- + * + * RecomputeNodeCounts -- + * + * This function is called to recompute all the counts in a node (tags, + * child information, etc.) by scanning the information in its + * descendants. This function is called during rebalancing when a node's + * child structure has changed. + * + * Results: + * None. + * + * Side effects: + * The tag counts for nodePtr are modified to reflect its current child + * structure, as are its numChildren and numLines fields. Also, all of + * the childrens' parentPtr fields are made to point to nodePtr. + * + *---------------------------------------------------------------------- + */ + +static void +RecomputeNodeCounts( + register BTree *treePtr, /* The whole B-tree. */ + register Node *nodePtr) /* Node whose tag summary information must be + * recomputed. */ +{ + register Summary *summaryPtr, *summaryPtr2; + register Node *childPtr; + register TkTextLine *linePtr; + register TkTextSegment *segPtr; + TkTextTag *tagPtr; + int ref; + + /* + * Zero out all the existing counts for the node, but don't delete the + * existing Summary records (most of them will probably be reused). + */ + + for (summaryPtr = nodePtr->summaryPtr; summaryPtr != NULL; + summaryPtr = summaryPtr->nextPtr) { + summaryPtr->toggleCount = 0; + } + nodePtr->numChildren = 0; + nodePtr->numLines = 0; + for (ref = 0; ref<treePtr->pixelReferences; ref++) { + nodePtr->numPixels[ref] = 0; + } + + /* + * Scan through the children, adding the childrens' tag counts into the + * node's tag counts and adding new Summary structures if necessary. + */ + + if (nodePtr->level == 0) { + for (linePtr = nodePtr->children.linePtr; linePtr != NULL; + linePtr = linePtr->nextPtr) { + nodePtr->numChildren++; + nodePtr->numLines++; + for (ref = 0; ref<treePtr->pixelReferences; ref++) { + nodePtr->numPixels[ref] += linePtr->pixels[2 * ref]; + } + linePtr->parentPtr = nodePtr; + for (segPtr = linePtr->segPtr; segPtr != NULL; + segPtr = segPtr->nextPtr) { + if (((segPtr->typePtr != &tkTextToggleOnType) + && (segPtr->typePtr != &tkTextToggleOffType)) + || !(segPtr->body.toggle.inNodeCounts)) { + continue; + } + tagPtr = segPtr->body.toggle.tagPtr; + for (summaryPtr = nodePtr->summaryPtr; ; + summaryPtr = summaryPtr->nextPtr) { + if (summaryPtr == NULL) { + summaryPtr = ckalloc(sizeof(Summary)); + summaryPtr->tagPtr = tagPtr; + summaryPtr->toggleCount = 1; + summaryPtr->nextPtr = nodePtr->summaryPtr; + nodePtr->summaryPtr = summaryPtr; + break; + } + if (summaryPtr->tagPtr == tagPtr) { + summaryPtr->toggleCount++; + break; + } + } + } + } + } else { + for (childPtr = nodePtr->children.nodePtr; childPtr != NULL; + childPtr = childPtr->nextPtr) { + nodePtr->numChildren++; + nodePtr->numLines += childPtr->numLines; + for (ref = 0; ref<treePtr->pixelReferences; ref++) { + nodePtr->numPixels[ref] += childPtr->numPixels[ref]; + } + childPtr->parentPtr = nodePtr; + for (summaryPtr2 = childPtr->summaryPtr; summaryPtr2 != NULL; + summaryPtr2 = summaryPtr2->nextPtr) { + for (summaryPtr = nodePtr->summaryPtr; ; + summaryPtr = summaryPtr->nextPtr) { + if (summaryPtr == NULL) { + summaryPtr = ckalloc(sizeof(Summary)); + summaryPtr->tagPtr = summaryPtr2->tagPtr; + summaryPtr->toggleCount = summaryPtr2->toggleCount; + summaryPtr->nextPtr = nodePtr->summaryPtr; + nodePtr->summaryPtr = summaryPtr; + break; + } + if (summaryPtr->tagPtr == summaryPtr2->tagPtr) { + summaryPtr->toggleCount += summaryPtr2->toggleCount; + break; + } + } + } + } + } + + /* + * Scan through the node's tag records again and delete any Summary + * records that still have a zero count, or that have all the toggles. + * The node with the children that account for all the tags toggles have + * no summary information, and they become the tagRootPtr for the tag. + */ + + summaryPtr2 = NULL; + for (summaryPtr = nodePtr->summaryPtr; summaryPtr != NULL; ) { + if (summaryPtr->toggleCount > 0 && + summaryPtr->toggleCount < summaryPtr->tagPtr->toggleCount) { + if (nodePtr->level == summaryPtr->tagPtr->tagRootPtr->level) { + /* + * The tag's root node split and some toggles left. The tag + * root must move up a level. + */ + + summaryPtr->tagPtr->tagRootPtr = nodePtr->parentPtr; + } + summaryPtr2 = summaryPtr; + summaryPtr = summaryPtr->nextPtr; + continue; + } + if (summaryPtr->toggleCount == summaryPtr->tagPtr->toggleCount) { + /* + * A node merge has collected all the toggles under one node. Push + * the root down to this level. + */ + + summaryPtr->tagPtr->tagRootPtr = nodePtr; + } + if (summaryPtr2 != NULL) { + summaryPtr2->nextPtr = summaryPtr->nextPtr; + ckfree(summaryPtr); + summaryPtr = summaryPtr2->nextPtr; + } else { + nodePtr->summaryPtr = summaryPtr->nextPtr; + ckfree(summaryPtr); + summaryPtr = nodePtr->summaryPtr; + } + } +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeNumLines -- + * + * This function returns a count of the number of logical lines of text + * present in a given B-tree. + * + * Results: + * The return value is a count of the number of usable lines in tree + * (i.e. it doesn't include the dummy line that is just used to mark the + * end of the tree). + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +int +TkBTreeNumLines( + TkTextBTree tree, /* Information about tree. */ + const TkText *textPtr) /* Relative to this client of the B-tree. */ +{ + BTree *treePtr = (BTree *) tree; + int count; + + if (textPtr != NULL && textPtr->end != NULL) { + count = TkBTreeLinesTo(NULL, textPtr->end); + } else { + count = treePtr->rootPtr->numLines - 1; + } + if (textPtr != NULL && textPtr->start != NULL) { + count -= TkBTreeLinesTo(NULL, textPtr->start); + } + + return count; +} + +/* + *---------------------------------------------------------------------- + * + * TkBTreeNumPixels -- + * + * This function returns a count of the number of pixels of text present + * in a given widget's B-tree representation. + * + * Results: + * The return value is a count of the number of usable pixels in tree + * (since the dummy line used to mark the end of the B-tree is maintained + * with zero height, as are any lines that are before or after the + * '-start -end' range of the text widget in question, the number stored + * at the root is the number we want). + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +int +TkBTreeNumPixels( + TkTextBTree tree, /* The B-tree. */ + const TkText *textPtr) /* Relative to this client of the B-tree. */ +{ + BTree *treePtr = (BTree *) tree; + return treePtr->rootPtr->numPixels[textPtr->pixelReference]; +} + +/* + *-------------------------------------------------------------- + * + * CharSplitProc -- + * + * This function implements splitting for character segments. + * + * Results: + * The return value is a pointer to a chain of two segments that have the + * same characters as segPtr except split among the two segments. + * + * Side effects: + * Storage for segPtr is freed. + * + *-------------------------------------------------------------- + */ + +static TkTextSegment * +CharSplitProc( + TkTextSegment *segPtr, /* Pointer to segment to split. */ + int index) /* Position within segment at which to + * split. */ +{ + TkTextSegment *newPtr1, *newPtr2; + + newPtr1 = ckalloc(CSEG_SIZE(index)); + newPtr2 = ckalloc(CSEG_SIZE(segPtr->size - index)); + newPtr1->typePtr = &tkTextCharType; + newPtr1->nextPtr = newPtr2; + newPtr1->size = index; + memcpy(newPtr1->body.chars, segPtr->body.chars, (size_t) index); + newPtr1->body.chars[index] = 0; + newPtr2->typePtr = &tkTextCharType; + newPtr2->nextPtr = segPtr->nextPtr; + newPtr2->size = segPtr->size - index; + memcpy(newPtr2->body.chars, segPtr->body.chars + index, newPtr2->size); + newPtr2->body.chars[newPtr2->size] = 0; + ckfree(segPtr); + return newPtr1; +} + +/* + *-------------------------------------------------------------- + * + * CharCleanupProc -- + * + * This function merges adjacent character segments into a single + * character segment, if possible. + * + * Results: + * The return value is a pointer to the first segment in the (new) list + * of segments that used to start with segPtr. + * + * Side effects: + * Storage for the segments may be allocated and freed. + * + *-------------------------------------------------------------- + */ + + /* ARGSUSED */ +static TkTextSegment * +CharCleanupProc( + TkTextSegment *segPtr, /* Pointer to first of two adjacent segments + * to join. */ + TkTextLine *linePtr) /* Line containing segments (not used). */ +{ + TkTextSegment *segPtr2, *newPtr; + + segPtr2 = segPtr->nextPtr; + if ((segPtr2 == NULL) || (segPtr2->typePtr != &tkTextCharType)) { + return segPtr; + } + newPtr = ckalloc(CSEG_SIZE(segPtr->size + segPtr2->size)); + newPtr->typePtr = &tkTextCharType; + newPtr->nextPtr = segPtr2->nextPtr; + newPtr->size = segPtr->size + segPtr2->size; + memcpy(newPtr->body.chars, segPtr->body.chars, segPtr->size); + memcpy(newPtr->body.chars + segPtr->size, segPtr2->body.chars, segPtr2->size); + newPtr->body.chars[newPtr->size] = 0; + ckfree(segPtr); + ckfree(segPtr2); + return newPtr; +} + +/* + *-------------------------------------------------------------- + * + * CharDeleteProc -- + * + * This function is invoked to delete a character segment. + * + * Results: + * Always returns 0 to indicate that the segment was deleted. + * + * Side effects: + * Storage for the segment is freed. + * + *-------------------------------------------------------------- + */ + + /* ARGSUSED */ +static int +CharDeleteProc( + TkTextSegment *segPtr, /* Segment to delete. */ + TkTextLine *linePtr, /* Line containing segment. */ + int treeGone) /* Non-zero means the entire tree is being + * deleted, so everything must get cleaned + * up. */ +{ + ckfree(segPtr); + return 0; +} + +/* + *-------------------------------------------------------------- + * + * CharCheckProc -- + * + * This function is invoked to perform consistency checks on character + * segments. + * + * Results: + * None. + * + * Side effects: + * If the segment isn't inconsistent then the function panics. + * + *-------------------------------------------------------------- + */ + + /* ARGSUSED */ +static void +CharCheckProc( + TkTextSegment *segPtr, /* Segment to check. */ + TkTextLine *linePtr) /* Line containing segment. */ +{ + /* + * Make sure that the segment contains the number of characters indicated + * by its header, and that the last segment in a line ends in a newline. + * Also make sure that there aren't ever two character segments adjacent + * to each other: they should be merged together. + */ + + if (segPtr->size <= 0) { + Tcl_Panic("CharCheckProc: segment has size <= 0"); + } + if (strlen(segPtr->body.chars) != (size_t) segPtr->size) { + Tcl_Panic("CharCheckProc: segment has wrong size"); + } + if (segPtr->nextPtr == NULL) { + if (segPtr->body.chars[segPtr->size-1] != '\n') { + Tcl_Panic("CharCheckProc: line doesn't end with newline"); + } + } else if (segPtr->nextPtr->typePtr == &tkTextCharType) { + Tcl_Panic("CharCheckProc: adjacent character segments weren't merged"); + } +} + +/* + *-------------------------------------------------------------- + * + * ToggleDeleteProc -- + * + * This function is invoked to delete toggle segments. + * + * Results: + * Returns 1 to indicate that the segment may not be deleted, unless the + * entire B-tree is going away. + * + * Side effects: + * If the tree is going away then the toggle's memory is freed; otherwise + * the toggle counts in nodes above the segment get updated. + * + *-------------------------------------------------------------- + */ + +static int +ToggleDeleteProc( + TkTextSegment *segPtr, /* Segment to check. */ + TkTextLine *linePtr, /* Line containing segment. */ + int treeGone) /* Non-zero means the entire tree is being + * deleted, so everything must get cleaned + * up. */ +{ + if (treeGone) { + ckfree(segPtr); + return 0; + } + + /* + * This toggle is in the middle of a range of characters that's being + * deleted. Refuse to die. We'll be moved to the end of the deleted range + * and our cleanup function will be called later. Decrement node toggle + * counts here, and set a flag so we'll re-increment them in the cleanup + * function. + */ + + if (segPtr->body.toggle.inNodeCounts) { + ChangeNodeToggleCount(linePtr->parentPtr, + segPtr->body.toggle.tagPtr, -1); + segPtr->body.toggle.inNodeCounts = 0; + } + return 1; +} + +/* + *-------------------------------------------------------------- + * + * ToggleCleanupProc -- + * + * This function is called when a toggle is part of a line that's been + * modified in some way. It's invoked after the modifications are + * complete. + * + * Results: + * The return value is the head segment in a new list that is to replace + * the tail of the line that used to start at segPtr. This allows the + * function to delete or modify segPtr. + * + * Side effects: + * Toggle counts in the nodes above the new line will be updated if + * they're not already. Toggles may be collapsed if there are duplicate + * toggles at the same position. + * + *-------------------------------------------------------------- + */ + +static TkTextSegment * +ToggleCleanupProc( + TkTextSegment *segPtr, /* Segment to check. */ + TkTextLine *linePtr) /* Line that now contains segment. */ +{ + TkTextSegment *segPtr2, *prevPtr; + int counts; + + /* + * If this is a toggle-off segment, look ahead through the next segments + * to see if there's a toggle-on segment for the same tag before any + * segments with non-zero size. If so then the two toggles cancel each + * other; remove them both. + */ + + if (segPtr->typePtr == &tkTextToggleOffType) { + for (prevPtr = segPtr, segPtr2 = prevPtr->nextPtr; + (segPtr2 != NULL) && (segPtr2->size == 0); + prevPtr = segPtr2, segPtr2 = prevPtr->nextPtr) { + if (segPtr2->typePtr != &tkTextToggleOnType) { + continue; + } + if (segPtr2->body.toggle.tagPtr != segPtr->body.toggle.tagPtr) { + continue; + } + counts = segPtr->body.toggle.inNodeCounts + + segPtr2->body.toggle.inNodeCounts; + if (counts != 0) { + ChangeNodeToggleCount(linePtr->parentPtr, + segPtr->body.toggle.tagPtr, -counts); + } + prevPtr->nextPtr = segPtr2->nextPtr; + ckfree(segPtr2); + segPtr2 = segPtr->nextPtr; + ckfree(segPtr); + return segPtr2; + } + } + + if (!segPtr->body.toggle.inNodeCounts) { + ChangeNodeToggleCount(linePtr->parentPtr, + segPtr->body.toggle.tagPtr, 1); + segPtr->body.toggle.inNodeCounts = 1; + } + return segPtr; +} + +/* + *-------------------------------------------------------------- + * + * ToggleLineChangeProc -- + * + * This function is invoked when a toggle segment is about to move from + * one line to another. + * + * Results: + * None. + * + * Side effects: + * Toggle counts are decremented in the nodes above the line. + * + *-------------------------------------------------------------- + */ + +static void +ToggleLineChangeProc( + TkTextSegment *segPtr, /* Segment to check. */ + TkTextLine *linePtr) /* Line that used to contain segment. */ +{ + if (segPtr->body.toggle.inNodeCounts) { + ChangeNodeToggleCount(linePtr->parentPtr, + segPtr->body.toggle.tagPtr, -1); + segPtr->body.toggle.inNodeCounts = 0; + } +} + +/* + *-------------------------------------------------------------- + * + * ToggleCheckProc -- + * + * This function is invoked to perform consistency checks on toggle + * segments. + * + * Results: + * None. + * + * Side effects: + * If a consistency problem is found the function panics. + * + *-------------------------------------------------------------- + */ + +static void +ToggleCheckProc( + TkTextSegment *segPtr, /* Segment to check. */ + TkTextLine *linePtr) /* Line containing segment. */ +{ + register Summary *summaryPtr; + int needSummary; + + if (segPtr->size != 0) { + Tcl_Panic("ToggleCheckProc: segment had non-zero size"); + } + if (!segPtr->body.toggle.inNodeCounts) { + Tcl_Panic("ToggleCheckProc: toggle counts not updated in nodes"); + } + needSummary = (segPtr->body.toggle.tagPtr->tagRootPtr!=linePtr->parentPtr); + for (summaryPtr = linePtr->parentPtr->summaryPtr; ; + summaryPtr = summaryPtr->nextPtr) { + if (summaryPtr == NULL) { + if (needSummary) { + Tcl_Panic("ToggleCheckProc: tag not present in node"); + } else { + break; + } + } + if (summaryPtr->tagPtr == segPtr->body.toggle.tagPtr) { + if (!needSummary) { + Tcl_Panic("ToggleCheckProc: tag present in root node summary"); + } + break; + } + } +} + +/* + * Local Variables: + * mode: c + * c-basic-offset: 4 + * fill-column: 78 + * End: + */ |