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authorrjohnson <rjohnson>1998-04-01 09:51:44 (GMT)
committerrjohnson <rjohnson>1998-04-01 09:51:44 (GMT)
commit066ea7fd88d49cb456f74da71dbe875e4fc0aabb (patch)
tree8fb30cb152c4dc191be47fa043d2e6f5ea38c7ba /generic/tkTextMark.c
parent13242623d2ff3ea02ab6a62bfb48a7dbb5c27e22 (diff)
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diff --git a/generic/tkTextMark.c b/generic/tkTextMark.c
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+/*
+ * tkTextMark.c --
+ *
+ * This file contains the procedure that implement marks for
+ * text widgets.
+ *
+ * Copyright (c) 1994 The Regents of the University of California.
+ * Copyright (c) 1994-1997 Sun Microsystems, Inc.
+ *
+ * See the file "license.terms" for information on usage and redistribution
+ * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ *
+ * SCCS: @(#) tkTextMark.c 1.18 97/10/20 11:12:50
+ */
+
+#include "tkInt.h"
+#include "tkText.h"
+#include "tkPort.h"
+
+/*
+ * Macro that determines the size of a mark segment:
+ */
+
+#define MSEG_SIZE ((unsigned) (Tk_Offset(TkTextSegment, body) \
+ + sizeof(TkTextMark)))
+
+/*
+ * Forward references for procedures defined in this file:
+ */
+
+static void InsertUndisplayProc _ANSI_ARGS_((TkText *textPtr,
+ TkTextDispChunk *chunkPtr));
+static int MarkDeleteProc _ANSI_ARGS_((TkTextSegment *segPtr,
+ TkTextLine *linePtr, int treeGone));
+static TkTextSegment * MarkCleanupProc _ANSI_ARGS_((TkTextSegment *segPtr,
+ TkTextLine *linePtr));
+static void MarkCheckProc _ANSI_ARGS_((TkTextSegment *segPtr,
+ TkTextLine *linePtr));
+static int MarkLayoutProc _ANSI_ARGS_((TkText *textPtr,
+ TkTextIndex *indexPtr, TkTextSegment *segPtr,
+ int offset, int maxX, int maxChars,
+ int noCharsYet, Tk_Uid wrapMode,
+ TkTextDispChunk *chunkPtr));
+static int MarkFindNext _ANSI_ARGS_((Tcl_Interp *interp,
+ TkText *textPtr, char *markName));
+static int MarkFindPrev _ANSI_ARGS_((Tcl_Interp *interp,
+ TkText *textPtr, char *markName));
+
+
+/*
+ * The following structures declare the "mark" segment types.
+ * There are actually two types for marks, one with left gravity
+ * and one with right gravity. They are identical except for
+ * their gravity property.
+ */
+
+Tk_SegType tkTextRightMarkType = {
+ "mark", /* name */
+ 0, /* leftGravity */
+ (Tk_SegSplitProc *) NULL, /* splitProc */
+ MarkDeleteProc, /* deleteProc */
+ MarkCleanupProc, /* cleanupProc */
+ (Tk_SegLineChangeProc *) NULL, /* lineChangeProc */
+ MarkLayoutProc, /* layoutProc */
+ MarkCheckProc /* checkProc */
+};
+
+Tk_SegType tkTextLeftMarkType = {
+ "mark", /* name */
+ 1, /* leftGravity */
+ (Tk_SegSplitProc *) NULL, /* splitProc */
+ MarkDeleteProc, /* deleteProc */
+ MarkCleanupProc, /* cleanupProc */
+ (Tk_SegLineChangeProc *) NULL, /* lineChangeProc */
+ MarkLayoutProc, /* layoutProc */
+ MarkCheckProc /* checkProc */
+};
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TkTextMarkCmd --
+ *
+ * This procedure is invoked to process the "mark" options of
+ * the widget command for text widgets. See the user documentation
+ * for details on what it does.
+ *
+ * Results:
+ * A standard Tcl result.
+ *
+ * Side effects:
+ * See the user documentation.
+ *
+ *--------------------------------------------------------------
+ */
+
+int
+TkTextMarkCmd(textPtr, interp, argc, argv)
+ register TkText *textPtr; /* Information about text widget. */
+ Tcl_Interp *interp; /* Current interpreter. */
+ int argc; /* Number of arguments. */
+ char **argv; /* Argument strings. Someone else has already
+ * parsed this command enough to know that
+ * argv[1] is "mark". */
+{
+ int c, i;
+ size_t length;
+ Tcl_HashEntry *hPtr;
+ TkTextSegment *markPtr;
+ Tcl_HashSearch search;
+ TkTextIndex index;
+ Tk_SegType *newTypePtr;
+
+ if (argc < 3) {
+ Tcl_AppendResult(interp, "wrong # args: should be \"",
+ argv[0], " mark option ?arg arg ...?\"", (char *) NULL);
+ return TCL_ERROR;
+ }
+ c = argv[2][0];
+ length = strlen(argv[2]);
+ if ((c == 'g') && (strncmp(argv[2], "gravity", length) == 0)) {
+ if (argc < 4 || argc > 5) {
+ Tcl_AppendResult(interp, "wrong # args: should be \"",
+ argv[0], " mark gravity markName ?gravity?\"",
+ (char *) NULL);
+ return TCL_ERROR;
+ }
+ hPtr = Tcl_FindHashEntry(&textPtr->markTable, argv[3]);
+ if (hPtr == NULL) {
+ Tcl_AppendResult(interp, "there is no mark named \"",
+ argv[3], "\"", (char *) NULL);
+ return TCL_ERROR;
+ }
+ markPtr = (TkTextSegment *) Tcl_GetHashValue(hPtr);
+ if (argc == 4) {
+ if (markPtr->typePtr == &tkTextRightMarkType) {
+ interp->result = "right";
+ } else {
+ interp->result = "left";
+ }
+ return TCL_OK;
+ }
+ length = strlen(argv[4]);
+ c = argv[4][0];
+ if ((c == 'l') && (strncmp(argv[4], "left", length) == 0)) {
+ newTypePtr = &tkTextLeftMarkType;
+ } else if ((c == 'r') && (strncmp(argv[4], "right", length) == 0)) {
+ newTypePtr = &tkTextRightMarkType;
+ } else {
+ Tcl_AppendResult(interp, "bad mark gravity \"",
+ argv[4], "\": must be left or right", (char *) NULL);
+ return TCL_ERROR;
+ }
+ TkTextMarkSegToIndex(textPtr, markPtr, &index);
+ TkBTreeUnlinkSegment(textPtr->tree, markPtr,
+ markPtr->body.mark.linePtr);
+ markPtr->typePtr = newTypePtr;
+ TkBTreeLinkSegment(markPtr, &index);
+ } else if ((c == 'n') && (strncmp(argv[2], "names", length) == 0)) {
+ if (argc != 3) {
+ Tcl_AppendResult(interp, "wrong # args: should be \"",
+ argv[0], " mark names\"", (char *) NULL);
+ return TCL_ERROR;
+ }
+ for (hPtr = Tcl_FirstHashEntry(&textPtr->markTable, &search);
+ hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
+ Tcl_AppendElement(interp,
+ Tcl_GetHashKey(&textPtr->markTable, hPtr));
+ }
+ } else if ((c == 'n') && (strncmp(argv[2], "next", length) == 0)) {
+ if (argc != 4) {
+ Tcl_AppendResult(interp, "wrong # args: should be \"",
+ argv[0], " mark next index\"", (char *) NULL);
+ return TCL_ERROR;
+ }
+ return MarkFindNext(interp, textPtr, argv[3]);
+ } else if ((c == 'p') && (strncmp(argv[2], "previous", length) == 0)) {
+ if (argc != 4) {
+ Tcl_AppendResult(interp, "wrong # args: should be \"",
+ argv[0], " mark previous index\"", (char *) NULL);
+ return TCL_ERROR;
+ }
+ return MarkFindPrev(interp, textPtr, argv[3]);
+ } else if ((c == 's') && (strncmp(argv[2], "set", length) == 0)) {
+ if (argc != 5) {
+ Tcl_AppendResult(interp, "wrong # args: should be \"",
+ argv[0], " mark set markName index\"", (char *) NULL);
+ return TCL_ERROR;
+ }
+ if (TkTextGetIndex(interp, textPtr, argv[4], &index) != TCL_OK) {
+ return TCL_ERROR;
+ }
+ TkTextSetMark(textPtr, argv[3], &index);
+ } else if ((c == 'u') && (strncmp(argv[2], "unset", length) == 0)) {
+ for (i = 3; i < argc; i++) {
+ hPtr = Tcl_FindHashEntry(&textPtr->markTable, argv[i]);
+ if (hPtr != NULL) {
+ markPtr = (TkTextSegment *) Tcl_GetHashValue(hPtr);
+ if ((markPtr == textPtr->insertMarkPtr)
+ || (markPtr == textPtr->currentMarkPtr)) {
+ continue;
+ }
+ TkBTreeUnlinkSegment(textPtr->tree, markPtr,
+ markPtr->body.mark.linePtr);
+ Tcl_DeleteHashEntry(hPtr);
+ ckfree((char *) markPtr);
+ }
+ }
+ } else {
+ Tcl_AppendResult(interp, "bad mark option \"", argv[2],
+ "\": must be gravity, names, next, previous, set, or unset",
+ (char *) NULL);
+ return TCL_ERROR;
+ }
+ return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TkTextSetMark --
+ *
+ * Set a mark to a particular position, creating a new mark if
+ * one doesn't already exist.
+ *
+ * Results:
+ * The return value is a pointer to the mark that was just set.
+ *
+ * Side effects:
+ * A new mark is created, or an existing mark is moved.
+ *
+ *----------------------------------------------------------------------
+ */
+
+TkTextSegment *
+TkTextSetMark(textPtr, name, indexPtr)
+ TkText *textPtr; /* Text widget in which to create mark. */
+ char *name; /* Name of mark to set. */
+ TkTextIndex *indexPtr; /* Where to set mark. */
+{
+ Tcl_HashEntry *hPtr;
+ TkTextSegment *markPtr;
+ TkTextIndex insertIndex;
+ int new;
+
+ hPtr = Tcl_CreateHashEntry(&textPtr->markTable, name, &new);
+ markPtr = (TkTextSegment *) Tcl_GetHashValue(hPtr);
+ if (!new) {
+ /*
+ * If this is the insertion point that's being moved, be sure
+ * to force a display update at the old position. Also, don't
+ * let the insertion cursor be after the final newline of the
+ * file.
+ */
+
+ if (markPtr == textPtr->insertMarkPtr) {
+ TkTextIndex index, index2;
+ TkTextMarkSegToIndex(textPtr, textPtr->insertMarkPtr, &index);
+ TkTextIndexForwChars(&index, 1, &index2);
+ TkTextChanged(textPtr, &index, &index2);
+ if (TkBTreeLineIndex(indexPtr->linePtr)
+ == TkBTreeNumLines(textPtr->tree)) {
+ TkTextIndexBackChars(indexPtr, 1, &insertIndex);
+ indexPtr = &insertIndex;
+ }
+ }
+ TkBTreeUnlinkSegment(textPtr->tree, markPtr,
+ markPtr->body.mark.linePtr);
+ } else {
+ markPtr = (TkTextSegment *) ckalloc(MSEG_SIZE);
+ markPtr->typePtr = &tkTextRightMarkType;
+ markPtr->size = 0;
+ markPtr->body.mark.textPtr = textPtr;
+ markPtr->body.mark.linePtr = indexPtr->linePtr;
+ markPtr->body.mark.hPtr = hPtr;
+ Tcl_SetHashValue(hPtr, markPtr);
+ }
+ TkBTreeLinkSegment(markPtr, indexPtr);
+
+ /*
+ * If the mark is the insertion cursor, then update the screen at the
+ * mark's new location.
+ */
+
+ if (markPtr == textPtr->insertMarkPtr) {
+ TkTextIndex index2;
+
+ TkTextIndexForwChars(indexPtr, 1, &index2);
+ TkTextChanged(textPtr, indexPtr, &index2);
+ }
+ return markPtr;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TkTextMarkSegToIndex --
+ *
+ * Given a segment that is a mark, create an index that
+ * refers to the next text character (or other text segment
+ * with non-zero size) after the mark.
+ *
+ * Results:
+ * *IndexPtr is filled in with index information.
+ *
+ * Side effects:
+ * None.
+ *
+ *--------------------------------------------------------------
+ */
+
+void
+TkTextMarkSegToIndex(textPtr, markPtr, indexPtr)
+ TkText *textPtr; /* Text widget containing mark. */
+ TkTextSegment *markPtr; /* Mark segment. */
+ TkTextIndex *indexPtr; /* Index information gets stored here. */
+{
+ TkTextSegment *segPtr;
+
+ indexPtr->tree = textPtr->tree;
+ indexPtr->linePtr = markPtr->body.mark.linePtr;
+ indexPtr->charIndex = 0;
+ for (segPtr = indexPtr->linePtr->segPtr; segPtr != markPtr;
+ segPtr = segPtr->nextPtr) {
+ indexPtr->charIndex += segPtr->size;
+ }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TkTextMarkNameToIndex --
+ *
+ * Given the name of a mark, return an index corresponding
+ * to the mark name.
+ *
+ * Results:
+ * The return value is TCL_OK if "name" exists as a mark in
+ * the text widget. In this case *indexPtr is filled in with
+ * the next segment whose after the mark whose size is
+ * non-zero. TCL_ERROR is returned if the mark doesn't exist
+ * in the text widget.
+ *
+ * Side effects:
+ * None.
+ *
+ *--------------------------------------------------------------
+ */
+
+int
+TkTextMarkNameToIndex(textPtr, name, indexPtr)
+ TkText *textPtr; /* Text widget containing mark. */
+ char *name; /* Name of mark. */
+ TkTextIndex *indexPtr; /* Index information gets stored here. */
+{
+ Tcl_HashEntry *hPtr;
+
+ hPtr = Tcl_FindHashEntry(&textPtr->markTable, name);
+ if (hPtr == NULL) {
+ return TCL_ERROR;
+ }
+ TkTextMarkSegToIndex(textPtr, (TkTextSegment *) Tcl_GetHashValue(hPtr),
+ indexPtr);
+ return TCL_OK;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * MarkDeleteProc --
+ *
+ * This procedure is invoked by the text B-tree code whenever
+ * a mark lies in a range of characters being deleted.
+ *
+ * Results:
+ * Returns 1 to indicate that deletion has been rejected.
+ *
+ * Side effects:
+ * None (even if the whole tree is being deleted we don't
+ * free up the mark; it will be done elsewhere).
+ *
+ *--------------------------------------------------------------
+ */
+
+ /* ARGSUSED */
+static int
+MarkDeleteProc(segPtr, linePtr, treeGone)
+ TkTextSegment *segPtr; /* Segment being deleted. */
+ TkTextLine *linePtr; /* Line containing segment. */
+ int treeGone; /* Non-zero means the entire tree is
+ * being deleted, so everything must
+ * get cleaned up. */
+{
+ return 1;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * MarkCleanupProc --
+ *
+ * This procedure is invoked by the B-tree code whenever a
+ * mark segment is moved from one line to another.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * The linePtr field of the segment gets updated.
+ *
+ *--------------------------------------------------------------
+ */
+
+static TkTextSegment *
+MarkCleanupProc(markPtr, linePtr)
+ TkTextSegment *markPtr; /* Mark segment that's being moved. */
+ TkTextLine *linePtr; /* Line that now contains segment. */
+{
+ markPtr->body.mark.linePtr = linePtr;
+ return markPtr;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * MarkLayoutProc --
+ *
+ * This procedure is the "layoutProc" for mark segments.
+ *
+ * Results:
+ * If the mark isn't the insertion cursor then the return
+ * value is -1 to indicate that this segment shouldn't be
+ * displayed. If the mark is the insertion character then
+ * 1 is returned and the chunkPtr structure is filled in.
+ *
+ * Side effects:
+ * None, except for filling in chunkPtr.
+ *
+ *--------------------------------------------------------------
+ */
+
+ /*ARGSUSED*/
+static int
+MarkLayoutProc(textPtr, indexPtr, segPtr, offset, maxX, maxChars,
+ noCharsYet, wrapMode, chunkPtr)
+ TkText *textPtr; /* Text widget being layed out. */
+ TkTextIndex *indexPtr; /* Identifies first character in chunk. */
+ TkTextSegment *segPtr; /* Segment corresponding to indexPtr. */
+ int offset; /* Offset within segPtr corresponding to
+ * indexPtr (always 0). */
+ int maxX; /* Chunk must not occupy pixels at this
+ * position or higher. */
+ int maxChars; /* Chunk must not include more than this
+ * many characters. */
+ int noCharsYet; /* Non-zero means no characters have been
+ * assigned to this line yet. */
+ Tk_Uid wrapMode; /* Not used. */
+ register TkTextDispChunk *chunkPtr;
+ /* Structure to fill in with information
+ * about this chunk. The x field has already
+ * been set by the caller. */
+{
+ if (segPtr != textPtr->insertMarkPtr) {
+ return -1;
+ }
+
+ chunkPtr->displayProc = TkTextInsertDisplayProc;
+ chunkPtr->undisplayProc = InsertUndisplayProc;
+ chunkPtr->measureProc = (Tk_ChunkMeasureProc *) NULL;
+ chunkPtr->bboxProc = (Tk_ChunkBboxProc *) NULL;
+ chunkPtr->numChars = 0;
+ chunkPtr->minAscent = 0;
+ chunkPtr->minDescent = 0;
+ chunkPtr->minHeight = 0;
+ chunkPtr->width = 0;
+
+ /*
+ * Note: can't break a line after the insertion cursor: this
+ * prevents the insertion cursor from being stranded at the end
+ * of a line.
+ */
+
+ chunkPtr->breakIndex = -1;
+ chunkPtr->clientData = (ClientData) textPtr;
+ return 1;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * TkTextInsertDisplayProc --
+ *
+ * This procedure is called to display the insertion
+ * cursor.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * Graphics are drawn.
+ *
+ *--------------------------------------------------------------
+ */
+
+ /* ARGSUSED */
+void
+TkTextInsertDisplayProc(chunkPtr, x, y, height, baseline, display, dst, screenY)
+ TkTextDispChunk *chunkPtr; /* Chunk that is to be drawn. */
+ int x; /* X-position in dst at which to
+ * draw this chunk (may differ from
+ * the x-position in the chunk because
+ * of scrolling). */
+ int y; /* Y-position at which to draw this
+ * chunk in dst (x-position is in
+ * the chunk itself). */
+ int height; /* Total height of line. */
+ int baseline; /* Offset of baseline from y. */
+ Display *display; /* Display to use for drawing. */
+ Drawable dst; /* Pixmap or window in which to draw
+ * chunk. */
+ int screenY; /* Y-coordinate in text window that
+ * corresponds to y. */
+{
+ TkText *textPtr = (TkText *) chunkPtr->clientData;
+ int halfWidth = textPtr->insertWidth/2;
+
+ if ((x + halfWidth) < 0) {
+ /*
+ * The insertion cursor is off-screen. Just return.
+ */
+
+ return;
+ }
+
+ /*
+ * As a special hack to keep the cursor visible on mono displays
+ * (or anywhere else that the selection and insertion cursors
+ * have the same color) write the default background in the cursor
+ * area (instead of nothing) when the cursor isn't on. Otherwise
+ * the selection might hide the cursor.
+ */
+
+ if (textPtr->flags & INSERT_ON) {
+ Tk_Fill3DRectangle(textPtr->tkwin, dst, textPtr->insertBorder,
+ x - textPtr->insertWidth/2, y, textPtr->insertWidth,
+ height, textPtr->insertBorderWidth, TK_RELIEF_RAISED);
+ } else if (textPtr->selBorder == textPtr->insertBorder) {
+ Tk_Fill3DRectangle(textPtr->tkwin, dst, textPtr->border,
+ x - textPtr->insertWidth/2, y, textPtr->insertWidth,
+ height, 0, TK_RELIEF_FLAT);
+ }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * InsertUndisplayProc --
+ *
+ * This procedure is called when the insertion cursor is no
+ * longer at a visible point on the display. It does nothing
+ * right now.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * None.
+ *
+ *--------------------------------------------------------------
+ */
+
+ /* ARGSUSED */
+static void
+InsertUndisplayProc(textPtr, chunkPtr)
+ TkText *textPtr; /* Overall information about text
+ * widget. */
+ TkTextDispChunk *chunkPtr; /* Chunk that is about to be freed. */
+{
+ return;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * MarkCheckProc --
+ *
+ * This procedure is invoked by the B-tree code to perform
+ * consistency checks on mark segments.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * The procedure panics if it detects anything wrong with
+ * the mark.
+ *
+ *--------------------------------------------------------------
+ */
+
+static void
+MarkCheckProc(markPtr, linePtr)
+ TkTextSegment *markPtr; /* Segment to check. */
+ TkTextLine *linePtr; /* Line containing segment. */
+{
+ Tcl_HashSearch search;
+ Tcl_HashEntry *hPtr;
+
+ if (markPtr->body.mark.linePtr != linePtr) {
+ panic("MarkCheckProc: markPtr->body.mark.linePtr bogus");
+ }
+
+ /*
+ * Make sure that the mark is still present in the text's mark
+ * hash table.
+ */
+
+ for (hPtr = Tcl_FirstHashEntry(&markPtr->body.mark.textPtr->markTable,
+ &search); hPtr != markPtr->body.mark.hPtr;
+ hPtr = Tcl_NextHashEntry(&search)) {
+ if (hPtr == NULL) {
+ panic("MarkCheckProc couldn't find hash table entry for mark");
+ }
+ }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * MarkFindNext --
+ *
+ * This procedure searches forward for the next mark.
+ *
+ * Results:
+ * A standard Tcl result, which is a mark name or an empty string.
+ *
+ * Side effects:
+ * None.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+MarkFindNext(interp, textPtr, string)
+ Tcl_Interp *interp; /* For error reporting */
+ TkText *textPtr; /* The widget */
+ char *string; /* The starting index or mark name */
+{
+ TkTextIndex index;
+ Tcl_HashEntry *hPtr;
+ register TkTextSegment *segPtr;
+ int offset;
+
+
+ hPtr = Tcl_FindHashEntry(&textPtr->markTable, string);
+ if (hPtr != NULL) {
+ /*
+ * If given a mark name, return the next mark in the list of
+ * segments, even if it happens to be at the same character position.
+ */
+ segPtr = (TkTextSegment *) Tcl_GetHashValue(hPtr);
+ TkTextMarkSegToIndex(textPtr, segPtr, &index);
+ segPtr = segPtr->nextPtr;
+ } else {
+ /*
+ * For non-mark name indices we want to return any marks that
+ * are right at the index.
+ */
+ if (TkTextGetIndex(interp, textPtr, string, &index) != TCL_OK) {
+ return TCL_ERROR;
+ }
+ for (offset = 0, segPtr = index.linePtr->segPtr;
+ segPtr != NULL && offset < index.charIndex;
+ offset += segPtr->size, segPtr = segPtr->nextPtr) {
+ /* Empty loop body */ ;
+ }
+ }
+ while (1) {
+ /*
+ * segPtr points at the first possible candidate,
+ * or NULL if we ran off the end of the line.
+ */
+ for ( ; segPtr != NULL ; segPtr = segPtr->nextPtr) {
+ if (segPtr->typePtr == &tkTextRightMarkType ||
+ segPtr->typePtr == &tkTextLeftMarkType) {
+ Tcl_SetResult(interp,
+ Tcl_GetHashKey(&textPtr->markTable, segPtr->body.mark.hPtr),
+ TCL_STATIC);
+ return TCL_OK;
+ }
+ }
+ index.linePtr = TkBTreeNextLine(index.linePtr);
+ if (index.linePtr == (TkTextLine *) NULL) {
+ return TCL_OK;
+ }
+ index.charIndex = 0;
+ segPtr = index.linePtr->segPtr;
+ }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * MarkFindPrev --
+ *
+ * This procedure searches backwards for the previous mark.
+ *
+ * Results:
+ * A standard Tcl result, which is a mark name or an empty string.
+ *
+ * Side effects:
+ * None.
+ *
+ *--------------------------------------------------------------
+ */
+
+static int
+MarkFindPrev(interp, textPtr, string)
+ Tcl_Interp *interp; /* For error reporting */
+ TkText *textPtr; /* The widget */
+ char *string; /* The starting index or mark name */
+{
+ TkTextIndex index;
+ Tcl_HashEntry *hPtr;
+ register TkTextSegment *segPtr, *seg2Ptr, *prevPtr;
+ int offset;
+
+
+ hPtr = Tcl_FindHashEntry(&textPtr->markTable, string);
+ if (hPtr != NULL) {
+ /*
+ * If given a mark name, return the previous mark in the list of
+ * segments, even if it happens to be at the same character position.
+ */
+ segPtr = (TkTextSegment *) Tcl_GetHashValue(hPtr);
+ TkTextMarkSegToIndex(textPtr, segPtr, &index);
+ } else {
+ /*
+ * For non-mark name indices we do not return any marks that
+ * are right at the index.
+ */
+ if (TkTextGetIndex(interp, textPtr, string, &index) != TCL_OK) {
+ return TCL_ERROR;
+ }
+ for (offset = 0, segPtr = index.linePtr->segPtr;
+ segPtr != NULL && offset < index.charIndex;
+ offset += segPtr->size, segPtr = segPtr->nextPtr) {
+ /* Empty loop body */ ;
+ }
+ }
+ while (1) {
+ /*
+ * segPtr points just past the first possible candidate,
+ * or at the begining of the line.
+ */
+ for (prevPtr = NULL, seg2Ptr = index.linePtr->segPtr;
+ seg2Ptr != NULL && seg2Ptr != segPtr;
+ seg2Ptr = seg2Ptr->nextPtr) {
+ if (seg2Ptr->typePtr == &tkTextRightMarkType ||
+ seg2Ptr->typePtr == &tkTextLeftMarkType) {
+ prevPtr = seg2Ptr;
+ }
+ }
+ if (prevPtr != NULL) {
+ Tcl_SetResult(interp,
+ Tcl_GetHashKey(&textPtr->markTable, prevPtr->body.mark.hPtr),
+ TCL_STATIC);
+ return TCL_OK;
+ }
+ index.linePtr = TkBTreePreviousLine(index.linePtr);
+ if (index.linePtr == (TkTextLine *) NULL) {
+ return TCL_OK;
+ }
+ segPtr = NULL;
+ }
+}