diff options
Diffstat (limited to 'generic/tkCursor.c')
| -rw-r--r-- | generic/tkCursor.c | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/generic/tkCursor.c b/generic/tkCursor.c new file mode 100644 index 0000000..e185109 --- /dev/null +++ b/generic/tkCursor.c @@ -0,0 +1,384 @@ +/* + * tkCursor.c -- + * + * This file maintains a database of read-only cursors for the Tk + * toolkit. This allows cursors to be shared between widgets and + * also avoids round-trips to the X server. + * + * Copyright (c) 1990-1994 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. + * + * SCCS: @(#) tkCursor.c 1.27 96/02/15 18:52:40 + */ + +#include "tkPort.h" +#include "tkInt.h" + +/* + * A TkCursor structure exists for each cursor that is currently + * active. Each structure is indexed with two hash tables defined + * below. One of the tables is idTable, and the other is either + * nameTable or dataTable, also defined below. + */ + +/* + * Hash table to map from a textual description of a cursor to the + * TkCursor record for the cursor, and key structure used in that + * hash table: + */ + +static Tcl_HashTable nameTable; +typedef struct { + Tk_Uid name; /* Textual name for desired cursor. */ + Display *display; /* Display for which cursor will be used. */ +} NameKey; + +/* + * Hash table to map from a collection of in-core data about a + * cursor (bitmap contents, etc.) to a TkCursor structure: + */ + +static Tcl_HashTable dataTable; +typedef struct { + char *source; /* Cursor bits. */ + char *mask; /* Mask bits. */ + int width, height; /* Dimensions of cursor (and data + * and mask). */ + int xHot, yHot; /* Location of cursor hot-spot. */ + Tk_Uid fg, bg; /* Colors for cursor. */ + Display *display; /* Display on which cursor will be used. */ +} DataKey; + +/* + * Hash table that maps from <display + cursor id> to the TkCursor structure + * for the cursor. This table is used by Tk_FreeCursor. + */ + +static Tcl_HashTable idTable; +typedef struct { + Display *display; /* Display for which cursor was allocated. */ + Tk_Cursor cursor; /* Cursor identifier. */ +} IdKey; + +static int initialized = 0; /* 0 means static structures haven't been + * initialized yet. */ + +/* + * Forward declarations for procedures defined in this file: + */ + +static void CursorInit _ANSI_ARGS_((void)); + +/* + *---------------------------------------------------------------------- + * + * Tk_GetCursor -- + * + * Given a string describing a cursor, locate (or create if necessary) + * a cursor that fits the description. + * + * Results: + * The return value is the X identifer for the desired cursor, + * unless string couldn't be parsed correctly. In this case, + * None is returned and an error message is left in interp->result. + * The caller should never modify the cursor that is returned, and + * should eventually call Tk_FreeCursor when the cursor is no longer + * needed. + * + * Side effects: + * The cursor is added to an internal database with a reference count. + * For each call to this procedure, there should eventually be a call + * to Tk_FreeCursor, so that the database can be cleaned up when cursors + * aren't needed anymore. + * + *---------------------------------------------------------------------- + */ + +Tk_Cursor +Tk_GetCursor(interp, tkwin, string) + Tcl_Interp *interp; /* Interpreter to use for error reporting. */ + Tk_Window tkwin; /* Window in which cursor will be used. */ + Tk_Uid string; /* Description of cursor. See manual entry + * for details on legal syntax. */ +{ + NameKey nameKey; + IdKey idKey; + Tcl_HashEntry *nameHashPtr, *idHashPtr; + register TkCursor *cursorPtr; + int new; + + if (!initialized) { + CursorInit(); + } + + nameKey.name = string; + nameKey.display = Tk_Display(tkwin); + nameHashPtr = Tcl_CreateHashEntry(&nameTable, (char *) &nameKey, &new); + if (!new) { + cursorPtr = (TkCursor *) Tcl_GetHashValue(nameHashPtr); + cursorPtr->refCount++; + return cursorPtr->cursor; + } + + cursorPtr = TkGetCursorByName(interp, tkwin, string); + + if (cursorPtr == NULL) { + Tcl_DeleteHashEntry(nameHashPtr); + return None; + } + + /* + * Add information about this cursor to our database. + */ + + cursorPtr->refCount = 1; + cursorPtr->otherTable = &nameTable; + cursorPtr->hashPtr = nameHashPtr; + idKey.display = nameKey.display; + idKey.cursor = cursorPtr->cursor; + idHashPtr = Tcl_CreateHashEntry(&idTable, (char *) &idKey, &new); + if (!new) { + panic("cursor already registered in Tk_GetCursor"); + } + Tcl_SetHashValue(nameHashPtr, cursorPtr); + Tcl_SetHashValue(idHashPtr, cursorPtr); + + return cursorPtr->cursor; +} + +/* + *---------------------------------------------------------------------- + * + * Tk_GetCursorFromData -- + * + * Given a description of the bits and colors for a cursor, + * make a cursor that has the given properties. + * + * Results: + * The return value is the X identifer for the desired cursor, + * unless it couldn't be created properly. In this case, None is + * returned and an error message is left in interp->result. The + * caller should never modify the cursor that is returned, and + * should eventually call Tk_FreeCursor when the cursor is no + * longer needed. + * + * Side effects: + * The cursor is added to an internal database with a reference count. + * For each call to this procedure, there should eventually be a call + * to Tk_FreeCursor, so that the database can be cleaned up when cursors + * aren't needed anymore. + * + *---------------------------------------------------------------------- + */ + +Tk_Cursor +Tk_GetCursorFromData(interp, tkwin, source, mask, width, height, + xHot, yHot, fg, bg) + Tcl_Interp *interp; /* Interpreter to use for error reporting. */ + Tk_Window tkwin; /* Window in which cursor will be used. */ + char *source; /* Bitmap data for cursor shape. */ + char *mask; /* Bitmap data for cursor mask. */ + int width, height; /* Dimensions of cursor. */ + int xHot, yHot; /* Location of hot-spot in cursor. */ + Tk_Uid fg; /* Foreground color for cursor. */ + Tk_Uid bg; /* Background color for cursor. */ +{ + DataKey dataKey; + IdKey idKey; + Tcl_HashEntry *dataHashPtr, *idHashPtr; + register TkCursor *cursorPtr; + int new; + XColor fgColor, bgColor; + + if (!initialized) { + CursorInit(); + } + + dataKey.source = source; + dataKey.mask = mask; + dataKey.width = width; + dataKey.height = height; + dataKey.xHot = xHot; + dataKey.yHot = yHot; + dataKey.fg = fg; + dataKey.bg = bg; + dataKey.display = Tk_Display(tkwin); + dataHashPtr = Tcl_CreateHashEntry(&dataTable, (char *) &dataKey, &new); + if (!new) { + cursorPtr = (TkCursor *) Tcl_GetHashValue(dataHashPtr); + cursorPtr->refCount++; + return cursorPtr->cursor; + } + + /* + * No suitable cursor exists yet. Make one using the data + * available and add it to the database. + */ + + if (XParseColor(dataKey.display, Tk_Colormap(tkwin), fg, &fgColor) == 0) { + Tcl_AppendResult(interp, "invalid color name \"", fg, "\"", + (char *) NULL); + goto error; + } + if (XParseColor(dataKey.display, Tk_Colormap(tkwin), bg, &bgColor) == 0) { + Tcl_AppendResult(interp, "invalid color name \"", bg, "\"", + (char *) NULL); + goto error; + } + + cursorPtr = TkCreateCursorFromData(tkwin, source, mask, width, height, + xHot, yHot, fgColor, bgColor); + + if (cursorPtr == NULL) { + goto error; + } + + cursorPtr->refCount = 1; + cursorPtr->otherTable = &dataTable; + cursorPtr->hashPtr = dataHashPtr; + idKey.display = dataKey.display; + idKey.cursor = cursorPtr->cursor; + idHashPtr = Tcl_CreateHashEntry(&idTable, (char *) &idKey, &new); + if (!new) { + panic("cursor already registered in Tk_GetCursorFromData"); + } + Tcl_SetHashValue(dataHashPtr, cursorPtr); + Tcl_SetHashValue(idHashPtr, cursorPtr); + return cursorPtr->cursor; + + error: + Tcl_DeleteHashEntry(dataHashPtr); + return None; +} + +/* + *-------------------------------------------------------------- + * + * Tk_NameOfCursor -- + * + * Given a cursor, return a textual string identifying it. + * + * Results: + * If cursor was created by Tk_GetCursor, then the return + * value is the "string" that was used to create it. + * Otherwise the return value is a string giving the X + * identifier for the cursor. The storage for the returned + * string is only guaranteed to persist up until the next + * call to this procedure. + * + * Side effects: + * None. + * + *-------------------------------------------------------------- + */ + +char * +Tk_NameOfCursor(display, cursor) + Display *display; /* Display for which cursor was allocated. */ + Tk_Cursor cursor; /* Identifier for cursor whose name is + * wanted. */ +{ + IdKey idKey; + Tcl_HashEntry *idHashPtr; + TkCursor *cursorPtr; + static char string[20]; + + if (!initialized) { + printid: + sprintf(string, "cursor id 0x%x", (unsigned int) cursor); + return string; + } + idKey.display = display; + idKey.cursor = cursor; + idHashPtr = Tcl_FindHashEntry(&idTable, (char *) &idKey); + if (idHashPtr == NULL) { + goto printid; + } + cursorPtr = (TkCursor *) Tcl_GetHashValue(idHashPtr); + if (cursorPtr->otherTable != &nameTable) { + goto printid; + } + return ((NameKey *) cursorPtr->hashPtr->key.words)->name; +} + +/* + *---------------------------------------------------------------------- + * + * Tk_FreeCursor -- + * + * This procedure is called to release a cursor allocated by + * Tk_GetCursor or TkGetCursorFromData. + * + * Results: + * None. + * + * Side effects: + * The reference count associated with cursor is decremented, and + * it is officially deallocated if no-one is using it anymore. + * + *---------------------------------------------------------------------- + */ + +void +Tk_FreeCursor(display, cursor) + Display *display; /* Display for which cursor was allocated. */ + Tk_Cursor cursor; /* Identifier for cursor to be released. */ +{ + IdKey idKey; + Tcl_HashEntry *idHashPtr; + register TkCursor *cursorPtr; + + if (!initialized) { + panic("Tk_FreeCursor called before Tk_GetCursor"); + } + + idKey.display = display; + idKey.cursor = cursor; + idHashPtr = Tcl_FindHashEntry(&idTable, (char *) &idKey); + if (idHashPtr == NULL) { + panic("Tk_FreeCursor received unknown cursor argument"); + } + cursorPtr = (TkCursor *) Tcl_GetHashValue(idHashPtr); + cursorPtr->refCount--; + if (cursorPtr->refCount == 0) { + Tcl_DeleteHashEntry(cursorPtr->hashPtr); + Tcl_DeleteHashEntry(idHashPtr); + TkFreeCursor(cursorPtr); + } +} + +/* + *---------------------------------------------------------------------- + * + * CursorInit -- + * + * Initialize the structures used for cursor management. + * + * Results: + * None. + * + * Side effects: + * Read the code. + * + *---------------------------------------------------------------------- + */ + +static void +CursorInit() +{ + initialized = 1; + Tcl_InitHashTable(&nameTable, sizeof(NameKey)/sizeof(int)); + Tcl_InitHashTable(&dataTable, sizeof(DataKey)/sizeof(int)); + + /* + * The call below is tricky: can't use sizeof(IdKey) because it + * gets padded with extra unpredictable bytes on some 64-bit + * machines. + */ + + Tcl_InitHashTable(&idTable, (sizeof(Display *) + sizeof(Tk_Cursor)) + /sizeof(int)); +} |