/* * 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) 1994-1997 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: @(#) tkCursor.c 1.35 98/01/19 11:50:15 */ #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 string name for a cursor to the TkCursor * record for the cursor: */ static Tcl_HashTable nameTable; /* * 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 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)); static void DupCursorObjProc _ANSI_ARGS_((Tcl_Obj *srcObjPtr, Tcl_Obj *dupObjPtr)); static void FreeCursor _ANSI_ARGS_((TkCursor *cursorPtr)); static void FreeCursorObjProc _ANSI_ARGS_((Tcl_Obj *objPtr)); static TkCursor * GetCursor _ANSI_ARGS_((Tcl_Interp *interp, Tk_Window tkwin, char *name)); static TkCursor * GetCursorFromObj _ANSI_ARGS_((Tk_Window tkwin, Tcl_Obj *objPtr)); static void InitCursorObj _ANSI_ARGS_((Tcl_Obj *objPtr)); /* * The following structure defines the implementation of the "cursor" Tcl * object, used for drawing. The color object remembers the hash table * entry associated with a color. The actual allocation and deallocation * of the color should be done by the configuration package when the cursor * option is set. */ static Tcl_ObjType cursorObjType = { "cursor", /* name */ FreeCursorObjProc, /* freeIntRepProc */ DupCursorObjProc, /* dupIntRepProc */ NULL, /* updateStringProc */ NULL /* setFromAnyProc */ }; /* *---------------------------------------------------------------------- * * Tk_AllocCursorFromObj -- * * Given a Tcl_Obj *, map the value to a corresponding * Tk_Cursor structure based on the tkwin given. * * Results: * The return value is the X identifer for the desired cursor, * unless objPtr couldn't be parsed correctly. In this case, * None is returned and an error message is left in the interp's result. * The caller should never modify the cursor that is returned, and * should eventually call Tk_FreeCursorFromObj 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_FreeCursorFromObj, so that the database can be cleaned up * when cursors aren't needed anymore. * *---------------------------------------------------------------------- */ Tk_Cursor Tk_AllocCursorFromObj(interp, tkwin, objPtr) Tcl_Interp *interp; /* Interp for error results. */ Tk_Window tkwin; /* Window in which the cursor will be used.*/ Tcl_Obj *objPtr; /* Object describing cursor; see manual * entry for description of legal * syntax of this obj's string rep. */ { TkCursor *cursorPtr; if (objPtr->typePtr != &cursorObjType) { InitCursorObj(objPtr); } cursorPtr = (TkCursor *) objPtr->internalRep.twoPtrValue.ptr1; /* * If the object currently points to a TkCursor, see if it's the * one we want. If so, increment its reference count and return. */ if (cursorPtr != NULL) { if (cursorPtr->resourceRefCount == 0) { /* * This is a stale reference: it refers to a TkCursor that's * no longer in use. Clear the reference. */ FreeCursorObjProc(objPtr); cursorPtr = NULL; } else if (Tk_Display(tkwin) == cursorPtr->display) { cursorPtr->resourceRefCount++; return cursorPtr->cursor; } } /* * The object didn't point to the TkCursor that we wanted. Search * the list of TkCursors with the same name to see if one of the * other TkCursors is the right one. */ if (cursorPtr != NULL) { TkCursor *firstCursorPtr = (TkCursor *) Tcl_GetHashValue(cursorPtr->hashPtr); FreeCursorObjProc(objPtr); for (cursorPtr = firstCursorPtr; cursorPtr != NULL; cursorPtr = cursorPtr->nextPtr) { if (Tk_Display(tkwin) == cursorPtr->display) { cursorPtr->resourceRefCount++; cursorPtr->objRefCount++; objPtr->internalRep.twoPtrValue.ptr1 = (VOID *) cursorPtr; return cursorPtr->cursor; } } } /* * Still no luck. Call GetCursor to allocate a new TkCursor object. */ cursorPtr = GetCursor(interp, tkwin, Tcl_GetString(objPtr)); objPtr->internalRep.twoPtrValue.ptr1 = (VOID *) cursorPtr; if (cursorPtr == NULL) { return None; } else { cursorPtr->objRefCount++; return cursorPtr->cursor; } } /* *---------------------------------------------------------------------- * * 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 the interp's 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. */ char *string; /* Description of cursor. See manual entry * for details on legal syntax. */ { TkCursor *cursorPtr = GetCursor(interp, tkwin, string); if (cursorPtr == NULL) { return None; } return cursorPtr->cursor; } /* *---------------------------------------------------------------------- * * GetCursor -- * * Given a string describing a cursor, locate (or create if necessary) * a cursor that fits the description. This routine returns the * internal data structure for the cursor, which avoids extra * hash table lookups in Tk_AllocCursorFromObj. * * Results: * The return value is a pointer to the TkCursor for the desired * cursor, unless string couldn't be parsed correctly. In this * case, NULL is returned and an error message is left in the * interp's 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. * *---------------------------------------------------------------------- */ static TkCursor * GetCursor(interp, tkwin, string) Tcl_Interp *interp; /* Interpreter to use for error reporting. */ Tk_Window tkwin; /* Window in which cursor will be used. */ char *string; /* Description of cursor. See manual entry * for details on legal syntax. */ { IdKey idKey; Tcl_HashEntry *nameHashPtr; register TkCursor *cursorPtr; TkCursor *existingCursorPtr = NULL; int new; if (!initialized) { CursorInit(); } nameHashPtr = Tcl_CreateHashEntry(&nameTable, string, &new); if (!new) { existingCursorPtr = (TkCursor *) Tcl_GetHashValue(nameHashPtr); for (cursorPtr = existingCursorPtr; cursorPtr != NULL; cursorPtr = cursorPtr->nextPtr) { if (Tk_Display(tkwin) == cursorPtr->display) { cursorPtr->resourceRefCount++; return cursorPtr; } } } else { existingCursorPtr = NULL; } cursorPtr = TkGetCursorByName(interp, tkwin, string); if (cursorPtr == NULL) { if (new) { Tcl_DeleteHashEntry(nameHashPtr); } return NULL; } /* * Add information about this cursor to our database. */ cursorPtr->display = Tk_Display(tkwin); cursorPtr->resourceRefCount = 1; cursorPtr->objRefCount = 0; cursorPtr->otherTable = &nameTable; cursorPtr->hashPtr = nameHashPtr; idKey.display = Tk_Display(tkwin); idKey.cursor = cursorPtr->cursor; cursorPtr->idHashPtr = Tcl_CreateHashEntry(&idTable, (char *) &idKey, &new); if (!new) { panic("cursor already registered in Tk_GetCursor"); } cursorPtr->nextPtr = existingCursorPtr; Tcl_SetHashValue(nameHashPtr, cursorPtr); Tcl_SetHashValue(cursorPtr->idHashPtr, cursorPtr); return cursorPtr; } /* *---------------------------------------------------------------------- * * 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 the interp's 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; 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->resourceRefCount++; 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->resourceRefCount = 1; cursorPtr->otherTable = &dataTable; cursorPtr->hashPtr = dataHashPtr; cursorPtr->objRefCount = 0; idKey.display = dataKey.display; idKey.cursor = cursorPtr->cursor; cursorPtr->idHashPtr = Tcl_CreateHashEntry(&idTable, (char *) &idKey, &new); if (!new) { panic("cursor already registered in Tk_GetCursorFromData"); } Tcl_SetHashValue(dataHashPtr, cursorPtr); Tcl_SetHashValue(cursorPtr->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 cursorPtr->hashPtr->key.string; } /* *---------------------------------------------------------------------- * * FreeCursor -- * * This procedure is invoked by both Tk_FreeCursor and * Tk_FreeCursorFromObj; it does all the real work of deallocating * a cursor. * * Results: * None. * * Side effects: * The reference count associated with cursor is decremented, and * it is officially deallocated if no-one is using it anymore. * *---------------------------------------------------------------------- */ static void FreeCursor(cursorPtr) TkCursor *cursorPtr; /* Cursor to be released. */ { TkCursor *prevPtr; cursorPtr->resourceRefCount--; if (cursorPtr->resourceRefCount > 0) { return; } Tcl_DeleteHashEntry(cursorPtr->idHashPtr); prevPtr = (TkCursor *) Tcl_GetHashValue(cursorPtr->hashPtr); if (prevPtr == cursorPtr) { if (cursorPtr->nextPtr == NULL) { Tcl_DeleteHashEntry(cursorPtr->hashPtr); } else { Tcl_SetHashValue(cursorPtr->hashPtr, cursorPtr->nextPtr); } } else { while (prevPtr->nextPtr != cursorPtr) { prevPtr = prevPtr->nextPtr; } prevPtr->nextPtr = cursorPtr->nextPtr; } TkpFreeCursor(cursorPtr); if (cursorPtr->objRefCount == 0) { ckfree((char *) cursorPtr); } } /* *---------------------------------------------------------------------- * * 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; 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"); } FreeCursor((TkCursor *) Tcl_GetHashValue(idHashPtr)); } /* *---------------------------------------------------------------------- * * Tk_FreeCursorFromObj -- * * This procedure is called to release a cursor allocated by * Tk_AllocCursorFromObj. It does not throw away the Tcl_Obj *; * it only gets rid of the hash table entry for this cursor * and clears the cached value that is normally stored in the object. * * Results: * None. * * Side effects: * The reference count associated with the cursor represented by * objPtr is decremented, and the cursor is released to X if there are * no remaining uses for it. * *---------------------------------------------------------------------- */ void Tk_FreeCursorFromObj(tkwin, objPtr) Tk_Window tkwin; /* The window this cursor lives in. Needed * for the display value. */ Tcl_Obj *objPtr; /* The Tcl_Obj * to be freed. */ { FreeCursor(GetCursorFromObj(tkwin, objPtr)); } /* *--------------------------------------------------------------------------- * * FreeCursorFromObjProc -- * * This proc is called to release an object reference to a cursor. * Called when the object's internal rep is released or when * the cached tkColPtr needs to be changed. * * Results: * None. * * Side effects: * The object reference count is decremented. When both it * and the hash ref count go to zero, the color's resources * are released. * *--------------------------------------------------------------------------- */ static void FreeCursorObjProc(objPtr) Tcl_Obj *objPtr; /* The object we are releasing. */ { TkCursor *cursorPtr = (TkCursor *) objPtr->internalRep.twoPtrValue.ptr1; if (cursorPtr != NULL) { cursorPtr->objRefCount--; if ((cursorPtr->objRefCount == 0) && (cursorPtr->resourceRefCount == 0)) { ckfree((char *) cursorPtr); } objPtr->internalRep.twoPtrValue.ptr1 = (VOID *) NULL; } } /* *--------------------------------------------------------------------------- * * DupCursorObjProc -- * * When a cached cursor object is duplicated, this is called to * update the internal reps. * * Results: * None. * * Side effects: * The color's objRefCount is incremented and the internal rep * of the copy is set to point to it. * *--------------------------------------------------------------------------- */ static void DupCursorObjProc(srcObjPtr, dupObjPtr) Tcl_Obj *srcObjPtr; /* The object we are copying from. */ Tcl_Obj *dupObjPtr; /* The object we are copying to. */ { TkCursor *cursorPtr = (TkCursor *) srcObjPtr->internalRep.twoPtrValue.ptr1; dupObjPtr->typePtr = srcObjPtr->typePtr; dupObjPtr->internalRep.twoPtrValue.ptr1 = (VOID *) cursorPtr; if (cursorPtr != NULL) { cursorPtr->objRefCount++; } } /* *---------------------------------------------------------------------- * * Tk_GetCursorFromObj -- * * Returns the cursor referred to buy a Tcl object. The cursor must * already have been allocated via a call to Tk_AllocCursorFromObj or * Tk_GetCursor. * * Results: * Returns the Tk_Cursor that matches the tkwin and the string rep * of the name of the cursor given in objPtr. * * Side effects: * If the object is not already a cursor, the conversion will free * any old internal representation. * *---------------------------------------------------------------------- */ Tk_Cursor Tk_GetCursorFromObj(tkwin, objPtr) Tk_Window tkwin; Tcl_Obj *objPtr; /* The object from which to get pixels. */ { TkCursor *cursorPtr = GetCursorFromObj(tkwin, objPtr); return cursorPtr->cursor; } /* *---------------------------------------------------------------------- * * GetCursorFromObj -- * * Returns the cursor referred to by a Tcl object. The cursor must * already have been allocated via a call to Tk_AllocCursorFromObj * or Tk_GetCursor. * * Results: * Returns the TkCursor * that matches the tkwin and the string rep * of the name of the cursor given in objPtr. * * Side effects: * If the object is not already a cursor, the conversion will free * any old internal representation. * *---------------------------------------------------------------------- */ static TkCursor * GetCursorFromObj(tkwin, objPtr) Tk_Window tkwin; /* Window in which the cursor will be used. */ Tcl_Obj *objPtr; /* The object that describes the desired * cursor. */ { TkCursor *cursorPtr; Tcl_HashEntry *hashPtr; if (objPtr->typePtr != &cursorObjType) { InitCursorObj(objPtr); } cursorPtr = (TkCursor *) objPtr->internalRep.twoPtrValue.ptr1; if (cursorPtr != NULL) { if (Tk_Display(tkwin) == cursorPtr->display) { return cursorPtr; } hashPtr = cursorPtr->hashPtr; } else { hashPtr = Tcl_FindHashEntry(&nameTable, Tcl_GetString(objPtr)); if (hashPtr == NULL) { goto error; } } /* * At this point we've got a hash table entry, off of which hang * one or more TkCursor structures. See if any of them will work. */ for (cursorPtr = (TkCursor *) Tcl_GetHashValue(hashPtr); cursorPtr != NULL; cursorPtr = cursorPtr->nextPtr) { if (Tk_Display(tkwin) != cursorPtr->display) { objPtr->internalRep.twoPtrValue.ptr1 = (VOID *) cursorPtr; cursorPtr->objRefCount++; return cursorPtr; } } error: panic("GetCursorFromObj called with non-existent cursor!"); /* * The following code isn't reached; it's just there to please compilers. */ return NULL; } /* *---------------------------------------------------------------------- * * InitCursorObj -- * * Bookeeping procedure to change an objPtr to a cursor type. * * Results: * None. * * Side effects: * The old internal rep of the object is freed. The internal * rep is cleared. The final form of the object is set * by either Tk_AllocCursorFromObj or GetCursorFromObj. * *---------------------------------------------------------------------- */ static void InitCursorObj(objPtr) Tcl_Obj *objPtr; /* The object to convert. */ { Tcl_ObjType *typePtr; /* * Free the old internalRep before setting the new one. */ Tcl_GetString(objPtr); typePtr = objPtr->typePtr; if ((typePtr != NULL) && (typePtr->freeIntRepProc != NULL)) { (*typePtr->freeIntRepProc)(objPtr); } objPtr->typePtr = &cursorObjType; objPtr->internalRep.twoPtrValue.ptr1 = (VOID *) NULL; } /* *---------------------------------------------------------------------- * * CursorInit -- * * Initialize the structures used for cursor management. * * Results: * None. * * Side effects: * Read the code. * *---------------------------------------------------------------------- */ static void CursorInit() { initialized = 1; Tcl_InitHashTable(&nameTable, TCL_STRING_KEYS); 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)); } /* *---------------------------------------------------------------------- * * TkDebugCursor -- * * This procedure returns debugging information about a cursor. * * Results: * The return value is a list with one sublist for each TkCursor * corresponding to "name". Each sublist has two elements that * contain the resourceRefCount and objRefCount fields from the * TkCursor structure. * * Side effects: * None. * *---------------------------------------------------------------------- */ Tcl_Obj * TkDebugCursor(tkwin, name) Tk_Window tkwin; /* The window in which the cursor will be * used (not currently used). */ char *name; /* Name of the desired color. */ { TkCursor *cursorPtr; Tcl_HashEntry *hashPtr; Tcl_Obj *resultPtr, *objPtr; resultPtr = Tcl_NewObj(); hashPtr = Tcl_FindHashEntry(&nameTable, name); if (hashPtr != NULL) { cursorPtr = (TkCursor *) Tcl_GetHashValue(hashPtr); if (cursorPtr == NULL) { panic("TkDebugCursor found empty hash table entry"); } for ( ; (cursorPtr != NULL); cursorPtr = cursorPtr->nextPtr) { objPtr = Tcl_NewObj(); Tcl_ListObjAppendElement(NULL, objPtr, Tcl_NewIntObj(cursorPtr->resourceRefCount)); Tcl_ListObjAppendElement(NULL, objPtr, Tcl_NewIntObj(cursorPtr->objRefCount)); Tcl_ListObjAppendElement(NULL, resultPtr, objPtr); } } return resultPtr; }