/*
* 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 "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;
void *ptr;
static char string[20];
if (!initialized) {
printid:
sprintf(string, "cursor id %p", 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;
}
ptr = cursorPtr->hashPtr->key.words;
return ((NameKey *) ptr)->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));
}