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Diffstat (limited to 'generic/tkVisual.c')
| -rw-r--r-- | generic/tkVisual.c | 540 |
1 files changed, 540 insertions, 0 deletions
diff --git a/generic/tkVisual.c b/generic/tkVisual.c new file mode 100644 index 0000000..207b905 --- /dev/null +++ b/generic/tkVisual.c @@ -0,0 +1,540 @@ +/* + * tkVisual.c -- + * + * This file contains library procedures for allocating and + * freeing visuals and colormaps. This code is based on a + * prototype implementation by Paul Mackerras. + * + * Copyright (c) 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: @(#) tkVisual.c 1.19 97/04/25 16:52:17 + */ + +#include "tkInt.h" +#include "tkPort.h" + +/* + * The table below maps from symbolic names for visual classes + * to the associated X class symbols. + */ + +typedef struct VisualDictionary { + char *name; /* Textual name of class. */ + int minLength; /* Minimum # characters that must be + * specified for an unambiguous match. */ + int class; /* X symbol for class. */ +} VisualDictionary; +static VisualDictionary visualNames[] = { + {"best", 1, 0}, + {"directcolor", 2, DirectColor}, + {"grayscale", 1, GrayScale}, + {"greyscale", 1, GrayScale}, + {"pseudocolor", 1, PseudoColor}, + {"staticcolor", 7, StaticColor}, + {"staticgray", 7, StaticGray}, + {"staticgrey", 7, StaticGray}, + {"truecolor", 1, TrueColor}, + {NULL, 0, 0}, +}; + +/* + * One of the following structures exists for each distinct non-default + * colormap allocated for a display by Tk_GetColormap. + */ + +struct TkColormap { + Colormap colormap; /* X's identifier for the colormap. */ + Visual *visual; /* Visual for which colormap was + * allocated. */ + int refCount; /* How many uses of the colormap are still + * outstanding (calls to Tk_GetColormap + * minus calls to Tk_FreeColormap). */ + int shareable; /* 0 means this colormap was allocated by + * a call to Tk_GetColormap with "new", + * implying that the window wants it all + * for itself. 1 means that the colormap + * was allocated as a default for a particular + * visual, so it can be shared. */ + struct TkColormap *nextPtr; /* Next in list of colormaps for this display, + * or NULL for end of list. */ +}; + +/* + *---------------------------------------------------------------------- + * + * Tk_GetVisual -- + * + * Given a string identifying a particular kind of visual, this + * procedure returns a visual and depth that matches the specification. + * + * Results: + * The return value is normally a pointer to a visual. If an + * error occurred in looking up the visual, NULL is returned and + * an error message is left in interp->result. The depth of the + * visual is returned to *depthPtr under normal returns. If + * colormapPtr is non-NULL, then this procedure also finds a + * suitable colormap for use with the visual in tkwin, and it + * returns that colormap in *colormapPtr unless an error occurs. + * + * Side effects: + * A new colormap may be allocated. + * + *---------------------------------------------------------------------- + */ + +Visual * +Tk_GetVisual(interp, tkwin, string, depthPtr, colormapPtr) + Tcl_Interp *interp; /* Interpreter to use for error + * reporting. */ + Tk_Window tkwin; /* Window in which visual will be + * used. */ + char *string; /* String describing visual. See + * manual entry for details. */ + int *depthPtr; /* The depth of the returned visual + * is stored here. */ + Colormap *colormapPtr; /* If non-NULL, then a suitable + * colormap for visual is placed here. + * This colormap must eventually be + * freed by calling Tk_FreeColormap. */ +{ + Tk_Window tkwin2; + XVisualInfo template, *visInfoList, *bestPtr; + long mask; + Visual *visual; + int length, c, numVisuals, prio, bestPrio, i; + char *p; + VisualDictionary *dictPtr; + TkColormap *cmapPtr; + TkDisplay *dispPtr = ((TkWindow *) tkwin)->dispPtr; + + /* + * Parse string and set up a template for use in searching for + * an appropriate visual. + */ + + c = string[0]; + if (c == '.') { + /* + * The string must be a window name. If the window is on the + * same screen as tkwin, then just use its visual. Otherwise + * use the information about the visual as a template for the + * search. + */ + + tkwin2 = Tk_NameToWindow(interp, string, tkwin); + if (tkwin2 == NULL) { + return NULL; + } + visual = Tk_Visual(tkwin2); + if (Tk_Screen(tkwin) == Tk_Screen(tkwin2)) { + *depthPtr = Tk_Depth(tkwin2); + if (colormapPtr != NULL) { + /* + * Use the colormap from the other window too (but be sure + * to increment its reference count if it's one of the ones + * allocated here). + */ + + *colormapPtr = Tk_Colormap(tkwin2); + for (cmapPtr = dispPtr->cmapPtr; cmapPtr != NULL; + cmapPtr = cmapPtr->nextPtr) { + if (cmapPtr->colormap == *colormapPtr) { + cmapPtr->refCount += 1; + break; + } + } + } + return visual; + } + template.depth = Tk_Depth(tkwin2); + template.class = visual->class; + template.red_mask = visual->red_mask; + template.green_mask = visual->green_mask; + template.blue_mask = visual->blue_mask; + template.colormap_size = visual->map_entries; + template.bits_per_rgb = visual->bits_per_rgb; + mask = VisualDepthMask|VisualClassMask|VisualRedMaskMask + |VisualGreenMaskMask|VisualBlueMaskMask|VisualColormapSizeMask + |VisualBitsPerRGBMask; + } else if ((c == 0) || ((c == 'd') && (string[1] != 0) + && (strncmp(string, "default", strlen(string)) == 0))) { + /* + * Use the default visual for the window's screen. + */ + + if (colormapPtr != NULL) { + *colormapPtr = DefaultColormapOfScreen(Tk_Screen(tkwin)); + } + *depthPtr = DefaultDepthOfScreen(Tk_Screen(tkwin)); + return DefaultVisualOfScreen(Tk_Screen(tkwin)); + } else if (isdigit(UCHAR(c))) { + int visualId; + + /* + * This is a visual ID. + */ + + if (Tcl_GetInt(interp, string, &visualId) == TCL_ERROR) { + Tcl_ResetResult(interp); + Tcl_AppendResult(interp, "bad X identifier for visual: ", + string, "\"", (char *) NULL); + return NULL; + } + template.visualid = visualId; + mask = VisualIDMask; + } else { + /* + * Parse the string into a class name (or "best") optionally + * followed by whitespace and a depth. + */ + + for (p = string; *p != 0; p++) { + if (isspace(UCHAR(*p)) || isdigit(UCHAR(*p))) { + break; + } + } + length = p - string; + template.class = -1; + for (dictPtr = visualNames; dictPtr->name != NULL; dictPtr++) { + if ((dictPtr->name[0] == c) && (length >= dictPtr->minLength) + && (strncmp(string, dictPtr->name, + (size_t) length) == 0)) { + template.class = dictPtr->class; + break; + } + } + if (template.class == -1) { + Tcl_AppendResult(interp, "unknown or ambiguous visual name \"", + string, "\": class must be ", (char *) NULL); + for (dictPtr = visualNames; dictPtr->name != NULL; dictPtr++) { + Tcl_AppendResult(interp, dictPtr->name, ", ", (char *) NULL); + } + Tcl_AppendResult(interp, "or default", (char *) NULL); + return NULL; + } + while (isspace(UCHAR(*p))) { + p++; + } + if (*p == 0) { + template.depth = 10000; + } else { + if (Tcl_GetInt(interp, p, &template.depth) != TCL_OK) { + return NULL; + } + } + if (c == 'b') { + mask = 0; + } else { + mask = VisualClassMask; + } + } + + /* + * Find all visuals that match the template we've just created, + * and return an error if there are none that match. + */ + + template.screen = Tk_ScreenNumber(tkwin); + mask |= VisualScreenMask; + visInfoList = XGetVisualInfo(Tk_Display(tkwin), mask, &template, + &numVisuals); + if (visInfoList == NULL) { + interp->result = "couldn't find an appropriate visual"; + return NULL; + } + + /* + * Search through the visuals that were returned to find the best + * one. The choice is based on the following criteria, in decreasing + * order of importance: + * + * 1. Depth: choose a visual with exactly the desired depth, + * else one with more bits than requested but as few bits + * as possible, else one with fewer bits but as many as + * possible. + * 2. Class: some visual classes are more desirable than others; + * pick the visual with the most desirable class. + * 3. Default: the default visual for the screen gets preference + * over other visuals, all else being equal. + */ + + bestPrio = 0; + bestPtr = NULL; + for (i = 0; i < numVisuals; i++) { + switch (visInfoList[i].class) { + case DirectColor: prio = 5; break; + case GrayScale: prio = 1; break; + case PseudoColor: prio = 7; break; + case StaticColor: prio = 3; break; + case StaticGray: prio = 1; break; + case TrueColor: prio = 5; break; + default: prio = 0; break; + } + if (visInfoList[i].visual + == DefaultVisualOfScreen(Tk_Screen(tkwin))) { + prio++; + } + if (bestPtr == NULL) { + goto newBest; + } + if (visInfoList[i].depth < bestPtr->depth) { + if (visInfoList[i].depth >= template.depth) { + goto newBest; + } + } else if (visInfoList[i].depth > bestPtr->depth) { + if (bestPtr->depth < template.depth) { + goto newBest; + } + } else { + if (prio > bestPrio) { + goto newBest; + } + } + continue; + + newBest: + bestPtr = &visInfoList[i]; + bestPrio = prio; + } + *depthPtr = bestPtr->depth; + visual = bestPtr->visual; + XFree((char *) visInfoList); + + /* + * If we need to find a colormap for this visual, do it now. + * If the visual is the default visual for the screen, then + * use the default colormap. Otherwise search for an existing + * colormap that's shareable. If all else fails, create a new + * colormap. + */ + + if (colormapPtr != NULL) { + if (visual == DefaultVisualOfScreen(Tk_Screen(tkwin))) { + *colormapPtr = DefaultColormapOfScreen(Tk_Screen(tkwin)); + } else { + for (cmapPtr = dispPtr->cmapPtr; cmapPtr != NULL; + cmapPtr = cmapPtr->nextPtr) { + if (cmapPtr->shareable && (cmapPtr->visual == visual)) { + *colormapPtr = cmapPtr->colormap; + cmapPtr->refCount += 1; + goto done; + } + } + cmapPtr = (TkColormap *) ckalloc(sizeof(TkColormap)); + cmapPtr->colormap = XCreateColormap(Tk_Display(tkwin), + RootWindowOfScreen(Tk_Screen(tkwin)), visual, + AllocNone); + cmapPtr->visual = visual; + cmapPtr->refCount = 1; + cmapPtr->shareable = 1; + cmapPtr->nextPtr = dispPtr->cmapPtr; + dispPtr->cmapPtr = cmapPtr; + *colormapPtr = cmapPtr->colormap; + } + } + + done: + return visual; +} + +/* + *---------------------------------------------------------------------- + * + * Tk_GetColormap -- + * + * Given a string identifying a colormap, this procedure finds + * an appropriate colormap. + * + * Results: + * The return value is normally the X resource identifier for the + * colormap. If an error occurs, None is returned and an error + * message is placed in interp->result. + * + * Side effects: + * A reference count is incremented for the colormap, so + * Tk_FreeColormap must eventually be called exactly once for + * each call to Tk_GetColormap. + * + *---------------------------------------------------------------------- + */ + +Colormap +Tk_GetColormap(interp, tkwin, string) + Tcl_Interp *interp; /* Interpreter to use for error + * reporting. */ + Tk_Window tkwin; /* Window where colormap will be + * used. */ + char *string; /* String that identifies colormap: + * either "new" or the name of + * another window. */ +{ + Colormap colormap; + TkColormap *cmapPtr; + TkDisplay *dispPtr = ((TkWindow *) tkwin)->dispPtr; + Tk_Window other; + + /* + * Allocate a new colormap, if that's what is wanted. + */ + + if (strcmp(string, "new") == 0) { + cmapPtr = (TkColormap *) ckalloc(sizeof(TkColormap)); + cmapPtr->colormap = XCreateColormap(Tk_Display(tkwin), + RootWindowOfScreen(Tk_Screen(tkwin)), Tk_Visual(tkwin), + AllocNone); + cmapPtr->visual = Tk_Visual(tkwin); + cmapPtr->refCount = 1; + cmapPtr->shareable = 0; + cmapPtr->nextPtr = dispPtr->cmapPtr; + dispPtr->cmapPtr = cmapPtr; + return cmapPtr->colormap; + } + + /* + * Use a colormap from an existing window. It must have the same + * visual as tkwin (which means, among other things, that the + * other window must be on the same screen). + */ + + other = Tk_NameToWindow(interp, string, tkwin); + if (other == NULL) { + return None; + } + if (Tk_Screen(other) != Tk_Screen(tkwin)) { + Tcl_AppendResult(interp, "can't use colormap for ", string, + ": not on same screen", (char *) NULL); + return None; + } + if (Tk_Visual(other) != Tk_Visual(tkwin)) { + Tcl_AppendResult(interp, "can't use colormap for ", string, + ": incompatible visuals", (char *) NULL); + return None; + } + colormap = Tk_Colormap(other); + + /* + * If the colormap was a special one allocated by code in this file, + * increment its reference count. + */ + + for (cmapPtr = dispPtr->cmapPtr; cmapPtr != NULL; + cmapPtr = cmapPtr->nextPtr) { + if (cmapPtr->colormap == colormap) { + cmapPtr->refCount += 1; + } + } + return colormap; +} + +/* + *---------------------------------------------------------------------- + * + * Tk_FreeColormap -- + * + * This procedure is called to release a colormap that was + * previously allocated by Tk_GetColormap. + * + * Results: + * None. + * + * Side effects: + * The colormap's reference count is decremented. If this was the + * last reference to the colormap, then the colormap is freed. + * + *---------------------------------------------------------------------- + */ + +void +Tk_FreeColormap(display, colormap) + Display *display; /* Display for which colormap was + * allocated. */ + Colormap colormap; /* Colormap that is no longer needed. + * Must have been returned by previous + * call to Tk_GetColormap, or + * preserved by a previous call to + * Tk_PreserveColormap. */ +{ + TkDisplay *dispPtr; + TkColormap *cmapPtr, *prevPtr; + + /* + * Find Tk's information about the display, then see if this + * colormap is a non-default one (if it's a default one, there + * won't be an entry for it in the display's list). + */ + + dispPtr = TkGetDisplay(display); + if (dispPtr == NULL) { + panic("unknown display passed to Tk_FreeColormap"); + } + for (prevPtr = NULL, cmapPtr = dispPtr->cmapPtr; cmapPtr != NULL; + prevPtr = cmapPtr, cmapPtr = cmapPtr->nextPtr) { + if (cmapPtr->colormap == colormap) { + cmapPtr->refCount -= 1; + if (cmapPtr->refCount == 0) { + XFreeColormap(display, colormap); + if (prevPtr == NULL) { + dispPtr->cmapPtr = cmapPtr->nextPtr; + } else { + prevPtr->nextPtr = cmapPtr->nextPtr; + } + ckfree((char *) cmapPtr); + } + return; + } + } +} + +/* + *---------------------------------------------------------------------- + * + * Tk_PreserveColormap -- + * + * This procedure is called to indicate to Tk that the specified + * colormap is being referenced from another location and should + * not be freed until all extra references are eliminated. The + * colormap must have been returned by Tk_GetColormap. + * + * Results: + * None. + * + * Side effects: + * The colormap's reference count is incremented, so + * Tk_FreeColormap must eventually be called exactly once for + * each call to Tk_PreserveColormap. + * + *---------------------------------------------------------------------- + */ + +void +Tk_PreserveColormap(display, colormap) + Display *display; /* Display for which colormap was + * allocated. */ + Colormap colormap; /* Colormap that should be + * preserved. */ +{ + TkDisplay *dispPtr; + TkColormap *cmapPtr; + + /* + * Find Tk's information about the display, then see if this + * colormap is a non-default one (if it's a default one, there + * won't be an entry for it in the display's list). + */ + + dispPtr = TkGetDisplay(display); + if (dispPtr == NULL) { + panic("unknown display passed to Tk_PreserveColormap"); + } + for (cmapPtr = dispPtr->cmapPtr; cmapPtr != NULL; + cmapPtr = cmapPtr->nextPtr) { + if (cmapPtr->colormap == colormap) { + cmapPtr->refCount += 1; + return; + } + } +} |