Fix text clipping when working with the Xft-based renderer.

5 files changed, 63 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 7ac76d5..c5bee52 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2012-06-12  Donal K. Fellows  <dkf@users.sf.net>
+
+	* unix/tkUnixRFont.c (Tk_DrawChars, TkUnixSetXftClipRegion): Add some
+	* generic/ttk/ttkEntry.c (EntryDisplay): special magic to make the
+	* generic/ttk/ttkLabel.c (TextDraw): text clipping work right with the
+	Xft-based renderer (which doesn't use the standard Tk GC except to
+	supply the color).
+
 2012-06-11  Donal K. Fellows  <dkf@users.sf.net>
 
 	* generic/ttk/ttkLabel.c (TextDraw): [Bug 3294450]: Get the clipping
diff --git a/generic/tkInt.h b/generic/tkInt.h
index b152a7a..a95adf8 100644
--- a/generic/tkInt.h
+++ b/generic/tkInt.h
@@ -1186,6 +1186,9 @@ MODULE_SCOPE Status TkParseColor (Display * display,
 				Colormap map, CONST char* spec,
 				XColor * colorPtr);
 #endif
+#ifdef HAVE_XFT
+MODULE_SCOPE void	TkUnixSetXftClipRegion(Region clipRegion);
+#endif
 
 /*
  * Unsupported commands.
diff --git a/generic/ttk/ttkEntry.c b/generic/ttk/ttkEntry.c
index e5d0ef2..a3d0179 100644
--- a/generic/ttk/ttkEntry.c
+++ b/generic/ttk/ttkEntry.c
@@ -1221,7 +1221,8 @@ static void EntryDisplay(void *clientData, Drawable d)
 	}
     }
 
-    /* Initialize the clip region:
+    /* Initialize the clip region. Note that Xft does _not_ derive its
+     * clipping area from the GC, so we have to supply that by other means.
      */
 
     rect.x = textarea.x;
@@ -1230,6 +1231,9 @@ static void EntryDisplay(void *clientData, Drawable d)
     rect.height = textarea.height;
     clipRegion = TkCreateRegion();
     TkUnionRectWithRegion(&rect, clipRegion, clipRegion);
+#ifdef HAVE_XFT
+    TkUnixSetXftClipRegion(clipRegion);
+#endif
 
     /* Draw cursor:
      */
@@ -1272,6 +1276,13 @@ static void EntryDisplay(void *clientData, Drawable d)
 	    selFirst, selLast);
 	Tk_FreeGC(Tk_Display(tkwin), gc);
     }
+
+    /* Drop the region. Note that we have to manually remove the reference to
+     * it from the Xft guts (if they're being used).
+     */
+#ifdef HAVE_XFT
+    TkUnixSetXftClipRegion(None);
+#endif
     TkDestroyRegion(clipRegion);
 }
 
diff --git a/generic/ttk/ttkLabel.c b/generic/ttk/ttkLabel.c
index df6a686..52782ea 100644
--- a/generic/ttk/ttkLabel.c
+++ b/generic/ttk/ttkLabel.c
@@ -131,6 +131,7 @@ static void TextDraw(TextElement *text, Tk_Window tkwin, Drawable d, Ttk_Box b)
     XGCValues gcValues;
     GC gc1, gc2;
     Tk_Anchor anchor = TK_ANCHOR_CENTER;
+    TkRegion clipRegion = NULL;
 
     gcValues.font = Tk_FontId(text->tkfont);
     gcValues.foreground = color->pixel;
@@ -148,9 +149,9 @@ static void TextDraw(TextElement *text, Tk_Window tkwin, Drawable d, Ttk_Box b)
      * Clip text if it's too wide:
      */
     if (b.width < text->width) {
-	TkRegion clipRegion = TkCreateRegion();
 	XRectangle rect;
 
+	clipRegion = TkCreateRegion();
 	rect.x = b.x;
 	rect.y = b.y;
 	rect.width = b.width + (text->embossed ? 1 : 0);
@@ -158,7 +159,11 @@ static void TextDraw(TextElement *text, Tk_Window tkwin, Drawable d, Ttk_Box b)
 	TkUnionRectWithRegion(&rect, clipRegion, clipRegion);
 	TkSetRegion(Tk_Display(tkwin), gc1, clipRegion);
 	TkSetRegion(Tk_Display(tkwin), gc2, clipRegion);
+#ifdef HAVE_XFT
+	TkUnixSetXftClipRegion(clipRegion);
+#else
 	TkDestroyRegion(clipRegion);
+#endif
     }
 
     if (text->embossed) {
@@ -180,6 +185,12 @@ static void TextDraw(TextElement *text, Tk_Window tkwin, Drawable d, Ttk_Box b)
 
     Tk_FreeGC(Tk_Display(tkwin), gc1);
     Tk_FreeGC(Tk_Display(tkwin), gc2);
+#ifdef HAVE_XFT
+    if (clipRegion != NULL) {
+	TkUnixSetXftClipRegion(None);
+	TkDestroyRegion(clipRegion);
+    }
+#endif
 }
 
 static void TextElementSize(
diff --git a/unix/tkUnixRFont.c b/unix/tkUnixRFont.c
index 134bb45..deecceb 100644
--- a/unix/tkUnixRFont.c
+++ b/unix/tkUnixRFont.c
@@ -33,6 +33,16 @@ typedef struct {
     XftDraw *ftDraw;
     XftColor color;
 } UnixFtFont;
+
+/*
+ * Used to describe the current clipping box. Can't be passed normally because
+ * the information isn't retrievable from the GC.
+ */
+
+typedef struct ThreadSpecificData {
+    Region clipRegion;		/* The clipping region, or None. */
+} ThreadSpecificData;
+static Tcl_ThreadDataKey dataKey;
 
 /*
  * Package initialization:
@@ -712,6 +722,8 @@ Tk_DrawChars(
     int clen, nspec, xStart = x;
     XftGlyphFontSpec specs[NUM_SPEC];
     XGlyphInfo metrics;
+    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
+            Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
 
     if (fontPtr->ftDraw == 0) {
 #if DEBUG_FONTSEL
@@ -738,6 +750,9 @@ Tk_DrawChars(
 	fontPtr->color.color.alpha = 0xffff;
 	fontPtr->color.pixel = values.foreground;
     }
+    if (tsdPtr->clipRegion != None) {
+	XftDrawSetClip(fontPtr->ftDraw, tsdPtr->clipRegion);
+    }
     nspec = 0;
     while (numBytes > 0 && x <= maxCoord && y <= maxCoord) {
 	XftFont *ftFont;
@@ -775,6 +790,9 @@ Tk_DrawChars(
     if (nspec) {
 	XftDrawGlyphFontSpec(fontPtr->ftDraw, &fontPtr->color, specs, nspec);
     }
+    if (tsdPtr->clipRegion != None) {
+	XftDrawSetClip(fontPtr->ftDraw, None);
+    }
 
   doUnderlineStrikeout:
     if (fontPtr->font.fa.underline != 0) {
@@ -789,3 +807,13 @@ Tk_DrawChars(
 		(unsigned) fontPtr->font.underlineHeight);
     }
 }
+
+void
+TkUnixSetXftClipRegion(
+    Region clipRegion)		/* The clipping region to install. */
+{
+    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
+            Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
+
+    tsdPtr->clipRegion = clipRegion;
+}