Fix for shimmering of buttons embedded when scrolled in text and canvas widgets; improvements in scrolling smoothness in text widget. Thanks to Marc Culler for patches.

3 files changed, 203 insertions, 95 deletions

diff --git a/macosx/tkMacOSXButton.c b/macosx/tkMacOSXButton.c
index 036624d..dd4cca7 100644
--- a/macosx/tkMacOSXButton.c
+++ b/macosx/tkMacOSXButton.c
@@ -7,6 +7,7 @@
  * Copyright (c) 1996-1997 by Sun Microsystems, Inc.
  * Copyright 2001-2009, Apple Inc.
  * Copyright (c) 2006-2009 Daniel A. Steffen <das@users.sourceforge.net>
+ * Copyright 2014 Marc Culler.
  *
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
@@ -23,9 +24,59 @@
 #endif
 */
 
+static NSRect TkMacOSXGetButtonFrame(TkButton *butPtr);
+
+/*
+ * A subclass of NSButton with sanity checking:
+ * NSButtons created by Tk will have their tag set to a pointer to the TkButton
+ * which manages the NSButton.  This allows a TkNSButton to be aware of the
+ * state of its Tk parent.  This subclass overrides the drawRect method
+ * so that it will not draw itself unless the NSButton frame matches
+ * the frame which was installed by DisplayButton, and the TkButton is
+ * mapped.  Also, it will not draw anything if the widget is completely
+ * outside of its container.
+ */
+
+@interface TkNSButton: NSButton
+
+@end
+
+@implementation TkNSButton
+
+    - (void)drawRect:(NSRect)dirtyRect
+    {
+	NSInteger tag = [self tag];
+	if ( tag != -1) {
+	    TkButton *butPtr = (TkButton *)tag;
+	    MacDrawable* macWin = (MacDrawable *)butPtr;
+	    NSRect Tkframe = TkMacOSXGetButtonFrame(butPtr);
+	    Tk_Window tkwin = butPtr->tkwin;
+	    /* Do not draw if the widget is misplaced or unmapped. */
+	    if ( NSIsEmptyRect(Tkframe) || 
+		 ! macWin->winPtr->flags & TK_MAPPED ||
+		 ! NSEqualRects(Tkframe, [self frame]) 
+		 ) {
+		return;
+	    }
+	     /* Do not draw if the widget is completely outside of its parent, or within 20 pixels of the lower border; this prevents buttons from being drawn on peer widgets as scrolling occurs. */
+	    if (tkwin) {
+		int parent_height = Tk_Height(Tk_Parent(tkwin));
+		int widget_height = Tk_Height(tkwin);
+		int y = Tk_Y(tkwin);
+		if ( y > parent_height - 20 || y + widget_height < 0 ) {
+		    return;
+		}
+	    }
+	[super drawRect:dirtyRect];
+    }
+ }
+
+@end
+
+
 typedef struct MacButton {
     TkButton info;
-    NSButton *button;
+    TkNSButton *button;
     NSImage *image, *selectImage, *tristateImage;
 #if TK_MAC_BUTTON_USE_COMPATIBILITY_METRICS
     int fix;
@@ -186,6 +237,45 @@ TkpDisplayButton(
 /*
  *----------------------------------------------------------------------
  *
+ * TkpShiftButton --
+ *
+ *	Moves the frame of an NSButton (or TkNSButton) and in case the tag is
+ *     set, also adjusts the xOff and yOff of the controlling TkButton's
+ *     MacDrawable.  This is used to avoid jitter when scrolling.
+ *
+ * Results:
+ *	None
+ *
+ * Side effects:
+ *	Moves the NSbutton after adjusting the associated MacDrawable.
+ *
+ *----------------------------------------------------------------------
+ */
+void
+TkpShiftButton(
+    NSButton *button,
+    NSPoint delta )
+    {
+	NSPoint origin = [button frame].origin;
+	NSInteger tag = [button tag];
+	if ( tag != -1) {
+	    TkButton* butPtr = (TkButton *)tag;
+	    TkWindow *winPtr = (TkWindow *) (butPtr->tkwin);
+	    if (winPtr) {
+		MacDrawable *macWin =  (MacDrawable *) winPtr->window;
+		macWin->xOff += delta.x;
+		macWin->yOff += delta.y;
+	    }
+	}
+        origin.x += delta.x;
+	origin.y -= delta.y;
+	[button setFrameOrigin:origin];
+    }
+
+
+/*
+ *----------------------------------------------------------------------
+ *
  * TkpComputeButtonGeometry --
  *
  *	After changes in a button's text or bitmap, this procedure
@@ -218,7 +308,8 @@ TkpComputeButtonGeometry(
     case TYPE_CHECK_BUTTON:
     case TYPE_RADIO_BUTTON:
 	if (!macButtonPtr->button) {
-	    NSButton *button = [[NSButton alloc] initWithFrame:NSZeroRect];
+	    TkNSButton *button = [[TkNSButton alloc] initWithFrame:NSZeroRect];
+	    [button setTag:(NSInteger)butPtr];
 	    macButtonPtr->button = TkMacOSXMakeUncollectable(button);
 	}
 	ComputeNativeButtonGeometry(butPtr);
@@ -266,6 +357,52 @@ TkpButtonSetDefaults()
 /*
  *----------------------------------------------------------------------
  *
+ * TkMacOSXGetButtonFrame --
+ *
+ *	Computes a frame for an NSButton that will correspond to where
+ *	Tk thinks the button is located.
+ *
+ * Results:
+ *	Returns an NSRect describing a frame for an NSButton.
+ *
+ * Side effects:
+ *	None
+ *
+ *----------------------------------------------------------------------
+ */
+NSRect TkMacOSXGetButtonFrame(
+     TkButton *butPtr)
+{
+    MacButton *macButtonPtr = (MacButton *) butPtr;
+    Tk_Window tkwin = butPtr->tkwin;
+    TkWindow *winPtr = (TkWindow *) tkwin;
+    if (tkwin) {
+	MacDrawable *macWin =  (MacDrawable *) winPtr->window;
+	NSView *view = TkMacOSXDrawableView(macWin);
+	CGFloat viewHeight = [view bounds].size.height;
+	NSRect frame = NSMakeRect(macWin->xOff, macWin->yOff,
+				  Tk_Width(tkwin), Tk_Height(tkwin));
+
+#if TK_MAC_BUTTON_USE_COMPATIBILITY_METRICS
+	if (tkMacOSXUseCompatibilityMetrics) {
+	    BoundsFix boundsFix = boundsFixes[macButtonPtr->fix];
+	    frame = NSOffsetRect(frame, boundsFix.offsetX, boundsFix.offsetY);
+	    frame.size.height -= boundsFix.shrinkH + NATIVE_BUTTON_EXTRA_H;
+	    frame = NSInsetRect(frame, boundsFix.inset + NATIVE_BUTTON_INSET,
+		boundsFix.inset + NATIVE_BUTTON_INSET);
+	}
+#endif
+
+	frame.origin.y = viewHeight - (frame.origin.y + frame.size.height);
+	return frame;
+    } else {
+	return NSZeroRect;
+    }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
  * DisplayNativeButton --
  *
  *	This procedure is invoked to display a button widget. It is
@@ -286,7 +423,7 @@ DisplayNativeButton(
     TkButton *butPtr)
 {
     MacButton *macButtonPtr = (MacButton *) butPtr;
-    NSButton *button = macButtonPtr->button;
+    TkNSButton *button = macButtonPtr->button;
     Tk_Window tkwin = butPtr->tkwin;
     TkWindow *winPtr = (TkWindow *) tkwin;
     MacDrawable *macWin =  (MacDrawable *) winPtr->window;
@@ -349,21 +486,8 @@ DisplayNativeButton(
     } else {
 	[button setKeyEquivalent:@""];
     }
-    frame = NSMakeRect(macWin->xOff, macWin->yOff, Tk_Width(tkwin),
-	    Tk_Height(tkwin));
-#if TK_MAC_BUTTON_USE_COMPATIBILITY_METRICS
-    if (tkMacOSXUseCompatibilityMetrics) {
-	BoundsFix boundsFix = boundsFixes[macButtonPtr->fix];
-	frame = NSOffsetRect(frame, boundsFix.offsetX, boundsFix.offsetY);
-	frame.size.height -= boundsFix.shrinkH + NATIVE_BUTTON_EXTRA_H;
-	frame = NSInsetRect(frame, boundsFix.inset + NATIVE_BUTTON_INSET,
-		boundsFix.inset + NATIVE_BUTTON_INSET);
-    }
-#endif
-    frame.origin.y = viewHeight - (frame.origin.y + frame.size.height);
-    if (!NSEqualRects(frame, [button frame])) {
-	[button setFrame:frame];
-    }
+    frame = TkMacOSXGetButtonFrame(butPtr);
+    [button setFrame:frame];
     [button displayRectIgnoringOpacity:[button bounds]];
     TkMacOSXRestoreDrawingContext(&dc);
 #ifdef TK_MAC_DEBUG_BUTTON
@@ -396,7 +520,7 @@ ComputeNativeButtonGeometry(
     TkButton *butPtr)		/* Button whose geometry may have changed. */
 {
     MacButton *macButtonPtr = (MacButton *) butPtr;
-    NSButton *button = macButtonPtr->button;
+    TkNSButton *button = macButtonPtr->button;
     NSButtonCell *cell = [button cell];
     NSButtonType type = -1;
     NSBezelStyle style = 0;
@@ -1169,6 +1293,7 @@ ComputeUnixButtonGeometry(
     Tk_SetInternalBorder(butPtr->tkwin, butPtr->inset);
 }
 
+
 /*
  * Local Variables:
  * mode: objc
diff --git a/macosx/tkMacOSXDraw.c b/macosx/tkMacOSXDraw.c
index 3a3e288..ce8bf9b 100644
--- a/macosx/tkMacOSXDraw.c
+++ b/macosx/tkMacOSXDraw.c
@@ -17,6 +17,7 @@
 #include "tkMacOSXPrivate.h"
 #include "tkMacOSXDebug.h"
 #include "xbytes.h"
+#include "tkButton.h"
 
 /*
 #ifdef TK_MAC_DEBUG
@@ -1479,86 +1480,67 @@ TkScrollWindow(
     TkRegion damageRgn)		/* Region to accumulate damage in. */
 {
     Drawable drawable = Tk_WindowId(tkwin);
-    MacDrawable *macDraw = (MacDrawable *) drawable;
+    MacDrawable *macDraw = (MacDrawable *) drawable; 
     NSView *view = TkMacOSXDrawableView(macDraw);
-    CGRect visRect, srcRect, dstRect, scroll_src, scroll_dst;
-    HIShapeRef dmgRgn = NULL;
-    NSRect bounds;
+    CGRect srcRect, dstRect;
+    HIShapeRef dmgRgn = NULL, extraRgn;
+    NSRect bounds, visRect, scrollSrc, scrollDst;
+    NSPoint delta = NSMakePoint(dx, dy);
     int result;
-
+  
     if ( view ) {
-	/*  Get the scroll area in NSView coordinates (origin at bottom left). */
-	bounds = [view bounds];
-	scroll_src = CGRectMake(
-				macDraw->xOff + x,
-				bounds.size.height - height - (macDraw->yOff + y),
-				width, height);
-	scroll_dst = CGRectOffset(scroll_src, dx, -dy);
-	/* Limit scrolling to the window content area. */
-	visRect = NSRectToCGRect([view visibleRect]);
-	scroll_src = CGRectIntersection(scroll_src, visRect);
-	scroll_dst = CGRectIntersection(scroll_dst, visRect);
-
-	if ( !CGRectIsEmpty(scroll_src) && !CGRectIsEmpty(scroll_dst) ) {
-
-	    /*
-	     * Mark the difference between source and destination as damaged.
-	     * This region is described in the Tk coordinate system, after shifting by dy.
-	     */
-
-	    srcRect = CGRectMake(x - macDraw->xOff, y - macDraw->yOff,
-				 width, height);
-	    dstRect = CGRectOffset(srcRect, dx, dy);
-	    dmgRgn = HIShapeCreateMutableWithRect(&srcRect);
-	    HIShapeRef dstRgn = HIShapeCreateWithRect(&dstRect);
-	    ChkErr(HIShapeDifference, dmgRgn, dstRgn, (HIMutableShapeRef) dmgRgn);
-	    CFRelease(dstRgn);
-
-	    /* Scroll the rectangle. */
-	    [view scrollRect:NSRectFromCGRect(scroll_src) by:NSMakeSize(dx, -dy)];
-	    [view displayRect:NSRectFromCGRect(scroll_dst)];
-
-	    /*
-	     * When a Text widget contains embedded images, scrolling generates
-	     * lots of artifacts involving multiple copies of the images
-	     * displayed on top of each other.  Extensive experimentation, with
-	     * very little help from the Apple documentation, indicates that
-	     * whenever an image is displayed it gets added as a subview, which
-	     * then gets automatically redisplayed in its original location.
-	     *
-	     * We do two things to combat this.  First, each subview that meets
-	     * the scroll area is added as a damage rectangle.  Second, we
-	     * redisplay the subviews after the scroll.
-	     */
-
-	    /*
-	     * Step 1: Find any subviews that meet the scroll area and mark
-	     * them as damaged.  Use Tk coordinates, shifted to account for the
-	     * future scrolling.
-	     */
-
-	    for (NSView *subview in [view subviews] ) {
-		NSRect frame = [subview frame];
-		CGRect subviewRect = CGRectMake(
-			frame.origin.x - macDraw->xOff + dx,
-			(bounds.size.height - frame.origin.y - frame.size.height) - macDraw->yOff + dy,
-			frame.size.width, frame.size.height);
-		/* Rectangles with negative coordinates seem to cause trouble. */
-		if (subviewRect.origin.y < 0 && subviewRect.origin.y + subviewRect.size.height > 0) {
-		    subviewRect.origin.y = 0;
-		}
-		CGRect intersection = CGRectIntersection(srcRect, subviewRect);
-		if (! CGRectIsEmpty(intersection) ){
-		    dstRgn = HIShapeCreateWithRect(&subviewRect);
-		    ChkErr(HIShapeUnion, dmgRgn, dstRgn, (HIMutableShapeRef) dmgRgn);
-		    CFRelease(dstRgn);
-		}
-	    }
-	}
+  	/*  Get the scroll area in NSView coordinates (origin at bottom left). */
+  	bounds = [view bounds];
+ 	scrollSrc = NSMakeRect(
+			       macDraw->xOff + x, 
+			       bounds.size.height - height - (macDraw->yOff + y),
+			       width, height);
+ 	scrollDst = NSOffsetRect(scrollSrc, dx, -dy);
+  	/* Limit scrolling to the window content area. */
+ 	visRect = [view visibleRect];
+ 	scrollSrc = NSIntersectionRect(scrollSrc, visRect);
+ 	scrollDst = NSIntersectionRect(scrollDst, visRect);
+  
+ 	if ( !NSIsEmptyRect(scrollSrc) && !NSIsEmptyRect(scrollDst) ) {
+  
+  	    /*
+  	     * Mark the difference between source and destination as damaged.
+ 	     * This region is described in the Tk coordinate system.
+  	     */
+  
+ 	    srcRect = CGRectMake(x, y, width, height);
+  	    dstRect = CGRectOffset(srcRect, dx, dy);
+  	    dmgRgn = HIShapeCreateMutableWithRect(&srcRect);
+ 	    extraRgn = HIShapeCreateWithRect(&dstRect);
+ 	    ChkErr(HIShapeDifference, dmgRgn, extraRgn, (HIMutableShapeRef) dmgRgn);
+ 	    CFRelease(extraRgn);
+  	    
+ 	    /* Scroll the rectangle. */
+ 	    [view scrollRect:scrollSrc by:NSMakeSize(dx, -dy)];
+  
+ 	    /* 
+ 	     * Adjust the positions of the button subwindows that meet the scroll
+ 	     * area.
+  	     */
+ 
+  	    for (NSView *subview in [view subviews] ) {
+ 	    	if ( [subview isKindOfClass:[NSButton class]] == YES ) {
+ 		    NSRect subframe = [subview frame];
+ 		    if  ( NSIntersectsRect(scrollSrc, subframe) ||
+ 			  NSIntersectsRect(scrollDst, subframe) ) { 
+ 			TkpShiftButton((NSButton *)subview, delta );
+ 		    }
+ 	    	}
+  	    }
+ 
+ 	    /* Redisplay the scrolled area. */
+ 	    [view displayRect:scrollDst];
+ 
+  	}
     }
-
+  
     if ( dmgRgn == NULL ) {
-	dmgRgn = HIShapeCreateEmpty();
+  	dmgRgn = HIShapeCreateEmpty();
     }
     TkMacOSXSetWithNativeRegion(damageRgn, dmgRgn);
     result = HIShapeIsEmpty(dmgRgn) ? 0 : 1;
diff --git a/macosx/tkMacOSXInt.h b/macosx/tkMacOSXInt.h
index 813acce..249d5cf 100644
--- a/macosx/tkMacOSXInt.h
+++ b/macosx/tkMacOSXInt.h
@@ -24,6 +24,7 @@
 
 #ifndef _TKMAC
 #include "tkMacOSX.h"
+#import <Cocoa/Cocoa.h>
 #endif
 
 /*
@@ -196,7 +197,7 @@ MODULE_SCOPE void TkpClipDrawableToRect(Display *display, Drawable d, int x,
 	int y, int width, int height);
 MODULE_SCOPE void TkpRetainRegion(TkRegion r);
 MODULE_SCOPE void TkpReleaseRegion(TkRegion r);
-
+MODULE_SCOPE void TkpShiftButton(NSButton *button, NSPoint delta);
 /*
  * Include the stubbed internal platform-specific API.
  */