From fc2388482a673cedc13b2e7a060175259243a33f Mon Sep 17 00:00:00 2001
From: Kevin Walzer <kw@codebykevin.com>
Date: Mon, 4 Aug 2014 21:14:32 +0000
Subject: Further refinement of Mac OS X scrolling; thanks to Marc Culler for
 an additional patch.

---
 macosx/tkMacOSXDraw.c       | 46 +++++----------------------------------------
 macosx/tkMacOSXSubwindows.c | 14 +++++++++-----
 2 files changed, 14 insertions(+), 46 deletions(-)

diff --git a/macosx/tkMacOSXDraw.c b/macosx/tkMacOSXDraw.c
index 6eef09d..40400c2 100644
--- a/macosx/tkMacOSXDraw.c
+++ b/macosx/tkMacOSXDraw.c
@@ -1460,12 +1460,12 @@ XMaxRequestSize(
  *	a damage region.
  *
  * Results:
- *	Returns 0 if the scroll genereated no additional damage.
+ *	Returns 0 if the scroll generated no additional damage.
  *	Otherwise, sets the region that needs to be repainted after
  *	scrolling and returns 1.
  *
  * Side effects:
- *	Scrolls the bits in the window.
+ *	Scrolls the rectangle in the window.
  *
  *----------------------------------------------------------------------
  */
@@ -1518,51 +1518,15 @@ TkScrollWindow(
 	    /* 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);
-		}
-	    }
-
 	}
     }
+	    
+
 
     if ( dmgRgn == NULL ) {
 	dmgRgn = HIShapeCreateEmpty();
     }
-    //TkMacOSXInvalidateViewRegion(view, dmgRgn);
+
     TkMacOSXSetWithNativeRegion(damageRgn, dmgRgn);
     result = HIShapeIsEmpty(dmgRgn) ? 0 : 1;
     CFRelease(dmgRgn);
diff --git a/macosx/tkMacOSXSubwindows.c b/macosx/tkMacOSXSubwindows.c
index 9ba7100..e4af406 100644
--- a/macosx/tkMacOSXSubwindows.c
+++ b/macosx/tkMacOSXSubwindows.c
@@ -651,7 +651,7 @@ XConfigureWindow(
  *
  * TkMacOSXUpdateClipRgn --
  *
- *	This function updates the cliping regions for a given window and all of
+ *	This function updates the clipping regions for a given window and all of
  *	its children. Once updated the TK_CLIP_INVALID flag in the subwindow
  *	data structure is unset. The TK_CLIP_INVALID flag should always be
  *	unset before any drawing is attempted.
@@ -677,7 +677,7 @@ TkMacOSXUpdateClipRgn(
     macWin = winPtr->privatePtr;
     if (macWin && macWin->flags & TK_CLIP_INVALID) {
 	TkWindow *win2Ptr;
-
+	
 #ifdef TK_MAC_DEBUG_CLIP_REGIONS
 	TkMacOSXDbgMsg("%s", winPtr->pathName);
 #endif
@@ -818,7 +818,7 @@ TkMacOSXUpdateClipRgn(
  *
  * TkMacOSXVisableClipRgn --
  *
- *	This function returns the Macintosh cliping region for the given
+ *	This function returns the Macintosh clipping region for the given
  *	window. The caller is responsible for disposing of the returned
  *	region via TkDestroyRegion().
  *
@@ -913,7 +913,7 @@ TkMacOSXInvalidateWindow(
 				 * TK_PARENT_WINDOW */
 {
 #ifdef TK_MAC_DEBUG_CLIP_REGIONS
-    TkMacOSXDbgMsg("%s", winPtr->pathName);
+    TkMacOSXDbgMsg("%s", macWin->winPtr->pathName);
 #endif
     if (macWin->flags & TK_CLIP_INVALID) {
 	TkMacOSXUpdateClipRgn(macWin->winPtr);
@@ -1071,7 +1071,7 @@ TkMacOSXGetRootControl(
  *	None.
  *
  * Side effects:
- *	The cliping regions for the window and its children are mark invalid.
+ *	The clipping regions for the window and its children are marked invalid.
  *	(Make sure they are valid before drawing.)
  *
  *----------------------------------------------------------------------
@@ -1090,6 +1090,10 @@ TkMacOSXInvalClipRgns(
      * be marked.
      */
 
+#ifdef TK_MAC_DEBUG_CLIP_REGIONS
+	TkMacOSXDbgMsg("%s", winPtr->pathName);
+#endif
+
     if (!macWin || macWin->flags & TK_CLIP_INVALID) {
 	return;
     }
-- 
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