From 4fbdf0d68060e7da0af3868294756c55c702dd72 Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Thu, 21 Nov 2024 14:07:20 -0700
Subject: [PATCH] macOS: catch spurious full redraw calls to NSView:drawRect
 and act appropriately

---
 libs/tk/ydk/quartz/GdkQuartzView.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/libs/tk/ydk/quartz/GdkQuartzView.c b/libs/tk/ydk/quartz/GdkQuartzView.c
index de6b9b868a..fcf4af8084 100644
--- a/libs/tk/ydk/quartz/GdkQuartzView.c
+++ b/libs/tk/ydk/quartz/GdkQuartzView.c
@@ -696,6 +696,7 @@
   NSInteger count;
   int i;
   GdkRegion *region;
+  gboolean full_draw;
 
   if (GDK_WINDOW_DESTROYED (gdk_window))
     return;
@@ -706,6 +707,22 @@
   if (NSEqualRects (rect, NSZeroRect))
     return;
 
+
+  /* Quartz/CoreGraphics/something on macOS causes occasional/periodic drawRect
+   * calls with a "dirty" rect that covers the entire NSView. As of 11/2024,
+   * this seems to be caused by how much of the NSView is redrawn in a given
+   * interval. The lower layers really do invalidate the contents of any
+   * backing store, so if we do not obey the drawRect call, portions of the
+   * window will remain undrawn.
+   */
+
+  if (NSContainsRect (rect, [self bounds])) {
+	  full_draw = TRUE;
+	  printf ("full draw seen!\n");
+  } else {
+	  full_draw = FALSE;
+  }
+
   if (!GDK_WINDOW_IS_MAPPED (gdk_window) && ((gdk_quartz_osx_version() >= GDK_OSX_LEOPARD) && [self wantsLayer]))
     {
       /* If the window is not yet mapped, clip_region_with_children
@@ -732,7 +749,7 @@
       return;
     }
 
-  if (!impl->needs_display_region || gdk_quartz_get_use_cocoa_invalidation()) {
+  if (!impl->needs_display_region || gdk_quartz_get_use_cocoa_invalidation() || full_draw) {
     [self getRectsBeingDrawn: &drawn_rects count: &count];
     region = gdk_region_new ();