[gtk/wip/chergert/macos-iosurface] experiment with altering how we change layers

[Christian Hergert <chergert src gnome org>]

commit 8ad385b9db305b601dabbe412178b310cbdd046d
Author: Christian Hergert <christian hergert me>
Date:   Fri Feb 11 17:03:06 2022 -0800

    experiment with altering how we change layers
    
    this still needs more work, but its a start. we can track teh edge were
    on and make it a bit better

 gdk/macos/GdkMacosWindow.c | 64 ++++++++++++++++------------------------------
 1 file changed, 22 insertions(+), 42 deletions(-)
---
diff --git a/gdk/macos/GdkMacosWindow.c b/gdk/macos/GdkMacosWindow.c
index 8401f45860..1eaff9b56f 100644
--- a/gdk/macos/GdkMacosWindow.c
+++ b/gdk/macos/GdkMacosWindow.c
@@ -21,6 +21,7 @@
 
 #include "config.h"
 
+#include <QuartzCore/QuartzCore.h>
 #include <gdk/gdk.h>
 
 #import "GdkMacosBaseView.h"
@@ -40,10 +41,6 @@
 #include "gdkmonitorprivate.h"
 #include "gdksurfaceprivate.h"
 
-#ifndef AVAILABLE_MAC_OS_X_VERSION_10_15_AND_LATER
-typedef NSString *CALayerContentsGravity;
-#endif
-
 @implementation GdkMacosWindow
 
 -(BOOL)windowShouldClose:(id)sender
@@ -148,9 +145,6 @@ typedef NSString *CALayerContentsGravity;
 
       _gdk_macos_display_break_all_grabs (GDK_MACOS_DISPLAY (display), time);
 
-      /* Reset gravity */
-      [[[self contentView] layer] setContentsGravity:kCAGravityBottomLeft];
-
       break;
     }
 
@@ -243,6 +237,8 @@ typedef NSString *CALayerContentsGravity;
   GdkSurface *surface;
   GdkDisplay *display;
   gboolean maximized;
+  int width_change;
+  int height_change;
 
   surface = GDK_SURFACE (gdk_surface);
   display = gdk_surface_get_display (surface);
@@ -254,6 +250,9 @@ typedef NSString *CALayerContentsGravity;
   if (maximized && !inMaximizeTransition && !NSEqualRects (lastMaximizedFrame, [self frame]))
     [self windowDidUnmaximize];
 
+  width_change = content_rect.size.width - surface->width;
+  height_change = content_rect.size.height - surface->height;
+
   surface->width = content_rect.size.width;
   surface->height = content_rect.size.height;
 
@@ -264,6 +263,13 @@ typedef NSString *CALayerContentsGravity;
 
   [[self contentView] setFrame:NSMakeRect (0, 0, surface->width, surface->height)];
 
+  /* Adjust things to align until the next buffer comes in */
+  [CATransaction setDisableActions:YES];
+  [[[self contentView] layer]
+    setFrame:NSMakeRect (width_change, height_change,
+                         surface->width + width_change,
+                         surface->height + height_change)];
+
   _gdk_macos_surface_update_size (gdk_surface);
 
   gdk_surface_request_layout (surface);
@@ -560,47 +566,12 @@ typedef NSString *CALayerContentsGravity;
 
 -(void)beginManualResize:(GdkSurfaceEdge)edge
 {
-  CALayerContentsGravity gravity = kCAGravityBottomLeft;
-
   if (inMove || inManualMove || inManualResize)
     return;
 
   inManualResize = YES;
   resizeEdge = edge;
 
-
-  switch (edge)
-    {
-    default:
-    case GDK_SURFACE_EDGE_NORTH:
-      gravity = kCAGravityTopLeft;
-      break;
-
-    case GDK_SURFACE_EDGE_NORTH_WEST:
-      gravity = kCAGravityTopRight;
-      break;
-
-    case GDK_SURFACE_EDGE_SOUTH_WEST:
-    case GDK_SURFACE_EDGE_WEST:
-      gravity = kCAGravityBottomRight;
-      break;
-
-    case GDK_SURFACE_EDGE_SOUTH:
-    case GDK_SURFACE_EDGE_SOUTH_EAST:
-      gravity = kCAGravityBottomLeft;
-      break;
-
-    case GDK_SURFACE_EDGE_EAST:
-      gravity = kCAGravityBottomLeft;
-      break;
-
-    case GDK_SURFACE_EDGE_NORTH_EAST:
-      gravity = kCAGravityTopLeft;
-      break;
-    }
-
-  [[[self contentView] layer] setContentsGravity:gravity];
-
   initialResizeFrame = [self frame];
   initialResizeLocation = convert_nspoint_to_screen (self, [self mouseLocationOutsideOfEventStream]);
 }
@@ -851,6 +822,15 @@ typedef NSString *CALayerContentsGravity;
 
 -(void)swapBuffer:(GdkMacosBuffer *)buffer withDamage:(const cairo_region_t *)damage
 {
+  CALayer *layer = [[self contentView] layer];
+  NSRect frame = [layer frame];
+
+  if (frame.origin.x != 0 || frame.origin.y != 0)
+    {
+      GdkSurface *surface = GDK_SURFACE ([self gdkSurface]);
+      [layer setFrame:NSMakeRect (0, 0, surface->width, surface->height)];
+    }
+
   [(GdkMacosView *)[self contentView] swapBuffer:buffer withDamage:damage];
 }