[gtk/wip/chergert/quartz4u] macos: clamp toplevel present to workarea for first present

[Christian Hergert <chergert src gnome org>]

commit 7f9066f2d3968472386a87951abe247f7927aac3
Author: Christian Hergert <chergert redhat com>
Date:   Thu May 21 09:45:33 2020 -0700

    macos: clamp toplevel present to workarea for first present
    
    This helps ensure that CSD windows do not fall outside the workarea
    for their first present. SSD windows already seem to get that so we
    don't need to deal with them specially.

 gdk/macos/gdkmacostoplevelsurface.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)
---
diff --git a/gdk/macos/gdkmacostoplevelsurface.c b/gdk/macos/gdkmacostoplevelsurface.c
index 7734b20420..bc5c398916 100644
--- a/gdk/macos/gdkmacostoplevelsurface.c
+++ b/gdk/macos/gdkmacostoplevelsurface.c
@@ -156,8 +156,25 @@ _gdk_macos_toplevel_surface_present (GdkToplevel       *toplevel,
           (GDK_MACOS_SURFACE (self)->shadow_left ||
            GDK_MACOS_SURFACE (self)->shadow_top))
         {
-          int x = GDK_SURFACE (self)->x - GDK_MACOS_SURFACE (self)->shadow_left;
-          int y = GDK_SURFACE (self)->y - GDK_MACOS_SURFACE (self)->shadow_top;
+          GdkMonitor *monitor = _gdk_macos_surface_get_best_monitor (GDK_MACOS_SURFACE (self));
+          int x = GDK_SURFACE (self)->x;
+          int y = GDK_SURFACE (self)->y;
+
+          if (monitor != NULL)
+            {
+              GdkRectangle visible;
+
+              gdk_monitor_get_workarea (monitor, &visible);
+
+              if (x < visible.x)
+                x = visible.x;
+
+              if (y < visible.y)
+                y = visible.y;
+            }
+
+          x -= GDK_MACOS_SURFACE (self)->shadow_left;
+          y -= GDK_MACOS_SURFACE (self)->shadow_top;
 
           _gdk_macos_surface_move (GDK_MACOS_SURFACE (self), x, y);
         }