[gtk+] quartz: make moving CSD windows right up to the screen's menu bar work.

[Christoph Reiter <creiter src gnome org>]

commit 61ce90a8e25ea63248ffa12707148e449494f34b
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Mon Jul 20 08:32:05 2015 +0200

    quartz: make moving CSD windows right up to the screen's menu bar work.
    
    The default implementation prevents the window + shadow to move above
    the menu bar. Change it so only the window is considered.

 gdk/quartz/GdkQuartzNSWindow.c |   16 ++++++++++++++++
 1 files changed, 16 insertions(+), 0 deletions(-)
---
diff --git a/gdk/quartz/GdkQuartzNSWindow.c b/gdk/quartz/GdkQuartzNSWindow.c
index 43348ef..8795d3d 100644
--- a/gdk/quartz/GdkQuartzNSWindow.c
+++ b/gdk/quartz/GdkQuartzNSWindow.c
@@ -673,4 +673,20 @@ update_context_from_dragging_info (id <NSDraggingInfo> sender)
 
 #endif
 
+- (NSRect)constrainFrameRect:(NSRect)frameRect toScreen:(NSScreen *)screen
+{
+  NSRect rect;
+  GdkWindow *window = [[self contentView] gdkWindow];
+  GdkWindowImplQuartz *impl = GDK_WINDOW_IMPL_QUARTZ (window->impl);
+
+  /* Allow the window to move up "shadow_top" more than normally allowed
+   * by the default impl. This makes it possible to move windows with
+   * client side shadow right up to the screen's menu bar. */
+  rect = [super constrainFrameRect:frameRect toScreen:screen];
+  if (frameRect.origin.y > rect.origin.y)
+    rect.origin.y = MIN (frameRect.origin.y, rect.origin.y + impl->shadow_top);
+
+  return rect;
+}
+
 @end