[gtk+/gtk-2-24-quartz] Handle implicit grabs

[John Ralls <jralls src gnome org>]

commit fb27b84746b065772e3d8e4513f93317fcfd1b99
Author: Alexander Larsson <alexl redhat com>
Date:   Tue Oct 18 16:52:41 2011 +0200

    Handle implicit grabs

 gdk/win32/gdkevents-win32.c |   23 ++++++++++++++++++++++-
 1 files changed, 22 insertions(+), 1 deletions(-)
---
diff --git a/gdk/win32/gdkevents-win32.c b/gdk/win32/gdkevents-win32.c
index 8dec80c..b3b095a 100644
--- a/gdk/win32/gdkevents-win32.c
+++ b/gdk/win32/gdkevents-win32.c
@@ -1855,6 +1855,12 @@ ensure_stacking_on_activate_app (MSG       *msg,
     }
 }
 
+#define GDK_ANY_BUTTON_MASK (GDK_BUTTON1_MASK | \
+			     GDK_BUTTON2_MASK | \
+			     GDK_BUTTON3_MASK | \
+			     GDK_BUTTON4_MASK | \
+			     GDK_BUTTON5_MASK)
+
 static gboolean
 gdk_event_translate (MSG  *msg,
 		     gint *ret_valp)
@@ -2261,7 +2267,12 @@ gdk_event_translate (MSG  *msg,
       if (GDK_WINDOW_DESTROYED (window))
 	break;
 
-      /* TODO_CSW? Emulate X11's automatic active grab */
+      grab = _gdk_display_get_last_pointer_grab (_gdk_display);
+      if (grab == NULL)
+	{
+	  SetCapture (GDK_WINDOW_HWND (window));
+	}
+
       generate_button_event (GDK_BUTTON_PRESS, button,
 			     window, msg);
 
@@ -2301,6 +2312,16 @@ gdk_event_translate (MSG  *msg,
 	}
 #endif
 
+      grab = _gdk_display_get_last_pointer_grab (_gdk_display);
+      if (grab != NULL && grab->implicit)
+	{
+	  gint state = build_pointer_event_state (msg);
+
+	  /* We keep the implicit grab until no buttons at all are held down */
+	  if ((state & GDK_ANY_BUTTON_MASK & ~(GDK_BUTTON1_MASK << (button - 1))) == 0)
+	    ReleaseCapture ();
+	}
+
       generate_button_event (GDK_BUTTON_RELEASE, button,
 			     window, msg);