[gtk+] Implement gtk_drag_begin_with_coordinates () for quartz.

[John Ralls <jralls src gnome org>]

commit 9e0faf6a38d9029485455d24d5cff0e42519ad01
Author: John Ralls <jralls ceridwen us>
Date:   Thu Oct 10 15:34:08 2013 -0700

    Implement gtk_drag_begin_with_coordinates () for quartz.

 gtk/gtkdnd-quartz.c |   88 ++++++++++++++++++++++++++++++++++-----------------
 1 files changed, 59 insertions(+), 29 deletions(-)
---
diff --git a/gtk/gtkdnd-quartz.c b/gtk/gtkdnd-quartz.c
index ff37b58..1ec5db5 100644
--- a/gtk/gtkdnd-quartz.c
+++ b/gtk/gtkdnd-quartz.c
@@ -1194,7 +1194,9 @@ gtk_drag_begin_internal (GtkWidget         *widget,
                         GtkTargetList     *target_list,
                         GdkDragAction      actions,
                         gint               button,
-                        GdkEvent          *event)
+                        GdkEvent          *event,
+                        gint               x,
+                        gint               y)
 {
   GtkDragSourceInfo *info;
   GdkDevice *pointer;
@@ -1202,36 +1204,49 @@ gtk_drag_begin_internal (GtkWidget         *widget,
   GdkDragContext *context;
   NSWindow *nswindow = get_toplevel_nswindow (widget);
   NSPoint point = {0, 0};
-  gdouble x, y;
   double time = (double)g_get_real_time ();
   NSEvent *nsevent;
   NSTimeInterval nstime;
 
-  if (event)
+  if ((x != -1 && y != -1) || event)
     {
-      if (gdk_event_get_coords (event, &x, &y))
-        {
-          /* We need to translate (x, y) to coordinates relative to the
-           * toplevel GdkWindow, which should be the GdkWindow backing
-           * nswindow. Then, we convert to the NSWindow coordinate system.
-           */
-          GdkWindow *window = event->any.window;
-          GdkWindow *toplevel = gdk_window_get_effective_toplevel (window);
-
-          while (window != toplevel)
-            {
-              double old_x = x;
-              double old_y = y;
-
-              gdk_window_coords_to_parent (window, old_x, old_y,
-                                           &x, &y);
-              window = gdk_window_get_effective_parent (window);
-            }
+      GdkWindow *window;
+      gdouble dx, dy;
+      if (x != -1 && y != -1)
+       {
+         GtkWidget *toplevel = gtk_widget_get_toplevel (widget);
+         window = gtk_widget_get_window (toplevel);
+         gtk_widget_translate_coordinates (widget, toplevel, x, y, &x, &y);
+         gdk_window_get_root_coords (gtk_widget_get_window (toplevel), x, y,
+                                                            &x, &y);
+         dx = (gdouble)x;
+         dy = (gdouble)y;
+       }
+      else if (event)
+       {
+         if (gdk_event_get_coords (event, &dx, &dy))
+           {
+             /* We need to translate (x, y) to coordinates relative to the
+              * toplevel GdkWindow, which should be the GdkWindow backing
+              * nswindow. Then, we convert to the NSWindow coordinate system.
+              */
+             window = event->any.window;
+             GdkWindow *toplevel = gdk_window_get_effective_toplevel (window);
+
+             while (window != toplevel)
+               {
+                 double old_x = dx;
+                 double old_y = dy;
 
-          point.x = x;
-          point.y = gdk_window_get_height (window) - y;
-        }
-      time = (double)gdk_event_get_time (event);
+                 gdk_window_coords_to_parent (window, old_x, old_y,
+                                              &dx, &dy);
+                 window = gdk_window_get_effective_parent (window);
+               }
+           }
+         time = (double)gdk_event_get_time (event);
+       }
+      point.x = dx;
+      point.y = gdk_window_get_height (window) - dy;
     }
 
   nstime = [[NSDate dateWithTimeIntervalSince1970: time / 1000] timeIntervalSinceReferenceDate];
@@ -1309,6 +1324,22 @@ gtk_drag_begin_internal (GtkWidget         *widget,
   return context;
 }
 
+GdkDragContext *
+gtk_drag_begin_with_coordinates (GtkWidget         *widget,
+                                GtkTargetList     *targets,
+                                GdkDragAction      actions,
+                                gint               button,
+                                GdkEvent          *event,
+                                gint               x,
+                                gint               y)
+{
+  g_return_val_if_fail (GTK_IS_WIDGET (widget), NULL);
+  g_return_val_if_fail (gtk_widget_get_realized (widget), NULL);
+  g_return_val_if_fail (targets != NULL, NULL);
+
+  return gtk_drag_begin_internal (widget, NULL, targets,
+                                 actions, button, event, x, y);
+}
 /**
  * gtk_drag_begin: (method)
  * @widget: the source widget.
@@ -1330,7 +1361,7 @@ gtk_drag_begin (GtkWidget         *widget,
   g_return_val_if_fail (targets != NULL, NULL);
 
   return gtk_drag_begin_internal (widget, NULL, targets,
-                                 actions, button, event);
+                                 actions, button, event, -1, -1);
 }
 
 
@@ -1368,7 +1399,7 @@ gtk_drag_source_event_cb (GtkWidget      *widget,
          int i;
          for (i=1; i<6; i++)
            {
-             if (site->state & event->motion.state & 
+             if (site->state & event->motion.state &
                  GDK_BUTTON1_MASK << (i - 1))
                break;
            }
@@ -1378,8 +1409,7 @@ gtk_drag_source_event_cb (GtkWidget      *widget,
            {
              site->state = 0;
              gtk_drag_begin_internal (widget, site, site->target_list,
-                                      site->actions, 
-                                      i, event);
+                                      site->actions, i, event, -1, -1);
 
              retval = TRUE;
            }