master f094120: Implement `pick_embedded_child' for offscreen xwidgets

[Po Lu]

branch: master
commit f094120360b4cfbb104496c0b3e21b26f88547a6
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Implement `pick_embedded_child' for offscreen xwidgets
    
    * src/xwidget.c (pick_embedded_child): New function.
    (Fmake_xwidget): Connect `pick-embedded-child' signal
    to offscreen window.
---
 src/xwidget.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/src/xwidget.c b/src/xwidget.c
index b0ff142..d88270d 100644
--- a/src/xwidget.c
+++ b/src/xwidget.c
@@ -64,6 +64,7 @@ static gboolean webkit_script_dialog_cb (WebKitWebView *, 
WebKitScriptDialog *,
 static void record_osr_embedder (struct xwidget_view *);
 static void from_embedder (GdkWindow *, double, double, gpointer, gpointer, 
gpointer);
 static void to_embedder (GdkWindow *, double, double, gpointer, gpointer, 
gpointer);
+static GdkWindow *pick_embedded_child (GdkWindow *, double, double, gpointer);
 #endif
 
 static struct xwidget *
@@ -243,6 +244,8 @@ fails.  */)
                        "from-embedder", G_CALLBACK (from_embedder), NULL);
       g_signal_connect (G_OBJECT (gtk_widget_get_window 
(xw->widgetwindow_osr)),
                        "to-embedder", G_CALLBACK (to_embedder), NULL);
+      g_signal_connect (G_OBJECT (gtk_widget_get_window 
(xw->widgetwindow_osr)),
+                       "pick-embedded-child", G_CALLBACK 
(pick_embedded_child), NULL);
 
       /* Store some xwidget data in the gtk widgets for convenient
          retrieval in the event handlers.  */
@@ -510,6 +513,32 @@ xwidget_from_id (uint32_t id)
 }
 
 #ifdef USE_GTK
+static GdkWindow *
+pick_embedded_child (GdkWindow *window, double x, double y,
+                    gpointer user_data)
+{
+  GtkWidget *widget;
+  GtkWidget *child;
+  GdkEvent event;
+  int xout, yout;
+
+  event.any.window = window;
+  event.any.type = GDK_NOTHING;
+
+  widget = gtk_get_event_widget (&event);
+
+  if (!widget)
+    return NULL;
+
+  child = find_widget_at_pos (widget, lrint (x), lrint (y),
+                             &xout, &yout);
+
+  if (!child)
+    return NULL;
+
+  return gtk_widget_get_window (child);
+}
+
 static void
 record_osr_embedder (struct xwidget_view *view)
 {