[gtk+/wip/carlosg/event-delivery: 23/105] gtk: Add private _gtk_toplevel_pick() method

[Carlos Garnacho <carlosg src gnome org>]

commit ba3bbc7320388fc256b6a4afc155748974738986
Author: Carlos Garnacho <carlosg gnome org>
Date:   Fri Mar 31 16:49:22 2017 +0200

    gtk: Add private _gtk_toplevel_pick() method
    
    This function returns both the widget at the given toplevel coordinates,
    and the translated x/y in widget relative coordinates.

 gtk/gtkmain.c    |   23 +++++++++++++++++++++++
 gtk/gtkprivate.h |    5 +++++
 2 files changed, 28 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkmain.c b/gtk/gtkmain.c
index b145f00..70b1439 100644
--- a/gtk/gtkmain.c
+++ b/gtk/gtkmain.c
@@ -2304,3 +2304,26 @@ _gtk_propagate_captured_event (GtkWidget *widget,
 {
   return propagate_event (widget, event, TRUE, topmost);
 }
+
+GtkWidget *
+_gtk_toplevel_pick (GtkWindow *toplevel,
+                    gdouble    x,
+                    gdouble    y,
+                    gdouble   *x_out,
+                    gdouble   *y_out)
+{
+  GtkWidget *target = NULL, *widget = GTK_WIDGET (toplevel);
+
+  while (widget)
+    {
+      target = widget;
+      widget = GTK_WIDGET_GET_CLASS (target)->pick (widget, x, y, &x, &y);
+    }
+
+  if (x_out)
+    *x_out = x;
+  if (y_out)
+    *y_out = y;
+
+  return target;
+}
diff --git a/gtk/gtkprivate.h b/gtk/gtkprivate.h
index de26e9f..21de486 100644
--- a/gtk/gtkprivate.h
+++ b/gtk/gtkprivate.h
@@ -91,6 +91,11 @@ gboolean        _gtk_propagate_captured_event  (GtkWidget       *widget,
                                                 GdkEvent        *event,
                                                 GtkWidget       *topmost);
 
+GtkWidget *     _gtk_toplevel_pick (GtkWindow *toplevel,
+                                    gdouble    x,
+                                    gdouble    y,
+                                    gdouble   *x_out,
+                                    gdouble   *y_out);
 
 gdouble _gtk_get_slowdown (void);
 void    _gtk_set_slowdown (gdouble slowdown_factor);