[evolution/wip/webkit2] [libgnomecanvas] Drag end not recognized with gtk+ 3.18.x

[Milan Crha <mcrha src gnome org>]

commit 3ad594f35ed1fa51a321fab8905a02e68d7feb26
Author: Milan Crha <mcrha redhat com>
Date:   Wed Nov 11 11:51:39 2015 +0100

    [libgnomecanvas] Drag end not recognized with gtk+ 3.18.x
    
    The gtk+ used to emit a fake button-released event, which had been
    used to recognize when the drag ended. This signal emission had been
    removed as a fix for bug #749737, but the code in the libgnomecanvas
    was not adapted.

 libgnomecanvas/gnome-canvas.c |   17 +++++++++++++++++
 1 files changed, 17 insertions(+), 0 deletions(-)
---
diff --git a/libgnomecanvas/gnome-canvas.c b/libgnomecanvas/gnome-canvas.c
index 4d482c5..fecce97 100644
--- a/libgnomecanvas/gnome-canvas.c
+++ b/libgnomecanvas/gnome-canvas.c
@@ -1725,6 +1725,8 @@ static void gnome_canvas_size_allocate       (GtkWidget        *widget,
                                              GtkAllocation    *allocation);
 static gint gnome_canvas_draw                (GtkWidget        *widget,
                                              cairo_t          *cr);
+static void gnome_canvas_drag_end            (GtkWidget        *widget,
+                                             GdkDragContext   *context);
 static gint gnome_canvas_button              (GtkWidget        *widget,
                                              GdkEventButton   *event);
 static gint gnome_canvas_motion              (GtkWidget        *widget,
@@ -1874,6 +1876,7 @@ gnome_canvas_class_init (GnomeCanvasClass *class)
        widget_class->unrealize = gnome_canvas_unrealize;
        widget_class->size_allocate = gnome_canvas_size_allocate;
        widget_class->draw = gnome_canvas_draw;
+       widget_class->drag_end = gnome_canvas_drag_end;
        widget_class->button_press_event = gnome_canvas_button;
        widget_class->button_release_event = gnome_canvas_button;
        widget_class->motion_notify_event = gnome_canvas_motion;
@@ -2320,6 +2323,20 @@ gnome_canvas_draw (GtkWidget *widget,
        return FALSE;
 }
 
+static void
+gnome_canvas_drag_end (GtkWidget *widget,
+                      GdkDragContext *context)
+{
+       GnomeCanvas *canvas = GNOME_CANVAS (widget);
+
+       if (canvas->grabbed_item) {
+               gnome_canvas_item_ungrab (canvas->grabbed_item, GDK_CURRENT_TIME);
+       }
+
+       if (GTK_WIDGET_CLASS (gnome_canvas_parent_class)->drag_end)
+               GTK_WIDGET_CLASS (gnome_canvas_parent_class)->drag_end (widget, context);
+}
+
 /* Emits an event for an item in the canvas, be it the current item, grabbed
  * item, or focused item, as appropriate.
  */