MessageBubble which does not require separate window and does not grab input on mouse press event.

views/widget/widget_gtk.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "views/widget/widget_gtk.h"
 
 #include <gdk/gdk.h>
 #include <gdk/gdkx.h>
 #include <X11/extensions/shape.h>
 
@@ skipping 1135 matching lines @@
   gtk_grab_add(window_contents_);
 }
 
 void WidgetGtk::ReleaseGrab() {
   if (has_capture_) {
     has_capture_ = false;
     gtk_grab_remove(window_contents_);
   }
 }
 
+void WidgetGtk::HandleGrabBroke() {
+  if (has_capture_) {
+    if (is_mouse_down_)
+      root_view_->ProcessMouseDragCanceled();
+    is_mouse_down_ = false;
+    has_capture_ = false;
+  }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // WidgetGtk, private:
 
 RootView* WidgetGtk::CreateRootView() {
   return new RootView(this);
 }
 
 gboolean WidgetGtk::OnWindowPaint(GtkWidget* widget, GdkEventExpose* event) {
   // Clear the background to be totally transparent. We don't need to
   // paint the root view here as that is done by OnPaint.
@@ skipping 226 matching lines @@
       win,
       ShapeInput,
       0,  // x offset
       0,  // y offset
       NULL,  // rectangles
       0,  // num rectangles
       ShapeSet,
       0);
 }
 
-void WidgetGtk::HandleGrabBroke() {
-  if (has_capture_) {
-    if (is_mouse_down_)
-      root_view_->ProcessMouseDragCanceled();
-    is_mouse_down_ = false;
-    has_capture_ = false;
-  }
-}
-
 void WidgetGtk::DrawTransparentBackground(GtkWidget* widget,
                                           GdkEventExpose* event) {
   cairo_t* cr = gdk_cairo_create(widget->window);
   cairo_set_operator(cr, CAIRO_OPERATOR_CLEAR);
   gdk_cairo_region(cr, event->region);
   cairo_fill(cr);
   cairo_destroy(cr);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ skipping 99 matching lines @@
     GtkWindow* window = GTK_WINDOW(element->data);
     DCHECK(window);
     RootView *root_view = FindRootView(window);
     if (root_view)
       root_view->NotifyLocaleChanged();
   }
   g_list_free(window_list);
 }
 
 }  // namespace views