MacViews: Implement Window-modal dialogs using sheets

ui/views/examples/widget_example.h

 // Copyright (c) 2011 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.
 
 #ifndef UI_VIEWS_EXAMPLES_WIDGET_EXAMPLE_H_
 #define UI_VIEWS_EXAMPLES_WIDGET_EXAMPLE_H_
 
 #include <string>
 
 #include "base/macros.h"
@@ skipping 12 matching lines @@
   ~WidgetExample() override;
 
   // ExampleBase:
   void CreateExampleView(View* container) override;
 
  private:
   // Button tags used to identify various commands.
   enum Command {
     POPUP,        // Show a popup widget.
     DIALOG,       // Show a dialog widget.
+    MODAL_DIALOG, // Show a modal dialog widget.
     CHILD,        // Show a child widget.
     CLOSE_WIDGET, // Close the sender button's widget.
   };
 
   // Construct a button with the specified |label| and |tag| in |container|.
   void BuildButton(View* container, const std::string& label, int tag);
 
   // Construct a Widget for |sender|, initialize with |params|, and call Show().
   void ShowWidget(View* sender, Widget::InitParams params);
 
   // ButtonListener:
   void ButtonPressed(Button* sender, const ui::Event& event) override;
 
   DISALLOW_COPY_AND_ASSIGN(WidgetExample);
 };
 
 }  // namespace examples
 }  // namespace views
 
 #endif  // UI_VIEWS_EXAMPLES_WIDGET_EXAMPLE_H_