ui/views/views_delegate.h

// Copyright (c) 2012 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_VIEWS_DELEGATE_H_
#define UI_VIEWS_VIEWS_DELEGATE_H_
#pragma once

#include <string>

#if defined(OS_WIN)
#include <windows.h>
#endif

#include "base/string16.h"
#include "ui/base/accessibility/accessibility_types.h"
#include "ui/base/ui_base_types.h"
#include "ui/views/views_export.h"

namespace gfx {
class Rect;
}

namespace ui {
class Clipboard;
}

namespace views {

class NonClientFrameView;
class View;
class Widget;

#if defined(USE_AURA)
class NativeWidgetAura;
class NativeWidgetHelperAura;
#endif

// ViewsDelegate is an interface implemented by an object using the views
// framework. It is used to obtain various high level application utilities
// and perform some actions such as window placement saving.
//
// The embedding app must set views_delegate to assign its ViewsDelegate
// implementation.
class VIEWS_EXPORT ViewsDelegate {
 public:
  // The active ViewsDelegate used by the views system.
  static ViewsDelegate* views_delegate;

  virtual ~ViewsDelegate() {}

  // Gets the clipboard.
  virtual ui::Clipboard* GetClipboard() const = 0;

  // Saves the position, size and "show" state for the window with the
  // specified name.
  virtual void SaveWindowPlacement(const Widget* widget,
                                   const std::string& window_name,
                                   const gfx::Rect& bounds,
                                   ui::WindowShowState show_state) = 0;

  // Retrieves the saved position and size and "show" state for the window with
  // the specified name.
  virtual bool GetSavedWindowPlacement(
      const std::string& window_name,
      gfx::Rect* bounds,
      ui::WindowShowState* show_state) const = 0;

  virtual void NotifyAccessibilityEvent(
      View* view,
      ui::AccessibilityTypes::Event event_type) = 0;

  // For accessibility, notify the delegate that a menu item was focused
  // so that alternate feedback (speech / magnified text) can be provided.
  virtual void NotifyMenuItemFocused(const string16& menu_name,
                                     const string16& menu_item_name,
                                     int item_index,
                                     int item_count,
                                     bool has_submenu) = 0;

#if defined(OS_WIN)
  // Retrieves the default window icon to use for windows if none is specified.
  virtual HICON GetDefaultWindowIcon() const = 0;
#endif

  // Creates a default NonClientFrameView to be used for windows that don't
  // specify their own. If this function returns NULL, the
  // views::CustomFrameView type will be used.
  virtual NonClientFrameView* CreateDefaultNonClientFrameView(
      Widget* widget) = 0;

  // Returns whether the embedding app wants windows to be created with the
  // views::Widget marked as transparent.  For example, an app may wish to
  // apply transparent window frames in the NonClientFrameView.
  virtual bool UseTransparentWindows() const = 0;

  // AddRef/ReleaseRef are invoked while a menu is visible. They are used to
  // ensure we don't attempt to exit while a menu is showing.
  virtual void AddRef() = 0;
  virtual void ReleaseRef() = 0;

  // Converts views::Event::flags to a WindowOpenDisposition.
  virtual int GetDispositionForEvent(int event_flags) = 0;

#if defined(USE_AURA)
  // Creates an object that implements desktop integration behavior. Returned
  // object is owned by the NativeWidgetAura passed in. May return NULL.
  virtual NativeWidgetHelperAura* CreateNativeWidgetHelper(
      NativeWidgetAura* native_widget) = 0;
#endif
};

}  // namespace views

#endif  // UI_VIEWS_VIEWS_DELEGATE_H_