components/mus/focus_controller.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_MUS_FOCUS_CONTROLLER_H_
   6 #define COMPONENTS_MUS_FOCUS_CONTROLLER_H_
   7
   8 #include "base/memory/scoped_ptr.h"
   9 #include "components/mus/server_view_drawn_tracker_observer.h"
  10
  11 namespace mus {
  12
  13 class FocusControllerDelegate;
  14 class ServerView;
  15 class ServerViewDrawnTracker;
  16
  17 // Tracks a focused view. Focus is moved to another view when the drawn state
  18 // of the focused view changes and the delegate is notified.
  19 class FocusController : public ServerViewDrawnTrackerObserver {
  20  public:
  21   explicit FocusController(FocusControllerDelegate* delegate);
  22   ~FocusController() override;
  23
  24   // Sets the focused view. Does nothing if |view| is currently focused. This
  25   // does not notify the delegate.
  26   void SetFocusedView(ServerView* view);
  27   ServerView* GetFocusedView();
  28
  29  private:
  30   // Describes the source of the change.
  31   enum ChangeSource {
  32     CHANGE_SOURCE_EXPLICIT,
  33     CHANGE_SOURCE_DRAWN_STATE_CHANGED,
  34   };
  35
  36   // Implementation of SetFocusedView().
  37   void SetFocusedViewImpl(ServerView* view, ChangeSource change_source);
  38
  39   // ServerViewDrawnTrackerObserver:
  40   void OnDrawnStateChanged(ServerView* ancestor,
  41                            ServerView* view,
  42                            bool is_drawn) override;
  43
  44   FocusControllerDelegate* delegate_;
  45   scoped_ptr<ServerViewDrawnTracker> drawn_tracker_;
  46
  47   DISALLOW_COPY_AND_ASSIGN(FocusController);
  48 };
  49
  50 }  // namespace mus
  51
  52 #endif  // COMPONENTS_MUS_FOCUS_CONTROLLER_H_