blob: 8080f3997f15e1c2702a0f4bd0c4579a9c449dd9 [file] [log] [blame]
// Copyright (c) 2006-2008 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 VIEWS_FOCUS_EXTERNAL_FOCUS_TRACKER_H_
#define VIEWS_FOCUS_EXTERNAL_FOCUS_TRACKER_H_
#pragma once
#include "views/focus/focus_manager.h"
namespace views {
class View;
class ViewStorage;
// ExternalFocusTracker tracks the last focused view which belongs to the
// provided focus manager and is not either the provided parent view or one of
// its descendants. This is generally used if the parent view want to return
// focus to some other view once it is dismissed. The parent view and the focus
// manager must exist for the duration of the tracking. If the focus manager
// must be deleted before this object is deleted, make sure to call
// SetFocusManager(NULL) first.
//
// Typical use: When a view is added to the view hierarchy, it instantiates an
// ExternalFocusTracker and passes in itself and its focus manager. Then,
// when that view wants to return focus to the last focused view which is not
// itself and not a descandant of itself, (usually when it is being closed)
// it calls FocusLastFocusedExternalView.
class ExternalFocusTracker : public FocusChangeListener {
public:
ExternalFocusTracker(View* parent_view, FocusManager* focus_manager);
virtual ~ExternalFocusTracker();
// FocusChangeListener implementation.
virtual void FocusWillChange(View* focused_before, View* focused_now);
// Focuses last focused view which is not a child of parent view and is not
// parent view itself. Returns true if focus for a view was requested, false
// otherwise.
void FocusLastFocusedExternalView();
// Sets the focus manager whose focus we are tracking. |focus_manager| can
// be NULL, but no focus changes will be tracked. This is useful if the focus
// manager went away, but you might later want to start tracking with a new
// manager later, or call FocusLastFocusedExternalView to focus the previous
// view.
void SetFocusManager(FocusManager* focus_manager);
private:
// Store the provided view. This view will be focused when
// FocusLastFocusedExternalView is called.
void StoreLastFocusedView(View* view);
// Store the currently focused view for our view manager and register as a
// listener for future focus changes.
void StartTracking();
// Focus manager which we are a listener for.
FocusManager* focus_manager_;
// ID of the last focused view, which we store in view_storage_.
int last_focused_view_storage_id_;
// Used to store the last focused view which is not a child of
// ExternalFocusTracker.
ViewStorage* view_storage_;
// The parent view of views which we should not track focus changes to. We
// also do not track changes to parent_view_ itself.
View* parent_view_;
DISALLOW_COPY_AND_ASSIGN(ExternalFocusTracker);
};
} // namespace views
#endif // VIEWS_FOCUS_EXTERNAL_FOCUS_TRACKER_H_