blob: aa667899d45e6e2cc7e70798b4ea067c9f1af9c9 [file] [log] [blame]
// 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.
#include <vector>
#include "ash/ash_export.h"
#include "base/basictypes.h"
#include "base/memory/scoped_ptr.h"
namespace aura {
class EventFilter;
class Window;
namespace ash {
class WindowCycleList;
// Controls cycling through windows with the keyboard, for example, via alt-tab.
// We activate windows as you cycle through them, so the order on the screen
// may change during the gesture. Thus we maintain the state of the windows
// at the beginning of the gesture so you can cycle through in a consistent
// order.
class ASH_EXPORT WindowCycleController {
enum Direction {
// Returns true if cycling through windows is enabled. This is false at
// certain times, such as when the lock screen is visible.
static bool CanCycle();
// Cycles between windows in the given |direction|. If |is_alt_down| then
// interprets this call as the start of a multi-step cycle sequence and
// installs a key filter to watch for alt being released.
void HandleCycleWindow(Direction direction, bool is_alt_down);
// Informs the controller that the Alt key has been released and it can
// terminate the existing multi-step cycle.
void AltKeyReleased();
// Returns true if we are in the middle of a window cycling gesture.
bool IsCycling() const { return windows_.get() != NULL; }
// Returns the WindowCycleList. Really only useful for testing.
const WindowCycleList* windows() const { return windows_.get(); }
// Returns the set of windows to cycle through. This method creates
// the vector based on the current set of windows across all valid root
// windows. As a result it is not necessarily the same as the set of
// windows being iterated over.
static std::vector<aura::Window*> BuildWindowList();
// Call to start cycling windows. You must call StopCycling() when done.
void StartCycling();
// Cycles to the next or previous window based on |direction|.
void Step(Direction direction);
// Installs an event filter to watch for release of the alt key.
void InstallEventFilter();
// Stops the current window cycle and cleans up the event filter.
void StopCycling();
scoped_ptr<WindowCycleList> windows_;
// Event filter to watch for release of alt key.
scoped_ptr<aura::EventFilter> event_filter_;
} // namespace ash