Unify and change logout/sleep/lock shortcuts

ash/accelerators/exit_warning_handler.h

Index: ash/accelerators/exit_warning_handler.h
diff --git a/ash/accelerators/exit_warning_handler.h b/ash/accelerators/exit_warning_handler.h
new file mode 100644
index 0000000000000000000000000000000000000000..033b2d0bb7f7ba586ced955a16d4635e568f766f
--- /dev/null
+++ b/ash/accelerators/exit_warning_handler.h
@@ -0,0 +1,106 @@
+// Copyright 2013 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 ASH_EXIT_WARNING_HANDLER_H_

[sky, 2013/05/13 15:40:32]

You missed the accelerators here, eg ASH_ACCELERATORS...

[sschmitz, 2013/05/14 16:49:11]

Done.

+#define ASH_EXIT_WARNING_HANDLER_H_
+
+#include "base/timer.h"
+
+namespace views {
+class Widget;
+}
+
+namespace ash {
+
+// In order to avoid accidental exits when the user presses the exit
+// shortcut by mistake, we require the user to hold the shortcut for
+// a period of time. During that time we show a popup informing the
+// user of this. We exit only if the user holds the shortcut longer
+// than this time limit.
+// An expert user may quickly release and then press again (double press)
+// for immediate exit. The press, release and press must happend within

[sky, 2013/05/13 15:40:32]

happend -> happen

[sschmitz, 2013/05/14 16:49:11]

Done.

+// the double press time limit.
+// If the user releases (without double press) before the required hold
+// time, we will cancel the exit, but show the ui until the hold time limit
+// has expired to avoid a short popup flash.
+//
+// State Transition Diagrams:
+//
+//  T1 - double press time limit (short)
+//  T2 - hold to exit time limit (long)
+//
+//  IDLE
+//   | Press
+//  WAIT_FOR_QUICK_RELEASE action: show ui & start timers
+//   | Release (DT < T1)
+//  WAIT_FOR_DOUBLE_PRESS
+//   | Press (DT < T1)
+//  EXITING action: hide ui, stop timers, exit
+//
+//  IDLE
+//   | Press
+//  WAIT_FOR_QUICK_RELEASE action: show ui & start timers
+//   | T1 timer expires
+//  WAIT_FOR_LONG_HOLD
+//   | T2 Timer exipres
+//  EXITING action: hide ui, exit
+//
+//  IDLE
+//   | Press
+//  WAIT_FOR_QUICK_RELEASE action: show ui & start timers
+//   | T1 timer expiers
+//  WAIT_FOR_LONG_HOLD
+//   | Release
+//  CANCELED
+//   | T2 timer expires
+//  IDLE action: hide ui
+//
+//  IDLE
+//   | Press
+//  WAIT_FOR_QUICK_RELEASE action: show ui & start timers
+//   | Release (DT < T1)
+//  WAIT_FOR_DOUBLE_PRESS
+//   | T1 timer expires
+//  CANCELED
+//   | T2 timer expires
+//  IDLE action: hide ui
+//
+
+class ExitWarningHandler {
+ public:
+

[sky, 2013/05/13 15:40:32]

nit: no newline here.

[sschmitz, 2013/05/14 16:49:11]

Done.

+  ExitWarningHandler();
+
+  ~ExitWarningHandler();
+
+  void HandleExitKey(bool press);

[sky, 2013/05/13 15:40:32]

Document what press is.

[sschmitz, 2013/05/14 16:49:11]

Done.

[sky, 2013/05/14 17:10:05]

It still isn't clear that |press| is true on a press and false on release.

+
+ private:
+  void Timer1Action();

[sky, 2013/05/13 15:40:32]

These need a description.

[sschmitz, 2013/05/14 16:49:11]

Done.

+  void Timer2Action();
+
+  void StartTimers();
+  void CancelTimers();
+
+  void Show();
+  void Hide();
+
+  enum State {

[sky, 2013/05/13 15:40:32]

enums should be first in section.

[sschmitz, 2013/05/14 16:49:11]

Done.

+    IDLE,
+    WAIT_FOR_QUICK_RELEASE,
+    WAIT_FOR_DOUBLE_PRESS,
+    WAIT_FOR_LONG_HOLD,
+    CANCELED,
+    EXITING
+  };
+
+  State state_;
+  views::Widget* widget_;

[sky, 2013/05/13 15:40:32]

Document ownership.

[sschmitz, 2013/05/14 16:49:11]

Done.

+  base::OneShotTimer<ExitWarningHandler> timer1_; // short; double press
+  base::OneShotTimer<ExitWarningHandler> timer2_; // long; hold to exit
+};

[sky, 2013/05/13 15:40:32]

DISALLOW_...

[sschmitz, 2013/05/14 16:49:11]

Done.

+
+}
+
+#endif