Unify and change logout/sleep/lock shortcuts

ash/accelerators/exit_warning_handler.h

 // 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_ACCELERATORS_EXIT_WARNING_HANDLER_H_
 #define ASH_ACCELERATORS_EXIT_WARNING_HANDLER_H_
 
 #include "ash/ash_export.h"
 #include "base/timer.h"
+#include "ui/base/accelerators/accelerator.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 happen within
-// 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.
+// An expert user may double press the shortcut for immediate exit.
+// The double press must happen within the double press time limit.
+// Unless the user performs a double press, we show the ui until the
+// hold time limit has expired to avoid a short popup flash.
+//
+// Notes:
+//
+// The corresponding accelerator must be non-repeatable (see
+// kNonrepeatableActions in accelerator_table.cc). Otherwise the "Double Press
+// Exit" will be activated just by holding it down, i.e. probably every time.
 //
 // 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
+//  WAIT_FOR_DOUBLE_PRESS action: show ui & start timers
 //   | Press (DT < T1)
 //  EXITING action: hide ui, stop timers, exit
 //
 //  IDLE
 //   | Press
-//  WAIT_FOR_QUICK_RELEASE action: show ui & start timers
+//  WAIT_FOR_DOUBLE_PRESS action: show ui & start timers
 //   | T1 timer expires
 //  WAIT_FOR_LONG_HOLD
-//   | T2 Timer exipres
+//   | T2 Timer exipres and
+//   | accelerator was held (matches current accelerator from context)
 //  EXITING action: hide ui, exit
 //
 //  IDLE
 //   | Press
-//  WAIT_FOR_QUICK_RELEASE action: show ui & start timers
-//   | T1 timer expiers
+//  WAIT_FOR_DOUBLE_PRESS action: show ui & start timers
+//   | T1 timer expires
 //  WAIT_FOR_LONG_HOLD
-//   | Release
-//  CANCELED
-//   | T2 timer expires
+//   | T2 Timer exipres and
+//   | accelerator was not held
 //  IDLE action: hide ui
 //
 //  IDLE
 //   | Press
-//  WAIT_FOR_QUICK_RELEASE action: show ui & start timers
-//   | Release (DT < T1)
-//  WAIT_FOR_DOUBLE_PRESS
+//  WAIT_FOR_DOUBLE_PRESS action: show ui & start timers
 //   | T1 timer expires
+//  WAIT_FOR_LONG_HOLD
+//   | Press
 //  CANCELED
 //   | T2 timer expires
 //  IDLE action: hide ui
 //
 
+class AcceleratorControllerContext;
 class AcceleratorControllerTest;
 
 class ASH_EXPORT ExitWarningHandler {
  public:
-  ExitWarningHandler();
+  explicit ExitWarningHandler(AcceleratorControllerContext* context);
 
   ~ExitWarningHandler();
 
-  // Handles shortcut key press and release (Ctrl-Shift-Q).
-  void HandleExitKey(bool press);
+  // Handles accelerator for exit (Ctrl-Shift-Q).
+  void HandleAccelerator();
 
  private:
   friend class AcceleratorControllerTest;
 
   enum State {
     IDLE,
-    WAIT_FOR_QUICK_RELEASE,
     WAIT_FOR_DOUBLE_PRESS,
     WAIT_FOR_LONG_HOLD,
     CANCELED,
     EXITING
   };
 
   // Performs actions (see state diagram above) when the "double key
   // press" time limit is exceeded. This is the shorter of the two
   // time limits.
   void Timer1Action();
 
   // Performs actions (see state diagram above) when the hold time
   // limit is exceeded.  See state diagram above. This is the longer
   // of the two time limits.
   void Timer2Action();
 
   void StartTimers();
   void CancelTimers();
 
   void Show();
   void Hide();
 
+  // AcceleratorControllerContext is used when a timer expires to test
+  // whether the user has held the accelerator key combination or has
+  // released (at least) one of the keys.
+  AcceleratorControllerContext* context_;
+  ui::Accelerator accelerator_;

[sky, 2013/05/17 19:22:11]

Document accelerator_ too.

   State state_;
   views::Widget* widget_; // owned by |this|.
   base::OneShotTimer<ExitWarningHandler> timer1_; // short; double press
   base::OneShotTimer<ExitWarningHandler> timer2_; // long; hold to exit
 
   // Flag to suppress starting the timers for testing. For test we
   // call TimerAction1() and TimerAction2() directly to simulate the
   // expiration of the timers.
   bool stub_timers_for_test_;
 
   DISALLOW_COPY_AND_ASSIGN(ExitWarningHandler);
 };
 
 }  // namespace ash
 
 #endif  // ASH_ACCELERATORS_EXIT_WARNING_HANDLER_H_