Corner Passthrough for Accessibility

ui/chromeos/touch_exploration_controller.h

Index: ui/chromeos/touch_exploration_controller.h
diff --git a/ui/chromeos/touch_exploration_controller.h b/ui/chromeos/touch_exploration_controller.h
index 59ff11444f54a4cf7bbd0b1a057e8de65ebfe23e..f53185efb09030dc60acb306655a85650461aa98 100644
--- a/ui/chromeos/touch_exploration_controller.h
+++ b/ui/chromeos/touch_exploration_controller.h
@@ -33,13 +33,25 @@ class TouchExplorationControllerDelegate {
  public:
   virtual ~TouchExplorationControllerDelegate() {}
 
-  // This function should be called whenever the delegate wants to play a sound
-  // when the volume adjusts.
-  virtual void PlayVolumeAdjustSound() = 0;
-
   // Takes an int from 0.0 to 100.0 that indicates the percent the volume
   // should be set to.
   virtual void SetOutputLevel(int volume) = 0;
+
+  // This function should be called when the volume adjust earcon should be
+  // played
+  virtual void PlayVolumeAdjustEarcon() = 0;
+
+  // This function should be called when the passthrough earcon should be
+  // played.
+  virtual void PlayPassthroughEarcon() = 0;
+
+  // This function should be called when the exit screen earcon should be
+  // played.
+  virtual void PlayExitScreenEarcon() = 0;
+
+  // This function should be called when the enter screen earcon should be
+  // played.
+  virtual void PlayEnterScreenEarcon() = 0;
 };
 
 // TouchExplorationController is used in tandem with "Spoken Feedback" to
@@ -57,7 +69,9 @@ class TouchExplorationControllerDelegate {
 // right would correspond to the keyboard short cut shift+search+right.
 // When two or more fingers are pressed initially, from then on the events
 // are passed through, but with the initial finger removed - so if you swipe
-// down with two fingers, the running app will see a one-finger swipe. Slide
+// down with two fingers, the running app will see a one-finger swipe. If the
+// user holds down the corner of the screen until an earcon sounds, all
+// subsequent fingers will also be passed through in a similar manner. Slide
 // gestures performed on the edge of the screen can change settings
 // continuously. For example, sliding a finger along the right side of the
 // screen will change the volume.
@@ -171,7 +185,7 @@ class UI_CHROMEOS_EXPORT TouchExplorationController
       const ui::TouchEvent& event, scoped_ptr<ui::Event>* rewritten_event);
   ui::EventRewriteStatus InTouchExploration(
       const ui::TouchEvent& event, scoped_ptr<ui::Event>* rewritten_event);
-  ui::EventRewriteStatus InTwoToOneFinger(
+  ui::EventRewriteStatus InCornerPassthrough(
       const ui::TouchEvent& event, scoped_ptr<ui::Event>* rewritten_event);
   ui::EventRewriteStatus InOneFingerPassthrough(
       const ui::TouchEvent& event, scoped_ptr<ui::Event>* rewritten_event);
@@ -194,6 +208,13 @@ class UI_CHROMEOS_EXPORT TouchExplorationController
   void StartTapTimer();
   void OnTapTimerFired();
 
+  // This timer is started every timer we get the first press event and the
+  // finger is in the corner of the screen.
+  // It fires after the long_press timeout elapses (500 ms by default). If the

[aboxhall, 2014/08/06 18:10:45]

Looks like it's 700ms now. Maybe just refer to the variable name instead, to
stop this comment getting out of date?

[lisayin, 2014/08/06 20:37:35]

Done.

+  // user is still in the corner by the time this timre fires, all subsequent
+  // fingers added on the screen will be passed through.
+  void OnLongPressTimerFired();
+
   // Dispatch a new event outside of the event rewriting flow.
   void DispatchEvent(ui::Event* event);
 
@@ -302,6 +323,11 @@ class UI_CHROMEOS_EXPORT TouchExplorationController
     // all fingers.
     ONE_FINGER_PASSTHROUGH,
 
+    // If the user has pressed and held down the left corner past long press,
+    // then as long as they are holding the corner, all subsequent fingers
+    // registered will be in passthrough.
+    CORNER_PASSTHROUGH,
+
     // If the user added another finger in SINGLE_TAP_PRESSED, or if the user
     // has multiple fingers fingers down in any other state between
     // passthrough, touch exploration, and gestures, they must release
@@ -323,6 +349,8 @@ class UI_CHROMEOS_EXPORT TouchExplorationController
     TOP_EDGE = 1 << 1,
     LEFT_EDGE = 1 << 2,
     BOTTOM_EDGE = 1 << 3,
+    BOTTOM_LEFT_CORNER = LEFT_EDGE | BOTTOM_EDGE,
+    BOTTOM_RIGHT_CORNER = RIGHT_EDGE | BOTTOM_EDGE,
   };
 
   // Given a point, if it is within the given bounds of an edge, returns the
@@ -368,9 +396,12 @@ class UI_CHROMEOS_EXPORT TouchExplorationController
   // we send the passed-through tap to the location of this event.
   scoped_ptr<ui::TouchEvent> last_touch_exploration_;
 
-  // A timer to fire the mouse move event after the double-tap delay.
+  // A timer that fires after the double-tap delay.
   base::OneShotTimer<TouchExplorationController> tap_timer_;
 
+  // A timer that fires after a long press delay.
+  base::OneShotTimer<TouchExplorationController> long_press_timer_;
+
   // A timer to fire an indicating sound when sliding to change volume.
   base::RepeatingTimer<TouchExplorationController> sound_timer_;
 
@@ -394,6 +425,10 @@ class UI_CHROMEOS_EXPORT TouchExplorationController
   // testing, this clock is set to the simulated clock and used.
   base::TickClock* tick_clock_;
 
+  // Indicates if a finger is in the lower left corner waiting for the timer to
+  // run out.
+  bool waiting_for_corner_passthrough_;
+
   DISALLOW_COPY_AND_ASSIGN(TouchExplorationController);
 };