Added multi-finger gestures to touch_exploration_controller

ui/chromeos/touch_exploration_controller.cc

 // Copyright 2014 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 "ui/chromeos/touch_exploration_controller.h"
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/time/default_tick_clock.h"
 #include "ui/aura/client/cursor_client.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/events/event.h"
 #include "ui/events/event_processor.h"
 #include "ui/events/event_utils.h"
 #include "ui/gfx/geometry/rect.h"
 
 #define VLOG_STATE() if (VLOG_IS_ON(0)) VlogState(__func__)
@@ skipping 10 matching lines @@
 const ui::KeyboardCode kChromeOSSearchKey = ui::VKEY_LWIN;
 }  // namespace
 
 TouchExplorationController::TouchExplorationController(
     aura::Window* root_window,
     TouchExplorationControllerDelegate* delegate)
     : root_window_(root_window),
       delegate_(delegate),
       state_(NO_FINGERS_DOWN),
       event_handler_for_testing_(NULL),
-      gesture_provider_(this),
       prev_state_(NO_FINGERS_DOWN),
       VLOG_on_(true),
       tick_clock_(NULL) {
   CHECK(root_window);
   root_window->GetHost()->GetEventSource()->AddEventRewriter(this);
+  InitializeSwipeGestureMaps();
+  gesture_provider_.reset(new GestureProviderAura(this));

[mfomitchev, 2014/08/07 18:34:58]

nit: I think you can just add gesture_provider_(new GestureProviderAura(this))
to initialization list (in place of gesture_provider_(this))

[evy, 2014/08/07 20:40:26]

Done.

 }
 
 TouchExplorationController::~TouchExplorationController() {
   root_window_->GetHost()->GetEventSource()->RemoveEventRewriter(this);
 }
 
 ui::EventRewriteStatus TouchExplorationController::RewriteEvent(
     const ui::Event& event,
     scoped_ptr<ui::Event>* rewritten_event) {
   if (!event.IsTouchEvent()) {
+    if (event.IsKeyEvent()) {
+      const ui::KeyEvent& key_event = static_cast<const ui::KeyEvent&>(event);
+      VLOG(0) << "\nKeyboard event: " << key_event.name()
+              << "\n Key code: " << key_event.key_code()
+              << ", Flags: " << key_event.flags()
+              << ", Is char: " << key_event.is_char();
+    }
     return ui::EVENT_REWRITE_CONTINUE;
   }
   const ui::TouchEvent& touch_event = static_cast<const ui::TouchEvent&>(event);
 
   // If the tap timer should have fired by now but hasn't, run it now and
   // stop the timer. This is important so that behavior is consistent with
   // the timestamps of the events, and not dependent on the granularity of
   // the timer.
   if (tap_timer_.IsRunning() &&
       touch_event.time_stamp() - initial_press_->time_stamp() >
           gesture_detector_config_.double_tap_timeout) {
     tap_timer_.Stop();
     OnTapTimerFired();
     // Note: this may change the state. We should now continue and process
     // this event under this new state.
   }
 
   const ui::EventType type = touch_event.type();
   const gfx::PointF& location = touch_event.location_f();
   const int touch_id = touch_event.touch_id();
 
   // Always update touch ids and touch locations, so we can use those
   // no matter what state we're in.
   if (type == ui::ET_TOUCH_PRESSED) {
     current_touch_ids_.push_back(touch_id);
     touch_locations_.insert(std::pair<int, gfx::PointF>(touch_id, location));
   } else if (type == ui::ET_TOUCH_RELEASED || type == ui::ET_TOUCH_CANCELLED) {
-    // In order to avoid accidentally double tapping when moving off the edge of
-    // the screen, the state will be rewritten to NoFingersDown.
+    // In order to avoid accidentally double tapping when moving off the edge
+    // of the screen, the state will be rewritten to NoFingersDown.
     TouchEvent touch_event = static_cast<const TouchEvent&>(event);
     if (FindEdgesWithinBounds(touch_event.location(), kLeavingScreenEdge) !=
         NO_EDGE) {
       if (current_touch_ids_.size() == 0) {

[mfomitchev, 2014/08/07 18:34:58]

Should this be == 1 instead? You shouldn't get a release if touch ids is empty
(unless the controller was activated when some fingers were already down)...

Also, does this really belong in the block of code updating current_touch_ids_?
Perhaps it would be worth moving it out to keep separate logical pieces things
separated?

[evy, 2014/08/07 20:40:26]

This block of code was actually here before we started.
I don't even see where the touch id is removed from current_touch_ids, but my
guess is that it was supposed to be updated before that size check. I'll look
into it, and ask Dominic next week if I can't find a clear answer.

[mfomitchev, 2014/08/08 20:23:13]

Sounds like lisayin@ wrote this, maybe ask her? The touch id is removed just a
few lines below - "current_touch_ids_.erase(it);"

Incidentally, if this code is moved out of the current_touch_ids_ update block,
I think it becomes correct :)

[evy, 2014/08/08 22:39:14]

Done.

         ResetToNoFingersDown();
       }
     }
 
     std::vector<int>::iterator it = std::find(
         current_touch_ids_.begin(), current_touch_ids_.end(), touch_id);
 
     // Can happen if touch exploration is enabled while fingers were down.
     if (it == current_touch_ids_.end())
       return ui::EVENT_REWRITE_CONTINUE;
 
     current_touch_ids_.erase(it);
     touch_locations_.erase(touch_id);
   } else if (type == ui::ET_TOUCH_MOVED) {
     std::vector<int>::iterator it = std::find(
         current_touch_ids_.begin(), current_touch_ids_.end(), touch_id);
 
     // Can happen if touch exploration is enabled while fingers were down.
     if (it == current_touch_ids_.end())
       return ui::EVENT_REWRITE_CONTINUE;
 
     touch_locations_[*it] = location;
+  } else {
+    NOTREACHED() << "Unexpected event type received: " << event.name();
+    return ui::EVENT_REWRITE_CONTINUE;
   }
   VLOG_STATE();
   VLOG_EVENT(touch_event);
+
+  // If the user is in a gesture state, or if there is a possiblity that the
+  // user will enter it in the future, we send the event to the gesture
+  // provider so it can keep track of the state of the fingers.
+  // TODO(lisayin, evy): Add the two finger hold state when that's completed.
+  if (state_ == NO_FINGERS_DOWN ||

[mfomitchev, 2014/08/07 18:34:58]

Hmm.. perhaps it would be better to do gesture_provider_.reset(NULL) whenever
transition to a state where you don't need a gesture recognizer anymore. You
could add a SetState() method to ensure you always do that (then you can also
ditch ResetToNoFingersDown()). One advantage is that you won't have
gesture_provider_ evaluating things like long presses in the background when you
no longer need it. Also, you reinforce the paradigm that once you go into a
state where gestures aren't supported - you have to go through NO_FINGERS_DOWN
to re-enable gestures. And then here you can simply check if
(gesture_provider_.get()).

[evy, 2014/08/07 20:40:26]

Done. Great idea - feels much cleaner this way.

+      state_ == SINGLE_TAP_PRESSED ||
+      state_ == GESTURE_IN_PROGRESS ||
+      state_ == SLIDE_GESTURE) {
+    gesture_provider_->OnTouchEvent(touch_event);
+    gesture_provider_->OnTouchEventAck(false);
+    ProcessGestureEvents();
+  }
+
   // The rest of the processing depends on what state we're in.
-  switch(state_) {
+  switch (state_) {
     case NO_FINGERS_DOWN:
       return InNoFingersDown(touch_event, rewritten_event);
     case SINGLE_TAP_PRESSED:
       return InSingleTapPressed(touch_event, rewritten_event);
     case SINGLE_TAP_RELEASED:
     case TOUCH_EXPLORE_RELEASED:
       return InSingleTapOrTouchExploreReleased(touch_event, rewritten_event);
     case DOUBLE_TAP_PENDING:
       return InDoubleTapPending(touch_event, rewritten_event);
     case TOUCH_RELEASE_PENDING:
       return InTouchReleasePending(touch_event, rewritten_event);
     case TOUCH_EXPLORATION:
       return InTouchExploration(touch_event, rewritten_event);
     case GESTURE_IN_PROGRESS:
       return InGestureInProgress(touch_event, rewritten_event);
     case TOUCH_EXPLORE_SECOND_PRESS:
       return InTouchExploreSecondPress(touch_event, rewritten_event);
+    case ONE_FINGER_PASSTHROUGH:
+      return InOneFingerPassthrough(touch_event, rewritten_event);
+    case WAIT_FOR_NO_FINGERS:
+      return InWaitForNoFingers(touch_event, rewritten_event);
     case SLIDE_GESTURE:
       return InSlideGesture(touch_event, rewritten_event);
-    case ONE_FINGER_PASSTHROUGH:
-      return InOneFingerPassthrough(touch_event, rewritten_event);
-    case WAIT_FOR_ONE_FINGER:
-      return InWaitForOneFinger(touch_event, rewritten_event);
   }
   NOTREACHED();
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
 ui::EventRewriteStatus TouchExplorationController::NextDispatchEvent(
     const ui::Event& last_event, scoped_ptr<ui::Event>* new_event) {
   NOTREACHED();
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
 ui::EventRewriteStatus TouchExplorationController::InNoFingersDown(
     const ui::TouchEvent& event, scoped_ptr<ui::Event>* rewritten_event) {
   const ui::EventType type = event.type();
   if (type == ui::ET_TOUCH_PRESSED) {
     initial_press_.reset(new TouchEvent(event));
     last_unused_finger_event_.reset(new TouchEvent(event));
     StartTapTimer();
-    gesture_provider_.OnTouchEvent(event);
-    gesture_provider_.OnTouchEventAck(false);
-    ProcessGestureEvents();
     state_ = SINGLE_TAP_PRESSED;
     VLOG_STATE();
     return ui::EVENT_REWRITE_DISCARD;
   }
   NOTREACHED() << "Unexpected event type received: " << event.name();
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
 ui::EventRewriteStatus TouchExplorationController::InSingleTapPressed(
     const ui::TouchEvent& event, scoped_ptr<ui::Event>* rewritten_event) {
   const ui::EventType type = event.type();
 
   if (type == ui::ET_TOUCH_PRESSED) {
-    // TODO (evy, lisayin) : add support for multifinger swipes.
-    // For now, we wait for there to be only one finger down again.
-    state_ = WAIT_FOR_ONE_FINGER;
-    return EVENT_REWRITE_DISCARD;
+    // This is the start of a multifinger gesture.
+    state_ = GESTURE_IN_PROGRESS;
+    VLOG_STATE();
+    return InGestureInProgress(event, rewritten_event);
   } else if (type == ui::ET_TOUCH_RELEASED || type == ui::ET_TOUCH_CANCELLED) {
     if (current_touch_ids_.size() == 0 &&
         event.touch_id() == initial_press_->touch_id()) {
       state_ = SINGLE_TAP_RELEASED;
       VLOG_STATE();
     } else if (current_touch_ids_.size() == 0) {
       ResetToNoFingersDown();
     }
     return EVENT_REWRITE_DISCARD;
   } else if (type == ui::ET_TOUCH_MOVED) {
@@ skipping 26 matching lines @@
     if (velocity > gesture_detector_config_.minimum_swipe_velocity) {
       state_ = GESTURE_IN_PROGRESS;
       VLOG_STATE();
       return InGestureInProgress(event, rewritten_event);
     }
     EnterTouchToMouseMode();
     state_ = TOUCH_EXPLORATION;
     VLOG_STATE();
     return InTouchExploration(event, rewritten_event);
   }
-  NOTREACHED() << "Unexpected event type received: " << event.name();
+  NOTREACHED();
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
 ui::EventRewriteStatus
 TouchExplorationController::InSingleTapOrTouchExploreReleased(
     const ui::TouchEvent& event,
     scoped_ptr<ui::Event>* rewritten_event) {
   const ui::EventType type = event.type();
-  // If there is more than one finger down, then discard to wait until only one
-  // finger is or no fingers are down.
+  // If there is more than one finger down, then discard to wait until no
+  // fingers are down.
   if (current_touch_ids_.size() > 1) {
-    state_ = WAIT_FOR_ONE_FINGER;
+    state_ = WAIT_FOR_NO_FINGERS;
+    VLOG_STATE();
     return ui::EVENT_REWRITE_DISCARD;
   }
   if (type == ui::ET_TOUCH_PRESSED) {
     // If there is no touch exploration yet, we can't send a click, so discard.
     if (!last_touch_exploration_) {
       tap_timer_.Stop();
       return ui::EVENT_REWRITE_DISCARD;
     }
     // This is the second tap in a double-tap (or double tap-hold).
     // We set the tap timer. If it fires before the user lifts their finger,
     // one-finger passthrough begins. Otherwise, there is a touch press and
     // release at the location of the last touch exploration.
     state_ = DOUBLE_TAP_PENDING;
     VLOG_STATE();
+    // The old tap timer (from the initial click) is stopped if it is still
+    // going, and the new one is set.
+    tap_timer_.Stop();
     StartTapTimer();
     // This will update as the finger moves before a possible passthrough, and
     // will determine the offset.
     last_unused_finger_event_.reset(new ui::TouchEvent(event));
     return ui::EVENT_REWRITE_DISCARD;
   } else if (type == ui::ET_TOUCH_RELEASED && !last_touch_exploration_) {
     // If the previous press was discarded, we need to also handle its
     // release.
     if (current_touch_ids_.size() == 0) {
       ResetToNoFingersDown();
     }
     return ui::EVENT_REWRITE_DISCARD;
   } else if (type == ui::ET_TOUCH_MOVED) {
     return ui::EVENT_REWRITE_DISCARD;
   }
-  NOTREACHED() << "Unexpected event type received: " << event.name();
+  NOTREACHED();
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
 ui::EventRewriteStatus TouchExplorationController::InDoubleTapPending(
     const ui::TouchEvent& event,
     scoped_ptr<ui::Event>* rewritten_event) {
   const ui::EventType type = event.type();
   if (type == ui::ET_TOUCH_PRESSED) {
     return ui::EVENT_REWRITE_DISCARD;
   } else if (type == ui::ET_TOUCH_MOVED) {
@@ skipping 18 matching lines @@
 
     rewritten_event->reset(
         new ui::TouchEvent(ui::ET_TOUCH_RELEASED,
                            last_touch_exploration_->location(),
                            initial_press_->touch_id(),
                            event.time_stamp()));
     (*rewritten_event)->set_flags(event.flags());
     ResetToNoFingersDown();
     return ui::EVENT_REWRITE_REWRITTEN;
   }
-  NOTREACHED() << "Unexpected event type received: " << event.name();
+  NOTREACHED();
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
 ui::EventRewriteStatus TouchExplorationController::InTouchReleasePending(
     const ui::TouchEvent& event,
     scoped_ptr<ui::Event>* rewritten_event) {
   const ui::EventType type = event.type();
   if (type == ui::ET_TOUCH_PRESSED || type == ui::ET_TOUCH_MOVED) {
     return ui::EVENT_REWRITE_DISCARD;
   } else if (type == ui::ET_TOUCH_RELEASED || type == ui::ET_TOUCH_CANCELLED) {
     if (current_touch_ids_.size() != 0)
       return EVENT_REWRITE_DISCARD;
 
     rewritten_event->reset(
         new ui::TouchEvent(ui::ET_TOUCH_RELEASED,
                            last_touch_exploration_->location(),
                            initial_press_->touch_id(),
                            event.time_stamp()));
     (*rewritten_event)->set_flags(event.flags());
     ResetToNoFingersDown();
     return ui::EVENT_REWRITE_REWRITTEN;
   }
-  NOTREACHED() << "Unexpected event type received: " << event.name();
+  NOTREACHED();
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
 ui::EventRewriteStatus TouchExplorationController::InTouchExploration(
     const ui::TouchEvent& event,
     scoped_ptr<ui::Event>* rewritten_event) {
   const ui::EventType type = event.type();
   if (type == ui::ET_TOUCH_PRESSED) {
     // Handle split-tap.
     initial_press_.reset(new TouchEvent(event));
-    if (tap_timer_.IsRunning())
-      tap_timer_.Stop();
+    tap_timer_.Stop();
     rewritten_event->reset(
         new ui::TouchEvent(ui::ET_TOUCH_PRESSED,
                            last_touch_exploration_->location(),
                            event.touch_id(),
                            event.time_stamp()));
     (*rewritten_event)->set_flags(event.flags());
     state_ = TOUCH_EXPLORE_SECOND_PRESS;
     VLOG_STATE();
     return ui::EVENT_REWRITE_REWRITTEN;
   } else if (type == ui::ET_TOUCH_RELEASED || type == ui::ET_TOUCH_CANCELLED) {
     initial_press_.reset(new TouchEvent(event));
     StartTapTimer();
     state_ = TOUCH_EXPLORE_RELEASED;
     VLOG_STATE();
   } else if (type != ui::ET_TOUCH_MOVED) {
-    NOTREACHED() << "Unexpected event type received: " << event.name();
+    NOTREACHED();
     return ui::EVENT_REWRITE_CONTINUE;
   }
 
   // Rewrite as a mouse-move event.
   *rewritten_event = CreateMouseMoveEvent(event.location(), event.flags());
   last_touch_exploration_.reset(new TouchEvent(event));
   return ui::EVENT_REWRITE_REWRITTEN;
 }
 
 ui::EventRewriteStatus TouchExplorationController::InGestureInProgress(
     const ui::TouchEvent& event,
     scoped_ptr<ui::Event>* rewritten_event) {
-  ui::EventType type = event.type();
-  // If additional fingers are added before a swipe gesture has been
-  // registered, then the state will no longer be GESTURE_IN_PROGRESS.
-  if (type == ui::ET_TOUCH_PRESSED ||
-      event.touch_id() != initial_press_->touch_id()) {
-    if (tap_timer_.IsRunning())
-      tap_timer_.Stop();
-    // Discard any pending gestures.
-    delete gesture_provider_.GetAndResetPendingGestures();
-    state_ = WAIT_FOR_ONE_FINGER;
-    return EVENT_REWRITE_DISCARD;
+  // The events were sent to the gesture provider in RewriteEvent already.
+  // If no gesture is registered before the tap timer times out, the state
+  // will change to wait for no fingers down and this function will stop

[mfomitchev, 2014/08/07 18:34:59]

"the state will change to wait for no fingers down" - could change to
exploration mode as well if only one finger is down, right?

[evy, 2014/08/07 20:40:26]

yup - thanks for catching that

+  // being called.
+  if (current_touch_ids_.size() == 0) {
+    ResetToNoFingersDown();
   }
-
-  // There should not be more than one finger down.
-  DCHECK(current_touch_ids_.size() <= 1);
-  if (type == ui::ET_TOUCH_MOVED) {
-    gesture_provider_.OnTouchEvent(event);
-    gesture_provider_.OnTouchEventAck(false);
-  }
-  if (type == ui::ET_TOUCH_RELEASED || type == ui::ET_TOUCH_CANCELLED) {
-    gesture_provider_.OnTouchEvent(event);
-    gesture_provider_.OnTouchEventAck(false);
-    if (current_touch_ids_.size() == 0) {
-      ResetToNoFingersDown();
-    }
-  }
-  ProcessGestureEvents();
   return ui::EVENT_REWRITE_DISCARD;
 }
 
 ui::EventRewriteStatus TouchExplorationController::InOneFingerPassthrough(
     const ui::TouchEvent& event,
     scoped_ptr<ui::Event>* rewritten_event) {
-  ui::EventType type = event.type();
-
-  if (!(type == ui::ET_TOUCH_RELEASED || type == ui::ET_TOUCH_CANCELLED ||
-        type == ui::ET_TOUCH_MOVED || type == ui::ET_TOUCH_PRESSED)) {
-    NOTREACHED() << "Unexpected event type received: " << event.name();
-    return ui::EVENT_REWRITE_CONTINUE;
-  }
   if (event.touch_id() != initial_press_->touch_id()) {
     if (current_touch_ids_.size() == 0) {
       ResetToNoFingersDown();
     }
     return ui::EVENT_REWRITE_DISCARD;
   }
   rewritten_event->reset(
       new ui::TouchEvent(event.type(),
                          event.location() - passthrough_offset_,
                          event.touch_id(),
                          event.time_stamp()));
 
   (*rewritten_event)->set_flags(event.flags());
   if (current_touch_ids_.size() == 0) {
     ResetToNoFingersDown();
   }
-
   return ui::EVENT_REWRITE_REWRITTEN;
 }
 
 ui::EventRewriteStatus TouchExplorationController::InTouchExploreSecondPress(
     const ui::TouchEvent& event,
     scoped_ptr<ui::Event>* rewritten_event) {
   ui::EventType type = event.type();
   gfx::PointF location = event.location_f();
   if (type == ui::ET_TOUCH_PRESSED) {
     return ui::EVENT_REWRITE_DISCARD;
@@ skipping 21 matching lines @@
         new ui::TouchEvent(ui::ET_TOUCH_RELEASED,
                            last_touch_exploration_->location(),
                            initial_press_->touch_id(),
                            event.time_stamp()));
     (*rewritten_event)->set_flags(event.flags());
     state_ = TOUCH_EXPLORATION;
     EnterTouchToMouseMode();
     VLOG_STATE();
     return ui::EVENT_REWRITE_REWRITTEN;
   }
-  NOTREACHED() << "Unexpected event type received: " << event.name();
+  NOTREACHED();
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
-ui::EventRewriteStatus TouchExplorationController::InWaitForOneFinger(
+ui::EventRewriteStatus TouchExplorationController::InWaitForNoFingers(
     const ui::TouchEvent& event,
     scoped_ptr<ui::Event>* rewritten_event) {
-  ui::EventType type = event.type();
-  if (!(type == ui::ET_TOUCH_PRESSED || type == ui::ET_TOUCH_MOVED ||
-        type == ui::ET_TOUCH_RELEASED || type == ui::ET_TOUCH_CANCELLED)) {
-    NOTREACHED() << "Unexpected event type received: " << event.name();
-    return ui::EVENT_REWRITE_CONTINUE;
-  }
-  if (current_touch_ids_.size() == 1) {
-    EnterTouchToMouseMode();
-    state_ = TOUCH_EXPLORATION;
-    VLOG_STATE();
-    *rewritten_event = CreateMouseMoveEvent(event.location(), event.flags());
-    last_touch_exploration_.reset(new TouchEvent(event));
-    return ui::EVENT_REWRITE_REWRITTEN;
-  }
+  if (current_touch_ids_.size() == 0)
+    ResetToNoFingersDown();
   return EVENT_REWRITE_DISCARD;
 }
 
 void TouchExplorationController::PlaySoundForTimer() {
   delegate_->PlayVolumeAdjustSound();
 }
 
 ui::EventRewriteStatus TouchExplorationController::InSlideGesture(
     const ui::TouchEvent& event,
     scoped_ptr<ui::Event>* rewritten_event) {
   // The timer should not fire when sliding.
-  if (tap_timer_.IsRunning())
-    tap_timer_.Stop();
+  tap_timer_.Stop();
 
   ui::EventType type = event.type();
   // If additional fingers are added before a swipe gesture has been registered,
   // then wait until all fingers have been lifted.
   if (type == ui::ET_TOUCH_PRESSED ||
       event.touch_id() != initial_press_->touch_id()) {
     if (sound_timer_.IsRunning())
       sound_timer_.Stop();
-    // Discard any pending gestures.
-    delete gesture_provider_.GetAndResetPendingGestures();
-    state_ = WAIT_FOR_ONE_FINGER;
+    state_ = WAIT_FOR_NO_FINGERS;
+    VLOG_STATE();
     return EVENT_REWRITE_DISCARD;
   }
 
+  // There should not be more than one finger down.
+  DCHECK(current_touch_ids_.size() <= 1);
+
+
   // Allows user to return to the edge to adjust the sound if they have left the
   // boundaries.
   int edge = FindEdgesWithinBounds(event.location(), kSlopDistanceFromEdge);
   if (!(edge & RIGHT_EDGE) && (type != ui::ET_TOUCH_RELEASED)) {
     if (sound_timer_.IsRunning()) {
       sound_timer_.Stop();
     }
     return EVENT_REWRITE_DISCARD;
   }
 
   // This can occur if the user leaves the screen edge and then returns to it to
   // continue adjusting the sound.
   if (!sound_timer_.IsRunning()) {
     sound_timer_.Start(FROM_HERE,
                        kSoundDelay,
                        this,
                        &ui::TouchExplorationController::PlaySoundForTimer);
     delegate_->PlayVolumeAdjustSound();
   }
 
-  // There should not be more than one finger down.
-  DCHECK(current_touch_ids_.size() <= 1);
-  if (type == ui::ET_TOUCH_MOVED) {
-    gesture_provider_.OnTouchEvent(event);
-    gesture_provider_.OnTouchEventAck(false);
-  }
-  if (type == ui::ET_TOUCH_RELEASED || type == ui::ET_TOUCH_CANCELLED) {
-    gesture_provider_.OnTouchEvent(event);
-    gesture_provider_.OnTouchEventAck(false);
-    delete gesture_provider_.GetAndResetPendingGestures();
-    if (current_touch_ids_.size() == 0) {
-      ResetToNoFingersDown();
-    }
-    return ui::EVENT_REWRITE_DISCARD;
+  if (current_touch_ids_.size() == 0) {
+    ResetToNoFingersDown();
   }
 
-  ProcessGestureEvents();
   return ui::EVENT_REWRITE_DISCARD;
 }
 
 base::TimeDelta TouchExplorationController::Now() {
   if (tick_clock_) {
     // This is the same as what EventTimeForNow() does, but here we do it
     // with a clock that can be replaced with a simulated clock for tests.
     return base::TimeDelta::FromInternalValue(
         tick_clock_->NowTicks().ToInternalValue());
   }
@@ skipping 23 matching lines @@
                             last_touch_exploration_->location();
       scoped_ptr<ui::TouchEvent> passthrough_press(
           new ui::TouchEvent(ui::ET_TOUCH_PRESSED,
                              last_touch_exploration_->location(),
                              last_unused_finger_event_->touch_id(),
                              Now()));
       DispatchEvent(passthrough_press.get());
       return;
     }
     case SINGLE_TAP_PRESSED:
-    case GESTURE_IN_PROGRESS:
-      // Discard any pending gestures.
-      delete gesture_provider_.GetAndResetPendingGestures();
       EnterTouchToMouseMode();
       state_ = TOUCH_EXPLORATION;
+      break;
+    case GESTURE_IN_PROGRESS:
+      // If only one finger is down, go into touch exploration.
+      if (current_touch_ids_.size() == 1) {
+        EnterTouchToMouseMode();
+        state_ = TOUCH_EXPLORATION;
+        VLOG_STATE();
+        break;
+      }
+      // Otherwise wait for all fingers to be lifted.
+      state_ = WAIT_FOR_NO_FINGERS;
       VLOG_STATE();
-      break;
+      return;
     default:
       return;
   }
   scoped_ptr<ui::Event> mouse_move =
       CreateMouseMoveEvent(initial_press_->location(), initial_press_->flags());
   DispatchEvent(mouse_move.get());
   last_touch_exploration_.reset(new TouchEvent(*initial_press_));
 }
 
 void TouchExplorationController::DispatchEvent(ui::Event* event) {
   if (event_handler_for_testing_) {
     event_handler_for_testing_->OnEvent(event);
     return;
   }
   ui::EventDispatchDetails result ALLOW_UNUSED =
       root_window_->GetHost()->dispatcher()->OnEventFromSource(event);
 }
 
-void TouchExplorationController::OnGestureEvent(
-    ui::GestureEvent* gesture) {
-  CHECK(gesture->IsGestureEvent());
-  ui::EventType type = gesture->type();
-  if (VLOG_on_)
-    VLOG(0) << " \n Gesture Triggered: " << gesture->name();
-  if (type == ui::ET_GESTURE_SWIPE && state_ != SLIDE_GESTURE) {
-    if (VLOG_on_)
-      VLOG(0) << "Swipe!";
-    delete gesture_provider_.GetAndResetPendingGestures();
-    OnSwipeEvent(gesture);
-    return;
-  }
+// This is an override. We're using other more specific functions for possible

[mfomitchev, 2014/08/07 18:34:58]

Would be good to clarify that this is only called for timer-based events like
long press. Events that are created synchronously as a result of certain touch
events are added to the vector accessible via GetAndResetPendingGestures(). We
only care about swipes (which are created synchronously), so we ignore this
callback.

[evy, 2014/08/07 20:40:26]

Done.

+// processed gesture events.
+void TouchExplorationController::OnGestureEvent(ui::GestureEvent* gesture) {
 }
 
 void TouchExplorationController::ProcessGestureEvents() {
   scoped_ptr<ScopedVector<ui::GestureEvent> > gestures(
-      gesture_provider_.GetAndResetPendingGestures());
+      gesture_provider_->GetAndResetPendingGestures());
   if (gestures) {
     for (ScopedVector<GestureEvent>::iterator i = gestures->begin();
          i != gestures->end();
          ++i) {
-      if (state_ == SLIDE_GESTURE)
+      if ((*i)->type() == ui::ET_GESTURE_SWIPE &&
+          state_ == GESTURE_IN_PROGRESS) {
+        OnSwipeEvent(*i);
+        // The tap timer to leave gesture state is ended, and we now wait for
+        // all fingers to be released.
+        tap_timer_.Stop();
+        state_ = WAIT_FOR_NO_FINGERS;
+        VLOG_STATE();
+        return;
+      }
+      if (state_ == SLIDE_GESTURE && (*i)->IsScrollGestureEvent()) {
         SideSlideControl(*i);
-      else
-        OnGestureEvent(*i);
+        return;

[mfomitchev, 2014/08/07 18:34:58]

Are you sure we want to ignore all the subsequent gestures (if any) in this
case? I'd think we'd want to process all scrolls?

[evy, 2014/08/07 20:40:26]

yeah, we would - thanks

+      }
     }
   }
 }
 
 void TouchExplorationController::SideSlideControl(ui::GestureEvent* gesture) {
   ui::EventType type = gesture->type();
-  if (!gesture->IsScrollGestureEvent())
-    return;
+  CHECK(gesture->IsGestureEvent());

[mfomitchev, 2014/08/07 18:34:58]

I don't think this can ever fail since gesture is an instance of GestureEvent?

[evy, 2014/08/07 20:40:26]

Done.

+  CHECK(gesture->IsScrollGestureEvent());

[mfomitchev, 2014/08/07 18:34:58]

If you do this, I don't think you need the above? Also, why not DCHECK instead
of CHECK? CHECKs waste CPU time in prod.

[evy, 2014/08/07 20:40:26]

Done.

 
   if (type == ET_GESTURE_SCROLL_BEGIN) {
     delegate_->PlayVolumeAdjustSound();
   }
 
   if (type == ET_GESTURE_SCROLL_END) {
     if (sound_timer_.IsRunning())
       sound_timer_.Stop();
     delegate_->PlayVolumeAdjustSound();
   }
@@ skipping 24 matching lines @@
   float ratio = (location.y() - kMaxDistanceFromEdge) / volume_adjust_height;
   float volume = 100 - 100 * ratio;
   if (VLOG_on_) {
     VLOG(0) << "\n Volume = " << volume
             << "\n Location = " << location.ToString()
             << "\n Bounds = " << root_window_->bounds().right();
   }
   delegate_->SetOutputLevel(int(volume));
 }
 
-
 void TouchExplorationController::OnSwipeEvent(ui::GestureEvent* swipe_gesture) {
   // A swipe gesture contains details for the direction in which the swipe
-  // occurred.
+  // occurred. TODO(evy) : Research which swipe results users most want and
+  // remap these swipes to the best events. Hopefully in the near future
+  // there will also be a menu for users to pick custom mappings.
+  CHECK(swipe_gesture->IsGestureEvent());

[mfomitchev, 2014/08/07 18:34:58]

I don't think this can ever fail since gesture is an instance of GestureEvent?

[evy, 2014/08/07 20:40:26]

Yeah there are a few of these checks around - I'll remove them

   GestureEventDetails event_details = swipe_gesture->details();
-  if (event_details.swipe_left()) {
-    DispatchShiftSearchKeyEvent(ui::VKEY_LEFT);
+  int num_fingers = event_details.touch_points();
+  if(VLOG_on_)
+    VLOG(0) << "\nSwipe with " << num_fingers << " fingers.";
+
+  if (num_fingers > 4)
     return;
-  } else if (event_details.swipe_right()) {
-    DispatchShiftSearchKeyEvent(ui::VKEY_RIGHT);
-    return;
-  } else if (event_details.swipe_up()) {
-    DispatchShiftSearchKeyEvent(ui::VKEY_UP);
-    return;
-  } else if (event_details.swipe_down()) {
-    DispatchShiftSearchKeyEvent(ui::VKEY_DOWN);
-    return;
-  }
+
+  if (event_details.swipe_left())
+    left_swipe_gestures_[num_fingers].Run();
+  else if (event_details.swipe_right())
+    right_swipe_gestures_[num_fingers].Run();
+  else if (event_details.swipe_up())
+    up_swipe_gestures_[num_fingers].Run();
+  else if (event_details.swipe_down())
+    down_swipe_gestures_[num_fingers].Run();
 }
 
 int TouchExplorationController::FindEdgesWithinBounds(gfx::Point point,
                                                       float bounds) {
   // Since GetBoundsInScreen is in DIPs but point is not, then point needs to be
   // converted.
   root_window_->GetHost()->ConvertPointFromNativeScreen(&point);
   gfx::Rect window = root_window_->GetBoundsInScreen();
 
   float left_edge_limit = window.x() + bounds;
@@ skipping 11 matching lines @@
   if (point.x() > right_edge_limit)
     result |= RIGHT_EDGE;
   if (point.y() < top_edge_limit)
     result |= TOP_EDGE;
   if (point.y() > bottom_edge_limit)
     result |= BOTTOM_EDGE;
   return result;
 }
 
 void TouchExplorationController::DispatchShiftSearchKeyEvent(
-    const ui::KeyboardCode direction) {
-  // In order to activate the shortcut shift+search+<arrow key>
+    const ui::KeyboardCode third_key) {
+  // In order to activate the shortcut shift+search+<key>
   // three KeyPressed events must be dispatched in succession along
   // with three KeyReleased events.
-  ui::KeyEvent shift_down = ui::KeyEvent(
+
+  ui::KeyEvent shift_down(
       ui::ET_KEY_PRESSED, ui::VKEY_SHIFT, ui::EF_SHIFT_DOWN);
-  ui::KeyEvent search_down = ui::KeyEvent(
+  ui::KeyEvent search_down(
       ui::ET_KEY_PRESSED, kChromeOSSearchKey, ui::EF_SHIFT_DOWN);
-  ui::KeyEvent direction_down =
-      ui::KeyEvent(ui::ET_KEY_PRESSED, direction, ui::EF_SHIFT_DOWN);
+  ui::KeyEvent third_key_down(ui::ET_KEY_PRESSED, third_key, ui::EF_SHIFT_DOWN);
 
-  ui::KeyEvent direction_up =
-      ui::KeyEvent(ui::ET_KEY_RELEASED, direction, ui::EF_SHIFT_DOWN);
-  ui::KeyEvent search_up = ui::KeyEvent(
+  ui::KeyEvent third_key_up(ui::ET_KEY_RELEASED, third_key, ui::EF_SHIFT_DOWN);
+  ui::KeyEvent search_up(
       ui::ET_KEY_RELEASED, kChromeOSSearchKey, ui::EF_SHIFT_DOWN);
-  ui::KeyEvent shift_up =
-      ui::KeyEvent(ui::ET_KEY_RELEASED, ui::VKEY_SHIFT, ui::EF_NONE);
+  ui ::KeyEvent shift_up(ui::ET_KEY_RELEASED, ui::VKEY_SHIFT, ui::EF_NONE);
 
   DispatchEvent(&shift_down);
   DispatchEvent(&search_down);
-  DispatchEvent(&direction_down);
-  DispatchEvent(&direction_up);
+  DispatchEvent(&third_key_down);
+  DispatchEvent(&third_key_up);
   DispatchEvent(&search_up);
   DispatchEvent(&shift_up);
 }
 
+void TouchExplorationController::DispatchKeyWithFlags(
+    const ui::KeyboardCode key,
+    int flags) {
+  ui::KeyEvent key_down(ui::ET_KEY_PRESSED, key, flags);
+  ui::KeyEvent key_up(ui::ET_KEY_RELEASED, key, flags);
+  DispatchEvent(&key_down);
+  DispatchEvent(&key_up);
+  if(VLOG_on_) {
+    VLOG(0) << "\nKey down: key code : " << key_down.key_code()
+            << ", flags: " << key_down.flags()
+            << "\nKey up: key code : " << key_up.key_code()
+            << ", flags: " << key_up.flags();
+  }
+}
+
 scoped_ptr<ui::Event> TouchExplorationController::CreateMouseMoveEvent(
     const gfx::PointF& location,
     int flags) {
   // The "synthesized" flag should be set on all events that don't have a
   // backing native event.
   flags |= ui::EF_IS_SYNTHESIZED;
 
   // This flag is used to identify mouse move events that were generated from
   // touch exploration in Chrome code.
   flags |= ui::EF_TOUCH_ACCESSIBILITY;
@@ skipping 16 matching lines @@
 void TouchExplorationController::EnterTouchToMouseMode() {
   aura::client::CursorClient* cursor_client =
       aura::client::GetCursorClient(root_window_);
   if (cursor_client && !cursor_client->IsMouseEventsEnabled())
     cursor_client->EnableMouseEvents();
   if (cursor_client && cursor_client->IsCursorVisible())
     cursor_client->HideCursor();
 }
 
 void TouchExplorationController::ResetToNoFingersDown() {
-  ProcessGestureEvents();
+  gesture_provider_.reset(new GestureProviderAura(this));
   if (sound_timer_.IsRunning())
     sound_timer_.Stop();
   state_ = NO_FINGERS_DOWN;
   VLOG_STATE();
-  if (tap_timer_.IsRunning())
-    tap_timer_.Stop();
+  tap_timer_.Stop();
 }
 
 void TouchExplorationController::VlogState(const char* function_name) {
   if (!VLOG_on_)
     return;
   if (prev_state_ == state_)
     return;
   prev_state_ = state_;
   const char* state_string = EnumStateToString(state_);
   VLOG(0) << "\n Function name: " << function_name
@@ skipping 12 matching lines @@
     return;
   }
   // The above statement prevents events of the same type and id from being
   // printed in a row. However, if two fingers are down, they would both be
   // moving and alternating printing move events unless we check for this.
   if (prev_event_ != NULL &&
       prev_event_->type() == ET_TOUCH_MOVED &&
       touch_event.type() == ET_TOUCH_MOVED){
     return;
   }
+
   const std::string& type = touch_event.name();
   const gfx::PointF& location = touch_event.location_f();
   const int touch_id = touch_event.touch_id();
 
   VLOG(0) << "\n Function name: " << function_name
           << "\n Event Type: " << type
           << "\n Location: " << location.ToString()
           << "\n Touch ID: " << touch_id;
   prev_event_.reset(new TouchEvent(touch_event));
 }
@@ skipping 11 matching lines @@
     case DOUBLE_TAP_PENDING:
       return "DOUBLE_TAP_PENDING";
     case TOUCH_RELEASE_PENDING:
       return "TOUCH_RELEASE_PENDING";
     case TOUCH_EXPLORATION:
       return "TOUCH_EXPLORATION";
     case GESTURE_IN_PROGRESS:
       return "GESTURE_IN_PROGRESS";
     case TOUCH_EXPLORE_SECOND_PRESS:
       return "TOUCH_EXPLORE_SECOND_PRESS";
+    case ONE_FINGER_PASSTHROUGH:
+      return "ONE_FINGER_PASSTHROUGH";
+    case WAIT_FOR_NO_FINGERS:
+      return "WAIT_FOR_NO_FINGERS";
     case SLIDE_GESTURE:
       return "SLIDE_GESTURE";
-    case ONE_FINGER_PASSTHROUGH:
-      return "ONE_FINGER_PASSTHROUGH";
-    case WAIT_FOR_ONE_FINGER:
-      return "WAIT_FOR_ONE_FINGER";
   }
   return "Not a state";
 }
 
+void TouchExplorationController::InitializeSwipeGestureMaps() {
+  // Gestures with one finger are used for navigation.
+  left_swipe_gestures_[1] =
+      base::Bind(&TouchExplorationController::DispatchShiftSearchKeyEvent,
+                 base::Unretained(this),
+                 ui::VKEY_LEFT);
+  right_swipe_gestures_[1] =
+      base::Bind(&TouchExplorationController::DispatchShiftSearchKeyEvent,
+                 base::Unretained(this),
+                 ui::VKEY_RIGHT);
+  up_swipe_gestures_[1] =
+      base::Bind(&TouchExplorationController::DispatchShiftSearchKeyEvent,
+                 base::Unretained(this),
+                 ui::VKEY_UP);
+  down_swipe_gestures_[1] =
+      base::Bind(&TouchExplorationController::DispatchShiftSearchKeyEvent,
+                 base::Unretained(this),
+                 ui::VKEY_DOWN);
+
+  // Gestures with two fingers.
+  left_swipe_gestures_[2] =
+      base::Bind(&TouchExplorationController::DispatchKeyWithFlags,
+                 base::Unretained(this),
+                 ui::VKEY_BROWSER_BACK,
+                 ui::EF_NONE);
+  right_swipe_gestures_[2] =
+      base::Bind(&TouchExplorationController::DispatchKeyWithFlags,
+                 base::Unretained(this),
+                 ui::VKEY_BROWSER_FORWARD,
+                 ui::EF_NONE);
+  // Jump to top.
+  up_swipe_gestures_[2] =
+      base::Bind(&TouchExplorationController::DispatchShiftSearchKeyEvent,
+                 base::Unretained(this),
+                 ui::VKEY_A);
+  // Read from here.
+  down_swipe_gestures_[2] =
+      base::Bind(&TouchExplorationController::DispatchShiftSearchKeyEvent,
+                 base::Unretained(this),
+                 ui::VKEY_R);
+
+  // Gestures with three fingers switch tabs left/right and scroll up/down.
+  left_swipe_gestures_[3] =
+      base::Bind(&TouchExplorationController::DispatchKeyWithFlags,
+                 base::Unretained(this),
+                 ui::VKEY_TAB,
+                 ui::EF_CONTROL_DOWN | ui::EF_SHIFT_DOWN);
+  right_swipe_gestures_[3] =
+      base::Bind(&TouchExplorationController::DispatchKeyWithFlags,
+                 base::Unretained(this),
+                 ui::VKEY_TAB,
+                 ui::EF_CONTROL_DOWN);
+  up_swipe_gestures_[3] =
+      base::Bind(&TouchExplorationController::DispatchKeyWithFlags,
+                 base::Unretained(this),
+                 ui::VKEY_NEXT,
+                 ui::EF_NONE);
+  down_swipe_gestures_[3] =
+      base::Bind(&TouchExplorationController::DispatchKeyWithFlags,
+                 base::Unretained(this),
+                 ui::VKEY_PRIOR,
+                 ui::EF_NONE);
+
+  // Gestures with four fingers should probably eventually be used for rare
+  // needs that are hard to access through menus.
+  // Note that brightness levels are here because they can be important for low
+  // vision users. However, none of these mappings are permanent.
+  left_swipe_gestures_[4] =
+      base::Bind(&TouchExplorationController::DispatchKeyWithFlags,
+                 base::Unretained(this),
+                 ui::VKEY_BRIGHTNESS_DOWN,
+                 ui::EF_NONE);
+  right_swipe_gestures_[4] =
+      base::Bind(&TouchExplorationController::DispatchKeyWithFlags,
+                 base::Unretained(this),
+                 VKEY_BRIGHTNESS_UP,
+                 ui::EF_NONE);
+  up_swipe_gestures_[4] =
+      base::Bind(&TouchExplorationController::DispatchKeyWithFlags,
+                 base::Unretained(this),
+                 VKEY_BROWSER_HOME,
+                 ui::EF_NONE);
+  down_swipe_gestures_[4] =
+      base::Bind(&TouchExplorationController::DispatchKeyWithFlags,
+                 base::Unretained(this),
+                 VKEY_BROWSER_REFRESH,
+                 ui::EF_NONE);
+
+}
+
 }  // namespace ui