Added multi-finger gestures to touch_exploration_controller

ui/chromeos/touch_exploration_controller.cc

Index: ui/chromeos/touch_exploration_controller.cc
diff --git a/ui/chromeos/touch_exploration_controller.cc b/ui/chromeos/touch_exploration_controller.cc
index 71cf325b1fab8c5005d426e274ca6959e90e7eb9..96b4e436dee2cd93392d974e5773669c7b469307 100644
--- a/ui/chromeos/touch_exploration_controller.cc
+++ b/ui/chromeos/touch_exploration_controller.cc
@@ -6,6 +6,7 @@
 
 #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"
@@ -15,7 +16,7 @@
 #include "ui/events/event_utils.h"
 #include "ui/gfx/geometry/rect.h"
 
-#define VLOG_STATE() if (VLOG_IS_ON(0)) VlogState(__func__)
+#define SET_STATE(state) SetState(state, __func__)
 #define VLOG_EVENT(event) if (VLOG_IS_ON(0)) VlogEvent(event, __func__)
 
 namespace ui {
@@ -35,12 +36,13 @@ TouchExplorationController::TouchExplorationController(
     : root_window_(root_window),
       delegate_(delegate),
       state_(NO_FINGERS_DOWN),
-      gesture_provider_(this),
+      gesture_provider_(new GestureProviderAura(this)),
       prev_state_(NO_FINGERS_DOWN),
       VLOG_on_(true),
       tick_clock_(NULL) {
   CHECK(root_window);
   root_window->GetHost()->GetEventSource()->AddEventRewriter(this);
+  InitializeSwipeGestureMaps();
 }
 
 TouchExplorationController::~TouchExplorationController() {
@@ -51,6 +53,13 @@ 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);
@@ -78,16 +87,6 @@ ui::EventRewriteStatus TouchExplorationController::RewriteEvent(
     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.
-    TouchEvent touch_event = static_cast<const TouchEvent&>(event);
-    if (FindEdgesWithinBounds(touch_event.location(), kLeavingScreenEdge) !=
-        NO_EDGE) {
-      if (current_touch_ids_.size() == 0) {
-        ResetToNoFingersDown();
-      }
-    }
-
     std::vector<int>::iterator it = std::find(
         current_touch_ids_.begin(), current_touch_ids_.end(), touch_id);
 
@@ -106,11 +105,40 @@ ui::EventRewriteStatus TouchExplorationController::RewriteEvent(
       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);
+
+  // In order to avoid accidentally double tapping when moving off the edge
+  // of the screen, the state will be rewritten to NoFingersDown.
+  if ((type == ui::ET_TOUCH_RELEASED || type == ui::ET_TOUCH_CANCELLED) &&
+      FindEdgesWithinBounds(touch_event.location(), kLeavingScreenEdge) !=
+          NO_EDGE) {
+    if (current_touch_ids_.size() == 0) {
+      SET_STATE(NO_FINGERS_DOWN);
+      if (VLOG_on_) {
+        VLOG(0) << "Reset to no fingers in Rewrite event because the touch  "
+                   "release or cancel was on the edge of the screen.";
+      }
+      return ui::EVENT_REWRITE_DISCARD;
+    }
+  }
+
+  // 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. When the user
+  // leaves one of these states, SET_STATE will set the gesture provider to
+  // NULL.
+  if (gesture_provider_.get()) {
+    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:
@@ -132,8 +160,8 @@ ui::EventRewriteStatus TouchExplorationController::RewriteEvent(
       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);
+    case WAIT_FOR_NO_FINGERS:
+      return InWaitForNoFingers(touch_event, rewritten_event);
     case TWO_FINGER_TAP:
       return InTwoFingerTap(touch_event, rewritten_event);
   }
@@ -149,21 +177,17 @@ ui::EventRewriteStatus TouchExplorationController::NextDispatchEvent(
 
 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) {
-    NOTREACHED() << "Unexpected event type received: " << event.name();
-    return ui::EVENT_REWRITE_CONTINUE;
+  ui::EventType type = event.type();
+  if (type == ui::ET_TOUCH_PRESSED) {
+    initial_press_.reset(new TouchEvent(event));
+    initial_presses_[event.touch_id()] = event.location();
+    last_unused_finger_event_.reset(new TouchEvent(event));
+    StartTapTimer();
+    SET_STATE(SINGLE_TAP_PRESSED);
+    return ui::EVENT_REWRITE_DISCARD;
   }
-  initial_press_.reset(new TouchEvent(event));
-  initial_presses_[event.touch_id()] = event.location();
-  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(
@@ -172,16 +196,14 @@ ui::EventRewriteStatus TouchExplorationController::InSingleTapPressed(
 
   if (type == ui::ET_TOUCH_PRESSED) {
     initial_presses_[event.touch_id()] = event.location();
-    state_ = TWO_FINGER_TAP;
-    VLOG_STATE();
+    SET_STATE(TWO_FINGER_TAP);
     return EVENT_REWRITE_DISCARD;
   } 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();
+      SET_STATE(SINGLE_TAP_RELEASED);
     } else if (current_touch_ids_.size() == 0) {
-      ResetToNoFingersDown();
+      SET_STATE(NO_FINGERS_DOWN);
     }
     return EVENT_REWRITE_DISCARD;
   } else if (type == ui::ET_TOUCH_MOVED) {
@@ -204,24 +226,21 @@ ui::EventRewriteStatus TouchExplorationController::InSingleTapPressed(
     // Change to slide gesture if the slide occurred at the right edge.
     int edge = FindEdgesWithinBounds(event.location(), kMaxDistanceFromEdge);
     if (edge & RIGHT_EDGE) {
-      state_ = SLIDE_GESTURE;
-      VLOG_STATE();
+      SET_STATE(SLIDE_GESTURE);
       return InSlideGesture(event, rewritten_event);
     }
 
     // If the user moves fast enough from the initial touch location, start
     // gesture detection. Otherwise, jump to the touch exploration mode early.
     if (velocity > gesture_detector_config_.minimum_swipe_velocity) {
-      state_ = GESTURE_IN_PROGRESS;
-      VLOG_STATE();
+      SET_STATE(GESTURE_IN_PROGRESS);
       return InGestureInProgress(event, rewritten_event);
     }
     EnterTouchToMouseMode();
-    state_ = TOUCH_EXPLORATION;
-    VLOG_STATE();
+    SET_STATE(TOUCH_EXPLORATION);
     return InTouchExploration(event, rewritten_event);
   }
-  NOTREACHED() << "Unexpected event type received: " << event.name();
+  NOTREACHED();
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
@@ -230,10 +249,10 @@ 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;
+    SET_STATE(WAIT_FOR_NO_FINGERS);
     return ui::EVENT_REWRITE_DISCARD;
   }
   if (type == ui::ET_TOUCH_PRESSED) {
@@ -246,8 +265,10 @@ TouchExplorationController::InSingleTapOrTouchExploreReleased(
     // 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();
+    SET_STATE(DOUBLE_TAP_PENDING);
+    // 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.
@@ -257,13 +278,13 @@ TouchExplorationController::InSingleTapOrTouchExploreReleased(
     // If the previous press was discarded, we need to also handle its
     // release.
     if (current_touch_ids_.size() == 0) {
-      ResetToNoFingersDown();
+      SET_STATE(NO_FINGERS_DOWN);
     }
     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;
 }
 
@@ -299,10 +320,10 @@ ui::EventRewriteStatus TouchExplorationController::InDoubleTapPending(
                            initial_press_->touch_id(),
                            event.time_stamp()));
     (*rewritten_event)->set_flags(event.flags());
-    ResetToNoFingersDown();
+    SET_STATE(NO_FINGERS_DOWN);
     return ui::EVENT_REWRITE_REWRITTEN;
   }
-  NOTREACHED() << "Unexpected event type received: " << event.name();
+  NOTREACHED();
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
@@ -322,10 +343,10 @@ ui::EventRewriteStatus TouchExplorationController::InTouchReleasePending(
                            initial_press_->touch_id(),
                            event.time_stamp()));
     (*rewritten_event)->set_flags(event.flags());
-    ResetToNoFingersDown();
+    SET_STATE(NO_FINGERS_DOWN);
     return ui::EVENT_REWRITE_REWRITTEN;
   }
-  NOTREACHED() << "Unexpected event type received: " << event.name();
+  NOTREACHED();
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
@@ -336,24 +357,21 @@ ui::EventRewriteStatus TouchExplorationController::InTouchExploration(
   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();
+    SET_STATE(TOUCH_EXPLORE_SECOND_PRESS);
     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();
+    SET_STATE(TOUCH_EXPLORE_RELEASED);
   } else if (type != ui::ET_TOUCH_MOVED) {
-    NOTREACHED() << "Unexpected event type received: " << event.name();
+    NOTREACHED();
     return ui::EVENT_REWRITE_CONTINUE;
   }
 
@@ -366,49 +384,22 @@ ui::EventRewriteStatus TouchExplorationController::InTouchExploration(
 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;
-  }
-
-  // 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();
-    }
+  // 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" or "touch exploration" depending
+  // on the number of fingers down, and this function will stop being called.
+  if (current_touch_ids_.size() == 0) {
+    SET_STATE(NO_FINGERS_DOWN);
   }
-  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();
+      SET_STATE(NO_FINGERS_DOWN);
     }
     return ui::EVENT_REWRITE_DISCARD;
   }
@@ -420,9 +411,8 @@ ui::EventRewriteStatus TouchExplorationController::InOneFingerPassthrough(
 
   (*rewritten_event)->set_flags(event.flags());
   if (current_touch_ids_.size() == 0) {
-    ResetToNoFingersDown();
+    SET_STATE(NO_FINGERS_DOWN);
   }
-
   return ui::EVENT_REWRITE_REWRITTEN;
 }
 
@@ -442,8 +432,7 @@ ui::EventRewriteStatus TouchExplorationController::InTouchExploreSecondPress(
     // to touch explore anymore. The remaining finger acts as a pending
     // tap or long tap for the last touch explore location.
     if (event.touch_id() == last_touch_exploration_->touch_id()){
-      state_ = TOUCH_RELEASE_PENDING;
-      VLOG_STATE();
+      SET_STATE(TOUCH_RELEASE_PENDING);
       return EVENT_REWRITE_DISCARD;
     }
 
@@ -459,32 +448,19 @@ ui::EventRewriteStatus TouchExplorationController::InTouchExploreSecondPress(
                            initial_press_->touch_id(),
                            event.time_stamp()));
     (*rewritten_event)->set_flags(event.flags());
-    state_ = TOUCH_EXPLORATION;
+    SET_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)
+    SET_STATE(NO_FINGERS_DOWN);
   return EVENT_REWRITE_DISCARD;
 }
 
@@ -496,8 +472,7 @@ 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,
@@ -506,12 +481,13 @@ ui::EventRewriteStatus TouchExplorationController::InSlideGesture(
       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;
+    SET_STATE(WAIT_FOR_NO_FINGERS);
     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);
@@ -532,23 +508,9 @@ ui::EventRewriteStatus TouchExplorationController::InSlideGesture(
     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) {
+    SET_STATE(NO_FINGERS_DOWN);
   }
-
-  ProcessGestureEvents();
   return ui::EVENT_REWRITE_DISCARD;
 }
 
@@ -557,9 +519,8 @@ ui::EventRewriteStatus TouchExplorationController::InTwoFingerTap(
     scoped_ptr<ui::Event>* rewritten_event) {
   ui::EventType type = event.type();
   if (type == ui::ET_TOUCH_PRESSED) {
-    // TODO(evy): Process three finger gestures here.
-    state_ = WAIT_FOR_ONE_FINGER;
-    VLOG_STATE();
+    // This is now a three finger gesture.
+    SET_STATE(GESTURE_IN_PROGRESS);
     return ui::EVENT_REWRITE_DISCARD;
   }
 
@@ -569,9 +530,8 @@ ui::EventRewriteStatus TouchExplorationController::InTwoFingerTap(
     float distance = (event.location() - original_location).Length();
     // If the user moves too far from the original position, consider the
     // movement a swipe.
-    // TODO(evy, lisayin): Add multifinger swipe processing.
     if (distance > gesture_detector_config_.touch_slop) {
-      state_ = WAIT_FOR_ONE_FINGER;
+      SET_STATE(GESTURE_IN_PROGRESS);
     }
     return ui::EVENT_REWRITE_DISCARD;
   }
@@ -587,8 +547,7 @@ ui::EventRewriteStatus TouchExplorationController::InTwoFingerTap(
 
     DispatchEvent(&control_down);
     DispatchEvent(&control_up);
-
-    ResetToNoFingersDown();
+    SET_STATE(NO_FINGERS_DOWN);
     return ui::EVENT_REWRITE_DISCARD;
   }
   return ui::EVENT_REWRITE_DISCARD;
@@ -614,15 +573,14 @@ void TouchExplorationController::StartTapTimer() {
 void TouchExplorationController::OnTapTimerFired() {
   switch (state_) {
     case SINGLE_TAP_RELEASED:
-      ResetToNoFingersDown();
+      SET_STATE(NO_FINGERS_DOWN);
       break;
     case TOUCH_EXPLORE_RELEASED:
-      ResetToNoFingersDown();
+      SET_STATE(NO_FINGERS_DOWN);
       last_touch_exploration_.reset(new TouchEvent(*initial_press_));
       return;
     case DOUBLE_TAP_PENDING: {
-      state_ = ONE_FINGER_PASSTHROUGH;
-      VLOG_STATE();
+      SET_STATE(ONE_FINGER_PASSTHROUGH);
       passthrough_offset_ = last_unused_finger_event_->location() -
                             last_touch_exploration_->location();
       scoped_ptr<ui::TouchEvent> passthrough_press(
@@ -634,15 +592,21 @@ void TouchExplorationController::OnTapTimerFired() {
       return;
     }
     case SINGLE_TAP_PRESSED:
-    case GESTURE_IN_PROGRESS:
-      // Discard any pending gestures.
-      delete gesture_provider_.GetAndResetPendingGestures();
-      state_ = TOUCH_EXPLORATION;
-      VLOG_STATE();
+      EnterTouchToMouseMode();
+      SET_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();
+        SET_STATE(TOUCH_EXPLORATION);
+        break;
+      }
+      // Otherwise wait for all fingers to be lifted.
+      SET_STATE(WAIT_FOR_NO_FINGERS);
+      return;
     case TWO_FINGER_TAP:
-      state_ = WAIT_FOR_ONE_FINGER;
-      VLOG_STATE();
+      SET_STATE(WAIT_FOR_NO_FINGERS);
       break;
     default:
       return;
@@ -659,40 +623,39 @@ void TouchExplorationController::DispatchEvent(ui::Event* event) {
       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 for a function that 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.
+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();
+        SET_STATE(WAIT_FOR_NO_FINGERS);
+        return;
+      }
+      if (state_ == SLIDE_GESTURE && (*i)->IsScrollGestureEvent()) {
         SideSlideControl(*i);
-      else
-        OnGestureEvent(*i);
+      }
     }
   }
 }
 
 void TouchExplorationController::SideSlideControl(ui::GestureEvent* gesture) {
   ui::EventType type = gesture->type();
-  if (!gesture->IsScrollGestureEvent())
-    return;
 
   if (type == ET_GESTURE_SCROLL_BEGIN) {
     delegate_->PlayVolumeAdjustSound();
@@ -737,23 +700,31 @@ void TouchExplorationController::SideSlideControl(ui::GestureEvent* gesture) {
   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.
   GestureEventDetails event_details = swipe_gesture->details();
-  if (event_details.swipe_left()) {
-    DispatchShiftSearchKeyEvent(ui::VKEY_LEFT);
-    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);
+  int num_fingers = event_details.touch_points();
+  if(VLOG_on_)
+    VLOG(0) << "\nSwipe with " << num_fingers << " fingers.";
+
+  if (num_fingers > 4)
     return;
+
+  if (event_details.swipe_left() &&
+      !left_swipe_gestures_[num_fingers].is_null()) {
+    left_swipe_gestures_[num_fingers].Run();
+  } else if (event_details.swipe_right() &&
+             !right_swipe_gestures_[num_fingers].is_null()) {
+    right_swipe_gestures_[num_fingers].Run();
+  } else if (event_details.swipe_up() &&
+             !up_swipe_gestures_[num_fingers].is_null()) {
+    up_swipe_gestures_[num_fingers].Run();
+  } else if (event_details.swipe_down() &&
+             !down_swipe_gestures_[num_fingers].is_null()) {
+    down_swipe_gestures_[num_fingers].Run();
   }
 }
 
@@ -786,32 +757,61 @@ int TouchExplorationController::FindEdgesWithinBounds(gfx::Point point,
 }
 
 void TouchExplorationController::DispatchShiftSearchKeyEvent(
-    const ui::KeyboardCode direction) {
+    const ui::KeyboardCode third_key) {
   // In order to activate the shortcut shift+search+<arrow 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);
 }
 
+base::Closure TouchExplorationController::BindShiftSearchKeyEvent(
+    const ui::KeyboardCode third_key) {
+  return base::Bind(&TouchExplorationController::DispatchShiftSearchKeyEvent,
+                    base::Unretained(this),
+                    third_key);
+}
+
+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();
+  }
+}
+
+base::Closure TouchExplorationController::BindKeyEventWithFlags(
+    const ui::KeyboardCode key,
+    int flags) {
+  return base::Bind(&TouchExplorationController::DispatchKeyWithFlags,
+                    base::Unretained(this),
+                    key,
+                    flags);
+}
+
 scoped_ptr<ui::Event> TouchExplorationController::CreateMouseMoveEvent(
     const gfx::PointF& location,
     int flags) {
@@ -847,15 +847,38 @@ void TouchExplorationController::EnterTouchToMouseMode() {
     cursor_client->HideCursor();
 }
 
-void TouchExplorationController::ResetToNoFingersDown() {
-  ProcessGestureEvents();
-  initial_presses_.clear();
-  if (sound_timer_.IsRunning())
-    sound_timer_.Stop();
-  state_ = NO_FINGERS_DOWN;
-  VLOG_STATE();
-  if (tap_timer_.IsRunning())
-    tap_timer_.Stop();
+void TouchExplorationController::SetState(State new_state,
+                                          const char* function_name) {
+  state_ = new_state;
+  VlogState(function_name);
+  // These are the states the user can be in that will never result in a
+  // gesture before the user returns to NO_FINGERS_DOWN. Therefore, if the
+  // gesture provider still exists, it's reset to NULL until the user returns
+  // to NO_FINGERS_DOWN.
+  switch (new_state) {
+    case SINGLE_TAP_RELEASED:
+    case TOUCH_EXPLORE_RELEASED:
+    case DOUBLE_TAP_PENDING:
+    case TOUCH_RELEASE_PENDING:
+    case TOUCH_EXPLORATION:
+    case TOUCH_EXPLORE_SECOND_PRESS:
+    case ONE_FINGER_PASSTHROUGH:
+    case WAIT_FOR_NO_FINGERS:
+      if (gesture_provider_.get())
+        gesture_provider_.reset(NULL);
+      break;
+    case NO_FINGERS_DOWN:
+      gesture_provider_.reset(new GestureProviderAura(this));
+      if (sound_timer_.IsRunning())
+        sound_timer_.Stop();
+      tap_timer_.Stop();
+      break;
+    case SINGLE_TAP_PRESSED:
+    case GESTURE_IN_PROGRESS:
+    case SLIDE_GESTURE:
+    case TWO_FINGER_TAP:
+      break;
+  }
 }
 
 void TouchExplorationController::VlogState(const char* function_name) {
@@ -874,7 +897,6 @@ void TouchExplorationController::VlogEvent(const ui::TouchEvent& touch_event,
   if (!VLOG_on_)
     return;
 
-  CHECK(touch_event.IsTouchEvent());
   if (prev_event_ != NULL &&
       prev_event_->type() == touch_event.type() &&
       prev_event_->touch_id() == touch_event.touch_id()){
@@ -888,6 +910,7 @@ void TouchExplorationController::VlogEvent(const ui::TouchEvent& touch_event,
       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();
@@ -923,12 +946,55 @@ const char* TouchExplorationController::EnumStateToString(State state) {
       return "SLIDE_GESTURE";
     case ONE_FINGER_PASSTHROUGH:
       return "ONE_FINGER_PASSTHROUGH";
-    case WAIT_FOR_ONE_FINGER:
-      return "WAIT_FOR_ONE_FINGER";
+    case WAIT_FOR_NO_FINGERS:
+      return "WAIT_FOR_NO_FINGERS";
     case TWO_FINGER_TAP:
       return "TWO_FINGER_TAP";
   }
   return "Not a state";
 }
 
+// TODO(evy, lisayin) : Just call abstracted methods on the delegate (e.g.
+// Swipe(Direction direction, int num_fingers)), and add the DispatchXYZ
+// methods to the delegate. Avoid the middle step of dispatching keys at all,
+// and simply have ChromeVox/ChromeOS complete the required action.
+
+void TouchExplorationController::InitializeSwipeGestureMaps() {
+  // Gestures with one finger are used for navigation.
+  left_swipe_gestures_[1] = BindShiftSearchKeyEvent(ui::VKEY_LEFT);
+  right_swipe_gestures_[1] = BindShiftSearchKeyEvent(ui::VKEY_RIGHT);
+  up_swipe_gestures_[1] = BindShiftSearchKeyEvent(ui::VKEY_UP);
+  down_swipe_gestures_[1] = BindShiftSearchKeyEvent(ui::VKEY_DOWN);
+
+  // Gestures with two fingers.
+  left_swipe_gestures_[2] =
+      BindKeyEventWithFlags(ui::VKEY_BROWSER_BACK, ui::EF_NONE);
+  right_swipe_gestures_[2] =
+      BindKeyEventWithFlags(ui::VKEY_BROWSER_FORWARD, ui::EF_NONE);
+  // Jump to top.
+  up_swipe_gestures_[2] = BindShiftSearchKeyEvent(ui::VKEY_A);
+  // Read from here.
+  down_swipe_gestures_[2] = BindShiftSearchKeyEvent(ui::VKEY_R);
+
+  // Gestures with three fingers switch tabs left/right and scroll up/down.
+  left_swipe_gestures_[3] = BindKeyEventWithFlags(
+      ui::VKEY_TAB, ui::EF_CONTROL_DOWN | ui::EF_SHIFT_DOWN);
+  right_swipe_gestures_[3] =
+      BindKeyEventWithFlags(ui::VKEY_TAB, ui::EF_CONTROL_DOWN);
+  up_swipe_gestures_[3] = BindKeyEventWithFlags(ui::VKEY_NEXT, ui::EF_NONE);
+  down_swipe_gestures_[3] = BindKeyEventWithFlags(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] =
+      BindKeyEventWithFlags(ui::VKEY_BRIGHTNESS_DOWN, ui::EF_NONE);
+  right_swipe_gestures_[4] =
+      BindKeyEventWithFlags(VKEY_BRIGHTNESS_UP, ui::EF_NONE);
+  up_swipe_gestures_[4] = BindKeyEventWithFlags(VKEY_BROWSER_HOME, ui::EF_NONE);
+  down_swipe_gestures_[4] =
+      BindKeyEventWithFlags(VKEY_BROWSER_REFRESH, ui::EF_NONE);
+}
+
 }  // namespace ui