Added split tap to TouchExplorationController

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 f88aa3a79d730985ddbfb44b7679b1686befb88a..4e860b151261866ccc085cafc131b16f7818f604 100644
--- a/ui/chromeos/touch_exploration_controller.cc
+++ b/ui/chromeos/touch_exploration_controller.cc
@@ -129,6 +129,8 @@ ui::EventRewriteStatus TouchExplorationController::RewriteEvent(
       return InTouchExploration(touch_event, rewritten_event);
     case PASSTHROUGH_MINUS_ONE:
       return InPassthroughMinusOne(touch_event, rewritten_event);
+    case TOUCH_EXPL_SECOND_PRESS:
+      return InTouchExplSecondPress(touch_event, rewritten_event);
   }
 
   NOTREACHED();
@@ -197,18 +199,28 @@ ui::EventRewriteStatus TouchExplorationController::InSingleTapReleased(
   if (type == ui::ET_TOUCH_PRESSED) {
     // This is the second tap in a double-tap (or double tap-hold).
     // Rewrite at location of last touch exploration.
-    ui::TouchEvent* rewritten_press_event = new ui::TouchEvent(
-        ui::ET_TOUCH_PRESSED,
-        last_touch_exploration_location_,
-        event.touch_id(),
-        event.time_stamp());
+    // If there is no touch exploration yet, discard instead.
+    if (!last_touch_exploration_) {
+      return ui::EVENT_REWRITE_DISCARD;
+    }
+    ui::TouchEvent* rewritten_press_event =
+        new ui::TouchEvent(ui::ET_TOUCH_PRESSED,
+                           last_touch_exploration_->location(),
+                           event.touch_id(),
+                           event.time_stamp());
     rewritten_press_event->set_flags(event.flags());
     rewritten_event->reset(rewritten_press_event);
     state_ = DOUBLE_TAP_PRESSED;
     VLOG_STATE();
     return ui::EVENT_REWRITE_REWRITTEN;
   }
-
+  // If the previous press was discarded, we need to also handle its release.
+  if (type == ui::ET_TOUCH_RELEASED && !last_touch_exploration_){

[James Cook, 2014/06/17 17:06:17]

nit: space between ) and {

(I'm surprised git cl format didn't catch that. Maybe we don't have git cl
format as part of presubmit here.)

[evy, 2014/06/17 18:36:22]

Done.

+    if (current_touch_ids_.size() == 0) {
+      state_ = NO_FINGERS_DOWN;
+    }
+    return ui::EVENT_REWRITE_DISCARD;
+  }
   NOTREACHED();
   return ui::EVENT_REWRITE_CONTINUE;
 }
@@ -225,7 +237,7 @@ ui::EventRewriteStatus TouchExplorationController::InDoubleTapPressed(
     // Rewrite at location of last touch exploration.
     ui::TouchEvent* rewritten_release_event = new ui::TouchEvent(
         ui::ET_TOUCH_RELEASED,
-        last_touch_exploration_location_,
+        last_touch_exploration_->location(),
         event.touch_id(),
         event.time_stamp());
     rewritten_release_event->set_flags(event.flags());
@@ -243,10 +255,20 @@ 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) {
-
-    // Ignore any additional fingers when we're already in touch exploration
-    // mode. TODO(evy, lisayin): Support "split-tap" here instead.
-    return ui::EVENT_REWRITE_DISCARD;
+    // Handle split-tap.
+    initial_press_.reset(new TouchEvent(event));
+    if (tap_timer_.IsRunning())
+      tap_timer_.Stop();
+    ui::TouchEvent* rewritten_touch_event =
+        new ui::TouchEvent(ui::ET_TOUCH_PRESSED,
+                           last_touch_exploration_->location(),
+                           event.touch_id(),
+                           event.time_stamp());
+    rewritten_touch_event->set_flags(event.flags());
+    rewritten_event->reset(rewritten_touch_event);
+    state_ = TOUCH_EXPL_SECOND_PRESS;
+    VLOG_STATE();
+    return ui::EVENT_REWRITE_REWRITTEN;
   } else if (type == ui::ET_TOUCH_RELEASED || type == ui::ET_TOUCH_CANCELLED) {
     if (current_touch_ids_.size() == 0)
       ResetToNoFingersDown();
@@ -257,7 +279,7 @@ ui::EventRewriteStatus TouchExplorationController::InTouchExploration(
 
   // Rewrite as a mouse-move event.
   *rewritten_event = CreateMouseMoveEvent(event.location(), event.flags());
-  last_touch_exploration_location_ = event.location();
+  last_touch_exploration_.reset(new TouchEvent(event));
   return ui::EVENT_REWRITE_REWRITTEN;
 }
 
@@ -308,6 +330,48 @@ ui::EventRewriteStatus TouchExplorationController::InPassthroughMinusOne(
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
+ui::EventRewriteStatus TouchExplorationController::InTouchExplSecondPress(
+    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;
+  } else if (type == ui::ET_TOUCH_MOVED) {
+    // Currently this is a discard, but could be something like rotor

[James Cook, 2014/06/17 17:06:17]

rotor?

[evy, 2014/06/17 18:36:22]

On an iPad, rotating two fingers (like they are opposite ends of a circle) lets
the user select from a menu. A gesture like this is an option for something we
could support later - but I agree it's a bit vague here. Would it be best to
take out this comment until we decide to put something here?

+    // in the future.
+    return ui::EVENT_REWRITE_DISCARD;
+  } else if (type == ui::ET_TOUCH_RELEASED || type == ui::ET_TOUCH_CANCELLED) {
+    // If the touch exploration finger is lifted, there is no option to return
+    // 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_ = DOUBLE_TAP_PRESSED;
+      VLOG_STATE();
+      return EVENT_REWRITE_DISCARD;
+    }
+
+    // Continue to release the touch only if the touch explore finger is the
+    // only finger remaining.
+    if (current_touch_ids_.size() != 1)
+      return EVENT_REWRITE_DISCARD;
+
+    // Rewrite at location of last touch exploration.
+    ui::TouchEvent* rewritten_release_event = new ui::TouchEvent(

[James Cook, 2014/06/17 17:06:17]

Can you do it like this?

rewritten_event->reset(new ui::TouchEvent(...));
rewritten_event->set_flags(event.flags);

That makes it very clear who owns the new ui::TouchEvent from the beginning.

[evy, 2014/06/17 18:36:22]

Done. I also changed it the other few times this pattern shows up in this file.

+        ui::ET_TOUCH_RELEASED,
+        last_touch_exploration_->location(),
+        initial_press_->touch_id(),
+        event.time_stamp());
+    rewritten_release_event->set_flags(event.flags());
+    rewritten_event->reset(rewritten_release_event);
+    state_ = TOUCH_EXPLORATION;
+    VLOG_STATE();
+    return ui::EVENT_REWRITE_REWRITTEN;
+  }
+  NOTREACHED() << "Unexpected event type received.";
+  return ui::EVENT_REWRITE_CONTINUE;
+}
+
 void TouchExplorationController::OnTapTimerFired() {
   if (state_ != SINGLE_TAP_RELEASED && state_ != SINGLE_TAP_PRESSED)
     return;
@@ -323,7 +387,7 @@ void TouchExplorationController::OnTapTimerFired() {
   scoped_ptr<ui::Event> mouse_move = CreateMouseMoveEvent(
       initial_press_->location(), initial_press_->flags());
   DispatchEvent(mouse_move.get());
-  last_touch_exploration_location_ = initial_press_->location();
+  last_touch_exploration_.reset(new TouchEvent(*initial_press_));
 }
 
 void TouchExplorationController::DispatchEvent(ui::Event* event) {
@@ -405,6 +469,8 @@ const char* TouchExplorationController::EnumStateToString(State state) {
       return "TOUCH_EXPLORATION";
     case PASSTHROUGH_MINUS_ONE:
       return "PASSTHROUGH_MINUS_ONE";
+    case TOUCH_EXPL_SECOND_PRESS:
+      return "TOUCH_EXPL_SECOND_PRESS";
   }
   return "Not a state";
 }