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 7028d787d95b0039a719776191f3fc23311d36c1..2f9af8811e7dc0f345bfa2b7c559dbd6cd7da815 100644
--- a/ui/chromeos/touch_exploration_controller.cc
+++ b/ui/chromeos/touch_exploration_controller.cc
@@ -130,6 +130,8 @@ ui::EventRewriteStatus TouchExplorationController::RewriteEvent(
       return InTouchExploration(touch_event, rewritten_event);
     case PASSTHROUGH_MINUS_ONE:
       return InPassthroughMinusOne(touch_event, rewritten_event);
+    case TE_SECOND_PRESS:
+      return InTESecondPress(touch_event, rewritten_event);
   }
 
   NOTREACHED();
@@ -244,10 +246,20 @@ 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;
+    // Split-tap
+    initial_press_.reset(new TouchEvent(event));
+    if (tap_timer_.IsRunning())
+      tap_timer_.Stop();
+    ui::TouchEvent* rewritten_release_event =

[dmazzoni, 2014/06/13 05:52:38]

this should be rewritten_touch_event

[evy, 2014/06/13 16:48:07]

Done.

+        new ui::TouchEvent(ui::ET_TOUCH_PRESSED,
+                           last_touch_exploration_location_,
+                           event.touch_id(),
+                           event.time_stamp());
+    rewritten_release_event->set_flags(event.flags());
+    rewritten_event->reset(rewritten_release_event);
+    state_ = TE_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();
@@ -309,6 +321,50 @@ ui::EventRewriteStatus TouchExplorationController::InPassthroughMinusOne(
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
+ui::EventRewriteStatus TouchExplorationController::InTESecondPress(
+    const ui::TouchEvent& event,
+    scoped_ptr<ui::Event>* rewritten_event) {
+  ui::EventType type = event.type();
+  gfx::PointF location = event.location_f();
+  if (tap_timer_.IsRunning())

[dmazzoni, 2014/06/13 05:52:38]

This shouldn't be necessary - it's already done before entering this state,
right?

[evy, 2014/06/13 16:48:07]

Yeah - right before the state change - thanks

+    tap_timer_.Stop();
+  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
+    // 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() == 0){

[dmazzoni, 2014/06/13 05:52:38]

I don't think you can assume the touch id is 0 for the touch exploration finger
- you should use the touch id from when that finger was first pressed.

[evy, 2014/06/13 16:48:07]

Done. I changed last_touch_exploration_location to a pointer for the whole last
touch exploration event, and can now access its id.

+      state_ = DOUBLE_TAP_PRESSED;
+      VLOG_STATE();
+      return EVENT_REWRITE_DISCARD;
+    }
+
+    // Continue to rlease the touch only if the touch explore finger is the

[dmazzoni, 2014/06/13 05:52:38]

rlease -> release

[evy, 2014/06/13 16:48:07]

Done.

+    // 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(
+        ui::ET_TOUCH_RELEASED,
+        last_touch_exploration_location_,
+        event.touch_id(),

[dmazzoni, 2014/06/13 05:52:38]

This touch id might not be the same as the one that was pressed. Suppose you
touch explore with 1, then add finger 2, which generates a press with touch id
2, then add finger 3, which is discarded, then release 2, and finally release 3.
The end result is a press of 2 followed by a release of 3.

[evy, 2014/06/13 16:48:07]

Done. I used initial_press_ instead - which should be the first touch (since
every touch after is discarded)

+        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;
@@ -406,6 +462,8 @@ const char* TouchExplorationController::EnumStateToString(State state) {
       return "TOUCH_EXPLORATION";
     case PASSTHROUGH_MINUS_ONE:
       return "PASSTHROUGH_MINUS_ONE";
+    case TE_SECOND_PRESS:
+      return "TE_SECOND_PRESS";
   }
   return "Not a state";
 }