Implement touch exploration touch typing

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 <utility>
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 54 matching lines @@
   root_window_->GetHost()->ConvertDIPToScreenInPixels(&native_point);
 
   anchor_point_ = gfx::PointF(native_point.x(), native_point.y());
   anchor_point_state_ = ANCHOR_POINT_EXPLICITLY_SET;
 }
 
 void TouchExplorationController::SetExcludeBounds(const gfx::Rect& bounds) {
   exclude_bounds_ = bounds;
 }
 
+void TouchExplorationController::SetLiftActivationBounds(
+    const gfx::Rect& bounds) {
+  lift_activation_bounds_ = bounds;
+}
+
 ui::EventRewriteStatus TouchExplorationController::RewriteEvent(
     const ui::Event& event,
     std::unique_ptr<ui::Event>* rewritten_event) {
   if (!event.IsTouchEvent()) {
     if (event.IsKeyEvent()) {
       const ui::KeyEvent& key_event = static_cast<const ui::KeyEvent&>(event);
       VLOG(1) << "\nKeyboard event: " << key_event.GetName()
               << "\n Key code: " << key_event.key_code()
               << ", Flags: " << key_event.flags()
               << ", Is char: " << key_event.is_char();
@@ skipping 381 matching lines @@
   const ui::EventType type = event.type();
   if (type == ui::ET_TOUCH_PRESSED) {
     // Enter split-tap mode.
     initial_press_.reset(new TouchEvent(event));
     tap_timer_.Stop();
     SET_STATE(TOUCH_EXPLORE_SECOND_PRESS);
     return ui::EVENT_REWRITE_DISCARD;
   } else if (type == ui::ET_TOUCH_RELEASED || type == ui::ET_TOUCH_CANCELLED) {
     initial_press_.reset(new TouchEvent(event));
     StartTapTimer();
+    if (!lift_activation_bounds_.IsEmpty()) {
+      gfx::Point location = event.location();
+      root_window_->GetHost()->ConvertScreenInPixelsToDIP(&location);
+      if (lift_activation_bounds_.Contains(location))
+        DispatchSynthesizedTap();

[dmazzoni, 2017/05/15 21:24:34]

I think you'll want to call it from more than one state
than this. For example a quick tap without first
entering touch exploration should work too.

How about intercepting the code that sends a hover
event and have it send a click event instead?

[David Tseng, 2017/05/16 16:07:34]

Sending a click event maps to forceClickOnCurrentItem in ChromeVox which calls
doDefault (accessibility action).

Do default is not a click in Blink (as I found out) but it is simply calling
through to a node's access key action which in most cases is like a click.

However, for bare bones div's and even things with aria roles, this won't work.
That's why ChromeVox + space wasn't working when I was showing you the other
day.

We can dispatch a raw click event, but that is generally not the direction we
want to go as with context menus, sending click events can be tricky e.g. nodes
in z-coord ordering hiding other nodes.

[David Tseng, 2017/05/16 16:07:34]

Isn't a quick tap just pass through mode? i.e. it achieves the same thing.

+    }
     SET_STATE(TOUCH_EXPLORE_RELEASED);
   } else if (type != ui::ET_TOUCH_MOVED) {
     NOTREACHED();
     return ui::EVENT_REWRITE_CONTINUE;
   }
 
   // Rewrite as a mouse-move event.
   *rewritten_event = CreateMouseMoveEvent(event.location_f(), event.flags());
   last_touch_exploration_.reset(new TouchEvent(event));
   if (anchor_point_state_ != ANCHOR_POINT_EXPLICITLY_SET)
@@ skipping 151 matching lines @@
 }
 
 void TouchExplorationController::SendSimulatedClick() {
   // If we got an anchor point from ChromeVox, send a double-tap gesture
   // and let ChromeVox handle the click.
   if (anchor_point_state_ == ANCHOR_POINT_EXPLICITLY_SET) {
     delegate_->HandleAccessibilityGesture(ui::AX_GESTURE_CLICK);
     return;
   }
 
-  // If we don't have an anchor point, we can't send a simulated click.
+  DispatchSynthesizedTap();
+}
+
+void TouchExplorationController::DispatchSynthesizedTap() {

[dmazzoni, 2017/05/15 21:24:35]

Rather than splitting SendSimulatedClick into two
pieces, maybe you could just handle the anchor point -
like not setting an anchor point if it's within the
lift activation bounds? Or figure out why sending 
AX_GESTURE_CLICK doesn't work

[David Tseng, 2017/05/16 16:07:34]

Ditto.

   if (anchor_point_state_ == ANCHOR_POINT_NONE)
     return;
 
-  // Otherwise send a simulated press/release at the anchor point.
   std::unique_ptr<ui::TouchEvent> touch_press;
   touch_press.reset(new ui::TouchEvent(ui::ET_TOUCH_PRESSED, gfx::Point(),
                                        Now(),
                                        initial_press_->pointer_details()));
   touch_press->set_location_f(anchor_point_);
   touch_press->set_root_location_f(anchor_point_);
   DispatchEvent(touch_press.get());
 
   std::unique_ptr<ui::TouchEvent> touch_release;
   touch_release.reset(new ui::TouchEvent(ui::ET_TOUCH_RELEASED, gfx::Point(),
@@ skipping 136 matching lines @@
       // Otherwise wait for all fingers to be lifted.
       SET_STATE(WAIT_FOR_NO_FINGERS);
       return;
     case TWO_FINGER_TAP:
       SET_STATE(WAIT_FOR_NO_FINGERS);
       break;
     default:
       return;
   }
   EnterTouchToMouseMode();
   std::unique_ptr<ui::Event> mouse_move = CreateMouseMoveEvent(

[dmazzoni, 2017/05/15 21:24:34]

Here's the other place where you'll want to send
a simulated click in lift to touch mode, unless
you want to not even set a tap timer.

       initial_press_->location_f(), initial_press_->flags());
   DispatchEvent(mouse_move.get());
   last_touch_exploration_.reset(new TouchEvent(*initial_press_));
   anchor_point_ = last_touch_exploration_->location_f();
   anchor_point_state_ = ANCHOR_POINT_FROM_TOUCH_EXPLORATION;
 }
 
 void TouchExplorationController::OnPassthroughTimerFired() {
   // The passthrough timer will only fire if if the user has held a finger in
   // one of the passthrough corners for the duration of the passthrough timeout.
@@ skipping 373 matching lines @@
       return "TWO_FINGER_TAP";
   }
   return "Not a state";
 }
 
 float TouchExplorationController::GetSplitTapTouchSlop() {
   return gesture_detector_config_.touch_slop * 3;
 }
 
 }  // namespace ui