Move touch slop suppression to TouchEventManager

third_party/WebKit/Source/core/input/TouchEventManager.cpp

 // Copyright 2016 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 "core/input/TouchEventManager.h"
 
 #include "core/dom/Document.h"
 #include "core/events/TouchEvent.h"
 #include "core/frame/Deprecation.h"
 #include "core/frame/EventHandlerRegistry.h"
@@ skipping 77 matching lines @@
 
 TouchEventManager::TouchEventManager(LocalFrame& frame) : m_frame(frame) {
   clear();
 }
 
 void TouchEventManager::clear() {
   m_touchSequenceDocument.clear();
   m_targetForTouchID.clear();
   m_regionForTouchID.clear();
   m_touchPressed = false;
+  m_suppressingTouchmoves = false;
   m_currentTouchAction = TouchActionAuto;
 }
 
 DEFINE_TRACE(TouchEventManager) {
   visitor->trace(m_frame);
   visitor->trace(m_touchSequenceDocument);
   visitor->trace(m_targetForTouchID);
 }
 
 WebInputEventResult TouchEventManager::dispatchTouchEvents(
     const WebTouchEvent& event,
     const HeapVector<TouchInfo>& touchInfos,
     bool allTouchesReleased) {
   // Build up the lists to use for the |touches|, |targetTouches| and
   // |changedTouches| attributes in the JS event. See
   // http://www.w3.org/TR/touch-events/#touchevent-interface for how these
   // lists fit together.
 
+  // Suppress all the touch moves in the slop region.
+  if (event.type() == WebInputEvent::TouchStart)

[dtapuska, 2017/02/01 15:42:06]

I don't think this matches the consistent state we had before. For example if
you get a touch start for the second touch point it will enter suppression mode;
lift that finger and it will still be in supression mode.

touch slop supression should enter exactly as it was before. it is a touch start
and all the touch states are statepressed; likewise it should exit on touchend
and touchcancel and if the touchInfo.size() > 1

[lanwei, 2017/02/02 19:49:36]

Done.

+    m_suppressingTouchmoves = true;
+
+  if (m_suppressingTouchmoves && event.type() == WebInputEvent::TouchMove &&
+      touchInfos.size() == 1) {
+    if (!event.movedBeyondSlopRegion)
+      return WebInputEventResult::HandledSuppressed;
+    m_suppressingTouchmoves = false;
+  }
+
   // Holds the complete set of touches on the screen.
   TouchList* touches = TouchList::create();
 
   // A different view on the 'touches' list above, filtered and grouped by
   // event target. Used for the |targetTouches| list in the JS event.
   using TargetTouchesHeapMap = HeapHashMap<EventTarget*, Member<TouchList>>;
   TargetTouchesHeapMap touchesByTarget;
 
   // Array of touches per state, used to assemble the |changedTouches| list.
   ChangedTouches changedTouches[WebTouchPoint::StateMax + 1];
@@ skipping 357 matching lines @@
   }
 
   return dispatchTouchEvents(event, touchInfos, allTouchesReleased);
 }
 
 bool TouchEventManager::isAnyTouchActive() const {
   return m_touchPressed;
 }
 
 }  // namespace blink