Mark touchcancel events as uncancelable

content/common/input/web_touch_event_traits.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 "content/common/input/web_touch_event_traits.h"
+
+#include "base/logging.h"
+
+using blink::WebInputEvent;
+using blink::WebTouchEvent;
+using blink::WebTouchPoint;
+
+namespace content {
+
+bool WebTouchEventTraits::AllTouchPointsHaveState(const WebTouchEvent& event,
+    blink::WebTouchPoint::State state) {
+  if(!event.touchesLength)
+    return false;
+  for (size_t i = 0; i < event.touchesLength; ++i) {
+    if (event.touches[i].state != state)
+      return false;
+  }
+  return true;
+}
+
+bool WebTouchEventTraits::IsTouchSequenceStart(const WebTouchEvent& event) {
+  DCHECK(event.touchesLength);
+  if (event.type != WebInputEvent::TouchStart)
+    return false;
+  return AllTouchPointsHaveState(event, blink::WebTouchPoint::StatePressed);
+}
+
+void WebTouchEventTraits::ResetType(WebTouchEvent* event,
+    WebInputEvent::Type type,
+    double timestamp_sec,
+    WebTouchEventTraits::ResetTouchesMode resetTouchesMode) {
+  DCHECK(WebInputEvent::isTouchEventType(type));
+  event->type = type;
+  event->cancelable = (type != WebInputEvent::TouchCancel);
+  event->timeStampSeconds = timestamp_sec;
+
+  if (resetTouchesMode == RESET_TOUCHES_STATE) {
+    WebTouchPoint::State newState = WebTouchPoint::StateUndefined;
+    switch (event->type) {
+      case WebInputEvent::TouchStart:
+        newState = WebTouchPoint::StatePressed;
+        break;
+      case WebInputEvent::TouchMove:
+        newState = WebTouchPoint::StateMoved;
+        break;
+      case WebInputEvent::TouchEnd:
+        newState = WebTouchPoint::StateReleased;
+        break;
+      case WebInputEvent::TouchCancel:
+        newState = WebTouchPoint::StateCancelled;
+        break;
+      default:
+        NOTREACHED();
+        break;
+    }
+    for (size_t i = 0; i < event->touchesLength; ++i)
+      event->touches[i].state = newState;
+  }
+}
+
+}  // namespace content