content/common/input/web_touch_event_traits.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/common/input/web_touch_event_traits.h"
   6
   7 #include "base/logging.h"
   8
   9 using blink::WebInputEvent;
  10 using blink::WebTouchEvent;
  11 using blink::WebTouchPoint;
  12
  13 namespace content {
  14
  15 bool WebTouchEventTraits::AllTouchPointsHaveState(
  16     const WebTouchEvent& event,
  17     blink::WebTouchPoint::State state) {
  18   if (!event.touchesLength)
  19     return false;
  20   for (size_t i = 0; i < event.touchesLength; ++i) {
  21     if (event.touches[i].state != state)
  22       return false;
  23   }
  24   return true;
  25 }
  26
  27 bool WebTouchEventTraits::IsTouchSequenceStart(const WebTouchEvent& event) {
  28   DCHECK(event.touchesLength);
  29   if (event.type != WebInputEvent::TouchStart)
  30     return false;
  31   return AllTouchPointsHaveState(event, blink::WebTouchPoint::StatePressed);
  32 }
  33
  34 bool WebTouchEventTraits::IsTouchSequenceEnd(const WebTouchEvent& event) {
  35   if (event.type != WebInputEvent::TouchEnd &&
  36       event.type != WebInputEvent::TouchCancel)
  37     return false;
  38   if (!event.touchesLength)
  39     return true;
  40   for (size_t i = 0; i < event.touchesLength; ++i) {
  41     if (event.touches[i].state != blink::WebTouchPoint::StateReleased &&
  42         event.touches[i].state != blink::WebTouchPoint::StateCancelled)
  43       return false;
  44   }
  45   return true;
  46 }
  47
  48 void WebTouchEventTraits::ResetType(WebInputEvent::Type type,
  49                                     double timestamp_sec,
  50                                     WebTouchEvent* event) {
  51   DCHECK(WebInputEvent::isTouchEventType(type));
  52   event->type = type;
  53   event->cancelable = (type != WebInputEvent::TouchCancel);
  54   event->timeStampSeconds = timestamp_sec;
  55 }
  56
  57 void WebTouchEventTraits::ResetTypeAndTouchStates(WebInputEvent::Type type,
  58                                                   double timestamp_sec,
  59                                                   WebTouchEvent* event) {
  60   ResetType(type, timestamp_sec, event);
  61
  62   WebTouchPoint::State newState = WebTouchPoint::StateUndefined;
  63   switch (event->type) {
  64     case WebInputEvent::TouchStart:
  65       newState = WebTouchPoint::StatePressed;
  66       break;
  67     case WebInputEvent::TouchMove:
  68       newState = WebTouchPoint::StateMoved;
  69       break;
  70     case WebInputEvent::TouchEnd:
  71       newState = WebTouchPoint::StateReleased;
  72       break;
  73     case WebInputEvent::TouchCancel:
  74       newState = WebTouchPoint::StateCancelled;
  75       break;
  76     default:
  77       NOTREACHED();
  78       break;
  79   }
  80   for (size_t i = 0; i < event->touchesLength; ++i)
  81     event->touches[i].state = newState;
  82 }
  83
  84 }  // namespace content