content/common/input/web_touch_event_traits.h

   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 #ifndef CONTENT_COMMON_INPUT_WEB_TOUCH_EVENT_TRAITS_H_
   6 #define CONTENT_COMMON_INPUT_WEB_TOUCH_EVENT_TRAITS_H_
   7
   8 #include "base/basictypes.h"
   9 #include "content/common/input/scoped_web_input_event.h"
  10 #include "third_party/WebKit/public/web/WebInputEvent.h"
  11
  12 namespace content {
  13
  14 // Utility class for performing operations on and with WebTouchEvents.
  15 class CONTENT_EXPORT WebTouchEventTraits {
  16  public:
  17   // Returns whether all touches in the event have the specified state.
  18   static bool AllTouchPointsHaveState(const blink::WebTouchEvent& event,
  19                                       blink::WebTouchPoint::State state);
  20
  21   // Returns whether this event represents a transition from no active
  22   // touches to some active touches (the start of a new "touch sequence").
  23   static bool IsTouchSequenceStart(const blink::WebTouchEvent& event);
  24
  25   // Returns whether this event represents a transition from active
  26   // touches to no active touches (the end of a "touch sequence").
  27   static bool IsTouchSequenceEnd(const blink::WebTouchEvent& event);
  28
  29   // Sets the type of |event| to |type|, resetting any other type-specific
  30   // properties and updating the timestamp.
  31   static void ResetType(blink::WebInputEvent::Type type,
  32                         double timestamp_sec,
  33                         blink::WebTouchEvent* event);
  34
  35   // Like ResetType but also resets the state of all active touches
  36   // to match the event type.  This is particularly useful, for example,
  37   // in sending a touchcancel for all active touches.
  38   static void ResetTypeAndTouchStates(blink::WebInputEvent::Type type,
  39                                       double timestamp_sec,
  40                                       blink::WebTouchEvent* event);
  41 };
  42
  43 }  // namespace content
  44
  45 #endif  // CONTENT_COMMON_INPUT_WEB_TOUCH_EVENT_TRAITS_H_