content/browser/renderer_host/event_with_latency_info.h

   1 // Copyright 2013 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_BROWSER_RENDERER_HOST_EVENT_WITH_LATENCY_INFO_H_
   6 #define CONTENT_BROWSER_RENDERER_HOST_EVENT_WITH_LATENCY_INFO_H_
   7
   8 #include "ui/events/latency_info.h"
   9
  10 #include "content/common/input/web_input_event_traits.h"
  11
  12 namespace blink {
  13 class WebGestureEvent;
  14 class WebMouseEvent;
  15 class WebMouseWheelEvent;
  16 class WebTouchEvent;
  17 }
  18
  19 namespace content {
  20
  21 template <typename T>
  22 class EventWithLatencyInfo {
  23  public:
  24   T event;
  25   mutable ui::LatencyInfo latency;
  26
  27   explicit EventWithLatencyInfo(const T& e) : event(e) {}
  28
  29   EventWithLatencyInfo(const T& e, const ui::LatencyInfo& l)
  30       : event(e), latency(l) {}
  31
  32   EventWithLatencyInfo() {}
  33
  34   bool CanCoalesceWith(const EventWithLatencyInfo& other)
  35       const WARN_UNUSED_RESULT {
  36     return WebInputEventTraits::CanCoalesce(other.event, event);
  37   }
  38
  39   void CoalesceWith(const EventWithLatencyInfo& other) {
  40     WebInputEventTraits::Coalesce(other.event, &event);
  41     // When coalescing two input events, we keep the oldest LatencyInfo
  42     // for Telemetry latency test since it will represent the longest
  43     // latency.
  44     if (other.latency.trace_id >= 0 &&
  45         (latency.trace_id < 0 || other.latency.trace_id < latency.trace_id))
  46       latency = other.latency;
  47   }
  48 };
  49
  50 typedef EventWithLatencyInfo<blink::WebGestureEvent>
  51     GestureEventWithLatencyInfo;
  52 typedef EventWithLatencyInfo<blink::WebMouseWheelEvent>
  53     MouseWheelEventWithLatencyInfo;
  54 typedef EventWithLatencyInfo<blink::WebMouseEvent>
  55     MouseEventWithLatencyInfo;
  56 typedef EventWithLatencyInfo<blink::WebTouchEvent>
  57     TouchEventWithLatencyInfo;
  58
  59 }  // namespace content
  60
  61 #endif  // CONTENT_BROWSER_RENDERER_HOST_EVENT_WITH_LATENCY_INFO_H_