src/content/browser/renderer_host/input/synthetic_smooth_scroll_gesture_new.cc

   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 #include "content/browser/renderer_host/input/synthetic_smooth_scroll_gesture_new.h"
   6
   7 #include <cmath>
   8
   9 #include "content/common/input/input_event.h"
  10 #include "ui/events/latency_info.h"
  11
  12 namespace content {
  13 namespace {
  14
  15 // TODO(dominikg): Calibrate or add as another parameter.
  16 const float kDeltaInPixelsPerMs = 0.5f;
  17
  18 }
  19
  20 SyntheticSmoothScrollGestureNew::SyntheticSmoothScrollGestureNew(
  21     const SyntheticSmoothScrollGestureParams& params)
  22     : params_(params),
  23       current_y_(params_.anchor_y) {}
  24
  25 SyntheticSmoothScrollGestureNew::~SyntheticSmoothScrollGestureNew() {}
  26
  27 SyntheticGestureNew::Result SyntheticSmoothScrollGestureNew::ForwardInputEvents(
  28     const base::TimeDelta& interval, SyntheticGestureTarget* target) {
  29
  30   SyntheticGestureParams::GestureSourceType source =
  31       params_.gesture_source_type;
  32   if (source == SyntheticGestureParams::DEFAULT_INPUT)
  33     source = target->GetDefaultSyntheticGestureSourceType();
  34
  35   if (!target->SupportsSyntheticGestureSourceType(source)) {
  36     return SyntheticGestureNew::GESTURE_SOURCE_TYPE_NOT_SUPPORTED_BY_PLATFORM;
  37   }
  38
  39   if (source == SyntheticGestureParams::TOUCH_INPUT) {
  40     return ForwardTouchInputEvents(interval, target);
  41   }
  42   else if (source == SyntheticGestureParams::MOUSE_INPUT) {
  43     return ForwardMouseInputEvents(interval, target);
  44   }
  45   else {
  46     return SyntheticGestureNew::GESTURE_SOURCE_TYPE_NOT_IMPLEMENTED;
  47   }
  48 }
  49
  50 SyntheticGestureNew::Result
  51 SyntheticSmoothScrollGestureNew::ForwardTouchInputEvents(
  52     const base::TimeDelta& interval, SyntheticGestureTarget* target) {
  53   if (HasFinished())
  54     return SyntheticGestureNew::GESTURE_FINISHED;
  55
  56   if (current_y_ == params_.anchor_y) {
  57     touch_event_.PressPoint(params_.anchor_x, current_y_);
  58     ForwardTouchEvent(target);
  59   }
  60
  61   current_y_ += GetPositionDelta(interval);
  62   touch_event_.MovePoint(0, params_.anchor_x, current_y_);
  63   ForwardTouchEvent(target);
  64
  65   if (HasFinished()) {
  66     touch_event_.ReleasePoint(0);
  67     ForwardTouchEvent(target);
  68     return SyntheticGestureNew::GESTURE_FINISHED;
  69   }
  70   else {
  71     return SyntheticGestureNew::GESTURE_RUNNING;
  72   }
  73 }
  74
  75 SyntheticGestureNew::Result
  76 SyntheticSmoothScrollGestureNew::ForwardMouseInputEvents(
  77     const base::TimeDelta& interval, SyntheticGestureTarget* target) {
  78   if (HasFinished())
  79     return SyntheticGestureNew::GESTURE_FINISHED;
  80
  81   float delta = GetPositionDelta(interval);
  82   current_y_ += delta;
  83   ForwardMouseWheelEvent(target, delta);
  84
  85   if (HasFinished())
  86     return SyntheticGestureNew::GESTURE_FINISHED;
  87   else
  88     return SyntheticGestureNew::GESTURE_RUNNING;
  89 }
  90
  91 void SyntheticSmoothScrollGestureNew::ForwardTouchEvent(
  92     SyntheticGestureTarget* target) {
  93   target->QueueInputEventToPlatform(
  94       InputEvent(touch_event_, ui::LatencyInfo(), false));
  95 }
  96
  97 void SyntheticSmoothScrollGestureNew::ForwardMouseWheelEvent(
  98     SyntheticGestureTarget* target,
  99     float delta) {
 100   WebKit::WebMouseWheelEvent mouse_wheel_event =
 101       SyntheticWebMouseWheelEventBuilder::Build(0, delta, 0, false);
 102
 103   target->QueueInputEventToPlatform(
 104       InputEvent(mouse_wheel_event, ui::LatencyInfo(), false));
 105 }
 106
 107 float SyntheticSmoothScrollGestureNew::GetPositionDelta(
 108     const base::TimeDelta& interval) {
 109   float delta = kDeltaInPixelsPerMs * interval.InMillisecondsF();
 110   return (params_.distance > 0) ? delta : -delta;
 111 }
 112
 113 bool SyntheticSmoothScrollGestureNew::HasFinished() {
 114   return abs(current_y_ - params_.anchor_y) >= abs(params_.distance);
 115 }
 116
 117 }  // namespace content