content/browser/renderer_host/input/motion_event_web.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 // MSVC++ requires this to be set before any other includes to get M_PI.
   6 #define _USE_MATH_DEFINES
   7
   8 #include "content/browser/renderer_host/input/motion_event_web.h"
   9
  10 #include <cmath>
  11
  12 #include "base/logging.h"
  13 #include "content/browser/renderer_host/input/web_input_event_util.h"
  14 #include "content/common/input/web_touch_event_traits.h"
  15
  16 using blink::WebInputEvent;
  17 using blink::WebTouchEvent;
  18 using blink::WebTouchPoint;
  19
  20 namespace content {
  21 namespace {
  22
  23 ui::MotionEvent::Action GetActionFrom(const WebTouchEvent& event) {
  24   DCHECK(event.touchesLength);
  25   switch (event.type) {
  26     case WebInputEvent::TouchStart:
  27       if (WebTouchEventTraits::AllTouchPointsHaveState(
  28               event, WebTouchPoint::StatePressed))
  29         return ui::MotionEvent::ACTION_DOWN;
  30       else
  31         return ui::MotionEvent::ACTION_POINTER_DOWN;
  32     case WebInputEvent::TouchEnd:
  33       if (WebTouchEventTraits::AllTouchPointsHaveState(
  34               event, WebTouchPoint::StateReleased))
  35         return ui::MotionEvent::ACTION_UP;
  36       else
  37         return ui::MotionEvent::ACTION_POINTER_UP;
  38     case WebInputEvent::TouchCancel:
  39       DCHECK(WebTouchEventTraits::AllTouchPointsHaveState(
  40           event, WebTouchPoint::StateCancelled));
  41       return ui::MotionEvent::ACTION_CANCEL;
  42     case WebInputEvent::TouchMove:
  43       return ui::MotionEvent::ACTION_MOVE;
  44     default:
  45       break;
  46   };
  47   NOTREACHED()
  48       << "Unable to derive a valid MotionEvent::Action from the WebTouchEvent.";
  49   return ui::MotionEvent::ACTION_CANCEL;
  50 }
  51
  52 int GetActionIndexFrom(const WebTouchEvent& event) {
  53   for (size_t i = 0; i < event.touchesLength; ++i) {
  54     if (event.touches[i].state != WebTouchPoint::StateUndefined &&
  55         event.touches[i].state != WebTouchPoint::StateStationary)
  56       return i;
  57   }
  58   return -1;
  59 }
  60
  61 }  // namespace
  62
  63 MotionEventWeb::MotionEventWeb(const WebTouchEvent& event)
  64     : event_(event),
  65       cached_action_(GetActionFrom(event)),
  66       cached_action_index_(GetActionIndexFrom(event)),
  67       unique_event_id_(event.uniqueTouchEventId) {
  68   DCHECK_GT(GetPointerCount(), 0U);
  69 }
  70
  71 MotionEventWeb::~MotionEventWeb() {}
  72
  73 uint32 MotionEventWeb::GetUniqueEventId() const {
  74   return unique_event_id_;
  75 }
  76
  77 MotionEventWeb::Action MotionEventWeb::GetAction() const {
  78   return cached_action_;
  79 }
  80
  81 int MotionEventWeb::GetActionIndex() const {
  82   DCHECK(cached_action_ == ACTION_POINTER_UP ||
  83          cached_action_ == ACTION_POINTER_DOWN)
  84       << "Invalid action for GetActionIndex(): " << cached_action_;
  85   DCHECK_GE(cached_action_index_, 0);
  86   DCHECK_LT(cached_action_index_, static_cast<int>(event_.touchesLength));
  87   return cached_action_index_;
  88 }
  89
  90 size_t MotionEventWeb::GetPointerCount() const { return event_.touchesLength; }
  91
  92 int MotionEventWeb::GetPointerId(size_t pointer_index) const {
  93   DCHECK_LT(pointer_index, GetPointerCount());
  94   return event_.touches[pointer_index].id;
  95 }
  96
  97 float MotionEventWeb::GetX(size_t pointer_index) const {
  98   DCHECK_LT(pointer_index, GetPointerCount());
  99   return event_.touches[pointer_index].position.x;
 100 }
 101
 102 float MotionEventWeb::GetY(size_t pointer_index) const {
 103   DCHECK_LT(pointer_index, GetPointerCount());
 104   return event_.touches[pointer_index].position.y;
 105 }
 106
 107 float MotionEventWeb::GetRawX(size_t pointer_index) const {
 108   DCHECK_LT(pointer_index, GetPointerCount());
 109   return event_.touches[pointer_index].screenPosition.x;
 110 }
 111
 112 float MotionEventWeb::GetRawY(size_t pointer_index) const {
 113   DCHECK_LT(pointer_index, GetPointerCount());
 114   return event_.touches[pointer_index].screenPosition.y;
 115 }
 116
 117 float MotionEventWeb::GetTouchMajor(size_t pointer_index) const {
 118   DCHECK_LT(pointer_index, GetPointerCount());
 119   return 2.f * std::max(event_.touches[pointer_index].radiusX,
 120                         event_.touches[pointer_index].radiusY);
 121 }
 122
 123 float MotionEventWeb::GetTouchMinor(size_t pointer_index) const {
 124   DCHECK_LT(pointer_index, GetPointerCount());
 125   return 2.f * std::min(event_.touches[pointer_index].radiusX,
 126                         event_.touches[pointer_index].radiusY);
 127 }
 128
 129 float MotionEventWeb::GetOrientation(size_t pointer_index) const {
 130   DCHECK_LT(pointer_index, GetPointerCount());
 131
 132   float rotation_angle_rad = event_.touches[pointer_index].rotationAngle
 133       * M_PI / 180.f;
 134   DCHECK(0 <= rotation_angle_rad && rotation_angle_rad <= M_PI_2)
 135       << "Unexpected touch rotation angle";
 136
 137   if (event_.touches[pointer_index].radiusX
 138       > event_.touches[pointer_index].radiusY) {
 139     // The case radiusX == radiusY is omitted from here on purpose: for circles,
 140     // we want to pass the angle (which could be any value in such cases but
 141     // always seem to be set to zero) unchanged.
 142     rotation_angle_rad -= (float) M_PI_2;
 143   }
 144
 145   return rotation_angle_rad;
 146 }
 147
 148 float MotionEventWeb::GetPressure(size_t pointer_index) const {
 149   return 0.f;
 150 }
 151
 152 base::TimeTicks MotionEventWeb::GetEventTime() const {
 153   return base::TimeTicks() +
 154          base::TimeDelta::FromMicroseconds(event_.timeStampSeconds *
 155                                            base::Time::kMicrosecondsPerSecond);
 156 }
 157
 158 ui::MotionEvent::ToolType MotionEventWeb::GetToolType(
 159     size_t pointer_index) const {
 160   // TODO(jdduke): Plumb tool type from the platform event, crbug.com/404128.
 161   DCHECK_LT(pointer_index, GetPointerCount());
 162   return TOOL_TYPE_UNKNOWN;
 163 }
 164
 165 int MotionEventWeb::GetButtonState() const {
 166   return 0;
 167 }
 168
 169 int MotionEventWeb::GetFlags() const {
 170   return WebEventModifiersToEventFlags(event_.modifiers);
 171 }
 172
 173 }  // namespace content