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   DCHECK_GT(GetPointerCount(), 0U);
  68 }
  69
  70 MotionEventWeb::~MotionEventWeb() {}
  71
  72 int MotionEventWeb::GetId() const {
  73   return 0;
  74 }
  75
  76 MotionEventWeb::Action MotionEventWeb::GetAction() const {
  77   return cached_action_;
  78 }
  79
  80 int MotionEventWeb::GetActionIndex() const {
  81   DCHECK(cached_action_ == ACTION_POINTER_UP ||
  82          cached_action_ == ACTION_POINTER_DOWN)
  83       << "Invalid action for GetActionIndex(): " << cached_action_;
  84   DCHECK_GE(cached_action_index_, 0);
  85   DCHECK_LT(cached_action_index_, static_cast<int>(event_.touchesLength));
  86   return cached_action_index_;
  87 }
  88
  89 size_t MotionEventWeb::GetPointerCount() const { return event_.touchesLength; }
  90
  91 int MotionEventWeb::GetPointerId(size_t pointer_index) const {
  92   DCHECK_LT(pointer_index, GetPointerCount());
  93   return event_.touches[pointer_index].id;
  94 }
  95
  96 float MotionEventWeb::GetX(size_t pointer_index) const {
  97   DCHECK_LT(pointer_index, GetPointerCount());
  98   return event_.touches[pointer_index].position.x;
  99 }
 100
 101 float MotionEventWeb::GetY(size_t pointer_index) const {
 102   DCHECK_LT(pointer_index, GetPointerCount());
 103   return event_.touches[pointer_index].position.y;
 104 }
 105
 106 float MotionEventWeb::GetRawX(size_t pointer_index) const {
 107   DCHECK_LT(pointer_index, GetPointerCount());
 108   return event_.touches[pointer_index].screenPosition.x;
 109 }
 110
 111 float MotionEventWeb::GetRawY(size_t pointer_index) const {
 112   DCHECK_LT(pointer_index, GetPointerCount());
 113   return event_.touches[pointer_index].screenPosition.y;
 114 }
 115
 116 float MotionEventWeb::GetTouchMajor(size_t pointer_index) const {
 117   DCHECK_LT(pointer_index, GetPointerCount());
 118   return 2.f * std::max(event_.touches[pointer_index].radiusX,
 119                         event_.touches[pointer_index].radiusY);
 120 }
 121
 122 float MotionEventWeb::GetTouchMinor(size_t pointer_index) const {
 123   DCHECK_LT(pointer_index, GetPointerCount());
 124   return 2.f * std::min(event_.touches[pointer_index].radiusX,
 125                         event_.touches[pointer_index].radiusY);
 126 }
 127
 128 float MotionEventWeb::GetOrientation(size_t pointer_index) const {
 129   DCHECK_LT(pointer_index, GetPointerCount());
 130
 131   float rotation_angle_rad = event_.touches[pointer_index].rotationAngle
 132       * M_PI / 180.f;
 133   DCHECK(0 <= rotation_angle_rad && rotation_angle_rad <= M_PI_2)
 134       << "Unexpected touch rotation angle";
 135
 136   if (event_.touches[pointer_index].radiusX
 137       > event_.touches[pointer_index].radiusY) {
 138     // The case radiusX == radiusY is omitted from here on purpose: for circles,
 139     // we want to pass the angle (which could be any value in such cases but
 140     // always seem to be set to zero) unchanged.
 141     rotation_angle_rad -= (float) M_PI_2;
 142   }
 143
 144   return rotation_angle_rad;
 145 }
 146
 147 float MotionEventWeb::GetPressure(size_t pointer_index) const {
 148   return 0.f;
 149 }
 150
 151 base::TimeTicks MotionEventWeb::GetEventTime() const {
 152   return base::TimeTicks() +
 153          base::TimeDelta::FromMicroseconds(event_.timeStampSeconds *
 154                                            base::Time::kMicrosecondsPerSecond);
 155 }
 156
 157 ui::MotionEvent::ToolType MotionEventWeb::GetToolType(
 158     size_t pointer_index) const {
 159   // TODO(jdduke): Plumb tool type from the platform event, crbug.com/404128.
 160   DCHECK_LT(pointer_index, GetPointerCount());
 161   return TOOL_TYPE_UNKNOWN;
 162 }
 163
 164 int MotionEventWeb::GetButtonState() const {
 165   return 0;
 166 }
 167
 168 int MotionEventWeb::GetFlags() const {
 169   return WebEventModifiersToEventFlags(event_.modifiers);
 170 }
 171
 172 }  // namespace content