src/content/browser/renderer_host/input/touch_emulator.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 #include "content/browser/renderer_host/input/touch_emulator.h"
   6
   7 #include "content/browser/renderer_host/input/motion_event_web.h"
   8 #include "content/browser/renderer_host/input/web_input_event_util.h"
   9 #include "content/common/input/web_touch_event_traits.h"
  10 #include "content/public/common/content_client.h"
  11 #include "content/public/common/content_switches.h"
  12 #include "grit/content_resources.h"
  13 #include "third_party/WebKit/public/platform/WebCursorInfo.h"
  14 #include "ui/events/gesture_detection/gesture_config_helper.h"
  15 #include "ui/gfx/image/image.h"
  16 #include "ui/gfx/screen.h"
  17
  18 using blink::WebGestureEvent;
  19 using blink::WebInputEvent;
  20 using blink::WebKeyboardEvent;
  21 using blink::WebMouseEvent;
  22 using blink::WebMouseWheelEvent;
  23 using blink::WebTouchEvent;
  24 using blink::WebTouchPoint;
  25
  26 namespace content {
  27
  28 namespace {
  29
  30 ui::GestureProvider::Config GetGestureProviderConfig() {
  31   // TODO(dgozman): Use different configs to emulate mobile/desktop as
  32   // requested by renderer.
  33   ui::GestureProvider::Config config = ui::DefaultGestureProviderConfig();
  34   config.gesture_begin_end_types_enabled = false;
  35   return config;
  36 }
  37
  38 // Time between two consecutive mouse moves, during which second mouse move
  39 // is not converted to touch.
  40 const double kMouseMoveDropIntervalSeconds = 5.f / 1000;
  41
  42 } // namespace
  43
  44 TouchEmulator::TouchEmulator(TouchEmulatorClient* client)
  45     : client_(client),
  46       gesture_provider_(GetGestureProviderConfig(), this),
  47       enabled_(false),
  48       allow_pinch_(false) {
  49   DCHECK(client_);
  50   ResetState();
  51
  52   bool use_2x = gfx::Screen::GetNativeScreen()->
  53       GetPrimaryDisplay().device_scale_factor() > 1.5f;
  54   float cursor_scale_factor = use_2x ? 2.f : 1.f;
  55   InitCursorFromResource(&touch_cursor_,
  56       cursor_scale_factor,
  57       use_2x ? IDR_DEVTOOLS_TOUCH_CURSOR_ICON_2X :
  58           IDR_DEVTOOLS_TOUCH_CURSOR_ICON);
  59   InitCursorFromResource(&pinch_cursor_,
  60       cursor_scale_factor,
  61       use_2x ? IDR_DEVTOOLS_PINCH_CURSOR_ICON_2X :
  62           IDR_DEVTOOLS_PINCH_CURSOR_ICON);
  63
  64   WebCursor::CursorInfo cursor_info;
  65   cursor_info.type = blink::WebCursorInfo::TypePointer;
  66   pointer_cursor_.InitFromCursorInfo(cursor_info);
  67
  68   // TODO(dgozman): Use synthetic secondary touch to support multi-touch.
  69   gesture_provider_.SetMultiTouchZoomSupportEnabled(false);
  70   // TODO(dgozman): Enable double tap if requested by the renderer.
  71   // TODO(dgozman): Don't break double-tap-based pinch with shift handling.
  72   gesture_provider_.SetDoubleTapSupportForPlatformEnabled(false);
  73 }
  74
  75 TouchEmulator::~TouchEmulator() {
  76   // We cannot cleanup properly in destructor, as we need roundtrip to the
  77   // renderer for ack. Instead, the owner should call Disable, and only
  78   // destroy this object when renderer is dead.
  79 }
  80
  81 void TouchEmulator::ResetState() {
  82   last_mouse_event_was_move_ = false;
  83   last_mouse_move_timestamp_ = 0;
  84   mouse_pressed_ = false;
  85   shift_pressed_ = false;
  86   touch_active_ = false;
  87   suppress_next_fling_cancel_ = false;
  88   pinch_scale_ = 1.f;
  89   pinch_gesture_active_ = false;
  90 }
  91
  92 void TouchEmulator::Enable(bool allow_pinch) {
  93   if (!enabled_) {
  94     enabled_ = true;
  95     ResetState();
  96   }
  97   allow_pinch_ = allow_pinch;
  98   UpdateCursor();
  99 }
 100
 101 void TouchEmulator::Disable() {
 102   if (!enabled_)
 103     return;
 104
 105   enabled_ = false;
 106   UpdateCursor();
 107   CancelTouch();
 108 }
 109
 110 void TouchEmulator::InitCursorFromResource(
 111     WebCursor* cursor, float scale, int resource_id) {
 112   gfx::Image& cursor_image =
 113       content::GetContentClient()->GetNativeImageNamed(resource_id);
 114   WebCursor::CursorInfo cursor_info;
 115   cursor_info.type = blink::WebCursorInfo::TypeCustom;
 116   cursor_info.image_scale_factor = scale;
 117   cursor_info.custom_image = cursor_image.AsBitmap();
 118   cursor_info.hotspot =
 119       gfx::Point(cursor_image.Width() / 2, cursor_image.Height() / 2);
 120 #if defined(OS_WIN)
 121   cursor_info.external_handle = 0;
 122 #endif
 123
 124   cursor->InitFromCursorInfo(cursor_info);
 125 }
 126
 127 bool TouchEmulator::HandleMouseEvent(const WebMouseEvent& mouse_event) {
 128   if (!enabled_)
 129     return false;
 130
 131   if (mouse_event.button != WebMouseEvent::ButtonLeft)
 132     return true;
 133
 134   if (mouse_event.type == WebInputEvent::MouseMove) {
 135     if (last_mouse_event_was_move_ &&
 136         mouse_event.timeStampSeconds < last_mouse_move_timestamp_ +
 137             kMouseMoveDropIntervalSeconds)
 138       return true;
 139
 140     last_mouse_event_was_move_ = true;
 141     last_mouse_move_timestamp_ = mouse_event.timeStampSeconds;
 142   } else {
 143     last_mouse_event_was_move_ = false;
 144   }
 145
 146   if (mouse_event.type == WebInputEvent::MouseDown)
 147     mouse_pressed_ = true;
 148   else if (mouse_event.type == WebInputEvent::MouseUp)
 149     mouse_pressed_ = false;
 150
 151   UpdateShiftPressed((mouse_event.modifiers & WebInputEvent::ShiftKey) != 0);
 152
 153   if (FillTouchEventAndPoint(mouse_event) &&
 154       gesture_provider_.OnTouchEvent(MotionEventWeb(touch_event_))) {
 155     client_->ForwardTouchEvent(touch_event_);
 156   }
 157
 158   // Do not pass mouse events to the renderer.
 159   return true;
 160 }
 161
 162 bool TouchEmulator::HandleMouseWheelEvent(const WebMouseWheelEvent& event) {
 163   if (!enabled_)
 164     return false;
 165
 166   // Send mouse wheel for easy scrolling when there is no active touch.
 167   return touch_active_;
 168 }
 169
 170 bool TouchEmulator::HandleKeyboardEvent(const WebKeyboardEvent& event) {
 171   if (!enabled_)
 172     return false;
 173
 174   if (!UpdateShiftPressed((event.modifiers & WebInputEvent::ShiftKey) != 0))
 175     return false;
 176
 177   if (!mouse_pressed_)
 178     return false;
 179
 180   // Note: The necessary pinch events will be lazily inserted by
 181   // |OnGestureEvent| depending on the state of |shift_pressed_|, using the
 182   // scroll stream as the event driver.
 183   if (shift_pressed_) {
 184     // TODO(dgozman): Add secondary touch point and set anchor.
 185   } else {
 186     // TODO(dgozman): Remove secondary touch point and anchor.
 187   }
 188
 189   // Never block keyboard events.
 190   return false;
 191 }
 192
 193 bool TouchEmulator::HandleTouchEventAck(InputEventAckState ack_result) {
 194   const bool event_consumed = ack_result == INPUT_EVENT_ACK_STATE_CONSUMED;
 195   gesture_provider_.OnTouchEventAck(event_consumed);
 196   // TODO(dgozman): Disable emulation when real touch events are available.
 197   return true;
 198 }
 199
 200 void TouchEmulator::OnGestureEvent(const ui::GestureEventData& gesture) {
 201   WebGestureEvent gesture_event =
 202       CreateWebGestureEventFromGestureEventData(gesture);
 203
 204   switch (gesture_event.type) {
 205     case WebInputEvent::GestureScrollBegin:
 206       client_->ForwardGestureEvent(gesture_event);
 207       // PinchBegin must always follow ScrollBegin.
 208       if (InPinchGestureMode())
 209         PinchBegin(gesture_event);
 210       break;
 211
 212     case WebInputEvent::GestureScrollUpdate:
 213       if (InPinchGestureMode()) {
 214         // Convert scrolls to pinches while shift is pressed.
 215         if (!pinch_gesture_active_)
 216           PinchBegin(gesture_event);
 217         else
 218           PinchUpdate(gesture_event);
 219       } else {
 220         // Pass scroll update further. If shift was released, end the pinch.
 221         if (pinch_gesture_active_)
 222           PinchEnd(gesture_event);
 223         client_->ForwardGestureEvent(gesture_event);
 224       }
 225       break;
 226
 227     case WebInputEvent::GestureScrollEnd:
 228       // PinchEnd must precede ScrollEnd.
 229       if (pinch_gesture_active_)
 230         PinchEnd(gesture_event);
 231       client_->ForwardGestureEvent(gesture_event);
 232       break;
 233
 234     case WebInputEvent::GestureFlingStart:
 235       // PinchEnd must precede FlingStart.
 236       if (pinch_gesture_active_)
 237         PinchEnd(gesture_event);
 238       if (InPinchGestureMode()) {
 239         // No fling in pinch mode. Forward scroll end instead of fling start.
 240         suppress_next_fling_cancel_ = true;
 241         ScrollEnd(gesture_event);
 242       } else {
 243         suppress_next_fling_cancel_ = false;
 244         client_->ForwardGestureEvent(gesture_event);
 245       }
 246       break;
 247
 248     case WebInputEvent::GestureFlingCancel:
 249       // If fling start was suppressed, we should not send fling cancel either.
 250       if (!suppress_next_fling_cancel_)
 251         client_->ForwardGestureEvent(gesture_event);
 252       suppress_next_fling_cancel_ = false;
 253       break;
 254
 255     default:
 256       // Everything else goes through.
 257       client_->ForwardGestureEvent(gesture_event);
 258   }
 259 }
 260
 261 void TouchEmulator::CancelTouch() {
 262   if (!touch_active_)
 263     return;
 264
 265   WebTouchEventTraits::ResetTypeAndTouchStates(
 266       WebInputEvent::TouchCancel,
 267       (base::TimeTicks::Now() - base::TimeTicks()).InSecondsF(),
 268       &touch_event_);
 269   touch_active_ = false;
 270   if (gesture_provider_.OnTouchEvent(MotionEventWeb(touch_event_)))
 271     client_->ForwardTouchEvent(touch_event_);
 272 }
 273
 274 void TouchEmulator::UpdateCursor() {
 275   if (!enabled_)
 276     client_->SetCursor(pointer_cursor_);
 277   else
 278     client_->SetCursor(InPinchGestureMode() ? pinch_cursor_ : touch_cursor_);
 279 }
 280
 281 bool TouchEmulator::UpdateShiftPressed(bool shift_pressed) {
 282   if (shift_pressed_ == shift_pressed)
 283     return false;
 284   shift_pressed_ = shift_pressed;
 285   UpdateCursor();
 286   return true;
 287 }
 288
 289 void TouchEmulator::PinchBegin(const WebGestureEvent& event) {
 290   DCHECK(InPinchGestureMode());
 291   DCHECK(!pinch_gesture_active_);
 292   pinch_gesture_active_ = true;
 293   pinch_anchor_ = gfx::Point(event.x, event.y);
 294   pinch_scale_ = 1.f;
 295   FillPinchEvent(event);
 296   pinch_event_.type = WebInputEvent::GesturePinchBegin;
 297   client_->ForwardGestureEvent(pinch_event_);
 298 }
 299
 300 void TouchEmulator::PinchUpdate(const WebGestureEvent& event) {
 301   DCHECK(pinch_gesture_active_);
 302   int dy = pinch_anchor_.y() - event.y;
 303   float scale = exp(dy * 0.002f);
 304   FillPinchEvent(event);
 305   pinch_event_.type = WebInputEvent::GesturePinchUpdate;
 306   pinch_event_.data.pinchUpdate.scale = scale / pinch_scale_;
 307   client_->ForwardGestureEvent(pinch_event_);
 308   pinch_scale_ = scale;
 309 }
 310
 311 void TouchEmulator::PinchEnd(const WebGestureEvent& event) {
 312   DCHECK(pinch_gesture_active_);
 313   pinch_gesture_active_ = false;
 314   FillPinchEvent(event);
 315   pinch_event_.type = WebInputEvent::GesturePinchEnd;
 316   client_->ForwardGestureEvent(pinch_event_);
 317 }
 318
 319 void TouchEmulator::FillPinchEvent(const WebInputEvent& event) {
 320   pinch_event_.timeStampSeconds = event.timeStampSeconds;
 321   pinch_event_.modifiers = event.modifiers;
 322   pinch_event_.sourceDevice = blink::WebGestureEvent::Touchscreen;
 323   pinch_event_.x = pinch_anchor_.x();
 324   pinch_event_.y = pinch_anchor_.y();
 325 }
 326
 327 void TouchEmulator::ScrollEnd(const WebGestureEvent& event) {
 328   WebGestureEvent scroll_event;
 329   scroll_event.timeStampSeconds = event.timeStampSeconds;
 330   scroll_event.modifiers = event.modifiers;
 331   scroll_event.sourceDevice = blink::WebGestureEvent::Touchscreen;
 332   scroll_event.type = WebInputEvent::GestureScrollEnd;
 333   client_->ForwardGestureEvent(scroll_event);
 334 }
 335
 336 bool TouchEmulator::FillTouchEventAndPoint(const WebMouseEvent& mouse_event) {
 337   if (mouse_event.type != WebInputEvent::MouseDown &&
 338       mouse_event.type != WebInputEvent::MouseMove &&
 339       mouse_event.type != WebInputEvent::MouseUp) {
 340     return false;
 341   }
 342
 343   WebInputEvent::Type eventType;
 344   switch (mouse_event.type) {
 345     case WebInputEvent::MouseDown:
 346       eventType = WebInputEvent::TouchStart;
 347       touch_active_ = true;
 348       break;
 349     case WebInputEvent::MouseMove:
 350       eventType = WebInputEvent::TouchMove;
 351       break;
 352     case WebInputEvent::MouseUp:
 353       eventType = WebInputEvent::TouchEnd;
 354       touch_active_ = false;
 355       break;
 356     default:
 357       eventType = WebInputEvent::Undefined;
 358       NOTREACHED();
 359   }
 360   touch_event_.touchesLength = 1;
 361   touch_event_.modifiers = mouse_event.modifiers;
 362   WebTouchEventTraits::ResetTypeAndTouchStates(
 363       eventType, mouse_event.timeStampSeconds, &touch_event_);
 364
 365   WebTouchPoint& point = touch_event_.touches[0];
 366   point.id = 0;
 367   point.radiusX = point.radiusY = 1.f;
 368   point.force = 1.f;
 369   point.rotationAngle = 0.f;
 370   point.position.x = mouse_event.x;
 371   point.screenPosition.x = mouse_event.globalX;
 372   point.position.y = mouse_event.y;
 373   point.screenPosition.y = mouse_event.globalY;
 374
 375   return true;
 376 }
 377
 378 bool TouchEmulator::InPinchGestureMode() const {
 379   return shift_pressed_ && allow_pinch_;
 380 }
 381
 382 }  // namespace content