content/common/input/web_input_event_traits.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/common/input/web_input_event_traits.h"
   6
   7 #include <bitset>
   8 #include <limits>
   9
  10 #include "base/logging.h"
  11 #include "base/strings/stringprintf.h"
  12
  13 using base::StringAppendF;
  14 using base::SStringPrintf;
  15 using blink::WebGestureEvent;
  16 using blink::WebInputEvent;
  17 using blink::WebKeyboardEvent;
  18 using blink::WebMouseEvent;
  19 using blink::WebMouseWheelEvent;
  20 using blink::WebTouchEvent;
  21 using blink::WebTouchPoint;
  22 using std::numeric_limits;
  23
  24 namespace content {
  25 namespace {
  26
  27 const int kInvalidTouchIndex = -1;
  28
  29 void ApppendEventDetails(const WebKeyboardEvent& event, std::string* result) {
  30   StringAppendF(result,
  31                 "{\n WinCode: %d\n NativeCode: %d\n IsSystem: %d\n"
  32                 " Text: %s\n UnmodifiedText: %s\n KeyIdentifier: %s\n}",
  33                 event.windowsKeyCode,
  34                 event.nativeKeyCode,
  35                 event.isSystemKey,
  36                 reinterpret_cast<const char*>(event.text),
  37                 reinterpret_cast<const char*>(event.unmodifiedText),
  38                 reinterpret_cast<const char*>(event.keyIdentifier));
  39 }
  40
  41 void ApppendEventDetails(const WebMouseEvent& event, std::string* result) {
  42   StringAppendF(result,
  43                 "{\n Button: %d\n Pos: (%d, %d)\n WindowPos: (%d, %d)\n"
  44                 " GlobalPos: (%d, %d)\n Movement: (%d, %d)\n Clicks: %d\n}",
  45                 event.button,
  46                 event.x,
  47                 event.y,
  48                 event.windowX,
  49                 event.windowY,
  50                 event.globalX,
  51                 event.globalY,
  52                 event.movementX,
  53                 event.movementY,
  54                 event.clickCount);
  55 }
  56
  57 void ApppendEventDetails(const WebMouseWheelEvent& event, std::string* result) {
  58   StringAppendF(result,
  59                 "{\n Delta: (%f, %f)\n WheelTicks: (%f, %f)\n Accel: (%f, %f)\n"
  60                 " ScrollByPage: %d\n HasPreciseScrollingDeltas: %d\n"
  61                 " Phase: (%d, %d)\n CanRubberband: (%d, %d)\n}",
  62                 event.deltaX,
  63                 event.deltaY,
  64                 event.wheelTicksX,
  65                 event.wheelTicksY,
  66                 event.accelerationRatioX,
  67                 event.accelerationRatioY,
  68                 event.scrollByPage,
  69                 event.hasPreciseScrollingDeltas,
  70                 event.phase,
  71                 event.momentumPhase,
  72                 event.canRubberbandLeft,
  73                 event.canRubberbandRight);
  74 }
  75
  76 void ApppendEventDetails(const WebGestureEvent& event, std::string* result) {
  77   StringAppendF(result,
  78                 "{\n Pos: (%d, %d)\n GlobalPos: (%d, %d)\n SourceDevice: %d\n"
  79                 " RawData: (%f, %f, %f, %f, %d)\n}",
  80                 event.x,
  81                 event.y,
  82                 event.globalX,
  83                 event.globalY,
  84                 event.sourceDevice,
  85                 event.data.scrollUpdate.deltaX,
  86                 event.data.scrollUpdate.deltaY,
  87                 event.data.scrollUpdate.velocityX,
  88                 event.data.scrollUpdate.velocityY,
  89                 event.data.scrollUpdate.previousUpdateInSequencePrevented);
  90 }
  91
  92 void ApppendTouchPointDetails(const WebTouchPoint& point, std::string* result) {
  93   StringAppendF(result,
  94                  "  (ID: %d, State: %d, ScreenPos: (%f, %f), Pos: (%f, %f),"
  95                      " Radius: (%f, %f), Rot: %f, Force: %f),\n",
  96   point.id,
  97   point.state,
  98   point.screenPosition.x,
  99   point.screenPosition.y,
 100   point.position.x,
 101   point.position.y,
 102   point.radiusX,
 103   point.radiusY,
 104   point.rotationAngle,
 105   point.force);
 106 }
 107
 108 void ApppendEventDetails(const WebTouchEvent& event, std::string* result) {
 109   StringAppendF(result,
 110                 "{\n Touches: %u, Cancelable: %d, CausesScrolling: %d\n[\n",
 111                 event.touchesLength,
 112                 event.cancelable,
 113                 event.causesScrollingIfUncanceled);
 114   for (unsigned i = 0; i < event.touchesLength; ++i)
 115     ApppendTouchPointDetails(event.touches[i], result);
 116   result->append(" ]\n}");
 117 }
 118
 119 bool CanCoalesce(const WebKeyboardEvent& event_to_coalesce,
 120                  const WebKeyboardEvent& event) {
 121   return false;
 122 }
 123
 124 void Coalesce(const WebKeyboardEvent& event_to_coalesce,
 125               WebKeyboardEvent* event) {
 126   DCHECK(CanCoalesce(event_to_coalesce, *event));
 127 }
 128
 129 bool CanCoalesce(const WebMouseEvent& event_to_coalesce,
 130                  const WebMouseEvent& event) {
 131   return event.type == event_to_coalesce.type &&
 132          event.type == WebInputEvent::MouseMove;
 133 }
 134
 135 void Coalesce(const WebMouseEvent& event_to_coalesce, WebMouseEvent* event) {
 136   DCHECK(CanCoalesce(event_to_coalesce, *event));
 137   // Accumulate movement deltas.
 138   int x = event->movementX;
 139   int y = event->movementY;
 140   *event = event_to_coalesce;
 141   event->movementX += x;
 142   event->movementY += y;
 143 }
 144
 145 bool CanCoalesce(const WebMouseWheelEvent& event_to_coalesce,
 146                  const WebMouseWheelEvent& event) {
 147   return event.modifiers == event_to_coalesce.modifiers &&
 148          event.scrollByPage == event_to_coalesce.scrollByPage &&
 149          event.phase == event_to_coalesce.phase &&
 150          event.momentumPhase == event_to_coalesce.momentumPhase &&
 151          event.hasPreciseScrollingDeltas ==
 152              event_to_coalesce.hasPreciseScrollingDeltas;
 153 }
 154
 155 float GetUnacceleratedDelta(float accelerated_delta, float acceleration_ratio) {
 156   return accelerated_delta * acceleration_ratio;
 157 }
 158
 159 float GetAccelerationRatio(float accelerated_delta, float unaccelerated_delta) {
 160   if (unaccelerated_delta == 0.f || accelerated_delta == 0.f)
 161     return 1.f;
 162   return unaccelerated_delta / accelerated_delta;
 163 }
 164
 165 void Coalesce(const WebMouseWheelEvent& event_to_coalesce,
 166               WebMouseWheelEvent* event) {
 167   DCHECK(CanCoalesce(event_to_coalesce, *event));
 168   float unaccelerated_x =
 169       GetUnacceleratedDelta(event->deltaX,
 170                             event->accelerationRatioX) +
 171       GetUnacceleratedDelta(event_to_coalesce.deltaX,
 172                             event_to_coalesce.accelerationRatioX);
 173   float unaccelerated_y =
 174       GetUnacceleratedDelta(event->deltaY,
 175                             event->accelerationRatioY) +
 176       GetUnacceleratedDelta(event_to_coalesce.deltaY,
 177                             event_to_coalesce.accelerationRatioY);
 178   event->deltaX += event_to_coalesce.deltaX;
 179   event->deltaY += event_to_coalesce.deltaY;
 180   event->wheelTicksX += event_to_coalesce.wheelTicksX;
 181   event->wheelTicksY += event_to_coalesce.wheelTicksY;
 182   event->accelerationRatioX =
 183       GetAccelerationRatio(event->deltaX, unaccelerated_x);
 184   event->accelerationRatioY =
 185       GetAccelerationRatio(event->deltaY, unaccelerated_y);
 186   DCHECK_GE(event_to_coalesce.timeStampSeconds, event->timeStampSeconds);
 187   event->timeStampSeconds = event_to_coalesce.timeStampSeconds;
 188 }
 189
 190 // Returns |kInvalidTouchIndex| iff |event| lacks a touch with an ID of |id|.
 191 int GetIndexOfTouchID(const WebTouchEvent& event, int id) {
 192   for (unsigned i = 0; i < event.touchesLength; ++i) {
 193     if (event.touches[i].id == id)
 194       return i;
 195   }
 196   return kInvalidTouchIndex;
 197 }
 198
 199 bool CanCoalesce(const WebTouchEvent& event_to_coalesce,
 200                  const WebTouchEvent& event) {
 201   if (event.type != event_to_coalesce.type ||
 202       event.type != WebInputEvent::TouchMove ||
 203       event.modifiers != event_to_coalesce.modifiers ||
 204       event.touchesLength != event_to_coalesce.touchesLength ||
 205       event.touchesLength > WebTouchEvent::touchesLengthCap)
 206     return false;
 207
 208   COMPILE_ASSERT(WebTouchEvent::touchesLengthCap <= sizeof(int32_t) * 8U,
 209                  suboptimal_touches_length_cap_size);
 210   // Ensure that we have a 1-to-1 mapping of pointer ids between touches.
 211   std::bitset<WebTouchEvent::touchesLengthCap> unmatched_event_touches(
 212       (1 << event.touchesLength) - 1);
 213   for (unsigned i = 0; i < event_to_coalesce.touchesLength; ++i) {
 214     int event_touch_index =
 215         GetIndexOfTouchID(event, event_to_coalesce.touches[i].id);
 216     if (event_touch_index == kInvalidTouchIndex)
 217       return false;
 218     if (!unmatched_event_touches[event_touch_index])
 219       return false;
 220     unmatched_event_touches[event_touch_index] = false;
 221   }
 222   return unmatched_event_touches.none();
 223 }
 224
 225 void Coalesce(const WebTouchEvent& event_to_coalesce, WebTouchEvent* event) {
 226   DCHECK(CanCoalesce(event_to_coalesce, *event));
 227   // The WebTouchPoints include absolute position information. So it is
 228   // sufficient to simply replace the previous event with the new event->
 229   // However, it is necessary to make sure that all the points have the
 230   // correct state, i.e. the touch-points that moved in the last event, but
 231   // didn't change in the current event, will have Stationary state. It is
 232   // necessary to change them back to Moved state.
 233   WebTouchEvent old_event = *event;
 234   *event = event_to_coalesce;
 235   for (unsigned i = 0; i < event->touchesLength; ++i) {
 236     int i_old = GetIndexOfTouchID(old_event, event->touches[i].id);
 237     if (old_event.touches[i_old].state == blink::WebTouchPoint::StateMoved)
 238       event->touches[i].state = blink::WebTouchPoint::StateMoved;
 239   }
 240 }
 241
 242 bool CanCoalesce(const WebGestureEvent& event_to_coalesce,
 243                  const WebGestureEvent& event) {
 244   if (event.type != event_to_coalesce.type ||
 245       event.sourceDevice != event_to_coalesce.sourceDevice ||
 246       event.modifiers != event_to_coalesce.modifiers)
 247     return false;
 248
 249   if (event.type == WebInputEvent::GestureScrollUpdate)
 250     return true;
 251
 252   // GesturePinchUpdate scales can be combined only if they share a focal point,
 253   // e.g., with double-tap drag zoom.
 254   if (event.type == WebInputEvent::GesturePinchUpdate &&
 255       event.x == event_to_coalesce.x &&
 256       event.y == event_to_coalesce.y)
 257     return true;
 258
 259   return false;
 260 }
 261
 262 void Coalesce(const WebGestureEvent& event_to_coalesce,
 263               WebGestureEvent* event) {
 264   DCHECK(CanCoalesce(event_to_coalesce, *event));
 265   if (event->type == WebInputEvent::GestureScrollUpdate) {
 266     event->data.scrollUpdate.deltaX +=
 267         event_to_coalesce.data.scrollUpdate.deltaX;
 268     event->data.scrollUpdate.deltaY +=
 269         event_to_coalesce.data.scrollUpdate.deltaY;
 270     DCHECK_EQ(
 271         event->data.scrollUpdate.previousUpdateInSequencePrevented,
 272         event_to_coalesce.data.scrollUpdate.previousUpdateInSequencePrevented);
 273   } else if (event->type == WebInputEvent::GesturePinchUpdate) {
 274     event->data.pinchUpdate.scale *= event_to_coalesce.data.pinchUpdate.scale;
 275     // Ensure the scale remains bounded above 0 and below Infinity so that
 276     // we can reliably perform operations like log on the values.
 277     if (event->data.pinchUpdate.scale < numeric_limits<float>::min())
 278       event->data.pinchUpdate.scale = numeric_limits<float>::min();
 279     else if (event->data.pinchUpdate.scale > numeric_limits<float>::max())
 280       event->data.pinchUpdate.scale = numeric_limits<float>::max();
 281   }
 282 }
 283
 284 struct WebInputEventToString {
 285   template <class EventType>
 286   bool Execute(const WebInputEvent& event, std::string* result) const {
 287     SStringPrintf(result, "%s (Time: %lf, Modifiers: %d)\n",
 288                   WebInputEventTraits::GetName(event.type),
 289                   event.timeStampSeconds,
 290                   event.modifiers);
 291     const EventType& typed_event = static_cast<const EventType&>(event);
 292     ApppendEventDetails(typed_event, result);
 293     return true;
 294   }
 295 };
 296
 297 struct WebInputEventSize {
 298   template <class EventType>
 299   bool Execute(WebInputEvent::Type /* type */, size_t* type_size) const {
 300     *type_size = sizeof(EventType);
 301     return true;
 302   }
 303 };
 304
 305 struct WebInputEventClone {
 306   template <class EventType>
 307   bool Execute(const WebInputEvent& event,
 308                ScopedWebInputEvent* scoped_event) const {
 309     DCHECK_EQ(sizeof(EventType), event.size);
 310     *scoped_event = ScopedWebInputEvent(
 311         new EventType(static_cast<const EventType&>(event)));
 312     return true;
 313   }
 314 };
 315
 316 struct WebInputEventDelete {
 317   template <class EventType>
 318   bool Execute(WebInputEvent* event, bool* /* dummy_var */) const {
 319     if (!event)
 320       return false;
 321     DCHECK_EQ(sizeof(EventType), event->size);
 322     delete static_cast<EventType*>(event);
 323     return true;
 324   }
 325 };
 326
 327 struct WebInputEventCanCoalesce {
 328   template <class EventType>
 329   bool Execute(const WebInputEvent& event_to_coalesce,
 330                const WebInputEvent* event) const {
 331     if (event_to_coalesce.type != event->type)
 332       return false;
 333     DCHECK_EQ(sizeof(EventType), event->size);
 334     DCHECK_EQ(sizeof(EventType), event_to_coalesce.size);
 335     return CanCoalesce(static_cast<const EventType&>(event_to_coalesce),
 336                        *static_cast<const EventType*>(event));
 337   }
 338 };
 339
 340 struct WebInputEventCoalesce {
 341   template <class EventType>
 342   bool Execute(const WebInputEvent& event_to_coalesce,
 343                WebInputEvent* event) const {
 344     Coalesce(static_cast<const EventType&>(event_to_coalesce),
 345              static_cast<EventType*>(event));
 346     return true;
 347   }
 348 };
 349
 350 template <typename Operator, typename ArgIn, typename ArgOut>
 351 bool Apply(Operator op,
 352            WebInputEvent::Type type,
 353            const ArgIn& arg_in,
 354            ArgOut* arg_out) {
 355   if (WebInputEvent::isMouseEventType(type))
 356     return op.template Execute<WebMouseEvent>(arg_in, arg_out);
 357   else if (type == WebInputEvent::MouseWheel)
 358     return op.template Execute<WebMouseWheelEvent>(arg_in, arg_out);
 359   else if (WebInputEvent::isKeyboardEventType(type))
 360     return op.template Execute<WebKeyboardEvent>(arg_in, arg_out);
 361   else if (WebInputEvent::isTouchEventType(type))
 362     return op.template Execute<WebTouchEvent>(arg_in, arg_out);
 363   else if (WebInputEvent::isGestureEventType(type))
 364     return op.template Execute<WebGestureEvent>(arg_in, arg_out);
 365
 366   NOTREACHED() << "Unknown webkit event type " << type;
 367   return false;
 368 }
 369
 370 }  // namespace
 371
 372 const char* WebInputEventTraits::GetName(WebInputEvent::Type type) {
 373 #define CASE_TYPE(t) case WebInputEvent::t:  return #t
 374   switch(type) {
 375     CASE_TYPE(Undefined);
 376     CASE_TYPE(MouseDown);
 377     CASE_TYPE(MouseUp);
 378     CASE_TYPE(MouseMove);
 379     CASE_TYPE(MouseEnter);
 380     CASE_TYPE(MouseLeave);
 381     CASE_TYPE(ContextMenu);
 382     CASE_TYPE(MouseWheel);
 383     CASE_TYPE(RawKeyDown);
 384     CASE_TYPE(KeyDown);
 385     CASE_TYPE(KeyUp);
 386     CASE_TYPE(Char);
 387     CASE_TYPE(GestureScrollBegin);
 388     CASE_TYPE(GestureScrollEnd);
 389     CASE_TYPE(GestureScrollUpdate);
 390     CASE_TYPE(GestureFlingStart);
 391     CASE_TYPE(GestureFlingCancel);
 392     CASE_TYPE(GestureShowPress);
 393     CASE_TYPE(GestureTap);
 394     CASE_TYPE(GestureTapUnconfirmed);
 395     CASE_TYPE(GestureTapDown);
 396     CASE_TYPE(GestureTapCancel);
 397     CASE_TYPE(GestureDoubleTap);
 398     CASE_TYPE(GestureTwoFingerTap);
 399     CASE_TYPE(GestureLongPress);
 400     CASE_TYPE(GestureLongTap);
 401     CASE_TYPE(GesturePinchBegin);
 402     CASE_TYPE(GesturePinchEnd);
 403     CASE_TYPE(GesturePinchUpdate);
 404     CASE_TYPE(TouchStart);
 405     CASE_TYPE(TouchMove);
 406     CASE_TYPE(TouchEnd);
 407     CASE_TYPE(TouchCancel);
 408     default:
 409       // Must include default to let blink::WebInputEvent add new event types
 410       // before they're added here.
 411       DLOG(WARNING) <<
 412           "Unhandled WebInputEvent type in WebInputEventTraits::GetName.\n";
 413       break;
 414   }
 415 #undef CASE_TYPE
 416   return "";
 417 }
 418
 419 std::string WebInputEventTraits::ToString(const WebInputEvent& event) {
 420   std::string result;
 421   Apply(WebInputEventToString(), event.type, event, &result);
 422   return result;
 423 }
 424
 425 size_t WebInputEventTraits::GetSize(WebInputEvent::Type type) {
 426   size_t size = 0;
 427   Apply(WebInputEventSize(), type, type, &size);
 428   return size;
 429 }
 430
 431 ScopedWebInputEvent WebInputEventTraits::Clone(const WebInputEvent& event) {
 432   ScopedWebInputEvent scoped_event;
 433   Apply(WebInputEventClone(), event.type, event, &scoped_event);
 434   return scoped_event.Pass();
 435 }
 436
 437 void WebInputEventTraits::Delete(WebInputEvent* event) {
 438   if (!event)
 439     return;
 440   bool dummy_var = false;
 441   Apply(WebInputEventDelete(), event->type, event, &dummy_var);
 442 }
 443
 444 bool WebInputEventTraits::CanCoalesce(const WebInputEvent& event_to_coalesce,
 445                                       const WebInputEvent& event) {
 446   // Early out before casting.
 447   if (event_to_coalesce.type != event.type)
 448     return false;
 449   return Apply(WebInputEventCanCoalesce(),
 450                event.type,
 451                event_to_coalesce,
 452                &event);
 453 }
 454
 455 void WebInputEventTraits::Coalesce(const WebInputEvent& event_to_coalesce,
 456                                    WebInputEvent* event) {
 457   DCHECK(event);
 458   Apply(WebInputEventCoalesce(), event->type, event_to_coalesce, event);
 459 }
 460
 461 bool WebInputEventTraits::IgnoresAckDisposition(const WebInputEvent& event) {
 462   switch (event.type) {
 463     case WebInputEvent::MouseDown:
 464     case WebInputEvent::MouseUp:
 465     case WebInputEvent::MouseEnter:
 466     case WebInputEvent::MouseLeave:
 467     case WebInputEvent::ContextMenu:
 468     case WebInputEvent::GestureScrollBegin:
 469     case WebInputEvent::GestureScrollEnd:
 470     case WebInputEvent::GestureShowPress:
 471     case WebInputEvent::GestureTapUnconfirmed:
 472     case WebInputEvent::GestureTapDown:
 473     case WebInputEvent::GestureTapCancel:
 474     case WebInputEvent::GesturePinchBegin:
 475     case WebInputEvent::GesturePinchEnd:
 476     case WebInputEvent::TouchCancel:
 477       return true;
 478     case WebInputEvent::TouchStart:
 479     case WebInputEvent::TouchMove:
 480     case WebInputEvent::TouchEnd:
 481       return !static_cast<const WebTouchEvent&>(event).cancelable;
 482     default:
 483       return false;
 484   }
 485 }
 486
 487 }  // namespace content