ui/events/gestures/gesture_recognizer_impl.cc

   1 // Copyright (c) 2012 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 "ui/events/gestures/gesture_recognizer_impl.h"
   6
   7 #include <limits>
   8
   9 #include "base/command_line.h"
  10 #include "base/logging.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/time/time.h"
  14 #include "ui/events/event.h"
  15 #include "ui/events/event_constants.h"
  16 #include "ui/events/event_switches.h"
  17 #include "ui/events/event_utils.h"
  18 #include "ui/events/gestures/gesture_configuration.h"
  19 #include "ui/events/gestures/gesture_types.h"
  20
  21 namespace ui {
  22
  23 namespace {
  24
  25 template <typename T>
  26 void TransferConsumer(GestureConsumer* current_consumer,
  27                       GestureConsumer* new_consumer,
  28                       std::map<GestureConsumer*, T>* map) {
  29   if (map->count(current_consumer)) {
  30     (*map)[new_consumer] = (*map)[current_consumer];
  31     map->erase(current_consumer);
  32   }
  33 }
  34
  35 bool RemoveConsumerFromMap(GestureConsumer* consumer,
  36                            GestureRecognizerImpl::TouchIdToConsumerMap* map) {
  37   bool consumer_removed = false;
  38   for (GestureRecognizerImpl::TouchIdToConsumerMap::iterator i = map->begin();
  39        i != map->end();) {
  40     if (i->second == consumer) {
  41       map->erase(i++);
  42       consumer_removed = true;
  43     } else {
  44       ++i;
  45     }
  46   }
  47   return consumer_removed;
  48 }
  49
  50 void TransferTouchIdToConsumerMap(
  51     GestureConsumer* old_consumer,
  52     GestureConsumer* new_consumer,
  53     GestureRecognizerImpl::TouchIdToConsumerMap* map) {
  54   for (GestureRecognizerImpl::TouchIdToConsumerMap::iterator i = map->begin();
  55        i != map->end(); ++i) {
  56     if (i->second == old_consumer)
  57       i->second = new_consumer;
  58   }
  59 }
  60
  61 GestureProviderAura* CreateGestureProvider(GestureProviderAuraClient* client) {
  62   return new GestureProviderAura(client);
  63 }
  64
  65 }  // namespace
  66
  67 ////////////////////////////////////////////////////////////////////////////////
  68 // GestureRecognizerImpl, public:
  69
  70 GestureRecognizerImpl::GestureRecognizerImpl() {
  71 }
  72
  73 GestureRecognizerImpl::~GestureRecognizerImpl() {
  74   STLDeleteValues(&consumer_gesture_provider_);
  75 }
  76
  77 // Checks if this finger is already down, if so, returns the current target.
  78 // Otherwise, returns NULL.
  79 GestureConsumer* GestureRecognizerImpl::GetTouchLockedTarget(
  80     const TouchEvent& event) {
  81   return touch_id_target_[event.touch_id()];
  82 }
  83
  84 GestureConsumer* GestureRecognizerImpl::GetTargetForGestureEvent(
  85     const GestureEvent& event) {
  86   GestureConsumer* target = NULL;
  87   int touch_id = event.details().oldest_touch_id();
  88   target = touch_id_target_for_gestures_[touch_id];
  89   return target;
  90 }
  91
  92 GestureConsumer* GestureRecognizerImpl::GetTargetForLocation(
  93     const gfx::PointF& location, int source_device_id) {
  94   const float max_distance =
  95       GestureConfiguration::max_separation_for_gesture_touches_in_pixels();
  96
  97   gfx::PointF closest_point;
  98   int closest_touch_id = 0;
  99   double closest_distance_squared = std::numeric_limits<double>::infinity();
 100
 101   std::map<GestureConsumer*, GestureProviderAura*>::iterator i;
 102   for (i = consumer_gesture_provider_.begin();
 103        i != consumer_gesture_provider_.end();
 104        ++i) {
 105     const MotionEventAura& pointer_state = i->second->pointer_state();
 106     for (size_t j = 0; j < pointer_state.GetPointerCount(); ++j) {
 107       if (source_device_id != pointer_state.GetSourceDeviceId(j))
 108         continue;
 109       gfx::PointF point(pointer_state.GetX(j), pointer_state.GetY(j));
 110       // Relative distance is all we need here, so LengthSquared() is
 111       // appropriate, and cheaper than Length().
 112       double distance_squared = (point - location).LengthSquared();
 113       if (distance_squared < closest_distance_squared) {
 114         closest_point = point;
 115         closest_touch_id = pointer_state.GetPointerId(j);
 116         closest_distance_squared = distance_squared;
 117       }
 118     }
 119   }
 120
 121   if (closest_distance_squared < max_distance * max_distance)
 122     return touch_id_target_[closest_touch_id];
 123   return NULL;
 124 }
 125
 126 void GestureRecognizerImpl::TransferEventsTo(GestureConsumer* current_consumer,
 127                                              GestureConsumer* new_consumer) {
 128   // Send cancel to all those save |new_consumer| and |current_consumer|.
 129   // Don't send a cancel to |current_consumer|, unless |new_consumer| is NULL.
 130   // Dispatching a touch-cancel event can end up altering |touch_id_target_|
 131   // (e.g. when the target of the event is destroyed, causing it to be removed
 132   // from |touch_id_target_| in |CleanupStateForConsumer()|). So create a list
 133   // of the touch-ids that need to be cancelled, and dispatch the cancel events
 134   // for them at the end.
 135
 136   std::vector<GestureConsumer*> consumers;
 137   std::map<GestureConsumer*, GestureProviderAura*>::iterator i;
 138   for (i = consumer_gesture_provider_.begin();
 139        i != consumer_gesture_provider_.end();
 140        ++i) {
 141     if (i->first && i->first != new_consumer &&
 142         (i->first != current_consumer || new_consumer == NULL)) {
 143       consumers.push_back(i->first);
 144     }
 145   }
 146   for (std::vector<GestureConsumer*>::iterator iter = consumers.begin();
 147        iter != consumers.end();
 148        ++iter) {
 149     CancelActiveTouches(*iter);
 150   }
 151   // Transfer events from |current_consumer| to |new_consumer|.
 152   if (current_consumer && new_consumer) {
 153     TransferTouchIdToConsumerMap(current_consumer, new_consumer,
 154                                  &touch_id_target_);
 155     TransferTouchIdToConsumerMap(current_consumer, new_consumer,
 156                                  &touch_id_target_for_gestures_);
 157     TransferConsumer(
 158         current_consumer, new_consumer, &consumer_gesture_provider_);
 159   }
 160 }
 161
 162 bool GestureRecognizerImpl::GetLastTouchPointForTarget(
 163     GestureConsumer* consumer,
 164     gfx::PointF* point) {
 165     if (consumer_gesture_provider_.count(consumer) == 0)
 166       return false;
 167     const MotionEvent& pointer_state =
 168         consumer_gesture_provider_[consumer]->pointer_state();
 169     *point = gfx::PointF(pointer_state.GetX(), pointer_state.GetY());
 170     return true;
 171 }
 172
 173 bool GestureRecognizerImpl::CancelActiveTouches(GestureConsumer* consumer) {
 174   bool cancelled_touch = false;
 175   if (consumer_gesture_provider_.count(consumer) == 0)
 176     return false;
 177   const MotionEventAura& pointer_state =
 178       consumer_gesture_provider_[consumer]->pointer_state();
 179   if (pointer_state.GetPointerCount() == 0)
 180     return false;
 181   // Pointer_state is modified every time after DispatchCancelTouchEvent.
 182   scoped_ptr<MotionEvent> pointer_state_clone = pointer_state.Clone();
 183   for (size_t i = 0; i < pointer_state_clone->GetPointerCount(); ++i) {
 184     gfx::PointF point(pointer_state_clone->GetX(i),
 185                       pointer_state_clone->GetY(i));
 186     TouchEvent touch_event(ui::ET_TOUCH_CANCELLED,
 187                            point,
 188                            ui::EF_IS_SYNTHESIZED,
 189                            pointer_state_clone->GetPointerId(i),
 190                            ui::EventTimeForNow(),
 191                            0.0f,
 192                            0.0f,
 193                            0.0f,
 194                            0.0f);
 195     GestureEventHelper* helper = FindDispatchHelperForConsumer(consumer);
 196     if (helper)
 197       helper->DispatchCancelTouchEvent(&touch_event);
 198     cancelled_touch = true;
 199   }
 200   return cancelled_touch;
 201 }
 202
 203 ////////////////////////////////////////////////////////////////////////////////
 204 // GestureRecognizerImpl, private:
 205
 206 GestureProviderAura* GestureRecognizerImpl::GetGestureProviderForConsumer(
 207     GestureConsumer* consumer) {
 208   GestureProviderAura* gesture_provider = consumer_gesture_provider_[consumer];
 209   if (!gesture_provider) {
 210     gesture_provider = CreateGestureProvider(this);
 211     consumer_gesture_provider_[consumer] = gesture_provider;
 212   }
 213   return gesture_provider;
 214 }
 215
 216 void GestureRecognizerImpl::SetupTargets(const TouchEvent& event,
 217                                          GestureConsumer* target) {
 218   if (event.type() == ui::ET_TOUCH_RELEASED ||
 219       event.type() == ui::ET_TOUCH_CANCELLED) {
 220     touch_id_target_.erase(event.touch_id());
 221   } else if (event.type() == ui::ET_TOUCH_PRESSED) {
 222     touch_id_target_[event.touch_id()] = target;
 223     if (target)
 224       touch_id_target_for_gestures_[event.touch_id()] = target;
 225   }
 226 }
 227
 228 void GestureRecognizerImpl::DispatchGestureEvent(GestureEvent* event) {
 229   GestureConsumer* consumer = GetTargetForGestureEvent(*event);
 230   if (consumer) {
 231     GestureEventHelper* helper = FindDispatchHelperForConsumer(consumer);
 232     if (helper)
 233       helper->DispatchGestureEvent(event);
 234   }
 235 }
 236
 237 bool GestureRecognizerImpl::ProcessTouchEventPreDispatch(
 238     const TouchEvent& event,
 239     GestureConsumer* consumer) {
 240   SetupTargets(event, consumer);
 241
 242   if (event.result() & ER_CONSUMED)
 243     return false;
 244
 245   GestureProviderAura* gesture_provider =
 246       GetGestureProviderForConsumer(consumer);
 247   return gesture_provider->OnTouchEvent(event);
 248 }
 249
 250 GestureRecognizer::Gestures*
 251 GestureRecognizerImpl::ProcessTouchEventPostDispatch(
 252     const TouchEvent& event,
 253     ui::EventResult result,
 254     GestureConsumer* consumer) {
 255   GestureProviderAura* gesture_provider =
 256       GetGestureProviderForConsumer(consumer);
 257   gesture_provider->OnTouchEventAck(result != ER_UNHANDLED);
 258   return gesture_provider->GetAndResetPendingGestures();
 259 }
 260
 261 GestureRecognizer::Gestures* GestureRecognizerImpl::ProcessTouchEventOnAsyncAck(
 262     const TouchEvent& event,
 263     ui::EventResult result,
 264     GestureConsumer* consumer) {
 265   if (result & ui::ER_CONSUMED)
 266     return NULL;
 267   GestureProviderAura* gesture_provider =
 268       GetGestureProviderForConsumer(consumer);
 269   gesture_provider->OnTouchEventAck(result != ER_UNHANDLED);
 270   return gesture_provider->GetAndResetPendingGestures();
 271 }
 272
 273 bool GestureRecognizerImpl::CleanupStateForConsumer(
 274     GestureConsumer* consumer) {
 275   bool state_cleaned_up = false;
 276
 277   if (consumer_gesture_provider_.count(consumer)) {
 278     state_cleaned_up = true;
 279     delete consumer_gesture_provider_[consumer];
 280     consumer_gesture_provider_.erase(consumer);
 281   }
 282
 283   state_cleaned_up |= RemoveConsumerFromMap(consumer, &touch_id_target_);
 284   state_cleaned_up |=
 285       RemoveConsumerFromMap(consumer, &touch_id_target_for_gestures_);
 286   return state_cleaned_up;
 287 }
 288
 289 void GestureRecognizerImpl::AddGestureEventHelper(GestureEventHelper* helper) {
 290   helpers_.push_back(helper);
 291 }
 292
 293 void GestureRecognizerImpl::RemoveGestureEventHelper(
 294     GestureEventHelper* helper) {
 295   std::vector<GestureEventHelper*>::iterator it = std::find(helpers_.begin(),
 296       helpers_.end(), helper);
 297   if (it != helpers_.end())
 298     helpers_.erase(it);
 299 }
 300
 301 void GestureRecognizerImpl::OnGestureEvent(GestureEvent* event) {
 302   DispatchGestureEvent(event);
 303 }
 304
 305 GestureEventHelper* GestureRecognizerImpl::FindDispatchHelperForConsumer(
 306     GestureConsumer* consumer) {
 307   std::vector<GestureEventHelper*>::iterator it;
 308   for (it = helpers_.begin(); it != helpers_.end(); ++it) {
 309     if ((*it)->CanDispatchToConsumer(consumer))
 310       return (*it);
 311   }
 312   return NULL;
 313 }
 314
 315 // GestureRecognizer, static
 316 GestureRecognizer* GestureRecognizer::Create() {
 317   return new GestureRecognizerImpl();
 318 }
 319
 320 static GestureRecognizerImpl* g_gesture_recognizer_instance = NULL;
 321
 322 // GestureRecognizer, static
 323 GestureRecognizer* GestureRecognizer::Get() {
 324   if (!g_gesture_recognizer_instance)
 325     g_gesture_recognizer_instance = new GestureRecognizerImpl();
 326   return g_gesture_recognizer_instance;
 327 }
 328
 329 // GestureRecognizer, static
 330 void GestureRecognizer::Reset() {
 331   delete g_gesture_recognizer_instance;
 332   g_gesture_recognizer_instance = NULL;
 333 }
 334
 335 void SetGestureRecognizerForTesting(GestureRecognizer* gesture_recognizer) {
 336   // Transfer helpers to the new GR.
 337   std::vector<GestureEventHelper*>& helpers =
 338       g_gesture_recognizer_instance->helpers();
 339   std::vector<GestureEventHelper*>::iterator it;
 340   for (it = helpers.begin(); it != helpers.end(); ++it)
 341     gesture_recognizer->AddGestureEventHelper(*it);
 342
 343   helpers.clear();
 344   g_gesture_recognizer_instance =
 345       static_cast<GestureRecognizerImpl*>(gesture_recognizer);
 346 }
 347
 348 }  // namespace ui