dali/internal/event/events/tap-gesture/tap-gesture-recognizer.cpp

   1 /*
   2  * Copyright (c) 2021 Samsung Electronics Co., Ltd.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  *
  16  */
  17
  18 // CLASS HEADER
  19 #include <dali/internal/event/events/tap-gesture/tap-gesture-recognizer.h>
  20
  21 // EXTERNAL INCLUDES
  22 #include <cmath>
  23
  24 #include <dali/public-api/math/vector2.h>
  25
  26 #include <dali/integration-api/events/touch-event-integ.h>
  27
  28 // INTERNAL INCLUDES
  29 #include <dali/internal/event/common/scene-impl.h>
  30 #include <dali/internal/event/events/gesture-requests.h>
  31
  32 namespace Dali
  33 {
  34 namespace Internal
  35 {
  36 namespace
  37 {
  38 // TODO: Set these according to DPI
  39 const float         MAXIMUM_MOTION_ALLOWED = 20.0f;
  40 const unsigned long MAXIMUM_TIME_ALLOWED   = 500u;
  41 } // unnamed namespace
  42
  43 TapGestureRecognizer::TapGestureRecognizer(Observer& observer, Vector2 screenSize, const TapGestureRequest& request)
  44 : GestureRecognizer(screenSize, GestureType::TAP),
  45   mObserver(observer),
  46   mState(CLEAR),
  47   mMinimumTapsRequired(request.minTaps),
  48   mMaximumTapsRequired(request.maxTaps),
  49   mTapsRegistered(0),
  50   mTouchPosition(),
  51   mTouchTime(0u),
  52   mLastTapTime(0u),
  53   mGestureSourceType(GestureSourceType::INVALID)
  54 {
  55 }
  56
  57 TapGestureRecognizer::~TapGestureRecognizer() = default;
  58
  59 void TapGestureRecognizer::SendEvent(const Integration::TouchEvent& event)
  60 {
  61   GestureRecognizerPtr ptr(this); // To keep us from being destroyed during the life-time of this method
  62
  63   if(event.GetPointCount() == 1)
  64   {
  65     const Integration::Point& point      = event.points[0];
  66     PointState::Type          pointState = point.GetState();
  67
  68     MouseButton::Type mouseButton = point.GetMouseButton();
  69     switch(mouseButton)
  70     {
  71       case MouseButton::INVALID:
  72       {
  73         mGestureSourceType = GestureSourceType::INVALID;
  74         break;
  75       }
  76       case MouseButton::PRIMARY:
  77       {
  78         mGestureSourceType = GestureSourceType::PRIMARY;
  79         break;
  80       }
  81       case MouseButton::SECONDARY:
  82       {
  83         mGestureSourceType = GestureSourceType::SECONDARY;
  84         break;
  85       }
  86       case MouseButton::TERTIARY:
  87       {
  88         mGestureSourceType = GestureSourceType::TERTIARY;
  89         break;
  90       }
  91       default:
  92       {
  93         mGestureSourceType = GestureSourceType::INVALID;
  94         break;
  95       }
  96     }
  97
  98     switch(mState)
  99     {
 100       case CLEAR:
 101       {
 102         if(pointState == PointState::DOWN)
 103         {
 104           SetupForTouchDown(event, point);
 105         }
 106         break;
 107       }
 108
 109       case TOUCHED:
 110       {
 111         uint32_t deltaBetweenTouchDownTouchUp = event.time - mTouchTime;
 112
 113         if(pointState == PointState::UP)
 114         {
 115           if(deltaBetweenTouchDownTouchUp < MAXIMUM_TIME_ALLOWED)
 116           {
 117             mLastTapTime = mTouchTime;
 118             EmitSingleTap(event.time, point);
 119             mState = REGISTERED;
 120           }
 121           else
 122           {
 123             mState = CLEAR;
 124           }
 125         }
 126         else if(pointState == PointState::INTERRUPTED)
 127         {
 128           mState = CLEAR;
 129         }
 130         break;
 131       }
 132
 133       case REGISTERED:
 134       {
 135         if(pointState == PointState::UP)
 136         {
 137           // This is a possible multiple tap, so has it been quick enough?
 138           uint32_t timeDelta                    = event.time - mLastTapTime;
 139           uint32_t deltaBetweenTouchDownTouchUp = event.time - mTouchTime;
 140           if(timeDelta > MAXIMUM_TIME_ALLOWED) // If exceeded time between taps then just a single tap
 141           {
 142             mLastTapTime = event.time;
 143             EmitSingleTap(event.time, point);
 144           }
 145           else if(deltaBetweenTouchDownTouchUp < MAXIMUM_TIME_ALLOWED)
 146           {
 147             ++mTapsRegistered;
 148             EmitGesture(GestureState::STARTED, event.time);
 149           }
 150           else // Delta between touch down and touch up too long to be considered a TAP event
 151           {
 152             mState = CLEAR;
 153           }
 154         }
 155         else if(pointState == PointState::DOWN)
 156         {
 157           const Vector2& screen(point.GetScreenPosition());
 158           Vector2        distanceDelta(std::abs(mTouchPosition.x - screen.x),
 159                                 std::abs(mTouchPosition.y - screen.y));
 160
 161           uint32_t timeDelta = event.time - mLastTapTime;
 162
 163           if(distanceDelta.x > MAXIMUM_MOTION_ALLOWED ||
 164              distanceDelta.y > MAXIMUM_MOTION_ALLOWED ||
 165              timeDelta > MAXIMUM_TIME_ALLOWED)
 166           {
 167             SetupForTouchDown(event, point);
 168           }
 169           else
 170           {
 171             EmitPossibleState(event);
 172           }
 173         }
 174         break;
 175       }
 176
 177       case FAILED:
 178       default:
 179       {
 180         mState = CLEAR;
 181         break;
 182       }
 183     }
 184   }
 185   else
 186   {
 187     mState = FAILED;
 188
 189     // We have entered a multi-touch event so emit registered gestures if required.
 190     EmitGesture(GestureState::STARTED, event.time);
 191   }
 192 }
 193
 194 void TapGestureRecognizer::SetupForTouchDown(const Integration::TouchEvent& event, const Integration::Point& point)
 195 {
 196   mTouchPosition  = point.GetScreenPosition();
 197   mTouchTime      = event.time;
 198   mLastTapTime    = 0u;
 199   mTapsRegistered = 0;
 200   mState          = TOUCHED;
 201
 202   EmitPossibleState(event);
 203 }
 204
 205 void TapGestureRecognizer::EmitPossibleState(const Integration::TouchEvent& event)
 206 {
 207   TapGestureEvent tapEvent(GestureState::POSSIBLE);
 208   tapEvent.point             = mTouchPosition;
 209   tapEvent.time              = event.time;
 210   tapEvent.gestureSourceType = mGestureSourceType;
 211
 212   ProcessEvent(tapEvent);
 213 }
 214
 215 void TapGestureRecognizer::Update(const GestureRequest& request)
 216 {
 217   const TapGestureRequest& tap = static_cast<const TapGestureRequest&>(request);
 218
 219   mMinimumTapsRequired = tap.minTaps;
 220   mMaximumTapsRequired = tap.maxTaps;
 221 }
 222
 223 void TapGestureRecognizer::EmitGesture(GestureState state, uint32_t time)
 224 {
 225   if((state == GestureState::CANCELLED) ||
 226      (mTapsRegistered >= mMinimumTapsRequired && mTapsRegistered <= mMaximumTapsRequired))
 227
 228   {
 229     TapGestureEvent event(state);
 230     EmitTap(time, event);
 231   }
 232 }
 233
 234 void TapGestureRecognizer::EmitSingleTap(uint32_t time, const Integration::Point& point)
 235 {
 236   TapGestureEvent event(GestureState::STARTED);
 237   const Vector2&  screen(point.GetScreenPosition());
 238   Vector2         distanceDelta(std::abs(mTouchPosition.x - screen.x),
 239                         std::abs(mTouchPosition.y - screen.y));
 240
 241   if(distanceDelta.x > MAXIMUM_MOTION_ALLOWED ||
 242      distanceDelta.y > MAXIMUM_MOTION_ALLOWED)
 243   {
 244     event.state = GestureState::CANCELLED;
 245   }
 246   mTapsRegistered = 1u;
 247   EmitTap(time, event);
 248 }
 249
 250 void TapGestureRecognizer::EmitTap(uint32_t time, TapGestureEvent& event)
 251 {
 252   event.numberOfTaps      = mTapsRegistered;
 253   event.point             = mTouchPosition;
 254   event.time              = time;
 255   event.gestureSourceType = mGestureSourceType;
 256
 257   ProcessEvent(event);
 258 }
 259
 260 void TapGestureRecognizer::ProcessEvent(TapGestureEvent& event)
 261 {
 262   if(mScene)
 263   {
 264     // Create another handle so the recognizer cannot be destroyed during process function
 265     GestureRecognizerPtr recognizerHandle = this;
 266     mObserver.Process(*mScene, event);
 267   }
 268 }
 269
 270 } // namespace Internal
 271
 272 } // namespace Dali