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

   1 /*
   2  * Copyright (c) 2022 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 constexpr float MAXIMUM_MOTION_ALLOWED = 20.0f;
  40 } // unnamed namespace
  41
  42 TapGestureRecognizer::TapGestureRecognizer(Observer& observer, Vector2 screenSize, const TapGestureRequest& request, uint32_t maximumAllowedTime)
  43 : GestureRecognizer(screenSize, GestureType::TAP),
  44   mObserver(observer),
  45   mState(CLEAR),
  46   mMinimumTapsRequired(request.minTaps),
  47   mMaximumTapsRequired(request.maxTaps),
  48   mTapsRegistered(0),
  49   mTouchPosition(),
  50   mTouchTime(0u),
  51   mLastTapTime(0u),
  52   mGestureSourceType(GestureSourceType::INVALID),
  53   mMaximumAllowedTime(maximumAllowedTime)
  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 < mMaximumAllowedTime)
 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 > mMaximumAllowedTime || // If exceeded time between taps then just a single tap
 141              mMaximumTapsRequired == 1u)        // If MaximumTapsRequired is 1, it is not waiting for a multi-tap, so a Tap gesture send a single tap.
 142           {
 143             mLastTapTime = event.time;
 144             EmitSingleTap(event.time, point);
 145           }
 146           else if(deltaBetweenTouchDownTouchUp < mMaximumAllowedTime)
 147           {
 148             ++mTapsRegistered;
 149             EmitGesture(GestureState::STARTED, event.time);
 150           }
 151           else // Delta between touch down and touch up too long to be considered a TAP event
 152           {
 153             mState = CLEAR;
 154           }
 155         }
 156         else if(pointState == PointState::DOWN)
 157         {
 158           const Vector2& screen(point.GetScreenPosition());
 159           Vector2        distanceDelta(std::abs(mTouchPosition.x - screen.x),
 160                                 std::abs(mTouchPosition.y - screen.y));
 161
 162           uint32_t timeDelta = event.time - mLastTapTime;
 163
 164           if(distanceDelta.x > MAXIMUM_MOTION_ALLOWED ||
 165              distanceDelta.y > MAXIMUM_MOTION_ALLOWED ||
 166              timeDelta > mMaximumAllowedTime)
 167           {
 168             SetupForTouchDown(event, point);
 169           }
 170           else
 171           {
 172             EmitPossibleState(event);
 173           }
 174         }
 175         break;
 176       }
 177
 178       case FAILED:
 179       default:
 180       {
 181         mState = CLEAR;
 182         break;
 183       }
 184     }
 185   }
 186   else
 187   {
 188     mState = FAILED;
 189
 190     // We have entered a multi-touch event so emit registered gestures if required.
 191     EmitGesture(GestureState::STARTED, event.time);
 192   }
 193 }
 194
 195 void TapGestureRecognizer::SetupForTouchDown(const Integration::TouchEvent& event, const Integration::Point& point)
 196 {
 197   mTouchPosition  = point.GetScreenPosition();
 198   mTouchTime      = event.time;
 199   mLastTapTime    = 0u;
 200   mTapsRegistered = 0;
 201   mState          = TOUCHED;
 202
 203   EmitPossibleState(event);
 204 }
 205
 206 void TapGestureRecognizer::EmitPossibleState(const Integration::TouchEvent& event)
 207 {
 208   TapGestureEvent tapEvent(GestureState::POSSIBLE);
 209   tapEvent.point             = mTouchPosition;
 210   tapEvent.time              = event.time;
 211   tapEvent.gestureSourceType = mGestureSourceType;
 212
 213   ProcessEvent(tapEvent);
 214 }
 215
 216 void TapGestureRecognizer::Update(const GestureRequest& request)
 217 {
 218   const TapGestureRequest& tap = static_cast<const TapGestureRequest&>(request);
 219
 220   mMinimumTapsRequired = tap.minTaps;
 221   mMaximumTapsRequired = tap.maxTaps;
 222 }
 223
 224 void TapGestureRecognizer::SetMaximumAllowedTime(uint32_t time)
 225 {
 226   mMaximumAllowedTime = time;
 227 }
 228
 229 void TapGestureRecognizer::EmitGesture(GestureState state, uint32_t time)
 230 {
 231   if((state == GestureState::CANCELLED) ||
 232      (mTapsRegistered >= mMinimumTapsRequired && mTapsRegistered <= mMaximumTapsRequired))
 233
 234   {
 235     TapGestureEvent event(state);
 236     EmitTap(time, event);
 237   }
 238 }
 239
 240 void TapGestureRecognizer::EmitSingleTap(uint32_t time, const Integration::Point& point)
 241 {
 242   TapGestureEvent event(GestureState::STARTED);
 243   const Vector2&  screen(point.GetScreenPosition());
 244   Vector2         distanceDelta(std::abs(mTouchPosition.x - screen.x),
 245                         std::abs(mTouchPosition.y - screen.y));
 246
 247   if(distanceDelta.x > MAXIMUM_MOTION_ALLOWED ||
 248      distanceDelta.y > MAXIMUM_MOTION_ALLOWED)
 249   {
 250     event.state = GestureState::CANCELLED;
 251   }
 252   mTapsRegistered = 1u;
 253   EmitTap(time, event);
 254 }
 255
 256 void TapGestureRecognizer::EmitTap(uint32_t time, TapGestureEvent& event)
 257 {
 258   event.numberOfTaps      = mTapsRegistered;
 259   event.point             = mTouchPosition;
 260   event.time              = time;
 261   event.gestureSourceType = mGestureSourceType;
 262
 263   ProcessEvent(event);
 264 }
 265
 266 void TapGestureRecognizer::ProcessEvent(TapGestureEvent& event)
 267 {
 268   if(mScene)
 269   {
 270     // Create another handle so the recognizer cannot be destroyed during process function
 271     GestureRecognizerPtr recognizerHandle = this;
 272     mObserver.Process(*mScene, event);
 273   }
 274 }
 275
 276 } // namespace Internal
 277
 278 } // namespace Dali