Android手勢

     //如果不在主線程中創(chuàng)建,則需要 Looper.prepare(),因為內(nèi)部的創(chuàng)建Handler()用于數(shù)據(jù)傳輸需要 Loop,也可以傳一個Handler進去，Handler(Looper.getMainLooper())
        gestureDetector = GestureDetector(this, object : GestureDetector.SimpleOnGestureListener() {
            // OnContextClickListener
            override fun onContextClick(e: MotionEvent?): Boolean {
                // 監(jiān)聽外部設(shè)備按鈕
                Log.d("Gesture", "onContextClick")
                return super.onContextClick(e)
            }

            //OnDoubleTapListener
            override fun onSingleTapConfirmed(e: MotionEvent?): Boolean {
                //當(dāng)發(fā)生雙擊時不會觸發(fā),兩次點擊在300ms(ViewConfiguration.DOUBLE_TAP_TIMEOUT)之內(nèi) ，通過   Handler().sendEmptyMessageDelayed()實現(xiàn)
                Log.d("Gesture", "onSingleTapConfirmed")
                return super.onSingleTapConfirmed(e)
            }

            override fun onDoubleTap(e: MotionEvent?): Boolean {
                //當(dāng)?shù)诙?action 為 "0-down"的時候就觸發(fā)此方法
                Log.d("Gesture", "onDoubleTap")
                return super.onDoubleTap(e)
            }

            override fun onDoubleTapEvent(e: MotionEvent): Boolean {
                //二次點擊的Action 變化時會觸發(fā)，如果要在 action 為"1-up"的時候處理，就在這個方法里實現(xiàn)邏輯
                Log.d("Gesture", "onDoubleTapEvent - ${e.action}")
                return super.onDoubleTapEvent(e)
            }


            //OnGestureListener
            override fun onDown(e: MotionEvent?): Boolean {
                //按下
                Log.d("Gesture", "onDown")
                return super.onDown(e)
            }

            override fun onShowPress(e: MotionEvent?) {
                //延時回調(diào) 100(ViewConfiguration.TAP_TIMEOUT)后還是處于 action "0-down"就會觸發(fā)
                Log.d("Gesture", "onShowPress")
                super.onShowPress(e)
            }

            override fun onSingleTapUp(e: MotionEvent?): Boolean {
                //雙擊時，onDoubleTapUp會觸發(fā)，onSingleTapUp會在第一次"down"時觸發(fā)
                Log.d("Gesture", "onSingleTapUp")
                return super.onSingleTapUp(e)
            }

            override fun onScroll(e1: MotionEvent?, e2: MotionEvent?, distanceX: Float, distanceY: Float): Boolean {
                //快速滑動
                Log.d("Gesture", "onScroll")
                return super.onScroll(e1, e2, distanceX, distanceY)
            }

            override fun onLongPress(e: MotionEvent?) {
                //長按 500(ViewConfiguration.DEFAULT_LONG_PRESS_TIMEOUT)后還是處于 action "0-down"就會觸發(fā)
                Log.d("Gesture", "onLongPress")
                super.onLongPress(e)
            }

            override fun onFling(e1: MotionEvent?, e2: MotionEvent?, velocityX: Float, velocityY: Float): Boolean {
                //快速滑動后抬起
                Log.d("Gesture", "onFling")
                return super.onFling(e1, e2, velocityX, velocityY)
            }
        })

• GestureDetector

  1. 構(gòu)造方法，實際上調(diào)用的都是

  GestureDetector(Context context, OnGestureListener listener, Handler handler)

  其中handler 一般可以不傳，類內(nèi)部會自行創(chuàng)建。Handler用于處理數(shù)據(jù)需要Looper。如果不在主線程中創(chuàng)建
  GestureDetector，則在之前執(zhí)行Looper.prepare()或需傳Handler(Looper.getMainLooper()

  2. 監(jiān)聽器

  • OnContextClickListener

    API:23, detector.onGenericMotionEvent(MotionEvent)

    name	description
    onContextClick	監(jiān)聽外部設(shè)備按鈕

  • OnDoubleTapListener

  detector.onTouchEvent(MotionEvent)

  name	description
  onSingleTapConfirmed	當(dāng)發(fā)生雙擊時不會觸發(fā);延時回調(diào)，兩次點擊在300ms(ViewConfiguration.DOUBLE_TAP_TIMEOUT)之內(nèi) ，Handler().sendEmptyMessageDelayed()
  onDoubleTap	當(dāng)?shù)诙?300ms之內(nèi)) action 為 "0-down"的時候就觸發(fā)此方法
  onDoubleTapEvent	二次點擊的Action 變化時會觸發(fā)，如果要在 action 為"1-up"的時候處理，就在這個方法里實現(xiàn)邏輯

  • OnGestureListener

  detector.onTouchEvent(MotionEvent)

  name	description
  onDown	按下
  onShowPress	觸摸, 延時回調(diào) 100(ViewConfiguration.TAP_TIMEOUT)后還是處于 action "0-down"就會觸發(fā),Handler().sendEmptyMessageAtTime()
  onSingleTapUp	單擊時觸發(fā), 雙擊時onDoubleTapUp會觸發(fā),此時onSingleTapUp會在第一次"down"時觸發(fā),第二次不觸發(fā)
  onScroll	滑動
  onLongPress	長按 500(ViewConfiguration.DEFAULT_LONG_PRESS_TIMEOUT)后還是處于 action "0-down"就會觸發(fā),Handler().sendEmptyMessageAtTime()
  onFling	快速滑動后抬起

• ScaleGestureDetector

     private var preScale: Float = 1.0F
     private var curScale: Float = 1.0F
     scaleGestureDetector = ScaleGestureDetector(this, object : ScaleGestureDetector.SimpleOnScaleGestureListener() {
  
         override fun onScaleBegin(detector: ScaleGestureDetector): Boolean {
             Log.d(
                 "ScaleGesture",
                 "onScaleBegin: scaleFactor-${detector.scaleFactor} focusX-${detector.focusX} focusY-${detector.focusY}"
             )
             return true
         }
  
         override fun onScale(detector: ScaleGestureDetector): Boolean {
  
             //保證連續(xù)性，不處理的話有明顯的抖動
             curScale = detector.scaleFactor * preScale
             if (curScale > 5 || curScale < 0.1) {
                 curScale = preScale
                 return true
             }
             testV.scaleY = curScale
             testV.scaleX = curScale
             preScale = curScale
             Log.d(
                 "ScaleGesture",
                 "onScale: scaleFactor-${detector.scaleFactor} focusX-${detector.focusX} focusY-${detector.focusY}"
             )
             return super.onScale(detector)
         }
  
         override fun onScaleEnd(detector: ScaleGestureDetector) {
             Log.d(
                 "ScaleGesture",
                 "onScaleEnd: scaleFactor-${detector.scaleFactor} focusX-${detector.focusX} focusY-${detector.focusY}"
             )
         }
     })
  
  

  1. 構(gòu)造方法

  ScaleGestureDetector(Context context, OnScaleGestureListener listener, Handler handler)

  同GestureDetector

  2. 監(jiān)聽器
  • OnScaleGestureListener

  name	description
  onScaleBegin	縮放手勢開始，返回false時,不使用此次縮放手勢,繼續(xù)回調(diào)onScaleBegin();返回true 則回調(diào) onScale()
  onScale	觸發(fā)縮放，返回false,繼續(xù)回調(diào)onScale();返回true,回調(diào)onScaleEnd(),這次縮放結(jié)束
  onScaleEnd	縮放結(jié)束，在onScale()中返回為true, 或有手指抬起時，觸發(fā)此方法

資源

例子

Android開發(fā)藝術(shù)探索 - 任玉剛