Media App播放器界面左右滑动切换上下曲

1.布局

xml 复制代码

        <View
            android:id="@+id/v_moveUp"
            android:layout_width="@dimen/dp_0"
            android:layout_height="@dimen/dp_0"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_TopOf="parent"
            app:layout_constraintBottom_toBottomOf="parent" >
        </View>

2.监听事件

kotlin 复制代码

    private lateinit var gestureHandler: BaseGestureHandler //左右滑动切歌

------------------------------------------------------------------------------------
        gestureHandler = object : BaseGestureHandler() {
            override fun onSwipeRight() {
                playNext()
            }

            override fun onSwipeLeft() {
                playPrevious()
            }
        }

        vMoveUp.isSoundEffectsEnabled = false
        vMoveUp.setOnTouchListener { v, event ->
            event?.let {
                if (it.pointerCount >= 2) {
                    return@setOnTouchListener false
                }
                gestureHandler.onTouchEvent(it) } ?: true
        }

        vMoveUp.setOnSingleClickListener {

        }

3.核心实现

kotlin 复制代码

abstract class BaseGestureHandler {
    val gestureDetector: GestureDetector

    init {
        gestureDetector = GestureDetector(object : GestureDetector.SimpleOnGestureListener() {
            private val swipeThreshold = 100
            private val swipeVelocityThreshold = 100

            override fun onFling(e1: MotionEvent, e2: MotionEvent, velocityX: Float, velocityY: Float): Boolean {
                val pointCount = e1.pointerCount
                val pointCount2 = e2.pointerCount
                if (pointCount > 1 || pointCount2 > 1) {
                    return false
                }

                val diffY = e2.y - e1.y
                val diffX = e2.x - e1.x
                if (Math.abs(diffX) > Math.abs(diffY)) {
                    if (Math.abs(diffX) > swipeThreshold && Math.abs(velocityX) > swipeVelocityThreshold) {
                        if (diffX > 0) {
                            onSwipeRight()
                        } else {
                            onSwipeLeft()
                        }
                        return true
                    }
                }
                return false
            }
        })
    }

    fun onTouchEvent(event: MotionEvent): Boolean {
        return gestureDetector.onTouchEvent(event)
    }

    abstract fun onSwipeRight()
    abstract fun onSwipeLeft()
}