Android 控件自動貼邊實現實例詳解

class AutoEdgeHideActivity : BaseGestureDetectorActivity() {
    override fun dispatchTouchEvent(ev: MotionEvent): Boolean {
        when (ev.action) {
            MotionEvent.ACTION_DOWN -> {
                // 手指按下，開始本次交互
                // 在此實現隱藏邏輯
            }
            MotionEvent.ACTION_UP -> {
                // 手指抬起，結束本次交互
                // 在此實現延遲顯示功能
            }
        }
        return super.dispatchTouchEvent(ev)
    }
}

private fun xCoordinateAnimator(view: View, startX: Float, endX: Float) {
    val animator = ValueAnimator.ofFloat(startX, endX)
    animator.addUpdateListener {
        // 不斷更改控件的X坐標
        view.x = it.animatedValue as Float
    }
    // 設置插值器，速度由快變慢
    animator.interpolator = DecelerateInterpolator()
    // 設置動畫的持續時間
    animator.duration = 500
    animator.start()
}

class AutoEdgeHideActivity : BaseGestureDetectorActivity() {
    private lateinit var binding: LayoutAutoEdgeHideActivityBinding
    private var widthPixels: Int = 0
    private val autoShowInterval = 2
    private var interacting = false
    private var hidden = false
    private var lastPositionX: Float = 0f
    private val handler = Handler(Looper.myLooper() ?: Looper.getMainLooper())
    private val autoShowRunnable = Runnable { autoShow() }
    @SuppressLint("SetTextI18n")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = DataBindingUtil.setContentView(this, R.layout.layout_auto_edge_hide_activity)
        widthPixels = resources.displayMetrics.widthPixels
        binding.includeTitle.tvTitle.text = "AutoEdgeHideExample"
        binding.vFloatView.setOnClickListener {
            if (hidden) {
                // 當前為隱藏狀態，先顯示
                // 把之前的延遲線程先取消
                handler.removeCallbacks(autoShowRunnable)
                autoShow()
                Toast.makeText(this, "手動顯示控件", Toast.LENGTH_SHORT).show()
            } else {
                // 相應正常的事件
                Toast.makeText(this, "點擊瞭浮標控件", Toast.LENGTH_SHORT).show()
            }
        }
    }
    override fun dispatchTouchEvent(ev: MotionEvent): Boolean {
        when (ev.action) {
            MotionEvent.ACTION_DOWN -> {
                if (!checkIsTouchFloatView(ev, binding.vFloatView)) {
                    // 起始ACTION_DOWN事件在浮標控件外，自動隱藏浮標控件，標記正在交互
                    interacting = true
                    handler.removeCallbacks(autoShowRunnable)
                    autoHide()
                }
            }
            MotionEvent.ACTION_UP -> {
                if (interacting) {
                    // 交互結束，一定時間後自動顯示，時間可以自由配置
                    interacting = false
                    handler.postDelayed(autoShowRunnable, autoShowInterval * 1000L)
                }
            }
        }
        return super.dispatchTouchEvent(ev)
    }
    /**
     * 檢查是否觸摸浮標控件
     */
    private fun checkIsTouchFloatView(ev: MotionEvent, view: View): Boolean {
        val screenLocation = IntArray(2)
        view.getLocationOnScreen(screenLocation)
        val viewX = screenLocation[0]
        val viewY = screenLocation[1]
        return (ev.x >= viewX && ev.x <= (viewX + view.width)) && (ev.y >= viewY && ev.y <= (viewY + view.height))
    }
    private fun autoShow() {
        if (hidden) {
            hidden = false
            binding.vFloatView.let {
                xCoordinateAnimator(it, it.x, lastPositionX)
            }
        }
    }
    private fun autoHide() {
        if (!hidden) {
            hidden = true
            binding.vFloatView.let {
                // 記錄一下顯示狀態下的x坐標
                lastPositionX = it.x
                // 隱藏時的x坐標，留一點控件的邊緣顯示（示例中默認控件在屏幕右側）
                val endX = widthPixels - it.width * 0.23f
                xCoordinateAnimator(it, lastPositionX, endX)
            }
        }
    }
    private fun xCoordinateAnimator(view: View, startX: Float, endX: Float) {
        val animator = ValueAnimator.ofFloat(startX, endX)
        animator.addUpdateListener {
            view.x = it.animatedValue as Float
        }
        animator.interpolator = DecelerateInterpolator()
        animator.duration = 500
        animator.start()
    }
}