android - 动态地为 BottomSheet peekHeight 设置动画

Question

有人设法为 BottomSheet peekHeight 设置动画吗？

我目前正在做以下事情:

        bottom_sheet?.let {
            val behavior = BottomSheetBehavior.from(bottom_sheet)
            behavior.peekHeight = 500
            behavior.state = BottomSheetBehavior.STATE_COLLAPSED
        }

Bottom Sheet 窥视高度已更改，但我想要一个动画，例如当您将状态从 STATE_COLLAPSED 更改为 STATE_EXPANDED 时。

Answer 1

我能够通过使用 RxJava 和 Interval 来完成这个任务。每 15 毫秒运行一次并在每次间隔发生时更改 peekHeight 的运算符。

val interpolator = AccelerateDecelerateInterpolator()
val refreshInterval = 20L
val refreshCount = 15L
val totalRefreshTime = (refreshInterval * refreshCount).toFloat()
val startingHeight = bottomSheetBehavior.peekHeight

animationDisposable = Observable.interval(refreshInterval, TimeUnit.MILLISECONDS)
                .take(refreshCount)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe({ count: Long ->
                    if (show) {
                        val height = (startingHeight + (maxPeekHeight - minPeekHeight) *
                                interpolator.getInterpolation((count * refreshInterval) / totalRefreshTime)).toInt()
                        if (height > maxPeekHeight) {
                            bottomSheetBehavior.peekHeight = maxPeekHeight
                        } else {
                            bottomSheetBehavior.peekHeight = height
                        }

                    } else {
                        val height = (startingHeight - (maxPeekHeight - minPeekHeight) *
                                interpolator.getInterpolation((count * refreshInterval) / totalRefreshTime)).toInt()

                        if (height < minPeekHeight) {
                            bottomSheetBehavior.peekHeight = minPeekHeight
                        } else {
                            bottomSheetBehavior.peekHeight = height
                        }
                    }
                }, { _: Throwable ->
                    //do something here to reset peek height to original
                })