目录
先看效果
支持暂停，恢复，view自定义和池化回收复用。使用上，只需要引入xml，并绑定factory即可，内部会在attach时自动开始
<MarqueeAnimalView
android:id="@+id/marqueeView"
android:layout_width="200dp"
android:layout_height="30dp"
android:background="@color/color_yellow" />
val list = mutableListOf("我是跑马灯1", "我不是跑马灯", "你猜我是不是跑马灯")
var position = 0
view.marqueeView.setFactory(object : PoolViewFactory {
override fun makeView(layoutInflater: LayoutInflater, parent: ViewGroup): View {
val view = TextView(this@ViewActivity)
view.setPadding(0, 0, 20.dp(), 0)
view.textSize = 12f
view.setTextColor(ResourceUtil.getColor(R.color.white))
return view
}
override fun setAnimator(objectAnimator: ObjectAnimator, width: Int, parentWidth: Int) {
objectAnimator.duration = (parentWidth + width) * 5L
}
override fun setView(view: View): Boolean {
(view as? TextView)?.text = list[position++ % list.size]
return true
}
})
池化思路
参考Message的思路，对view进行回收复用，避免内存持续增长，增大GC压力
private fun obtain(): View? {
synchronized(sPoolSync) {
if (!isAttachedToWindow) {
return null
}
if (queue.isNotEmpty()) {
return queue.poll()
}
}
return factory?.makeView(layoutInflater, this@MarqueeAnimalView)?.apply {
addView(this, ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)
}
}
private fun recycle(view: View) {
synchronized(sPoolSync) {
if (queue.size < MAX_POOL_SIZE) {
queue.offer(view)
}
}
}
创造工厂
这里的思路源于ViewSwitchFactory
interface PoolViewFactory {
fun makeView(layoutInflater: LayoutInflater, parent: ViewGroup): View
fun setAnimator(objectAnimator: ObjectAnimator, width: Int, parentWidth: Int)
/**
* 返回值，代表view是否需要重新测量
*/
fun setView(view: View): Boolean
}
轮询切换
这里根据对动画进行初始化，并设置合适的监听。此时需要获取当view和parent的width，以用于标定始末位置，需要注意x轴的正负方向。animators用于存储开始的动画，这也是设计时存在的遗留问题，因为主动取消所有动画，但view->animator是单向绑定关系，所以需要保存发生的动画
private val animators = hashMapOf<String, ObjectAnimator>()
private fun next(view: View?) {
view ?: return
if (factory?.setView(view) == true) {
view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED))
}
val width = view.measuredWidth
val parentWidth = measuredWidth
val targetValue = parentWidth - width
val animator = ObjectAnimator.ofFloat(view, PROPERTY_NAME, parentWidth.toFloat(), -width.toFloat()).apply {
// null即为默认线性插值器
interpolator = null
addUpdateListener(
RecyclerAnimatorUpdateListener(targetValue) {
next(obtain())
removeUpdateListener(it)
}
)
addListener(this@MarqueeAnimalView)
factory?.setAnimator(this, width, parentWidth)
}
animators["${view.hashCode()}-${animator.hashCode()}"] = animator
animator.start()
}
动画监听
当动画结束时，需要对view进行回收，并对动画移除。取消动画时，需要将view强制归位
同时，为了方便使用，OnAttachStateChangeListener使得整体动画更加平滑，也避免了view不可见时，动画仍然在持续执行浪费资源。当然如fragment不可见时的监听需要完善
override fun onAnimationEnd(animation: Animator?) {
(animation as? ObjectAnimator)?.let { animator ->
(animator.target as? View)?.let { view ->
animators.remove("${view.hashCode()}-${animator.hashCode()}")
recycle(view)
}
// target释放
animator.target = null
}
}
override fun onAnimationCancel(animation: Animator?) {
(animation as? ObjectAnimator)?.let { animator ->
(animator.target as? View)?.let { view ->
view.translationX = measuredWidth.toFloat()
}
}
}
override fun onViewAttachedToWindow(v: View?) {
if (animators.isNotEmpty()) {
resume()
} else {
start()
}
}
override fun onViewDetachedFromWindow(v: View?) {
pause()
}
对外能力
fun start() {
if (measuredWidth == 0) {
this.post {
// 如果测量还未完成，那就等待post后发起
next(obtain())
}
return
}
next(obtain())
}
fun stop() {
val it = animators.values.iterator()
while (it.hasNext()) {
val i = it.next()
it.remove()
i.cancel()
}
}
fun pause() {
for (i in animators.values) {
i.pause()
}
}
fun resume() {
for (i in animators.values) {
i.resume()
}
}
完整代码
欢迎支持，搜索MarqueeAnimalView即可 github.com/wjf-962464/Self_Demo.git
