序言
當(dāng)前Android 主流的系統(tǒng)中粒子的實(shí)現(xiàn)方式大致可以分為兩類三種
1. 繼承普通的View善涨，主線程刷新繪制
2. 使用surfaceView，子線程刷新繪制
3. 使用surfaceView+openGl啃奴，子線程刷新繪制
因?yàn)榈谌N方式不是很常用潭陪，這里使用前兩種方式實(shí)現(xiàn)粒子
效果圖（視頻轉(zhuǎn)GIf有點(diǎn)卡）
image
實(shí)現(xiàn)功能
1. 可以自定義粒子刷新的頻率，每次刷新的數(shù)量
2. 粒子自己維護(hù)自己的生命周期
3. 可以預(yù)先自己定義的粒子數(shù)量加載粒子 避免一加載就是滿屏粒子的尷尬
4. 復(fù)用消亡粒子
5. 實(shí)現(xiàn)粒子的高度自定義 避免過度封裝
理論概述
兩種實(shí)現(xiàn)方式 對(duì)粒子的處理大致相同 不同的是繪制的位置區(qū)別
這里以第一種方式為例 畫出粒子的UML框架：
image
如上圖所示
ParticleView繼承Runnable 使用handler定時(shí)刷新最蕾，每次刷新進(jìn)行以下一個(gè)步驟
1. 新增粒子 從cacheItems集合中獲取緩存粒子 如果沒有則調(diào)用adapter進(jìn)行創(chuàng)建
2. 調(diào)用transForms 移動(dòng)粒子并將消亡粒子移除繪制集合中
3. 調(diào)用drawItems方法繪制所有的粒子
使用
這里因?yàn)槭歉叨荣Y質(zhì)粒子依溯，所以如果我們想要繪制粒子需要首先繼承BaseItem接口定義自己的粒子類：
然后實(shí)現(xiàn)適配器ParticleAdapter
如：
particle.setAdapter(object : ParticleAdapter() {
override fun newItem(parentWidth: Int, parentHeight: Int): BaseItem {
//返回自己實(shí)現(xiàn)的粒子
return BubbleItem(parentWidth, parentHeight, this@MainActivity)
}
override fun preCreateCount(): Int {
return 50
}
})
particle.setIncreaseParticleInterval(100)
particle.setRenderTime(16)
particle.setIncreaseParticleCount(1)
我這里實(shí)現(xiàn)的粒子如下：BubbleItem.kotlin
class BubbleItem(private val parentWidth: Int, private val parentHeight: Int,context: Context) :
BaseItem {
companion object {
const val STATE_LIVE = 1
const val STATE_DIE = 0
}
private val baseBubbleRadius = ScreenUtil.dip2px(context,2f)
private val intervalBubbleRadius = ScreenUtil.dip2px(context,3f)
//起點(diǎn)
private var origX: Float = 0f
private var origY: Float = parentHeight.toFloat()
//終點(diǎn)
private var desY: Float = 0f
//當(dāng)前的位置
private var curX = 0f
private var curY = 0f
//每次刷新 在Y軸的偏移量
private var speedY = ScreenUtil.dip2px(context,2f)
private val baseSpeedX =ScreenUtil.dip2px(context,0.5f)
//每次刷新 在X軸的偏移量
private var speedX = 0f
var radius = 20f
//透明的距離
private var alphaDis = 0f
var state = STATE_DIE
private val paint = Paint(Paint.ANTI_ALIAS_FLAG)
private var drawBitmap: Bitmap? = null
private var resRect: Rect? = null
init {
paint.style = Paint.Style.FILL_AND_STROKE
paint.color = Color.BLUE
}
/**
* 初始化 隨機(jī)生成氣泡的出生地點(diǎn)
*/
override fun init(context: Context) {
//獲取氣泡的bitmap
if (drawBitmap == null) {
drawBitmap = BitmapFactory.decodeResource(context.resources, R.drawable.bubble)
resRect = Rect(0, 0, drawBitmap?.width ?: 0, drawBitmap?.height ?: 0)
}
origX = Random.nextInt(100, parentWidth - 100).toFloat()
desY = 2 * parentHeight / 3 - Random.nextInt(0, parentHeight / 2).toFloat()
alphaDis = (origY - desY) * 0.2f
radius = Random.nextFloat() * intervalBubbleRadius + baseBubbleRadius
speedX = baseSpeedX * Random.nextFloat() * if (Random.nextBoolean()) {
1
} else {
-1
}
curX = origX
curY = origY
state = STATE_LIVE
//在邊界處的粒子 沒有橫向速度
if (curX <= 200 || curX > (parentWidth - 200)) {
speedX = 0f
}
paint.alpha = 255
}
override fun preInit(context: Context) {
//起點(diǎn)的X軸坐標(biāo)
init(context)
curY = desY + max((origY - desY) * Random.nextFloat(), 0f)
}
override fun move(): Boolean {
curY -= speedY
curX += speedX
val diff = curY - desY
if (diff <= alphaDis) {
if (diff <= alphaDis * 0.4 && diff >=0.3 * alphaDis) {
paint.alpha = 255
} else {
//開始透明
paint.alpha = (255 * diff / alphaDis + 0.5f).toInt()
}
}
if (curY < desY) {
state = STATE_DIE
return false
}
if (curX <= 20 || curX >= parentWidth - 20) {
state = STATE_DIE
return false
}
return true
}
override fun reset() {
}
override fun draw(canvas: Canvas) {
drawBitmap?.apply {
if (!isRecycled) {
canvas.drawBitmap(this, resRect, RectF(curX - radius, curY - radius, curX + radius, curY + radius), paint)
}
}
}
override fun isLive(): Boolean {
return state == STATE_LIVE
}
override fun destroy() {
drawBitmap?.recycle()
drawBitmap = null
}
}
使用普通View 主線程刷新繪制
普通的View繪制就是 使用handler主線程繪制刷新實(shí)現(xiàn)如下：
class ParticleView(context: Context, attributeSet: AttributeSet) : View(context, attributeSet),
BaseParticle, Runnable {
private var particleAdapter: ParticleAdapter? = null
private var isAutoPlay = true
private var intervalTime = 10 * Constant.RENDER_TIME
private var renderTime = Constant.RENDER_TIME
private var increaseParticleCount = 1
private var childTotal = Int.MAX_VALUE
private var temTime = -1
//緩存的view
private var cacheItems = LinkedList<BaseItem>()
//要繪制的所有View
private var drawItems = ArrayList<BaseItem>()
private var renderHandler: Handler = Handler()
private var isInit: Boolean = false
override fun preCreate() {
repeat(particleAdapter?.preCreateCount() ?: 0) {
val newItem = particleAdapter!!.newItem(measuredWidth, measuredHeight)
newItem.preInit(context)
drawItems.add(newItem)
}
}
override fun getItem(): BaseItem {
val newItem = if (cacheItems.size > 0) {
cacheItems.removeFirst()
} else {
particleAdapter!!.newItem(measuredWidth, measuredHeight)
}
newItem.init(context)
return newItem
}
override fun drawItems(canvas: Canvas) {
if (drawItems.size < childTotal) {
if (temTime == -1) {
temTime = ((intervalTime / renderTime.toFloat() + 0.5).toInt())
} else if (temTime == 0) {
repeat(increaseParticleCount) {
drawItems.add(getItem())
}
}
temTime--
}
drawItems.forEach {
it.draw(canvas)
}
}
override fun transForms() {
val iterator = drawItems.iterator()
while (iterator.hasNext()) {
val next = iterator.next()
val isLive = next.move()
if (!isLive) {
iterator.remove()
cacheItems.add(next)
}
}
}
override fun destroyAllView() {
drawItems.forEach {
it.destroy()
}
cacheItems.forEach {
it.destroy()
}
}
override fun startAnimation() {
renderHandler.removeCallbacks(this)
renderHandler.post(this)
}
override fun stopAnimation() {
renderHandler.removeCallbacks(this)
}
override fun setAdapter(adapter: ParticleAdapter) {
particleAdapter = adapter
if (particleAdapter!!.maxParticleCount() <= 0) {
return
}
childTotal = particleAdapter!!.maxParticleCount()
}
override fun setRenderTime(renderTime: Long) {
if (intervalTime < renderTime || renderTime < 0) {
return
}
this.renderTime = renderTime
}
override fun setIncreaseParticleInterval(intervalTime: Long) {
if (intervalTime < renderTime || renderTime < 0) {
return
}
this.intervalTime = intervalTime
}
override fun setIncreaseParticleCount(count: Int) {
if (count <= 0) {
return
}
increaseParticleCount = count
}
override fun setIsAutoPlay(isAuto: Boolean) {
isAutoPlay = isAuto
}
/**
* 設(shè)置大小則按照設(shè)置的大小計(jì)算 否則按照屏幕的寬高來計(jì)算
*/
override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
//獲取屏幕寬高
val screenWidth = ScreenUtil.getScreenWidth(context)
val screenHeight = ScreenUtil.getScreenRealHeight(context)
setMeasuredDimension(
getDefaultSize(screenWidth, widthMeasureSpec),
getDefaultSize(screenHeight, screenHeight)
)
}
override fun onLayout(changed: Boolean, left: Int, top: Int, right: Int, bottom: Int) {
super.onLayout(changed, left, top, right, bottom)
if (!isInit) {
isInit = true
preCreate()
}
}
override fun onDraw(canvas: Canvas?) {
if (visibility != VISIBLE) {
return
}
if (canvas == null) {
renderHandler.removeCallbacks(this)
return
}
drawItems(canvas)
}
override fun run() {
transForms()
invalidate()
renderHandler.postDelayed(this, renderTime)
}
override fun setVisibility(visibility: Int) {
super.setVisibility(visibility)
if (isAutoPlay) {
if (visibility == VISIBLE) {
startAnimation()
} else {
renderHandler.removeCallbacksAndMessages(null)
}
}
}
override fun onDetachedFromWindow() {
super.onDetachedFromWindow()
renderHandler.removeCallbacks(this)
}
override fun onAttachedToWindow() {
super.onAttachedToWindow()
renderHandler.post(this)
}
}
使用surfaceView，子線程刷新繪制
實(shí)現(xiàn)如下：
class ParticleSurfaceView(context: Context, attributeSet: AttributeSet) :
SurfaceView(context, attributeSet), BaseParticle, SurfaceHolder.Callback, Runnable {
private var particleAdapter: ParticleAdapter? = null
private var isAutoPlay = true
private var intervalTime = 10 * Constant.RENDER_TIME
private var renderTime = Constant.RENDER_TIME
private var increaseParticleCount = 1
private var childTotal = Int.MAX_VALUE
private var temTime = -1
private val surfaceHolder: SurfaceHolder = holder
private lateinit var handlerThread: HandlerThread
private lateinit var renderHandler: Handler
//緩存的view
private var cacheItems = LinkedList<BaseItem>()
//要繪制的所有View
private var drawItems = ArrayList<BaseItem>()
init {
surfaceHolder.setKeepScreenOn(true)
surfaceHolder.addCallback(this)
isFocusable = true
isFocusableInTouchMode = true
setZOrderOnTop(true)
//設(shè)置背景為透明色
surfaceHolder.setFormat(PixelFormat.TRANSPARENT)
}
override fun preCreate() {
repeat(particleAdapter?.preCreateCount() ?: 0) {
val newItem = particleAdapter!!.newItem(measuredWidth, measuredHeight)
newItem.preInit(context)
drawItems.add(newItem)
}
}
override fun getItem(): BaseItem {
val newItem = if (cacheItems.size > 0) {
cacheItems.removeFirst()
} else {
particleAdapter!!.newItem(measuredWidth, measuredHeight)
}
newItem.init(context)
return newItem
}
override fun drawItems(canvas: Canvas) {
if (drawItems.size < childTotal) {
if (temTime == -1) {
temTime = ((intervalTime / renderTime.toFloat() + 0.5).toInt())
} else if (temTime == 0) {
repeat(increaseParticleCount) {
drawItems.add(getItem())
}
}
temTime--
}
drawItems.forEach {
it.draw(canvas)
}
}
override fun transForms() {
val iterator = drawItems.iterator()
while (iterator.hasNext()) {
val next = iterator.next()
val isLive = next.move()
if (!isLive) {
iterator.remove()
cacheItems.add(next)
}
}
}
override fun destroyAllView() {
drawItems.forEach {
it.destroy()
}
cacheItems.forEach {
it.destroy()
}
}
override fun startAnimation() {
renderHandler.removeCallbacks(this)
renderHandler.post(this)
}
override fun stopAnimation() {
renderHandler.removeCallbacks(this)
}
override fun setAdapter(adapter: ParticleAdapter) {
particleAdapter = adapter
if (particleAdapter!!.maxParticleCount() <= 0) {
return
}
childTotal = particleAdapter!!.maxParticleCount()
}
override fun setRenderTime(renderTime: Long) {
if (intervalTime < renderTime || renderTime < 0) {
return
}
this.renderTime = renderTime
}
override fun setIncreaseParticleInterval(intervalTime: Long) {
if (intervalTime < renderTime || renderTime < 0) {
return
}
this.intervalTime = intervalTime
}
override fun setIncreaseParticleCount(count: Int) {
if (count <= 0) {
return
}
increaseParticleCount = count
}
override fun setIsAutoPlay(isAuto: Boolean) {
isAutoPlay = isAuto
}
override fun surfaceChanged(holder: SurfaceHolder?, format: Int, width: Int, height: Int) {
}
override fun surfaceDestroyed(holder: SurfaceHolder?) {
renderHandler.removeCallbacks(this)
destroyAllView()
}
override fun surfaceCreated(holder: SurfaceHolder?) {
if (particleAdapter == null) {
throw NullPointerException("particleAdapter must not be null")
}
handlerThread = HandlerThread("BaseSurfaceView")
handlerThread.start()
renderHandler = Handler(handlerThread.looper)
preCreate()
if (isAutoPlay) {
renderHandler.post(this)
}
}
override fun run() {
transForms()
val lockCanvas = surfaceHolder.lockCanvas(null)
lockCanvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR)
drawItems(lockCanvas)
surfaceHolder.unlockCanvasAndPost(lockCanvas)
renderHandler.postDelayed(this, renderTime)
}
}
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