标签：实现 WindowManager layoutParams 悬浮 LayoutParams fun Android windowInfo 浮窗
效果如下：
原生ViewManager接口提供了向窗口添加并操纵View的方法：
public interface ViewManager{
//‘向窗口添加视图’
public void addView(View view, ViewGroup.LayoutParams params);
//‘更新窗口中视图’
public void updateViewLayout(View view, ViewGroup.LayoutParams params);
//‘移除窗口中视图’
public void removeView(View view);
}
使用这个接口显示窗口的模版代码如下：
//‘解析布局文件为视图’
val windowView = LayoutInflater.from(context).inflate(R.id.window_view, null)
//‘获取WindowManager系统服务’
val windowManager = context.getSystemService(Context.WINDOW_SERVICE) as WindowManager
//‘构建窗口布局参数’
WindowManager.LayoutParams().apply {
type = WindowManager.LayoutParams.TYPE_APPLICATION
width = WindowManager.LayoutParams.WRAP_CONTENT
height = WindowManager.LayoutParams.WRAP_CONTENT
gravity = Gravity.START or Gravity.TOP
x = 0
y = 0
}.let { layoutParams->
//‘将视图添加到窗口’
windowManager.addView(windowView, layoutParams)
}
上述代码在当前界面的左上角显示R.id.window_view.xml中定义的布局。
为避免重复，将这段代码抽象成一个函数，其中窗口视图内容和展示位置会随着需求而变，遂将其参数化：
object FloatWindow{
private var context: Context? = n
《Android学习笔记总结+最新移动架构视频+大厂安卓面试真题+项目实战源码讲义》
【docs.qq.com/doc/DSkNLaERkbnFoS0ZF】 完整内容开源分享
ull
//‘当前窗口参数’
var windowInfo: WindowInfo? = null
//‘把和Window布局有关的参数打包成一个内部类’
class WindowInfo(var view: View?) {
var layoutParams: WindowManager.LayoutParams? = null
//‘窗口宽’
var width: Int = 0
//‘窗口高’
var height: Int = 0
//‘窗口中是否有视图’
fun hasView() = view != null && layoutParams != null
//‘窗口中视图是否有父亲’
fun hasParent() = hasView() && view?.parent != null
}
//‘显示窗口’
fun show(
context: Context,
windowInfo: WindowInfo?,
x: Int = windowInfo?.layoutParams?.x.value(),
y: Int = windowInfo?.layoutParams?.y.value(),
) {
if (windowInfo == null) { return }
if (windowInfo.view == null) { return }
this.windowInfo = windowInfo
this.context = context
//‘创建窗口布局参数’
windowInfo.layoutParams = createLayoutParam(x, y)
//‘显示窗口’
if (!windowInfo.hasParent().value()) {
val windowManager = this.context?.getSystemService(Context.WINDOW_SERVICE) as WindowManager
windowManager.addView(windowInfo.view, windowInfo.layoutParams)
}
}
//‘创建窗口布局参数’
private fun createLayoutParam(x: Int, y: Int): WindowManager.LayoutParams {
if (context == null) { return WindowManager.LayoutParams() }
return WindowManager.LayoutParams().apply {
//‘该类型不需要申请权限’
type = WindowManager.LayoutParams.TYPE_APPLICATION
format = PixelFormat.TRANSLUCENT
flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE or WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS
gravity = Gravity.START or Gravity.TOP
width = windowInfo?.width.value()
height = windowInfo?.height.value()
this.x = x
this.y = y
}
}
//‘为空Int提供默认值’
fun Int?.value() = this ?: 0
}
将FloatWindow声明成了单例，目的是在 app 整个生命周期，任何界面都可以方便地显示浮窗。
为了方便统一管理窗口的参数，抽象了内部类WindowInfo
现在就可以像这样在屏幕左上角显示一个浮窗了：
val windowView = LayoutInflater.from(context).inflate(R.id.window_view, null)
WindowInfo(windowView).apply{
width = 100
height = 100
}.let{ windowInfo ->
FloatWindow.show(context, windowInfo, 0, 0)
}
产品要求当浮窗显示时，屏幕变暗。设置WindowManager.LayoutParams.FLAG_DIM_BEHIND标签配合dimAmount就能轻松实现：
object FloatWindow{
//当前窗口参数
var windowInfo: WindowInfo? = null
private fun createLayoutParam(x: Int, y: Int): WindowManager.LayoutParams {
if (context == null) { return WindowManager.LayoutParams() }
return WindowManager.LayoutParams().apply {
type = WindowManager.LayoutParams.TYPE_APPLICATION
format = PixelFormat.TRANSLUCENT
flags =
WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE or
WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS or
//‘设置浮窗背景变暗’
WindowManager.LayoutParams.FLAG_DIM_BEHIND
//‘设置默认变暗程度为0，即不变暗，1表示全黑’
dimAmount = 0f
gravity = Gravity.START or Gravity.TOP
width = windowInfo?.width.value()
height = windowInfo?.height.value()
this.x = x
this.y = y
}
}
//‘供业务界面在需要的时候调整浮窗背景亮暗’
fun setDimAmount(amount:Float){
windowInfo?.layoutParams?.let { it.dimAmount = amount }
}
}
为浮窗设置点击事件等价于为浮窗视图设置点击事件，但如果直接对浮窗视图使用setOnClickListener()的话，浮窗的触摸事件就不会被响应，那拖拽就无法实现。所以只能从更底层的触摸事件着手：
object FloatWindow : View.OnTouchListener{
//‘显示窗口’
fun show(
context: Context,
windowInfo: WindowInfo?,
x: Int = windowInfo?.layoutParams?.x.value(),
y: Int = windowInfo?.layoutParams?.y.value(),
) {
if (windowInfo == null) { return }
if (windowInfo.view == null) { return }
this.windowInfo = windowInfo
this.context = context
//‘为浮窗视图设置触摸监听器’
windowInfo.view?.setOnTouchListener(this)
windowInfo.layoutParams = createLayoutParam(x, y)
if (!windowInfo.hasParent().value()) {
val windowManager = this.context?.getSystemService(Context.WINDOW_SERVICE) as WindowManager
windowManager.addView(windowInfo.view, windowInfo.layoutParams)
}
}
override fun onTouch(v: View, event: MotionEvent): Boolean {
return false
}
}
在onTouch(v: View, event: MotionEvent)中可以拿到更详细的触摸事件，比如ACTION_DOWN，ACTION_MOVE、ACTION_UP。这方便了拖拽的实现，但点击事件的捕获变得复杂，因为需要定义上述三个 ACTION 以怎样的序列出现时才判定为点击事件。幸好GestureDetector为我们做了这件事：
public class GestureDetector {
public interface OnGestureListener {
//‘ACTION_DOWN事件’
boolean onDown(MotionEvent e);
//‘单击事件’
boolean onSingleTapUp(MotionEvent e);
//‘拖拽事件’
boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY);
…
}
}
构建GestureDetector实例并将MotionEvent传递给它就能将触摸事件解析成感兴趣的上层事件：
object FloatWindow : View.OnTouchListener{
private var gestureDetector: GestureDetector = GestureDetector(context, GestureListener())
private var clickListener: WindowClickListener? = null
private var lastTouchX: Int = 0
private var lastTouchY: Int = 0
//‘为浮窗设置点击监听器’
fun setClickListener(listener: WindowClickListener) {
clickListener = listener
}
override fun onTouch(v: View, event: MotionEvent): Boolean {
//‘将触摸事件传递给 GestureDetector 解析’
gestureDetector.onTouchEvent(event)
return true
}
//‘记忆起始触摸点坐标’
private fun onActionDown(event: MotionEvent) {
lastTouchX = event.rawX.toInt()
lastTouchY = event.rawY.toInt()
}
private class GestureListener : GestureDetector.OnGestureListener {
//‘记忆起始触摸点坐标’
override fun onDown(e: MotionEvent): Boolean {
onActionDown(e)
return false
}
override fun onSingleTapUp(e: MotionEvent): Boolean {
//‘点击事件发生时，调用监听器’
return clickListener?.onWindowClick(windowInfo) ?: false
}
…
}
//‘浮窗点击监听器’
interface WindowClickListener {
fun onWindowClick(windowInfo: WindowInfo?): Boolean
}
}
ViewManager提供了updateViewLayout(View view, ViewGroup.LayoutParams params)用于更新浮窗位置，所以只需监听ACTION_MOVE事件并实时更新浮窗视图位置就可实现拖拽。ACTION_MOVE事件被GestureDetector解析成OnGestureListener.onScroll()回调：
object FloatWindow : View.OnTouchListener{
private var gestureDetector: GestureDetector = GestureDetector(context, GestureListener())
private var lastTouchX: Int = 0
private var lastTouchY: Int = 0
override fun onTouch(v: View, event: MotionEvent): Boolean {
//‘将触摸事件传递给GestureDetector解析’
gestureDetector.onTouchEvent(event)
return true
}
private class GestureListener : GestureDetector.OnGestureListener {
override fun onDown(e: MotionEvent): Boolean {
onActionDown(e)
return false
}
override fun onScroll(e1: MotionEvent,e2: MotionEvent,distanceX: Float,distanceY:Float): Boolean {
//‘响应手指滚动事件’
onActionMove(e2)
return true
}
}
private fun onActionMove(event: MotionEvent) {
//‘获取当前手指坐标’
val currentX = event.rawX.toInt()
val currentY = event.rawY.toInt()
//‘获取手指移动增量’
val dx = currentX - lastTouchX
val dy = currentY - lastTouchY
//‘将移动增量应用到窗口布局参数上’
windowInfo?.layoutParams!!.x += dx
windowInfo?.layoutParams!!.y += dy
val windowManager = context?.getSystemService(Context.WINDOW_SERVICE) as WindowManager
var rightMost = screenWidth - windowInfo?.layoutParams!!.width
var leftMost = 0
val topMost = 0
val bottomMost = screenHeight - windowInfo?.layoutParams!!.height - getNavigationBarHeight(context)
//‘将浮窗移动区域限制在屏幕内’
if (windowInfo?.layoutParams!!.x < leftMost) {
windowInfo?.layoutParams!!.x = leftMost
}
if (windowInfo?.layoutParams!!.x > rightMost) {
windowInfo?.layoutParams!!.x = rightMost
}
if (windowInfo?.layoutParams!!.y < topMost) {
windowInfo?.layoutParams!!.y = topMost
}
if (windowInfo?.layoutParams!!.y > bottomMost) {
windowInfo?.layoutParams!!.y = bottomMost
}
//‘更新浮窗位置’
windowManager.updateViewLayout(windowInfo?.view, windowInfo?.layoutParams)
lastTouchX = currentX
lastTouchY = currentY
}
}
新的需求来了，拖拽浮窗松手后，需要自动贴边。
把贴边理解成一个水平位移动画。在松手时求出动画起点和终点横坐标，利用动画值不断更新浮窗位置：
object FloatWindow : View.OnTouchListener{
private var gestureDetector: GestureDetector = GestureDetector(context, GestureListener())
private var lastTouchX: Int = 0
private var lastTouchY: Int = 0
//‘贴边动画’
private var weltAnimator: ValueAnimator? = null
override fun onTouch(v: View, event: MotionEvent): Boolean {
//‘将触摸事件传递给GestureDetector解析’
gestureDetector.onTouchEvent(event)
//‘处理ACTION_UP事件’
val action = event.action
when (action) {
MotionEvent.ACTION_UP -> onActionUp(event, screenWidth, windowInfo?.width ?: 0)
else -> {
}
}
return true
}
private fun onActionUp(event: MotionEvent, screenWidth: Int, width: Int) {
if (!windowInfo?.hasView().value()) { return }
//‘记录抬手横坐标’
val upX = event.rawX.toInt()
//‘贴边动画终点横坐标’
val endX = if (upX > screenWidth / 2) {
标签：实现,WindowManager,layoutParams,悬浮,LayoutParams,fun,Android,windowInfo,浮窗 来源： https://blog.csdn.net/flunsna/article/details/122169575
本站声明： 1. iCode9 技术分享网（下文简称本站）提供的所有内容，仅供技术学习、探讨和分享； 2. 关于本站的所有留言、评论、转载及引用，纯属内容发起人的个人观点，与本站观点和立场无关； 3. 关于本站的所有言论和文字，纯属内容发起人的个人观点，与本站观点和立场无关； 4. 本站文章均是网友提供，不完全保证技术分享内容的完整性、准确性、时效性、风险性和版权归属；如您发现该文章侵犯了您的权益，可联系我们第一时间进行删除； 5. 本站为非盈利性的个人网站，所有内容不会用来进行牟利，也不会利用任何形式的广告来间接获益，纯粹是为了广大技术爱好者提供技术内容和技术思想的分享性交流网站。