android 13 WMS/AMS系统开发-窗口层级相关DisplayArea,WindowContainer

WindowContainer类相关类解释

官方注释：

给可以直接持有窗口的自己或它的孩子定义了一些公共的方法和属性，像RootWindowContainer、DisplayContent、DisplayArea、DisplayArea.Tokens、TaskDisplayArea、Task、ActivityRecord、WindowToken、WindowState都是直接或间接的继承该类。

class WindowContainer<E extends WindowContainer> extends ConfigurationContainer<E>        implements Comparable<WindowContainer>, Animatable, SurfaceFreezer.Freezable,        InsetsControlTarget {        private WindowContainer<WindowContainer> mParent = null;    // List of children for this window container. List is in z-order as the children appear on    // screen with the top-most window container at the tail of the list.    protected final WindowList<E> mChildren = new WindowList<E>();}

这里面主要的重要要成员变量就是mParent和mChildren，一个代表父节点一个代表子节点，而且子节点的list顺序代表就是z轴的层级显示顺序，list尾巴在比list的头的z轴层级要高。

RootWindowContainer：根窗口容器，树的根是它。通过它遍历寻找，可以找到窗口树上的窗口。它的孩子是DisplayContent。
  DisplayContent：该类是对应着显示屏幕的，Android是支持多屏幕的，所以可能存在多个DisplayContent对象。上图只画了一个对象的结构，其他对象的结构也是和画的对象的结构是相似的。
DisplayArea：该类是对应着显示屏幕下面的，代表一组窗口合集,具有多个子类，如Tokens，TaskDisplayArea等
  TaskDisplayArea：它为DisplayContent的孩子，对应着窗口层次的第2层。第2层作为应用层，看它的定义：int APPLICATION_LAYER = 2，应用层的窗口是处于第2层。TaskDisplayArea的孩子是Task类，其实它的孩子类型也可以是TaskDisplayArea。而Task的孩子则可以是ActivityRecord，也可以是Task。
  Tokens：代表专门包含WindowTokens的容器，它的孩子是WindowToken，而WindowToken的孩子则为WindowState对象。WindowState是对应着一个窗口的。
  ImeContainer：它是输入法窗口的容器，它的孩子是WindowToken类型。WindowToken的孩子为WindowState类型，而WindowState类型则对应着输入法窗口。
  Task：任务，它的孩子可以是Task，也可以是ActivityRecord类型。
  ActivityRecord：是对应着应用进程中的Activity的。ActivityRecord是继承WindowToken的，它的孩子类型为WindowState。
  WindowState：WindowState是对应着一个窗口的。

窗口层级分析WindowContainer相关子类关联：
这里先我们用一个dumpsys命令来看看层级结构相关的输出
test@test:~$ adb shell dumpsys activity containers

ACTIVITY MANAGER CONTAINERS (dumpsys activity containers)ROOT type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]  #0 Display 0 name="Built-in Screen" type=undefined mode=fullscreen override-mode=fullscreen requested-bounds=[0,0][1440,2960] bounds=[0,0][1440,2960]   #2 Leaf:36:36 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]    #1 WindowToken{6e2757c type=2024 android.os.BinderProxy@6d43102} type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]     #0 81ffe05 ScreenDecorOverlayBottom type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]    #0 WindowToken{98a9487 type=2024 android.os.BinderProxy@2130925} type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]     #0 ac8fb4 ScreenDecorOverlay type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]   #1 HideDisplayCutout:32:35 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]    #2 OneHanded:34:35 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]     #0 FullscreenMagnification:34:35 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]      #0 Leaf:34:35 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]    #1 FullscreenMagnification:33:33 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]     #0 Leaf:33:33 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]    #0 OneHanded:32:32 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]     #0 Leaf:32:32 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]   #0 WindowedMagnification:0:31 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]    #6 HideDisplayCutout:26:31 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]     #0 OneHanded:26:31 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]      #2 FullscreenMagnification:29:31 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]       #0 Leaf:29:31 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]      #1 Leaf:28:28 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]      #0 FullscreenMagnification:26:27 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]       #0 Leaf:26:27 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]    #5 Leaf:24:25 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]     #1 WindowToken{696f278 type=2024 android.os.BinderProxy@31aecde} type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]      #0 cf5fd51 pip-dismiss-overlay type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]     #0 WindowToken{e74c3eb type=2019 android.os.BinderProxy@d19030} type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]      #0 e2b3548 NavigationBar0 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]    #4 HideDisplayCutout:18:23 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]     #0 OneHanded:18:23 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]      #0 FullscreenMagnification:18:23 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]       #0 Leaf:18:23 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]    #3 OneHanded:17:17 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]     #0 FullscreenMagnification:17:17 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]      #0 Leaf:17:17 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]       #0 WindowToken{34b13c0 type=2040 android.os.BinderProxy@710d2c1} type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]        #0 d7c18f9 NotificationShade type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]    #2 HideDisplayCutout:16:16 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]     #0 OneHanded:16:16 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]      #0 FullscreenMagnification:16:16 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]       #0 Leaf:16:16 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]    #1 OneHanded:15:15 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]     #0 FullscreenMagnification:15:15 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]      #0 Leaf:15:15 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]       #0 WindowToken{e183269 type=2000 android.os.BinderProxy@e488916} type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]        #0 5dfa4ee StatusBar type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]    #0 HideDisplayCutout:0:14 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]     #0 OneHanded:0:14 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]      #1 ImePlaceholder:13:14 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]       #0 ImeContainer type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]        #0 WindowToken{9439bd0 type=2011 android.os.Binder@f6126f6} type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]         #0 6060c0a InputMethod type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]      #0 FullscreenMagnification:0:12 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]       #2 Leaf:3:12 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]        #0 WindowToken{58fdd21 type=2038 android.os.BinderProxy@ff11113} type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]         #0 cd4a10f ShellDropTarget type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]       #1 DefaultTaskDisplayArea type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]        #2 Task=1 type=home mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]         #0 Task=8 type=home mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]          #0 ActivityRecord{6733b50 u0 com.android.launcher3/.uioverrides.QuickstepLauncher} t8} type=home mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]           #0 6e08fe2 com.android.launcher3/com.android.launcher3.uioverrides.QuickstepLauncher type=home mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]        #1 Task=3 type=undefined mode=fullscreen override-mode=fullscreen requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]        #0 Task=4 type=undefined mode=fullscreen override-mode=fullscreen requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]         #1 Task=6 type=undefined mode=multi-window override-mode=multi-window requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]         #0 Task=5 type=undefined mode=multi-window override-mode=multi-window requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]       #0 Leaf:0:1 type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]        #0 WallpaperWindowToken{76eaad0 token=android.os.Binder@28e6df6} type=undefined mode=fullscreen override-mode=fullscreen requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]         #0 19ddb72 com.android.systemui.ImageWallpaper type=undefined mode=fullscreen override-mode=undefined requested-bounds=[0,0][0,0] bounds=[0,0][1440,2960]

dumpsys的输出其实就是代表了整个图层结构的一个树形输出，可能这样看稍微有一些抽象，我们把他转成图如下：
其实你第一次看到一定一脸迷茫，不知道怎么看。
接下来我就来详细讲解这个层级结构是怎么来的
每个显示屏幕的窗口层级分为37层，0-36层。每层可以放置多个窗口，上层窗口覆盖下面的，这个树中每个点一般这样格式：
xxx名字：层级开始数 ：层级结束数

那么如下节点，代表当前名字为Leaf图层占领了0-1这两个层级
这一下解释以后是不是从右到左依次看每个节点是不是就可以看出来，0-36个图层每个图层都有对应节点进行占领，有的一个节点占领一层，如Leaf:16:16 ，有的一个节点可能占领多层如：Leaf:18:23

这个就是wms中可以起到分层的一个树，但是看了半天是不是发现好像和我们平时分析的WindowToken等身影，因为树最开始创建时候肯定还没有任何的有效Window，有效window都是各个app等触发来创建的，这里如果根据dumpsys加上常见几个window如下：
彩色部分就是我们常见的一些window的图层位置，明显可以看出，
Wallpaper处于0-1层节点
Activity处于DefaultTaskDisplayArea也就是第2层
InputMethod处于13-14层
StatusBar处于15层
NotificationShade处于17层
NavigationBar0处于24-25层
是不是这一下就亲切多了，瞬间就感觉平常见到的那些window都清楚知道他们的层级了，所以而且也完全符合我们的实际现象，比如Activity肯定要在Wallpaer的上面，NavigationBar0肯定在Activity的上面
当然同学会问：请问这个层级树是怎么构成的？这个部分相对比较复杂，后续再分享，本节我们就要掌握好可以根据dumpsys可以复原出树形图，也可以清楚自己的Window具体处在的层级

总结：

最后我们已经了解了层级结构树，这里又回到开始讨论的WindowContainer几个子类结合层级树关系大概如下：

来源地址：https://blog.csdn.net/learnframework/article/details/129101781