android 窗口焦点丢失,窗口焦点丢失问题分析

从slog中的systemlog可以看出如下信息：

01-01 08:29:03.732   633   936 I WindowManager: Relayout invis Window{42244420 u0 Keyguard}: mExiting=false

01-01 08:29:03.732   633  1011 D PowerManagerService: releaseWakeLockInternal: lock=1109498264 [NlpWakeLock], flags=0x0 pkg name:com.google.android.gms

01-01 08:29:03.732   633  1011 D PowerManagerService: updateSuspendBlockerLocked goto release:PowerManagerService.WakeLocks: ref count=1

01-01 08:29:03.732   633  1011 D PowerManagerService: Releasing suspend blocker "PowerManagerService.WakeLocks".

01-01 08:29:03.732   633   936 I WindowManager: Releasing surface in: Window{42244420 u0 Keyguard EXITING}

01-01 08:29:03.732   633   936 D WindowManager: Input focus has changed to null

01-01 08:29:03.752   633   644 D PowerManagerService: acquireWakeLockInternal: lock=1109498264, flags=0x1, tag="NlpWakeLock", ws=null, uid=10025, pid=968 pkg name:com.google.android.gms

01-01 08:29:03.752   633   644 D PowerManagerService: updateSuspendBlockerLocked goto acquire:PowerManagerService.WakeLocks: ref count=0

01-01 08:29:03.752   633   644 D PowerManagerService: Acquiring suspend blocker "PowerManagerService.WakeLocks".

01-01 08:29:03.762   633   648 I WindowManager: Focus moving from Window{42244420 u0 Keyguard EXITING} to null

01-01 08:29:03.762   633   648 I WindowManager: Losing focus: Window{42244420 u0 Keyguard EXITING}

01-01 08:29:03.792   633   648 D WindowManager: Input focus has changed to Window{42242428 u0 com.android.phone}

01-01 08:29:03.832   633   786 D PowerManagerService: acquireWakeLockInternal: lock=1110600800, flags=0x1, tag="UlrDispatchingService", ws=null, uid=10025, pid=968 pkg name:com.google.android.gms

可以使用针对一些系统窗口进行测试验证，

常见的系统窗口：

长按关机键出现的对话框

statusbar下拉框

低电警告

锁网

anr提示框

。。。

​

具体：

WindowManager.java中

public static final int TYPE_STATUS_BAR         = FIRST_SYSTEM_WINDOW;

。。。

public static final int LAST_SYSTEM_WINDOW      = 2999;

这之间的窗口类型全是系统窗口

原因已查明：

两个不同层级的系统级dialog开出顺序加上keyguard的特殊性导致了窗口focus错误

1.窗口堆栈初始状态：

...

keyguard

wallpaper

launcher

...

2.开出低电量后，由于低电警告层级>wallpaper，所以变化为：修改后与3一样

...

keyguard

low_battery

wallpaper

launcher

...

3.由于墙纸窗口的特殊性，总是显示在需要显示墙纸窗口(这里是keyguard)的下面，所以调整为：

...

keyguard

wallpaper

low_battery

launcher

...

4.开出锁网后，由于锁网窗口层级>wallpaper，所以 变化为：

...

keyguard

sim_lock

wallpaper

low_battery

launcher

...​

修改后:

keyguard

wallpaper

low_battery

sim_lock

launcher

5.墙纸窗口的特殊性，总是显示在需要显示墙纸窗口(这里是keyguard)的下面，所以调整为：

...

keyguard

wallpaper

sim_lock

low_battery

launcher

...​

虽然锁网层级

修改方案有两种：

1.锁网比低电后开出才有此问题，可以在锁网开出的时候发广播关闭低电警告(建议采用此规避方案，但是由于其他dialog也会出现该问题，故未采用该方案)

2.wms添加系统窗口修改，堆栈中碰到wallpaper窗口，直接pass，继续寻找，此方案修改方法如下：

diff --git a/services/java/com/android/server/wm/WindowManagerService.java b/services/java/com/android/server/wm/WindowManagerService

index 6099cfa..eebe4b4 100755

--- a/services/java/com/android/server/wm/WindowManagerService.java

+++ b/services/java/com/android/server/wm/WindowManagerService.java

@@ -1075,6 +1075,9 @@ public class WindowManagerService extends IWindowManager.Stub

int i;

for (i = windows.size() - 1; i >= 0; i--) {

if (windows.get(i).mBaseLayer <= myLayer) {

+                if (windows.get(i).mIsWallpaper) {

+                    continue;

+                }

break;

}

}

谢谢!