Android 11 添加找回锁屏密码的暗门

前景：
由于有些设备在用户的手上，自己设置了锁屏密码，但如果长时间不使用设备，用户容易忘记自己当初设备的密码了。

像这种情况，只能强制恢复出厂设置了。但这会导致用户的数据都丢失了。所以我们在锁屏界面做了暗门，可以找回锁屏密码。

暗门操作：
1.在锁屏界面连续点击锁屏图标10次，即在锁屏图标下方显示设置的密码。
2.或在密码输入界面连续点击锁屏图标10次，即在锁屏图标下方显示设置的密码。

功能实现：

1.在锁屏图标下方添加个textview，用于密码的显示

路径:frameworks/base/packages/SystemUI/res/layout/super_notification_shade.xml

@@ -92,5 +92,14 @@
             android:singleLine="true"
             android:ellipsize="marquee"
             android:focusable="true" />
+                       
     
 

2.在用户第一次或重置密码时，把当前密码保存到自定义的系统属性中。用于在textview只能获取。

路径： frameworks/base/services/core/java/com/android/server/locksettings/LockSettingsService.java

  import com.android.internal.annotations.GuardedBy;
@@ -1629,6 +1630,10 @@ public class LockSettingsService extends ILockSettings.Stub {
         }
         notifySeparateProfileChallengeChanged(userId);
         scheduleGc();
+       String pwd =  new String(credential.getCredential());
+       int type = credential.getStorageCryptType();
+       SystemProperties.set("persist.sys.password",pwd);
         return true;
     }

3.实现连续点击10次锁屏图标，把密码显示出来的逻辑。

路径：frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/StatusBar.java

import java.util.Optional;
 import java.util.concurrent.Executor;
+import android.widget.LinearLayout;
+import android.widget.TextView;
 
 import javax.inject.Named;
 import javax.inject.Provider;
@@ -383,6 +385,10 @@ public class StatusBar extends SystemUI implements DemoMode,
     DozeServiceHost mDozeServiceHost;
     private boolean mWakeUpComingFromTouch;
     private PointF mWakeUpTouchLocation;
+    private LinearLayout mLockContainer;
+       private TextView mLockPwd;
+       private int clickCount = 0;
+       private long lastTime = 0;
 
     private final Object mQueueLock = new Object();
 
@@ -1212,6 +1218,9 @@ public class StatusBar extends SystemUI implements DemoMode,
         inflateStatusBarWindow();
         mNotificationShadeWindowViewController.setService(this, mNotificationShadeWindowController);
         mNotificationShadeWindowView.setOnTouchListener(getStatusBarWindowTouchListener());
+           mLockContainer = mNotificationShadeWindowView.findViewById(R.id.lock_icon_container);
+               mLockContainer.setOnTouchListener(getLockIcomWindowTouchListener());
+               mLockPwd = mLockContainer.findViewById(R.id.lock_pwd);
 
         // TODO: Deal with the ugliness that comes from having some of the statusbar broken out
         // into fragments, but the rest here, it leaves some awkward lifecycle and whatnot.
@@ -1622,6 +1631,28 @@ public class StatusBar extends SystemUI implements DemoMode,
             return mNotificationShadeWindowView.onTouchEvent(event);
         };
     }
+       
+        protected View.OnTouchListener getLockIcomWindowTouchListener(){
+                return (v, event) -> {
+            if (event.getAction() == MotionEvent.ACTION_DOWN) {
+                               long newTime = System.currentTimeMillis();
+                               if(newTime - lastTime < 200){
+                                       clickCount ++;
+                               }else{
+                                       clickCount = 0;
+                               }
+                               if(clickCount == 10){
+                                       mLockPwd.setText(SystemProperties.get("persist.sys.password"));
+                                       mHandler.postDelayed(() -> {
+                       mLockPwd.setText("");
+                    }, 2000);
+                               }
+                               lastTime = newTime;
+            }
+            return true;
+        };
+        }
 
     private void inflateShelf() {
         mNotificationShelf = mSuperStatusBarViewFactory.getNotificationShelf(mStackScroller);