Fix a flicker when returning to the lockscreen

If we return to the lockscreen from a FLAG_SHOW_WHEN_LOCKED activity,
there was an additional black flicker as the wallpaper wasn't shown
for a couple of frames. The issue is that we didn't set the wallpaper
flag again, to fix another flicker with lockscreen wallpapers. Now,
we pass the state whether we currently have a lockscreen wallpaper
and if we don't have one, we immediately set the wallpaper flag
again.

Bug: 30829255
Bug: 30883413
Change-Id: I9faeaa77b98eb02058171ce19cf90b43826ebe9e

core/java/com/android/internal/policy/IKeyguardStateCallback.aidl

@@ -20,4 +20,5 @@ interface IKeyguardStateCallback {
     void onSimSecureStateChanged(boolean simSecure);
     void onInputRestrictedStateChanged(boolean inputRestricted);
     void onTrustedChanged(boolean trusted);
+    void onHasLockscreenWallpaperChanged(boolean hasLockscreenWallpaper);
 }

packages/Keyguard/src/com/android/keyguard/KeyguardUpdateMonitor.java

@@ -178,6 +178,7 @@ public class KeyguardUpdateMonitor implements TrustManager.TrustListener {
     private boolean mBouncer;
     private boolean mBootCompleted;
     private boolean mUserUnlocked;
+    private boolean mHasLockscreenWallpaper;
 
     // Device provisioning state
     private boolean mDeviceProvisioned;
@@ -1172,6 +1173,30 @@ public class KeyguardUpdateMonitor implements TrustManager.TrustListener {
         }
     }
 
+    /**
+     * Update the state whether Keyguard currently has a lockscreen wallpaper.
+     *
+     * @param hasLockscreenWallpaper Whether Keyguard has a lockscreen wallpaper.
+     */
+    public void setHasLockscreenWallpaper(boolean hasLockscreenWallpaper) {
+        if (hasLockscreenWallpaper != mHasLockscreenWallpaper) {
+            mHasLockscreenWallpaper = hasLockscreenWallpaper;
+            for (int i = mCallbacks.size() - 1; i >= 0; i--) {
+                KeyguardUpdateMonitorCallback cb = mCallbacks.get(i).get();
+                if (cb != null) {
+                    cb.onHasLockscreenWallpaperChanged(hasLockscreenWallpaper);
+                }
+            }
+        }
+    }
+
+    /**
+     * @return Whether Keyguard has a lockscreen wallpaper.
+     */
+    public boolean hasLockscreenWallpaper() {
+        return mHasLockscreenWallpaper;
+    }
+
     /**
      * Handle {@link #MSG_DPM_STATE_CHANGED}
      */

packages/Keyguard/src/com/android/keyguard/KeyguardUpdateMonitorCallback.java

@@ -240,4 +240,9 @@ public class KeyguardUpdateMonitorCallback {
      * has changed.
      */
     public void onStrongAuthStateChanged(int userId) { }
+
+    /**
+     * Called when the state whether we have a lockscreen wallpaper has changed.
+     */
+    public void onHasLockscreenWallpaperChanged(boolean hasLockscreenWallpaper) { }
 }

packages/SystemUI/src/com/android/systemui/keyguard/KeyguardViewMediator.java

@@ -16,7 +16,11 @@
 
 package com.android.systemui.keyguard;
 
-import android.annotation.UserIdInt;
+import static android.provider.Settings.System.SCREEN_OFF_TIMEOUT;
+import static com.android.internal.widget.LockPatternUtils.StrongAuthTracker.SOME_AUTH_REQUIRED_AFTER_USER_REQUEST;
+import static com.android.internal.widget.LockPatternUtils.StrongAuthTracker.STRONG_AUTH_REQUIRED_AFTER_DPM_LOCK_NOW;
+import static com.android.internal.widget.LockPatternUtils.StrongAuthTracker.STRONG_AUTH_REQUIRED_AFTER_LOCKOUT;
+
 import android.app.Activity;
 import android.app.ActivityManager;
 import android.app.ActivityManagerNative;
@@ -82,12 +86,6 @@ import com.android.systemui.statusbar.phone.StatusBarWindowManager;
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
 import java.util.ArrayList;
-import java.util.List;
-
-import static android.provider.Settings.System.SCREEN_OFF_TIMEOUT;
-import static com.android.internal.widget.LockPatternUtils.StrongAuthTracker.SOME_AUTH_REQUIRED_AFTER_USER_REQUEST;
-import static com.android.internal.widget.LockPatternUtils.StrongAuthTracker.STRONG_AUTH_REQUIRED_AFTER_DPM_LOCK_NOW;
-import static com.android.internal.widget.LockPatternUtils.StrongAuthTracker.STRONG_AUTH_REQUIRED_AFTER_LOCKOUT;
 
 /**
  * Mediates requests related to the keyguard.  This includes queries about the
@@ -509,7 +507,12 @@ public class KeyguardViewMediator extends SystemUI {
             }
         }
 
-
+        @Override
+        public void onHasLockscreenWallpaperChanged(boolean hasLockscreenWallpaper) {
+            synchronized (KeyguardViewMediator.this) {
+                notifyHasLockscreenWallpaperChanged(hasLockscreenWallpaper);
+            }
+        }
     };
 
     ViewMediatorCallback mViewMediatorCallback = new ViewMediatorCallback() {
@@ -2014,6 +2017,21 @@ public class KeyguardViewMediator extends SystemUI {
         }
     }
 
+    private void notifyHasLockscreenWallpaperChanged(boolean hasLockscreenWallpaper) {
+        int size = mKeyguardStateCallbacks.size();
+        for (int i = size - 1; i >= 0; i--) {
+            try {
+                mKeyguardStateCallbacks.get(i).onHasLockscreenWallpaperChanged(
+                        hasLockscreenWallpaper);
+            } catch (RemoteException e) {
+                Slog.w(TAG, "Failed to call onHasLockscreenWallpaperChanged", e);
+                if (e instanceof DeadObjectException) {
+                    mKeyguardStateCallbacks.remove(i);
+                }
+            }
+        }
+    }
+
     public void addStateMonitorCallback(IKeyguardStateCallback callback) {
         synchronized (this) {
             mKeyguardStateCallbacks.add(callback);
@@ -2023,6 +2041,7 @@ public class KeyguardViewMediator extends SystemUI {
                 callback.onInputRestrictedStateChanged(mInputRestricted);
                 callback.onTrustedChanged(mUpdateMonitor.getUserHasTrust(
                         KeyguardUpdateMonitor.getCurrentUser()));
+                callback.onHasLockscreenWallpaperChanged(mUpdateMonitor.hasLockscreenWallpaper());
             } catch (RemoteException e) {
                 Slog.w(TAG, "Failed to call to IKeyguardStateCallback", e);
             }

packages/SystemUI/src/com/android/systemui/statusbar/phone/LockscreenWallpaper.java

@@ -38,6 +38,8 @@ import android.os.ServiceManager;
 import android.os.UserHandle;
 import android.util.Log;
 
+import com.android.keyguard.KeyguardUpdateMonitor;
+
 import libcore.io.IoUtils;
 
 import java.util.Objects;
@@ -52,6 +54,7 @@ public class LockscreenWallpaper extends IWallpaperManagerCallback.Stub implemen
     private final PhoneStatusBar mBar;
     private final WallpaperManager mWallpaperManager;
     private final Handler mH;
+    private final KeyguardUpdateMonitor mUpdateMonitor;
 
     private boolean mCached;
     private Bitmap mCache;
@@ -66,6 +69,7 @@ public class LockscreenWallpaper extends IWallpaperManagerCallback.Stub implemen
         mH = h;
         mWallpaperManager = (WallpaperManager) ctx.getSystemService(Context.WALLPAPER_SERVICE);
         mCurrentUserId = ActivityManager.getCurrentUser();
+        mUpdateMonitor = KeyguardUpdateMonitor.getInstance(ctx);
 
         IWallpaperManager service = IWallpaperManager.Stub.asInterface(
                 ServiceManager.getService(Context.WALLPAPER_SERVICE));
@@ -89,6 +93,7 @@ public class LockscreenWallpaper extends IWallpaperManagerCallback.Stub implemen
         LoaderResult result = loadBitmap(mCurrentUserId, mSelectedUser);
         if (result.success) {
             mCached = true;
+            mUpdateMonitor.setHasLockscreenWallpaper(result.bitmap != null);
             mCache = result.bitmap;
         }
         return mCache;
@@ -181,6 +186,7 @@ public class LockscreenWallpaper extends IWallpaperManagerCallback.Stub implemen
                 if (result.success) {
                     mCached = true;
                     mCache = result.bitmap;
+                    mUpdateMonitor.setHasLockscreenWallpaper(result.bitmap != null);
                     mBar.updateMediaMetaData(
                             true /* metaDataChanged */, true /* allowEnterAnimation */);
                 }

services/core/java/com/android/server/policy/PhoneWindowManager.java

@@ -5319,6 +5319,9 @@ public class PhoneWindowManager implements WindowManagerPolicy {
             mKeyguardOccluded = false;
             mKeyguardDelegate.setOccluded(false);
             mStatusBar.getAttrs().privateFlags |= PRIVATE_FLAG_KEYGUARD;
+            if (!mKeyguardDelegate.hasLockscreenWallpaper()) {
+                mStatusBar.getAttrs().flags |= FLAG_SHOW_WALLPAPER;
+            }
             return true;
         } else if (!wasOccluded && isOccluded && showing) {
             mKeyguardOccluded = true;

services/core/java/com/android/server/policy/keyguard/KeyguardServiceDelegate.java

@@ -206,6 +206,13 @@ public class KeyguardServiceDelegate {
         return false;
     }
 
+    public boolean hasLockscreenWallpaper() {
+        if (mKeyguardService != null) {
+            return mKeyguardService.hasLockscreenWallpaper();
+        }
+        return false;
+    }
+
     public boolean isInputRestricted() {
         if (mKeyguardService != null) {
             mKeyguardState.inputRestricted = mKeyguardService.isInputRestricted();

services/core/java/com/android/server/policy/keyguard/KeyguardServiceWrapper.java

@@ -238,6 +238,10 @@ public class KeyguardServiceWrapper implements IKeyguardService {
         return mKeyguardStateMonitor.isTrusted();
     }
 
+    public boolean hasLockscreenWallpaper() {
+        return mKeyguardStateMonitor.hasLockscreenWallpaper();
+    }
+
     public boolean isSecure(int userId) {
         return mKeyguardStateMonitor.isSecure(userId);
     }

services/core/java/com/android/server/policy/keyguard/KeyguardStateMonitor.java

@@ -44,6 +44,7 @@ public class KeyguardStateMonitor extends IKeyguardStateCallback.Stub {
     private volatile boolean mSimSecure = true;
     private volatile boolean mInputRestricted = true;
     private volatile boolean mTrusted = false;
+    private volatile boolean mHasLockscreenWallpaper = false;
 
     private int mCurrentUserId;
 
@@ -75,6 +76,10 @@ public class KeyguardStateMonitor extends IKeyguardStateCallback.Stub {
         return mTrusted;
     }
 
+    public boolean hasLockscreenWallpaper() {
+        return mHasLockscreenWallpaper;
+    }
+
     @Override // Binder interface
     public void onShowingStateChanged(boolean showing) {
         mIsShowing = showing;
@@ -103,6 +108,11 @@ public class KeyguardStateMonitor extends IKeyguardStateCallback.Stub {
         mTrusted = trusted;
     }
 
+    @Override // Binder interface
+    public void onHasLockscreenWallpaperChanged(boolean hasLockscreenWallpaper) {
+        mHasLockscreenWallpaper = hasLockscreenWallpaper;
+    }
+
     public void dump(String prefix, PrintWriter pw) {
         pw.println(prefix + TAG);
         prefix += "  ";