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

2 files changed, 30 insertions, 0 deletions

diff --git a/packages/Keyguard/src/com/android/keyguard/KeyguardUpdateMonitor.java b/packages/Keyguard/src/com/android/keyguard/KeyguardUpdateMonitor.java
index 0a862914b14f..56f37414a0e6 100644
--- a/packages/Keyguard/src/com/android/keyguard/KeyguardUpdateMonitor.java
+++ b/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;
@@ -1173,6 +1174,30 @@ 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}
      */
     protected void handleDevicePolicyManagerStateChanged() {
diff --git a/packages/Keyguard/src/com/android/keyguard/KeyguardUpdateMonitorCallback.java b/packages/Keyguard/src/com/android/keyguard/KeyguardUpdateMonitorCallback.java
index bd6c51c3b89c..4a2d356b6ddd 100644
--- a/packages/Keyguard/src/com/android/keyguard/KeyguardUpdateMonitorCallback.java
+++ b/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) { }
 }