Merge "Multi-user and WallpaperColors" into oc-mr1-dev

am: 22b418448b

Change-Id: I366a0968883a57499392edafcc95c53416268329

10 files changed, 251 insertions, 80 deletions

diff --git a/core/java/android/app/IWallpaperManager.aidl b/core/java/android/app/IWallpaperManager.aidl
index 0e33934acf8e..49d58eb2c38d 100644
--- a/core/java/android/app/IWallpaperManager.aidl
+++ b/core/java/android/app/IWallpaperManager.aidl
@@ -144,15 +144,15 @@ interface IWallpaperManager {
      * or {@link WallpaperManager#FLAG_SYSTEM}
      * @return colors of chosen wallpaper
      */
-    WallpaperColors getWallpaperColors(int which);
+    WallpaperColors getWallpaperColors(int which, int userId);
 
     /**
      * Register a callback to receive color updates
      */
-    void registerWallpaperColorsCallback(IWallpaperManagerCallback cb);
+    void registerWallpaperColorsCallback(IWallpaperManagerCallback cb, int userId);
 
     /**
      * Unregister a callback that was receiving color updates
      */
-    void unregisterWallpaperColorsCallback(IWallpaperManagerCallback cb);
+    void unregisterWallpaperColorsCallback(IWallpaperManagerCallback cb, int userId);
 }
diff --git a/core/java/android/app/IWallpaperManagerCallback.aidl b/core/java/android/app/IWallpaperManagerCallback.aidl
index 0cfbaef6d6eb..ea0ceab9a8df 100644
--- a/core/java/android/app/IWallpaperManagerCallback.aidl
+++ b/core/java/android/app/IWallpaperManagerCallback.aidl
@@ -34,6 +34,6 @@ oneway interface IWallpaperManagerCallback {
     /**
      * Called when wallpaper colors change
      */
-    void onWallpaperColorsChanged(in WallpaperColors colors, int which);
+    void onWallpaperColorsChanged(in WallpaperColors colors, int which, int userId);
 
 }
diff --git a/core/java/android/app/WallpaperColors.java b/core/java/android/app/WallpaperColors.java
index d0791cf93469..2a8130f1bd5e 100644
--- a/core/java/android/app/WallpaperColors.java
+++ b/core/java/android/app/WallpaperColors.java
@@ -408,4 +408,13 @@ public final class WallpaperColors implements Parcelable {
 
         return new Size(newWidth, newHeight);
     }
+
+    @Override
+    public String toString() {
+        final StringBuilder colors = new StringBuilder();
+        for (int i = 0; i < mMainColors.size(); i++) {
+            colors.append(Integer.toHexString(mMainColors.get(i).toArgb())).append(" ");
+        }
+        return "[WallpaperColors: " + colors.toString() + "h: " + mColorHints + "]";
+    }
 }
diff --git a/core/java/android/app/WallpaperManager.java b/core/java/android/app/WallpaperManager.java
index 0398b47e8591..16d02149cc0d 100644
--- a/core/java/android/app/WallpaperManager.java
+++ b/core/java/android/app/WallpaperManager.java
@@ -307,13 +307,14 @@ public class WallpaperManager {
          * changes its colors.
          * @param callback Listener
          * @param handler Thread to call it from. Main thread if null.
+         * @param userId Owner of the wallpaper or UserHandle.USER_ALL
          */
         public void addOnColorsChangedListener(@NonNull OnColorsChangedListener callback,
-                @Nullable Handler handler) {
+                @Nullable Handler handler, int userId) {
             synchronized (this) {
                 if (!mColorCallbackRegistered) {
                     try {
-                        mService.registerWallpaperColorsCallback(this);
+                        mService.registerWallpaperColorsCallback(this, userId);
                         mColorCallbackRegistered = true;
                     } catch (RemoteException e) {
                         // Failed, service is gone
@@ -328,15 +329,17 @@ public class WallpaperManager {
          * Stop listening to wallpaper color events.
          *
          * @param callback listener
+         * @param userId Owner of the wallpaper or UserHandle.USER_ALL
          */
-        public void removeOnColorsChangedListener(@NonNull OnColorsChangedListener callback) {
+        public void removeOnColorsChangedListener(@NonNull OnColorsChangedListener callback,
+                int userId) {
             synchronized (this) {
                 mColorListeners.removeIf(pair -> pair.first == callback);
 
                 if (mColorListeners.size() == 0 && mColorCallbackRegistered) {
                     mColorCallbackRegistered = false;
                     try {
-                        mService.unregisterWallpaperColorsCallback(this);
+                        mService.unregisterWallpaperColorsCallback(this, userId);
                     } catch (RemoteException e) {
                         // Failed, service is gone
                         Log.w(TAG, "Can't unregister color updates", e);
@@ -346,7 +349,7 @@ public class WallpaperManager {
         }
 
         @Override
-        public void onWallpaperColorsChanged(WallpaperColors colors, int which) {
+        public void onWallpaperColorsChanged(WallpaperColors colors, int which, int userId) {
             synchronized (this) {
                 for (Pair<OnColorsChangedListener, Handler> listener : mColorListeners) {
                     Handler handler = listener.second;
@@ -361,21 +364,21 @@ public class WallpaperManager {
                             stillExists = mColorListeners.contains(listener);
                         }
                         if (stillExists) {
-                            listener.first.onColorsChanged(colors, which);
+                            listener.first.onColorsChanged(colors, which, userId);
                         }
                     });
                 }
             }
         }
 
-        WallpaperColors getWallpaperColors(int which) {
+        WallpaperColors getWallpaperColors(int which, int userId) {
             if (which != FLAG_LOCK && which != FLAG_SYSTEM) {
                 throw new IllegalArgumentException(
                         "Must request colors for exactly one kind of wallpaper");
             }
 
             try {
-                return mService.getWallpaperColors(which);
+                return mService.getWallpaperColors(which, userId);
             } catch (RemoteException e) {
                 // Can't get colors, connection lost.
             }
@@ -857,7 +860,7 @@ public class WallpaperManager {
      * @param listener A listener to register
      */
     public void addOnColorsChangedListener(@NonNull OnColorsChangedListener listener) {
-        sGlobals.addOnColorsChangedListener(listener, null);
+        addOnColorsChangedListener(listener, null);
     }
 
     /**
@@ -868,25 +871,61 @@ public class WallpaperManager {
      */
     public void addOnColorsChangedListener(@NonNull OnColorsChangedListener listener,
             @NonNull Handler handler) {
-        sGlobals.addOnColorsChangedListener(listener, handler);
+        addOnColorsChangedListener(listener, handler, mContext.getUserId());
+    }
+
+    /**
+     * Registers a listener to get notified when the wallpaper colors change
+     * @param listener A listener to register
+     * @param handler Where to call it from. Will be called from the main thread
+     *                if null.
+     * @param userId Owner of the wallpaper or UserHandle.USER_ALL.
+     * @hide
+     */
+    public void addOnColorsChangedListener(@NonNull OnColorsChangedListener listener,
+            @NonNull Handler handler, int userId) {
+        sGlobals.addOnColorsChangedListener(listener, handler, userId);
     }
 
     /**
      * Stop listening to color updates.
-     * @param callback A callback to unsubscribe
+     * @param callback A callback to unsubscribe.
      */
     public void removeOnColorsChangedListener(@NonNull OnColorsChangedListener callback) {
-        sGlobals.removeOnColorsChangedListener(callback);
+        removeOnColorsChangedListener(callback, mContext.getUserId());
+    }
+
+    /**
+     * Stop listening to color updates.
+     * @param callback A callback to unsubscribe.
+     * @param userId Owner of the wallpaper or UserHandle.USER_ALL.
+     * @hide
+     */
+    public void removeOnColorsChangedListener(@NonNull OnColorsChangedListener callback,
+            int userId) {
+        sGlobals.removeOnColorsChangedListener(callback, userId);
     }
 
     /**
      * Get the primary colors of a wallpaper
      * @param which wallpaper type. Must be either {@link #FLAG_SYSTEM} or
      *     {@link #FLAG_LOCK}
-     * @return a list of colors ordered by priority
+     * @return {@link WallpaperColors} or null if colors are unknown.
      */
     public @Nullable WallpaperColors getWallpaperColors(int which) {
-        return sGlobals.getWallpaperColors(which);
+        return getWallpaperColors(which, mContext.getUserId());
+    }
+
+    /**
+     * Get the primary colors of a wallpaper
+     * @param which wallpaper type. Must be either {@link #FLAG_SYSTEM} or
+     *     {@link #FLAG_LOCK}
+     * @param userId Owner of the wallpaper.
+     * @return {@link WallpaperColors} or null if colors are unknown.
+     * @hide
+     */
+    public @Nullable WallpaperColors getWallpaperColors(int which, int userId) {
+        return sGlobals.getWallpaperColors(which, userId);
     }
 
     /**
@@ -1902,9 +1941,9 @@ public class WallpaperManager {
         }
 
         @Override
-        public void onWallpaperColorsChanged(WallpaperColors colors, int which)
+        public void onWallpaperColorsChanged(WallpaperColors colors, int which, int userId)
             throws RemoteException {
-            sGlobals.onWallpaperColorsChanged(colors, which);
+            sGlobals.onWallpaperColorsChanged(colors, which, userId);
         }
     }
 
@@ -1921,5 +1960,19 @@ public class WallpaperManager {
          * @param which A combination of {@link #FLAG_LOCK} and {@link #FLAG_SYSTEM}
          */
         void onColorsChanged(WallpaperColors colors, int which);
+
+        /**
+         * Called when colors change.
+         * A {@link android.app.WallpaperColors} object containing a simplified
+         * color histogram will be given.
+         *
+         * @param colors Wallpaper color info
+         * @param which A combination of {@link #FLAG_LOCK} and {@link #FLAG_SYSTEM}
+         * @param userId Owner of the wallpaper
+         * @hide
+         */
+        default void onColorsChanged(WallpaperColors colors, int which, int userId) {
+            onColorsChanged(colors, which);
+        }
     }
 }
diff --git a/core/java/android/service/wallpaper/IWallpaperEngine.aidl b/core/java/android/service/wallpaper/IWallpaperEngine.aidl
index eff52e6ca1b5..fb6f637fd927 100644
--- a/core/java/android/service/wallpaper/IWallpaperEngine.aidl
+++ b/core/java/android/service/wallpaper/IWallpaperEngine.aidl
@@ -30,5 +30,6 @@ oneway interface IWallpaperEngine {
     void dispatchPointer(in MotionEvent event);
     void dispatchWallpaperCommand(String action, int x, int y,
             int z, in Bundle extras);
+    void requestWallpaperColors();
     void destroy();
 }
diff --git a/core/java/android/service/wallpaper/WallpaperService.java b/core/java/android/service/wallpaper/WallpaperService.java
index 1457adf7c146..65d66dc863d5 100644
--- a/core/java/android/service/wallpaper/WallpaperService.java
+++ b/core/java/android/service/wallpaper/WallpaperService.java
@@ -105,6 +105,7 @@ public abstract class WallpaperService extends Service {
     private static final int MSG_WINDOW_RESIZED = 10030;
     private static final int MSG_WINDOW_MOVED = 10035;
     private static final int MSG_TOUCH_EVENT = 10040;
+    private static final int MSG_REQUEST_WALLPAPER_COLORS = 10050;
     
     private final ArrayList<Engine> mActiveEngines
             = new ArrayList<Engine>();
@@ -626,8 +627,7 @@ public abstract class WallpaperService extends Service {
                 }
                 Message msg = mCaller.obtainMessageO(MSG_TOUCH_EVENT, event);
                 mCaller.sendMessage(msg);
-            } else {
-                event.recycle();
+            } else {event.recycle();
             }
         }
 
@@ -1192,6 +1192,11 @@ public abstract class WallpaperService extends Service {
             }
         }
 
+        public void requestWallpaperColors() {
+            Message msg = mCaller.obtainMessage(MSG_REQUEST_WALLPAPER_COLORS);
+            mCaller.sendMessage(msg);
+        }
+
         public void destroy() {
             Message msg = mCaller.obtainMessage(DO_DETACH);
             mCaller.sendMessage(msg);
@@ -1210,7 +1215,6 @@ public abstract class WallpaperService extends Service {
                     mEngine = engine;
                     mActiveEngines.add(engine);
                     engine.attach(this);
-                    engine.notifyColorsChanged();
                     return;
                 }
                 case DO_DETACH: {
@@ -1268,6 +1272,16 @@ public abstract class WallpaperService extends Service {
                     }
                     ev.recycle();
                 } break;
+                case MSG_REQUEST_WALLPAPER_COLORS: {
+                    if (mConnection == null) {
+                        break;
+                    }
+                    try {
+                        mConnection.onWallpaperColorsChanged(mEngine.onComputeColors());
+                    } catch (RemoteException e) {
+                        // Connection went away, nothing to do in here.
+                    }
+                } break;
                 default :
                     Log.w(TAG, "Unknown message type " + message.what);
             }
diff --git a/core/java/com/android/internal/colorextraction/ColorExtractor.java b/core/java/com/android/internal/colorextraction/ColorExtractor.java
index 727412b03e28..ef98a5e9f787 100644
--- a/core/java/com/android/internal/colorextraction/ColorExtractor.java
+++ b/core/java/com/android/internal/colorextraction/ColorExtractor.java
@@ -22,6 +22,7 @@ import android.app.WallpaperColors;
 import android.app.WallpaperManager;
 import android.content.Context;
 import android.os.Trace;
+import android.os.UserHandle;
 import android.util.Log;
 import android.util.SparseArray;
 
@@ -44,6 +45,7 @@ public class ColorExtractor implements WallpaperManager.OnColorsChangedListener
     private static final int[] sGradientTypes = new int[]{TYPE_NORMAL, TYPE_DARK, TYPE_EXTRA_DARK};
 
     private static final String TAG = "ColorExtractor";
+    private static final boolean DEBUG = false;
 
     protected final SparseArray<GradientColors[]> mGradientColors;
     private final ArrayList<WeakReference<OnColorsChangedListener>> mOnColorsChangedListeners;
@@ -147,6 +149,9 @@ public class ColorExtractor implements WallpaperManager.OnColorsChangedListener
 
     @Override
     public void onColorsChanged(WallpaperColors colors, int which) {
+        if (DEBUG) {
+            Log.d(TAG, "New wallpaper colors for " + which + ": " + colors);
+        }
         boolean changed = false;
         if ((which & WallpaperManager.FLAG_LOCK) != 0) {
             mLockColors = colors;
diff --git a/packages/SystemUI/src/com/android/systemui/colorextraction/SysuiColorExtractor.java b/packages/SystemUI/src/com/android/systemui/colorextraction/SysuiColorExtractor.java
index 9ba7be86aa0a..34c05a5a4a71 100644
--- a/packages/SystemUI/src/com/android/systemui/colorextraction/SysuiColorExtractor.java
+++ b/packages/SystemUI/src/com/android/systemui/colorextraction/SysuiColorExtractor.java
@@ -21,6 +21,8 @@ import android.app.WallpaperManager;
 import android.content.Context;
 import android.os.Handler;
 import android.os.RemoteException;
+import android.os.Trace;
+import android.os.UserHandle;
 import android.util.Log;
 import android.view.Display;
 import android.view.IWallpaperVisibilityListener;
@@ -31,6 +33,7 @@ import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.colorextraction.ColorExtractor;
 import com.android.internal.colorextraction.types.ExtractionType;
 import com.android.internal.colorextraction.types.Tonal;
+import com.android.keyguard.KeyguardUpdateMonitor;
 import com.android.systemui.Dumpable;
 
 import java.io.FileDescriptor;
@@ -75,6 +78,14 @@ public class SysuiColorExtractor extends ColorExtractor implements Dumpable {
                 Log.w(TAG, "Can't listen to wallpaper visibility changes", e);
             }
         }
+
+        WallpaperManager wallpaperManager = context.getSystemService(WallpaperManager.class);
+        if (wallpaperManager != null) {
+            // Listen to all users instead of only the current one.
+            wallpaperManager.removeOnColorsChangedListener(this);
+            wallpaperManager.addOnColorsChangedListener(this, null /* handler */,
+                    UserHandle.USER_ALL);
+        }
     }
 
     private void updateDefaultGradients(WallpaperColors colors) {
@@ -82,7 +93,12 @@ public class SysuiColorExtractor extends ColorExtractor implements Dumpable {
     }
 
     @Override
-    public void onColorsChanged(WallpaperColors colors, int which) {
+    public void onColorsChanged(WallpaperColors colors, int which, int userId) {
+        if (userId != KeyguardUpdateMonitor.getCurrentUser()) {
+            // Colors do not belong to current user, ignoring.
+            return;
+        }
+
         super.onColorsChanged(colors, which);
 
         if ((which & WallpaperManager.FLAG_SYSTEM) != 0) {
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/LockscreenWallpaper.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/LockscreenWallpaper.java
index c4879011b9f8..87f5ca7adf73 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/LockscreenWallpaper.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/LockscreenWallpaper.java
@@ -158,7 +158,7 @@ public class LockscreenWallpaper extends IWallpaperManagerCallback.Stub implemen
     }
 
     @Override
-    public void onWallpaperColorsChanged(WallpaperColors colors, int which) {
+    public void onWallpaperColorsChanged(WallpaperColors colors, int which, int userId) {
 
     }
 
diff --git a/services/core/java/com/android/server/wallpaper/WallpaperManagerService.java b/services/core/java/com/android/server/wallpaper/WallpaperManagerService.java
index 802054eed8ce..760e79729c97 100644
--- a/services/core/java/com/android/server/wallpaper/WallpaperManagerService.java
+++ b/services/core/java/com/android/server/wallpaper/WallpaperManagerService.java
@@ -25,6 +25,7 @@ import static android.os.ParcelFileDescriptor.MODE_TRUNCATE;
 import static android.view.Display.DEFAULT_DISPLAY;
 import static android.view.WindowManager.LayoutParams.TYPE_WALLPAPER;
 
+import android.annotation.NonNull;
 import android.app.ActivityManager;
 import android.app.AppGlobals;
 import android.app.AppOpsManager;
@@ -63,6 +64,7 @@ import android.os.FileObserver;
 import android.os.FileUtils;
 import android.os.Handler;
 import android.os.IBinder;
+import android.os.IInterface;
 import android.os.IRemoteCallback;
 import android.os.ParcelFileDescriptor;
 import android.os.Process;
@@ -331,11 +333,18 @@ public class WallpaperManagerService extends IWallpaperManager.Stub {
         }
     }
 
-    private void notifyWallpaperColorsChanged(WallpaperData wallpaper, int which) {
+    private void notifyWallpaperColorsChanged(@NonNull WallpaperData wallpaper, int which) {
         boolean needsExtraction;
         synchronized (mLock) {
-            if (mColorsChangedListeners.getRegisteredCallbackCount() == 0)
+            final RemoteCallbackList<IWallpaperManagerCallback> currentUserColorListeners =
+                    mColorsChangedListeners.get(wallpaper.userId);
+            final RemoteCallbackList<IWallpaperManagerCallback> userAllColorListeners =
+                    mColorsChangedListeners.get(UserHandle.USER_ALL);
+            // No-op until someone is listening to it.
+            if (emptyCallbackList(currentUserColorListeners)  &&
+                    emptyCallbackList(userAllColorListeners)) {
                 return;
+            }
 
             if (DEBUG) {
                 Slog.v(TAG, "notifyWallpaperColorsChanged " + which);
@@ -346,40 +355,66 @@ public class WallpaperManagerService extends IWallpaperManager.Stub {
 
         // Let's notify the current values, it's fine if it's null, it just means
         // that we don't know yet.
-        notifyColorListeners(wallpaper.primaryColors, which);
+        notifyColorListeners(wallpaper.primaryColors, which, wallpaper.userId);
 
         if (needsExtraction) {
             extractColors(wallpaper);
-            notifyColorListeners(wallpaper.primaryColors, which);
+            synchronized (mLock) {
+                // Don't need to notify if nothing changed.
+                if (wallpaper.primaryColors == null) {
+                    return;
+                }
+            }
+            notifyColorListeners(wallpaper.primaryColors, which, wallpaper.userId);
         }
     }
 
-    private void notifyColorListeners(WallpaperColors wallpaperColors, int which) {
-        final IWallpaperManagerCallback[] listeners;
+    private static <T extends IInterface> boolean emptyCallbackList(RemoteCallbackList<T> list) {
+        return (list == null || list.getRegisteredCallbackCount() == 0);
+    }
+
+    private void notifyColorListeners(@NonNull WallpaperColors wallpaperColors, int which,
+            int userId) {
         final IWallpaperManagerCallback keyguardListener;
+        final RemoteCallbackList<IWallpaperManagerCallback> currentUserColorListeners;
+        final RemoteCallbackList<IWallpaperManagerCallback> userAllColorListeners;
         synchronized (mLock) {
-            // Make a synchronized copy of the listeners to avoid concurrent list modification.
-            int callbackCount = mColorsChangedListeners.beginBroadcast();
-            listeners = new IWallpaperManagerCallback[callbackCount];
-            for (int i = 0; i < callbackCount; i++) {
-                listeners[i] = mColorsChangedListeners.getBroadcastItem(i);
-            }
-            mColorsChangedListeners.finishBroadcast();
+            currentUserColorListeners = mColorsChangedListeners.get(userId);
+            userAllColorListeners = mColorsChangedListeners.get(UserHandle.USER_ALL);
             keyguardListener = mKeyguardListener;
         }
 
-        for (int i = 0; i < listeners.length; i++) {
-            try {
-                listeners[i].onWallpaperColorsChanged(wallpaperColors, which);
-            } catch (RemoteException e) {
-                // Callback is gone, it's not necessary to unregister it since
-                // RemoteCallbackList#getBroadcastItem will take care of it.
+        if (currentUserColorListeners != null) {
+            int count = currentUserColorListeners.beginBroadcast();
+            for (int i = 0; i < count; i++) {
+                try {
+                    currentUserColorListeners.getBroadcastItem(i)
+                            .onWallpaperColorsChanged(wallpaperColors, which, userId);
+                } catch (RemoteException e) {
+                    // Callback is gone, it's not necessary to unregister it since
+                    // RemoteCallbackList#getBroadcastItem will take care of it.
+                }
+            }
+            currentUserColorListeners.finishBroadcast();
+        }
+
+        if (userAllColorListeners != null) {
+            int count = userAllColorListeners.beginBroadcast();
+            for (int i = 0; i < count; i++) {
+                try {
+                    userAllColorListeners.getBroadcastItem(i)
+                            .onWallpaperColorsChanged(wallpaperColors, which, userId);
+                } catch (RemoteException e) {
+                    // Callback is gone, it's not necessary to unregister it since
+                    // RemoteCallbackList#getBroadcastItem will take care of it.
+                }
             }
+            userAllColorListeners.finishBroadcast();
         }
 
         if (keyguardListener != null) {
             try {
-                keyguardListener.onWallpaperColorsChanged(wallpaperColors, which);
+                keyguardListener.onWallpaperColorsChanged(wallpaperColors, which, userId);
             } catch (RemoteException e) {
                 // Oh well it went away; no big deal
             }
@@ -595,7 +630,11 @@ public class WallpaperManagerService extends IWallpaperManager.Stub {
     final IPackageManager mIPackageManager;
     final MyPackageMonitor mMonitor;
     final AppOpsManager mAppOpsManager;
-    final RemoteCallbackList<IWallpaperManagerCallback> mColorsChangedListeners;
+    /**
+     * Map of color listeners per user id.
+     * The key will be the id of a user or UserHandle.USER_ALL - for wildcard listeners.
+     */
+    final SparseArray<RemoteCallbackList<IWallpaperManagerCallback>> mColorsChangedListeners;
     WallpaperData mLastWallpaper;
     IWallpaperManagerCallback mKeyguardListener;
     boolean mWaitingForUnlock;
@@ -858,11 +897,6 @@ public class WallpaperManagerService extends IWallpaperManager.Stub {
          */
         @Override
         public void onWallpaperColorsChanged(WallpaperColors primaryColors) {
-            // Do not override default color extraction if API isn't implemented.
-            if (primaryColors == null) {
-                return;
-            }
-
             int which;
             synchronized (mLock) {
                 // Do not broadcast changes on ImageWallpaper since it's handled
@@ -876,7 +910,7 @@ public class WallpaperManagerService extends IWallpaperManager.Stub {
                 // Live wallpapers always are system wallpapers.
                 which = FLAG_SYSTEM;
                 // It's also the lock screen wallpaper when we don't have a bitmap in there
-                WallpaperData lockedWallpaper = mLockWallpaperMap.get(mCurrentUserId);
+                WallpaperData lockedWallpaper = mLockWallpaperMap.get(mWallpaper.userId);
                 if (lockedWallpaper == null) {
                     which |= FLAG_LOCK;
                 }
@@ -906,6 +940,13 @@ public class WallpaperManagerService extends IWallpaperManager.Stub {
                     }
                     mPaddingChanged = false;
                 }
+                try {
+                    // This will trigger onComputeColors in the wallpaper engine.
+                    // It's fine to be locked in here since the binder is oneway.
+                    mEngine.requestWallpaperColors();
+                } catch (RemoteException e) {
+                    Slog.w(TAG, "Failed to request wallpaper colors", e);
+                }
             }
         }
 
@@ -1096,7 +1137,7 @@ public class WallpaperManagerService extends IWallpaperManager.Stub {
         mMonitor.register(context, null, UserHandle.ALL, true);
         getWallpaperDir(UserHandle.USER_SYSTEM).mkdirs();
         loadSettingsLocked(UserHandle.USER_SYSTEM, false);
-        mColorsChangedListeners = new RemoteCallbackList<>();
+        mColorsChangedListeners = new SparseArray<>();
     }
 
     private static File getWallpaperDir(int userId) {
@@ -1252,16 +1293,24 @@ public class WallpaperManagerService extends IWallpaperManager.Stub {
     }
 
     void switchUser(int userId, IRemoteCallback reply) {
+        WallpaperData systemWallpaper;
+        WallpaperData lockWallpaper;
         synchronized (mLock) {
             mCurrentUserId = userId;
-            WallpaperData wallpaper = getWallpaperSafeLocked(userId, FLAG_SYSTEM);
+            systemWallpaper = getWallpaperSafeLocked(userId, FLAG_SYSTEM);
+            lockWallpaper = mLockWallpaperMap.get(userId);
+            if (lockWallpaper == null) {
+                lockWallpaper = systemWallpaper;
+            }
             // Not started watching yet, in case wallpaper data was loaded for other reasons.
-            if (wallpaper.wallpaperObserver == null) {
-                wallpaper.wallpaperObserver = new WallpaperObserver(wallpaper);
-                wallpaper.wallpaperObserver.startWatching();
+            if (systemWallpaper.wallpaperObserver == null) {
+                systemWallpaper.wallpaperObserver = new WallpaperObserver(systemWallpaper);
+                systemWallpaper.wallpaperObserver.startWatching();
             }
-            switchWallpaper(wallpaper, reply);
+            switchWallpaper(systemWallpaper, reply);
         }
+        notifyWallpaperColorsChanged(systemWallpaper, FLAG_SYSTEM);
+        notifyWallpaperColorsChanged(lockWallpaper, FLAG_LOCK);
     }
 
     void switchWallpaper(WallpaperData wallpaper, IRemoteCallback reply) {
@@ -1634,16 +1683,30 @@ public class WallpaperManagerService extends IWallpaperManager.Stub {
     }
 
     @Override
-    public void registerWallpaperColorsCallback(IWallpaperManagerCallback cb) {
+    public void registerWallpaperColorsCallback(IWallpaperManagerCallback cb, int userId) {
+        userId = ActivityManager.handleIncomingUser(Binder.getCallingPid(), Binder.getCallingUid(),
+                userId, true, true, "registerWallpaperColorsCallback", null);
         synchronized (mLock) {
-            mColorsChangedListeners.register(cb);
+            RemoteCallbackList<IWallpaperManagerCallback> userColorsChangedListeners =
+                    mColorsChangedListeners.get(userId);
+            if (userColorsChangedListeners == null) {
+                userColorsChangedListeners = new RemoteCallbackList<>();
+                mColorsChangedListeners.put(userId, userColorsChangedListeners);
+            }
+            userColorsChangedListeners.register(cb);
         }
     }
 
     @Override
-    public void unregisterWallpaperColorsCallback(IWallpaperManagerCallback cb) {
+    public void unregisterWallpaperColorsCallback(IWallpaperManagerCallback cb, int userId) {
+        userId = ActivityManager.handleIncomingUser(Binder.getCallingPid(), Binder.getCallingUid(),
+                userId, true, true, "unregisterWallpaperColorsCallback", null);
         synchronized (mLock) {
-            mColorsChangedListeners.unregister(cb);
+            final RemoteCallbackList<IWallpaperManagerCallback> userColorsChangedListeners =
+                    mColorsChangedListeners.get(userId);
+            if (userColorsChangedListeners != null) {
+                userColorsChangedListeners.unregister(cb);
+            }
         }
     }
 
@@ -1657,23 +1720,25 @@ public class WallpaperManagerService extends IWallpaperManager.Stub {
     }
 
     @Override
-    public WallpaperColors getWallpaperColors(int which) throws RemoteException {
+    public WallpaperColors getWallpaperColors(int which, int userId) throws RemoteException {
         if (which != FLAG_LOCK && which != FLAG_SYSTEM) {
             throw new IllegalArgumentException("which should be either FLAG_LOCK or FLAG_SYSTEM");
         }
+        userId = ActivityManager.handleIncomingUser(Binder.getCallingPid(), Binder.getCallingUid(),
+                userId, false, true, "getWallpaperColors", null);
 
         WallpaperData wallpaperData = null;
         boolean shouldExtract;
 
         synchronized (mLock) {
             if (which == FLAG_LOCK) {
-                wallpaperData = mLockWallpaperMap.get(mCurrentUserId);
+                wallpaperData = mLockWallpaperMap.get(userId);
             }
 
             // Try to get the system wallpaper anyway since it might
             // also be the lock screen wallpaper
             if (wallpaperData == null) {
-                wallpaperData = mWallpaperMap.get(mCurrentUserId);
+                wallpaperData = mWallpaperMap.get(userId);
             }
 
             if (wallpaperData == null) {
@@ -1872,8 +1937,11 @@ public class WallpaperManagerService extends IWallpaperManager.Stub {
 
             try {
                 wallpaper.imageWallpaperPending = false;
+                boolean same = changingToSame(name, wallpaper);
                 if (bindWallpaperComponentLocked(name, false, true, wallpaper, null)) {
-                    wallpaper.primaryColors = null;
+                    if (!same) {
+                        wallpaper.primaryColors = null;
+                    }
                     wallpaper.wallpaperId = makeWallpaperIdLocked();
                     notifyCallbacksLocked(wallpaper);
                     shouldNotifyColors = true;
@@ -1888,26 +1956,31 @@ public class WallpaperManagerService extends IWallpaperManager.Stub {
         }
     }
 
+    private boolean changingToSame(ComponentName componentName, WallpaperData wallpaper) {
+        if (wallpaper.connection != null) {
+            if (wallpaper.wallpaperComponent == null) {
+                if (componentName == null) {
+                    if (DEBUG) Slog.v(TAG, "changingToSame: still using default");
+                    // Still using default wallpaper.
+                    return true;
+                }
+            } else if (wallpaper.wallpaperComponent.equals(componentName)) {
+                // Changing to same wallpaper.
+                if (DEBUG) Slog.v(TAG, "same wallpaper");
+                return true;
+            }
+        }
+        return false;
+    }
+
     boolean bindWallpaperComponentLocked(ComponentName componentName, boolean force,
             boolean fromUser, WallpaperData wallpaper, IRemoteCallback reply) {
         if (DEBUG_LIVE) {
             Slog.v(TAG, "bindWallpaperComponentLocked: componentName=" + componentName);
         }
         // Has the component changed?
-        if (!force) {
-            if (wallpaper.connection != null) {
-                if (wallpaper.wallpaperComponent == null) {
-                    if (componentName == null) {
-                        if (DEBUG) Slog.v(TAG, "bindWallpaperComponentLocked: still using default");
-                        // Still using default wallpaper.
-                        return true;
-                    }
-                } else if (wallpaper.wallpaperComponent.equals(componentName)) {
-                    // Changing to same wallpaper.
-                    if (DEBUG) Slog.v(TAG, "same wallpaper");
-                    return true;
-                }
-            }
+        if (!force && changingToSame(componentName, wallpaper)) {
+            return true;
         }
 
         try {