Merge "Freeze live wallpaper for letterbox background." into sc-v2-dev

core/java/android/app/WallpaperManager.java

@@ -220,6 +220,20 @@ public class WallpaperManager {
      */
     public static final String COMMAND_REAPPLY = "android.wallpaper.reapply";
 
+    /**
+     * Command for {@link #sendWallpaperCommand}: reported when the live wallpaper needs to be
+     * frozen.
+     * @hide
+     */
+    public static final String COMMAND_FREEZE = "android.wallpaper.freeze";
+
+    /**
+     * Command for {@link #sendWallpaperCommand}: reported when the live wallapper doesn't need
+     * to be frozen anymore.
+     * @hide
+     */
+    public static final String COMMAND_UNFREEZE = "android.wallpaper.unfreeze";
+
     /**
      * Extra passed back from setWallpaper() giving the new wallpaper's assigned ID.
      * @hide

core/java/android/service/wallpaper/WallpaperService.java

@@ -16,6 +16,8 @@
 
 package android.service.wallpaper;
 
+import static android.app.WallpaperManager.COMMAND_FREEZE;
+import static android.app.WallpaperManager.COMMAND_UNFREEZE;
 import static android.graphics.Matrix.MSCALE_X;
 import static android.graphics.Matrix.MSCALE_Y;
 import static android.graphics.Matrix.MSKEW_X;
@@ -42,12 +44,14 @@ import android.content.res.TypedArray;
 import android.graphics.BLASTBufferQueue;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
+import android.graphics.GraphicBuffer;
 import android.graphics.Matrix;
 import android.graphics.PixelFormat;
 import android.graphics.Point;
 import android.graphics.Rect;
 import android.graphics.RectF;
 import android.graphics.drawable.Drawable;
+import android.hardware.HardwareBuffer;
 import android.hardware.display.DisplayManager;
 import android.hardware.display.DisplayManager.DisplayListener;
 import android.os.Build;
@@ -56,6 +60,7 @@ import android.os.Handler;
 import android.os.IBinder;
 import android.os.Looper;
 import android.os.Message;
+import android.os.Process;
 import android.os.RemoteException;
 import android.os.SystemClock;
 import android.os.SystemProperties;
@@ -200,6 +205,12 @@ public abstract class WallpaperService extends Service {
         boolean mVisible;
         boolean mReportedVisible;
         boolean mDestroyed;
+        // Set to true after receiving WallpaperManager#COMMAND_FREEZE. It's reset back to false
+        // after receiving WallpaperManager#COMMAND_UNFREEZE. COMMAND_FREEZE is fully applied once
+        // mScreenshotSurfaceControl isn't null. When this happens, then Engine is notified through
+        // doVisibilityChanged that main wallpaper surface is no longer visible and the wallpaper
+        // host receives onVisibilityChanged(false) callback.
+        private boolean mFrozenRequested = false;
 
         // Current window state.
         boolean mCreated;
@@ -264,6 +275,8 @@ public abstract class WallpaperService extends Service {
         SurfaceControl mSurfaceControl = new SurfaceControl();
         SurfaceControl mBbqSurfaceControl;
         BLASTBufferQueue mBlastBufferQueue;
+        private SurfaceControl mScreenshotSurfaceControl;
+        private Point mScreenshotSize = new Point();
 
         final BaseSurfaceHolder mSurfaceHolder = new BaseSurfaceHolder() {
             {
@@ -1349,11 +1362,15 @@ public abstract class WallpaperService extends Service {
             if (!mDestroyed) {
                 mVisible = visible;
                 reportVisibility();
-                if (visible) processLocalColors(mPendingXOffset, mPendingXOffsetStep);
+                if (mReportedVisible) processLocalColors(mPendingXOffset, mPendingXOffsetStep);
             }
         }
 
         void reportVisibility() {
+            if (mScreenshotSurfaceControl != null && mVisible) {
+                if (DEBUG) Log.v(TAG, "Frozen so don't report visibility change");
+                return;
+            }
             if (!mDestroyed) {
                 mDisplayState = mDisplay == null ? Display.STATE_UNKNOWN : mDisplay.getState();
                 boolean visible = mVisible && mDisplayState != Display.STATE_OFF;
@@ -1370,6 +1387,10 @@ public abstract class WallpaperService extends Service {
                         updateSurface(true, false, false);
                     }
                     onVisibilityChanged(visible);
+                    if (mReportedVisible && mFrozenRequested) {
+                        if (DEBUG) Log.v(TAG, "Freezing wallpaper after visibility update");
+                        freeze();
+                    }
                 }
             }
         }
@@ -1830,6 +1851,9 @@ public abstract class WallpaperService extends Service {
         void doCommand(WallpaperCommand cmd) {
             Bundle result;
             if (!mDestroyed) {
+                if (COMMAND_FREEZE.equals(cmd.action) || COMMAND_UNFREEZE.equals(cmd.action)) {
+                    updateFrozenState(/* frozenRequested= */ !COMMAND_UNFREEZE.equals(cmd.action));
+                }
                 result = onCommand(cmd.action, cmd.x, cmd.y, cmd.z,
                         cmd.extras, cmd.sync);
             } else {
@@ -1844,6 +1868,159 @@ public abstract class WallpaperService extends Service {
             }
         }
 
+        private void updateFrozenState(boolean frozenRequested) {
+            if (mIWallpaperEngine.mWallpaperManager.getWallpaperInfo() == null
+                    // Procees the unfreeze command in case the wallaper became static while
+                    // being paused.
+                    && frozenRequested) {
+                if (DEBUG) Log.v(TAG, "Ignoring the freeze command for static wallpapers");
+                return;
+            }
+            mFrozenRequested = frozenRequested;
+            boolean isFrozen = mScreenshotSurfaceControl != null;
+            if (mFrozenRequested == isFrozen) {
+                return;
+            }
+            if (mFrozenRequested) {
+                freeze();
+            } else {
+                unfreeze();
+            }
+        }
+
+        private void freeze() {
+            if (!mReportedVisible || mDestroyed) {
+                // Screenshot can't be taken until visibility is reported to the wallpaper host.
+                return;
+            }
+            if (!showScreenshotOfWallpaper()) {
+                return;
+            }
+            // Prevent a wallpaper host from rendering wallpaper behind a screeshot.
+            doVisibilityChanged(false);
+            // Remember that visibility is requested since it's not guaranteed that
+            // mWindow#dispatchAppVisibility will be called when letterboxed application with
+            // wallpaper background transitions to the Home screen.
+            mVisible = true;
+        }
+
+        private void unfreeze() {
+            cleanUpScreenshotSurfaceControl();
+            if (mVisible) {
+                doVisibilityChanged(true);
+            }
+        }
+
+        private void cleanUpScreenshotSurfaceControl() {
+            // TODO(b/194399558): Add crossfade transition.
+            if (mScreenshotSurfaceControl != null) {
+                new SurfaceControl.Transaction()
+                        .remove(mScreenshotSurfaceControl)
+                        .show(mBbqSurfaceControl)
+                        .apply();
+                mScreenshotSurfaceControl = null;
+            }
+        }
+
+        void scaleAndCropScreenshot() {
+            if (mScreenshotSurfaceControl == null) {
+                return;
+            }
+            if (mScreenshotSize.x <= 0 || mScreenshotSize.y <= 0) {
+                Log.w(TAG, "Unexpected screenshot size: " + mScreenshotSize);
+                return;
+            }
+            // Don't scale down and using the same scaling factor for both dimensions to
+            // avoid stretching wallpaper image.
+            float scaleFactor = Math.max(1, Math.max(
+                    ((float) mSurfaceSize.x) / mScreenshotSize.x,
+                    ((float) mSurfaceSize.y) / mScreenshotSize.y));
+            int diffX =  ((int) (mScreenshotSize.x * scaleFactor)) - mSurfaceSize.x;
+            int diffY =  ((int) (mScreenshotSize.y * scaleFactor)) - mSurfaceSize.y;
+            if (DEBUG) {
+                Log.v(TAG, "Adjusting screenshot: scaleFactor=" + scaleFactor
+                        + " diffX=" + diffX + " diffY=" + diffY + " mSurfaceSize=" + mSurfaceSize
+                        + " mScreenshotSize=" + mScreenshotSize);
+            }
+            new SurfaceControl.Transaction()
+                        .setMatrix(
+                                mScreenshotSurfaceControl,
+                                /* dsdx= */ scaleFactor, /* dtdx= */ 0,
+                                /* dtdy= */ 0, /* dsdy= */ scaleFactor)
+                        .setWindowCrop(
+                                mScreenshotSurfaceControl,
+                                new Rect(
+                                        /* left= */ diffX / 2,
+                                        /* top= */ diffY / 2,
+                                        /* right= */ diffX / 2 + mScreenshotSize.x,
+                                        /* bottom= */ diffY / 2 + mScreenshotSize.y))
+                        .setPosition(mScreenshotSurfaceControl, -diffX / 2, -diffY / 2)
+                        .apply();
+        }
+
+        private boolean showScreenshotOfWallpaper() {
+            if (mDestroyed || mSurfaceControl == null || !mSurfaceControl.isValid()) {
+                if (DEBUG) Log.v(TAG, "Failed to screenshot wallpaper: surface isn't valid");
+                return false;
+            }
+
+            final Rect bounds = new Rect(0, 0, mSurfaceSize.x,  mSurfaceSize.y);
+            if (bounds.isEmpty()) {
+                Log.w(TAG, "Failed to screenshot wallpaper: surface bounds are empty");
+                return false;
+            }
+
+            if (mScreenshotSurfaceControl != null) {
+                Log.e(TAG, "Screenshot is unexpectedly not null");
+                // Destroying previous screenshot since it can have different size.
+                cleanUpScreenshotSurfaceControl();
+            }
+
+            SurfaceControl.ScreenshotHardwareBuffer screenshotBuffer =
+                    SurfaceControl.captureLayers(
+                            new SurfaceControl.LayerCaptureArgs.Builder(mSurfaceControl)
+                                    // Needed because SurfaceFlinger#validateScreenshotPermissions
+                                    // uses this parameter to check whether a caller only attempts
+                                    // to screenshot itself when call doesn't come from the system.
+                                    .setUid(Process.myUid())
+                                    .setChildrenOnly(false)
+                                    .setSourceCrop(bounds)
+                                    .build());
+
+            if (screenshotBuffer == null) {
+                Log.w(TAG, "Failed to screenshot wallpaper: screenshotBuffer is null");
+                return false;
+            }
+
+            final HardwareBuffer hardwareBuffer = screenshotBuffer.getHardwareBuffer();
+
+            SurfaceControl.Transaction t = new SurfaceControl.Transaction();
+
+            // TODO(b/194399558): Add crossfade transition.
+            mScreenshotSurfaceControl = new SurfaceControl.Builder()
+                    .setName("Wallpaper snapshot for engine " + this)
+                    .setFormat(hardwareBuffer.getFormat())
+                    .setParent(mSurfaceControl)
+                    .setSecure(screenshotBuffer.containsSecureLayers())
+                    .setCallsite("WallpaperService.Engine.showScreenshotOfWallpaper")
+                    .setBLASTLayer()
+                    .build();
+
+            mScreenshotSize.set(mSurfaceSize.x, mSurfaceSize.y);
+
+            GraphicBuffer graphicBuffer = GraphicBuffer.createFromHardwareBuffer(hardwareBuffer);
+
+            t.setBuffer(mScreenshotSurfaceControl, graphicBuffer);
+            t.setColorSpace(mScreenshotSurfaceControl, screenshotBuffer.getColorSpace());
+            // Place on top everything else.
+            t.setLayer(mScreenshotSurfaceControl, Integer.MAX_VALUE);
+            t.show(mScreenshotSurfaceControl);
+            t.hide(mBbqSurfaceControl);
+            t.apply();
+
+            return true;
+        }
+
         void reportSurfaceDestroyed() {
             if (mSurfaceCreated) {
                 mSurfaceCreated = false;
@@ -2166,6 +2343,7 @@ public abstract class WallpaperService extends Service {
                     final boolean reportDraw = message.arg1 != 0;
                     mEngine.updateSurface(true, false, reportDraw);
                     mEngine.doOffsetsChanged(true);
+                    mEngine.scaleAndCropScreenshot();
                 } break;
                 case MSG_WINDOW_MOVED: {
                     // Do nothing. What does it mean for a Wallpaper to move?

services/core/java/com/android/server/wm/WallpaperController.java

@@ -16,6 +16,8 @@
 
 package com.android.server.wm;
 
+import static android.app.WallpaperManager.COMMAND_FREEZE;
+import static android.app.WallpaperManager.COMMAND_UNFREEZE;
 import static android.app.WindowConfiguration.WINDOWING_MODE_FREEFORM;
 import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
 import static android.view.WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED;
@@ -79,6 +81,8 @@ class WallpaperController {
     private int mLastWallpaperDisplayOffsetX = Integer.MIN_VALUE;
     private int mLastWallpaperDisplayOffsetY = Integer.MIN_VALUE;
     private final float mMaxWallpaperScale;
+    // Whether COMMAND_FREEZE was dispatched.
+    private boolean mLastFrozen = false;
 
     // This is set when we are waiting for a wallpaper to tell us it is done
     // changing its scroll position.
@@ -194,6 +198,7 @@ class WallpaperController {
                 if (DEBUG_WALLPAPER) Slog.v(TAG,
                         "Win " + w + ": token animating, looking behind.");
             }
+            mFindResults.setIsWallpaperTargetForLetterbox(w.hasWallpaperForLetterboxBackground());
             // Found a target! End search.
             return true;
         }
@@ -424,6 +429,14 @@ class WallpaperController {
     Bundle sendWindowWallpaperCommand(
             WindowState window, String action, int x, int y, int z, Bundle extras, boolean sync) {
         if (window == mWallpaperTarget || window == mPrevWallpaperTarget) {
+            sendWindowWallpaperCommand(action, x, y, z, extras, sync);
+        }
+
+        return null;
+    }
+
+    private void sendWindowWallpaperCommand(
+                String action, int x, int y, int z, Bundle extras, boolean sync) {
         boolean doWait = sync;
         for (int curTokenNdx = mWallpaperTokens.size() - 1; curTokenNdx >= 0; curTokenNdx--) {
             final WallpaperWindowToken token = mWallpaperTokens.get(curTokenNdx);
@@ -435,9 +448,6 @@ class WallpaperController {
         }
     }
 
-        return null;
-    }
-
     private void updateWallpaperOffsetLocked(WindowState changingTarget, boolean sync) {
         WindowState target = mWallpaperTarget;
         if (target != null) {
@@ -641,6 +651,13 @@ class WallpaperController {
 
         updateWallpaperTokens(visible);
 
+        if (visible && mLastFrozen != mFindResults.isWallpaperTargetForLetterbox) {
+            mLastFrozen = mFindResults.isWallpaperTargetForLetterbox;
+            sendWindowWallpaperCommand(
+                    mFindResults.isWallpaperTargetForLetterbox ? COMMAND_FREEZE : COMMAND_UNFREEZE,
+                    /* x= */ 0, /* y= */ 0, /* z= */ 0, /* extras= */ null, /* sync= */ false);
+        }
+
         if (DEBUG_WALLPAPER_LIGHT)  Slog.d(TAG, "New wallpaper: target=" + mWallpaperTarget
                 + " prev=" + mPrevWallpaperTarget);
     }
@@ -838,6 +855,7 @@ class WallpaperController {
         boolean useTopWallpaperAsTarget = false;
         WindowState wallpaperTarget = null;
         boolean resetTopWallpaper = false;
+        boolean isWallpaperTargetForLetterbox = false;
 
         void setTopWallpaper(WindowState win) {
             topWallpaper = win;
@@ -851,11 +869,16 @@ class WallpaperController {
             useTopWallpaperAsTarget = topWallpaperAsTarget;
         }
 
+        void setIsWallpaperTargetForLetterbox(boolean isWallpaperTargetForLetterbox) {
+            this.isWallpaperTargetForLetterbox = isWallpaperTargetForLetterbox;
+        }
+
         void reset() {
             topWallpaper = null;
             wallpaperTarget = null;
             useTopWallpaperAsTarget = false;
             resetTopWallpaper = false;
+            isWallpaperTargetForLetterbox = false;
         }
     }
 }

services/core/java/com/android/server/wm/WindowState.java

@@ -6043,8 +6043,11 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
     }
 
     boolean hasWallpaper() {
-        return (mAttrs.flags & FLAG_SHOW_WALLPAPER) != 0
+        return (mAttrs.flags & FLAG_SHOW_WALLPAPER) != 0 || hasWallpaperForLetterboxBackground();
-                || (mActivityRecord != null && mActivityRecord.hasWallpaperBackgroudForLetterbox());
+    }
+
+    boolean hasWallpaperForLetterboxBackground() {
+        return mActivityRecord != null && mActivityRecord.hasWallpaperBackgroudForLetterbox();
     }
 
     /**