diff --git a/services/core/java/com/android/server/wm/AppWindowToken.java b/services/core/java/com/android/server/wm/AppWindowToken.java
index 80c302b..da144e6 100644
--- a/services/core/java/com/android/server/wm/AppWindowToken.java
+++ b/services/core/java/com/android/server/wm/AppWindowToken.java
@@ -20,6 +20,7 @@
 import static android.content.pm.ActivityInfo.CONFIG_SCREEN_SIZE;
 import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_BEHIND;
 import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_UNSET;
+import static android.os.Trace.TRACE_TAG_WINDOW_MANAGER;
 import static android.view.Display.DEFAULT_DISPLAY;
 import static android.view.WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD;
 import static android.view.WindowManager.LayoutParams.FLAG_SECURE;
@@ -54,19 +55,22 @@
 import android.annotation.NonNull;
 import android.app.Activity;
 import android.content.res.Configuration;
+import android.graphics.Point;
 import android.graphics.Rect;
 import android.os.Binder;
 import android.os.Debug;
 import android.os.IBinder;
 import android.os.RemoteException;
 import android.os.SystemClock;
+import android.os.Trace;
 import android.util.Slog;
 import android.util.proto.ProtoOutputStream;
+import android.view.DisplayInfo;
+import android.view.animation.Animation;
 import android.view.IApplicationToken;
 import android.view.SurfaceControl;
 import android.view.WindowManager;
 import android.view.WindowManager.LayoutParams;
-import android.view.animation.Transformation;
 
 import com.android.internal.util.ToBooleanFunction;
 import com.android.server.input.InputApplicationHandle;
@@ -189,6 +193,21 @@
      */
     private boolean mCanTurnScreenOn = true;
 
+    /**
+     * If we are running an animation, this determines the transition type. Must be one of
+     * AppTransition.TRANSIT_* constants.
+     */
+    private int mTransit;
+
+    /**
+     * If we are running an animation, this determines the flags during this animation. Must be a
+     * bitwise combination of AppTransition.TRANSIT_FLAG_* constants.
+     */
+    private int mTransitFlags;
+
+    /** Whether our surface was set to be showing in the last call to {@link #prepareSurfaces} */
+    private boolean mLastSurfaceShowing;
+
     AppWindowToken(WindowManagerService service, IApplicationToken token, boolean voiceInteraction,
             DisplayContent dc, long inputDispatchingTimeoutNanos, boolean fullscreen,
             boolean showForAllUsers, int targetSdk, int orientation, int rotationAnimationHint,
@@ -206,7 +225,7 @@
         mRotationAnimationHint = rotationAnimationHint;
 
         // Application tokens start out hidden.
-        hidden = true;
+        setHidden(true);
         hiddenRequested = true;
     }
 
@@ -218,7 +237,7 @@
         mVoiceInteraction = voiceInteraction;
         mFillsParent = fillsParent;
         mInputApplicationHandle = new InputApplicationHandle(this);
-        mAppAnimator = new AppWindowAnimator(this, service);
+        mAppAnimator = new AppWindowAnimator();
     }
 
     void onFirstWindowDrawn(WindowState win, WindowStateAnimator winAnimator) {
@@ -262,7 +281,7 @@
         boolean nowGone = mReportedVisibilityResults.nowGone;
 
         boolean nowDrawn = numInteresting > 0 && numDrawn >= numInteresting;
-        boolean nowVisible = numInteresting > 0 && numVisible >= numInteresting && !hidden;
+        boolean nowVisible = numInteresting > 0 && numVisible >= numInteresting && !isHidden();
         if (!nowGone) {
             // If the app is not yet gone, then it can only become visible/drawn.
             if (!nowDrawn) {
@@ -325,19 +344,16 @@
         // transition animation
         // * or this is an opening app and windows are being replaced.
         boolean visibilityChanged = false;
-        if (hidden == visible || (hidden && mIsExiting) || (visible && waitingForReplacement())) {
+        if (isHidden() == visible || (isHidden() && mIsExiting) || (visible && waitingForReplacement())) {
             final AccessibilityController accessibilityController = mService.mAccessibilityController;
             boolean changed = false;
             if (DEBUG_APP_TRANSITIONS) Slog.v(TAG_WM,
-                    "Changing app " + this + " hidden=" + hidden + " performLayout=" + performLayout);
+                    "Changing app " + this + " hidden=" + isHidden() + " performLayout=" + performLayout);
 
             boolean runningAppAnimation = false;
 
-            if (mAppAnimator.animation == AppWindowAnimator.sDummyAnimation) {
-                mAppAnimator.setNullAnimation();
-            }
             if (transit != AppTransition.TRANSIT_UNSET) {
-                if (mService.applyAnimationLocked(this, lp, transit, visible, isVoiceInteraction)) {
+                if (applyAnimationLocked(lp, transit, visible, isVoiceInteraction)) {
                     delayed = runningAppAnimation = true;
                 }
                 final WindowState window = findMainWindow();
@@ -355,7 +371,8 @@
                 changed |= win.onAppVisibilityChanged(visible, runningAppAnimation);
             }
 
-            hidden = hiddenRequested = !visible;
+            setHidden(!visible);
+            hiddenRequested = !visible;
             visibilityChanged = true;
             if (!visible) {
                 stopFreezingScreen(true, true);
@@ -373,7 +390,7 @@
             }
 
             if (DEBUG_APP_TRANSITIONS) Slog.v(TAG_WM, "setVisibility: " + this
-                    + ": hidden=" + hidden + " hiddenRequested=" + hiddenRequested);
+                    + ": hidden=" + isHidden() + " hiddenRequested=" + hiddenRequested);
 
             if (changed) {
                 mService.mInputMonitor.setUpdateInputWindowsNeededLw();
@@ -386,7 +403,7 @@
             }
         }
 
-        if (mAppAnimator.animation != null) {
+        if (isReallyAnimating()) {
             delayed = true;
         }
 
@@ -414,7 +431,7 @@
             // no animation but there will still be a transition set.
             // We still need to delay hiding the surface such that it
             // can be synchronized with showing the next surface in the transition.
-            if (hidden && !delayed && !mService.mAppTransition.isTransitionSet()) {
+            if (isHidden() && !delayed && !mService.mAppTransition.isTransitionSet()) {
                 SurfaceControl.openTransaction();
                 for (int i = mChildren.size() - 1; i >= 0; i--) {
                     mChildren.get(i).mWinAnimator.hide("immediately hidden");
@@ -487,7 +504,7 @@
     boolean isVisible() {
         // If the app token isn't hidden then it is considered visible and there is no need to check
         // its children windows to see if they are visible.
-        return !hidden;
+        return !isHidden();
     }
 
     @Override
@@ -533,7 +550,7 @@
         }
 
         if (DEBUG_APP_TRANSITIONS) Slog.v(TAG_WM, "Removing app " + this + " delayed=" + delayed
-                + " animation=" + mAppAnimator.animation + " animating=" + mAppAnimator.animating);
+                + " animation=" + getAnimation() + " animating=" + isSelfAnimating());
 
         if (DEBUG_ADD_REMOVE || DEBUG_TOKEN_MOVEMENT) Slog.v(TAG_WM, "removeAppToken: "
                 + this + " delayed=" + delayed + " Callers=" + Debug.getCallers(4));
@@ -545,7 +562,7 @@
         // If this window was animating, then we need to ensure that the app transition notifies
         // that animations have completed in WMS.handleAnimatingStoppedAndTransitionLocked(), so
         // add to that list now
-        if (mAppAnimator.animating) {
+        if (isSelfAnimating()) {
             mService.mNoAnimationNotifyOnTransitionFinished.add(token);
         }
 
@@ -561,8 +578,7 @@
         } else {
             // Make sure there is no animation running on this token, so any windows associated
             // with it will be removed as soon as their animations are complete
-            mAppAnimator.clearAnimation();
-            mAppAnimator.animating = false;
+            cancelAnimation();
             if (stack != null) {
                 stack.mExitingAppTokens.remove(this);
             }
@@ -710,7 +726,7 @@
                 // We set the hidden state to false for the token from a transferred starting window.
                 // We now reset it back to true since the starting window was the last window in the
                 // token.
-                hidden = true;
+                setHidden(true);
             }
         } else if (mChildren.size() == 1 && startingSurface != null && !isRelaunching()) {
             // If this is the last window except for a starting transition window,
@@ -756,14 +772,6 @@
             final WindowState w = mChildren.get(i);
             w.setWillReplaceWindow(animate);
         }
-        if (animate) {
-            // Set-up dummy animation so we can start treating windows associated with this
-            // token like they are in transition before the new app window is ready for us to
-            // run the real transition animation.
-            if (DEBUG_APP_TRANSITIONS) Slog.v(TAG_WM,
-                    "setWillReplaceWindow() Setting dummy animation on: " + this);
-            mAppAnimator.setDummyAnimation();
-        }
     }
 
     void setWillReplaceChildWindows() {
@@ -1007,7 +1015,7 @@
 
     void startFreezingScreen() {
         if (DEBUG_ORIENTATION) logWithStack(TAG, "Set freezing of " + appToken + ": hidden="
-                + hidden + " freezing=" + mAppAnimator.freezingScreen + " hiddenRequested="
+                + isHidden() + " freezing=" + mAppAnimator.freezingScreen + " hiddenRequested="
                 + hiddenRequested);
         if (!hiddenRequested) {
             if (!mAppAnimator.freezingScreen) {
@@ -1111,14 +1119,14 @@
                 if (fromToken.firstWindowDrawn) {
                     firstWindowDrawn = true;
                 }
-                if (!fromToken.hidden) {
-                    hidden = false;
+                if (!fromToken.isHidden()) {
+                    setHidden(false);
                     hiddenRequested = false;
                     mHiddenSetFromTransferredStartingWindow = true;
                 }
                 setClientHidden(fromToken.mClientHidden);
-                fromToken.mAppAnimator.transferCurrentAnimation(
-                        mAppAnimator, tStartingWindow.mWinAnimator);
+
+                // TODO: Transfer animation
 
                 mService.updateFocusedWindowLocked(
                         UPDATE_FOCUS_WILL_PLACE_SURFACES, true /*updateInputWindows*/);
@@ -1142,17 +1150,8 @@
             return true;
         }
 
-        final AppWindowAnimator tAppAnimator = fromToken.mAppAnimator;
-        final AppWindowAnimator wAppAnimator = mAppAnimator;
-        if (tAppAnimator.thumbnail != null) {
-            // The old token is animating with a thumbnail, transfer that to the new token.
-            if (wAppAnimator.thumbnail != null) {
-                wAppAnimator.thumbnail.destroy();
-            }
-            wAppAnimator.thumbnail = tAppAnimator.thumbnail;
-            wAppAnimator.thumbnailAnimation = tAppAnimator.thumbnailAnimation;
-            tAppAnimator.thumbnail = null;
-        }
+        // TODO: Transfer thumbnail
+
         return false;
     }
 
@@ -1207,7 +1206,7 @@
 
         // The token has now changed state to having all windows shown...  what to do, what to do?
         if (mAppAnimator.freezingScreen) {
-            mAppAnimator.showAllWindowsLocked();
+            showAllWindowsLocked();
             stopFreezingScreen(false, true);
             if (DEBUG_ORIENTATION) Slog.i(TAG,
                     "Setting mOrientationChangeComplete=true because wtoken " + this
@@ -1220,7 +1219,7 @@
 
             // We can now show all of the drawn windows!
             if (!mService.mOpeningApps.contains(this)) {
-                mAppAnimator.showAllWindowsLocked();
+                showAllWindowsLocked();
             }
         }
     }
@@ -1310,13 +1309,13 @@
         if (!allDrawn && w.mightAffectAllDrawn()) {
             if (DEBUG_VISIBILITY || DEBUG_ORIENTATION) {
                 Slog.v(TAG, "Eval win " + w + ": isDrawn=" + w.isDrawnLw()
-                        + ", isAnimationSet=" + winAnimator.isAnimationSet());
+                        + ", isAnimationSet=" + isSelfAnimating());
                 if (!w.isDrawnLw()) {
                     Slog.v(TAG, "Not displayed: s=" + winAnimator.mSurfaceController
                             + " pv=" + w.mPolicyVisibility
                             + " mDrawState=" + winAnimator.drawStateToString()
                             + " ph=" + w.isParentWindowHidden() + " th=" + hiddenRequested
-                            + " a=" + winAnimator.isAnimationSet());
+                            + " a=" + isSelfAnimating());
                 }
             }
 
@@ -1346,21 +1345,6 @@
     }
 
     @Override
-    void stepAppWindowsAnimation(long currentTime) {
-        mAppAnimator.wasAnimating = mAppAnimator.animating;
-        if (mAppAnimator.stepAnimationLocked(currentTime)) {
-            mAppAnimator.animating = true;
-            mService.mAnimator.setAnimating(true);
-            mService.mAnimator.mAppWindowAnimating = true;
-        } else if (mAppAnimator.wasAnimating) {
-            // stopped animating, do one more pass through the layout
-            setAppLayoutChanges(FINISH_LAYOUT_REDO_WALLPAPER,
-                    DEBUG_LAYOUT_REPEATS ? "appToken " + this + " done" : null);
-            if (DEBUG_ANIM) Slog.v(TAG, "updateWindowsApps...: done animating " + this);
-        }
-    }
-
-    @Override
     boolean forAllWindows(ToBooleanFunction<WindowState> callback, boolean traverseTopToBottom) {
         // For legacy reasons we process the TaskStack.mExitingAppTokens first in DisplayContent
         // before the non-exiting app tokens. So, we skip the exiting app tokens here.
@@ -1515,14 +1499,179 @@
         return mAppAnimator.animLayerAdjustment;
     }
 
-    @Override
-    boolean isSelfAnimating() {
-        return mAppAnimator.isAnimating();
+    boolean applyAnimationLocked(WindowManager.LayoutParams lp, int transit, boolean enter,
+            boolean isVoiceInteraction) {
+
+        if (mService.mDisableTransitionAnimation) {
+            if (DEBUG_APP_TRANSITIONS || DEBUG_ANIM) {
+                Slog.v(TAG_WM, "applyAnimation: transition animation is disabled. atoken=" + this);
+            }
+            cancelAnimation();
+            return false;
+        }
+
+        // Only apply an animation if the display isn't frozen. If it is frozen, there is no reason
+        // to animate and it can cause strange artifacts when we unfreeze the display if some
+        // different animation is running.
+        Trace.traceBegin(TRACE_TAG_WINDOW_MANAGER, "AWT#applyAnimationLocked");
+        if (okToAnimate()) {
+            final Animation a = loadAnimation(lp, transit, enter, isVoiceInteraction);
+            if (a != null) {
+                final AnimationAdapter adapter = new LocalAnimationAdapter(
+                        new WindowAnimationSpec(a, new Point()), mService.mSurfaceAnimationRunner);
+                startAnimation(getPendingTransaction(), adapter, !isVisible());
+                if (a.getZAdjustment() == Animation.ZORDER_TOP) {
+                    mAppAnimator.animLayerAdjustment = 1;
+                    getDisplayContent().assignWindowLayers(false /* setLayoutNeeded */);
+                }
+                mTransit = transit;
+                mTransitFlags = mService.mAppTransition.getTransitFlags();
+                // TODO: Skip first frame and app stack clip mode.
+            }
+        } else {
+            cancelAnimation();
+        }
+        Trace.traceEnd(TRACE_TAG_WINDOW_MANAGER);
+
+        return isReallyAnimating();
+    }
+
+    private Animation loadAnimation(WindowManager.LayoutParams lp, int transit, boolean enter,
+            boolean isVoiceInteraction) {
+        final DisplayContent displayContent = getTask().getDisplayContent();
+        final DisplayInfo displayInfo = displayContent.getDisplayInfo();
+        final int width = displayInfo.appWidth;
+        final int height = displayInfo.appHeight;
+        if (DEBUG_APP_TRANSITIONS || DEBUG_ANIM) Slog.v(TAG_WM,
+                "applyAnimation: atoken=" + this);
+
+        // Determine the visible rect to calculate the thumbnail clip
+        final WindowState win = findMainWindow();
+        final Rect frame = new Rect(0, 0, width, height);
+        final Rect displayFrame = new Rect(0, 0,
+                displayInfo.logicalWidth, displayInfo.logicalHeight);
+        final Rect insets = new Rect();
+        final Rect stableInsets = new Rect();
+        Rect surfaceInsets = null;
+        final boolean freeform = win != null && win.inFreeformWindowingMode();
+        if (win != null) {
+            // Containing frame will usually cover the whole screen, including dialog windows.
+            // For freeform workspace windows it will not cover the whole screen and it also
+            // won't exactly match the final freeform window frame (e.g. when overlapping with
+            // the status bar). In that case we need to use the final frame.
+            if (freeform) {
+                frame.set(win.mFrame);
+            } else {
+                frame.set(win.mContainingFrame);
+            }
+            surfaceInsets = win.getAttrs().surfaceInsets;
+            insets.set(win.mContentInsets);
+            stableInsets.set(win.mStableInsets);
+        }
+
+        if (mLaunchTaskBehind) {
+            // Differentiate the two animations. This one which is briefly on the screen
+            // gets the !enter animation, and the other activity which remains on the
+            // screen gets the enter animation. Both appear in the mOpeningApps set.
+            enter = false;
+        }
+        if (DEBUG_APP_TRANSITIONS) Slog.d(TAG_WM, "Loading animation for app transition."
+                + " transit=" + AppTransition.appTransitionToString(transit) + " enter=" + enter
+                + " frame=" + frame + " insets=" + insets + " surfaceInsets=" + surfaceInsets);
+        final Configuration displayConfig = displayContent.getConfiguration();
+        final Animation a = mService.mAppTransition.loadAnimation(lp, transit, enter,
+                displayConfig.uiMode, displayConfig.orientation, frame, displayFrame, insets,
+                surfaceInsets, stableInsets, isVoiceInteraction, freeform, getTask().mTaskId);
+        if (a != null) {
+            if (DEBUG_ANIM) logWithStack(TAG, "Loaded animation " + a + " for " + this);
+            final int containingWidth = frame.width();
+            final int containingHeight = frame.height();
+            a.initialize(containingWidth, containingHeight, width, height);
+            a.scaleCurrentDuration(mService.getTransitionAnimationScaleLocked());
+        }
+        return a;
+    }
+
+    /**
+     * This must be called while inside a transaction.
+     */
+    void showAllWindowsLocked() {
+        forAllWindows(windowState -> {
+            if (DEBUG_VISIBILITY) Slog.v(TAG, "performing show on: " + windowState);
+            windowState.performShowLocked();
+        }, false /* traverseTopToBottom */);
     }
 
     @Override
-    void dump(PrintWriter pw, String prefix) {
-        super.dump(pw, prefix);
+    protected void onAnimationFinished() {
+        super.onAnimationFinished();
+
+        mTransit = TRANSIT_UNSET;
+        mTransitFlags = 0;
+        mAppAnimator.animLayerAdjustment = 0;
+
+        setAppLayoutChanges(FINISH_LAYOUT_REDO_ANIM | FINISH_LAYOUT_REDO_WALLPAPER,
+                "AppWindowToken");
+
+        if (mService.mInputMethodTarget != null && mService.mInputMethodTarget.mAppToken == this) {
+            getDisplayContent().computeImeTarget(true /* updateImeTarget */);
+        }
+
+        if (DEBUG_ANIM) Slog.v(TAG, "Animation done in " + this
+                + ": reportedVisible=" + reportedVisible
+                + " okToDisplay=" + okToDisplay()
+                + " okToAnimate=" + okToAnimate()
+                + " startingDisplayed=" + startingDisplayed);
+
+        // WindowState.onExitAnimationDone might modify the children list, so make a copy and then
+        // traverse the copy.
+        final ArrayList<WindowState> children = new ArrayList<>(mChildren);
+        children.forEach(WindowState::onExitAnimationDone);
+
+        mService.mAppTransition.notifyAppTransitionFinishedLocked(token);
+        scheduleAnimation();
+    }
+
+    @Override
+    boolean isAppAnimating() {
+        return isSelfAnimating();
+    }
+
+    @Override
+    boolean isSelfAnimating() {
+        // If we are about to start a transition, we also need to be considered animating.
+        return isWaitingForTransitionStart() || isReallyAnimating();
+    }
+
+    /**
+     * @return True if and only if we are actually running an animation. Note that
+     *         {@link #isSelfAnimating} also returns true if we are waiting for an animation to
+     *         start.
+     */
+    private boolean isReallyAnimating() {
+        return super.isSelfAnimating();
+    }
+
+    boolean isWaitingForTransitionStart() {
+        return mService.mAppTransition.isTransitionSet()
+                && (mService.mOpeningApps.contains(this) || mService.mClosingApps.contains(this));
+    }
+
+    public int getTransit() {
+        return mTransit;
+    }
+
+    int getTransitFlags() {
+        return mTransitFlags;
+    }
+
+    void clearThumbnail() {
+        // TODO
+    }
+
+    @Override
+    void dump(PrintWriter pw, String prefix, boolean dumpAll) {
+        super.dump(pw, prefix, dumpAll);
         if (appToken != null) {
             pw.println(prefix + "app=true mVoiceInteraction=" + mVoiceInteraction);
         }
@@ -1580,9 +1729,27 @@
         if (mRemovingFromDisplay) {
             pw.println(prefix + "mRemovingFromDisplay=" + mRemovingFromDisplay);
         }
-        if (mAppAnimator.isAnimating()) {
-            mAppAnimator.dump(pw, prefix + "  ");
+    }
+
+    @Override
+    void setHidden(boolean hidden) {
+        super.setHidden(hidden);
+        scheduleAnimation();
+    }
+
+    @Override
+    void prepareSurfaces() {
+        // isSelfAnimating also returns true when we are about to start a transition, so we need
+        // to check super here.
+        final boolean reallyAnimating = super.isSelfAnimating();
+        final boolean show = !isHidden() || reallyAnimating;
+        if (show && !mLastSurfaceShowing) {
+            mPendingTransaction.show(mSurfaceControl);
+        } else if (!show && mLastSurfaceShowing) {
+            mPendingTransaction.hide(mSurfaceControl);
         }
+        mLastSurfaceShowing = show;
+        super.prepareSurfaces();
     }
 
     @CallSuper