services/java/com/android/server/wm/WindowAnimator.java

// Copyright 2012 Google Inc. All Rights Reserved.

package com.android.server.wm;

import static android.view.WindowManager.LayoutParams.FLAG_SHOW_WALLPAPER;

import static com.android.server.wm.WindowManagerService.LayoutFields.SET_UPDATE_ROTATION;
import static com.android.server.wm.WindowManagerService.LayoutFields.SET_WALLPAPER_MAY_CHANGE;
import static com.android.server.wm.WindowManagerService.LayoutFields.SET_FORCE_HIDING_CHANGED;

import static com.android.server.wm.WindowManagerService.H.SET_DIM_PARAMETERS;

import android.content.Context;
import android.os.SystemClock;
import android.util.Log;
import android.util.Slog;
import android.view.Surface;
import android.view.WindowManager;
import android.view.WindowManagerPolicy;
import android.view.animation.Animation;

import com.android.internal.policy.impl.PhoneWindowManager;

import java.io.PrintWriter;
import java.util.ArrayList;

/**
 * Singleton class that carries out the animations and Surface operations in a separate task
 * on behalf of WindowManagerService.
 */
public class WindowAnimator {
    private static final String TAG = "WindowAnimator";

    final WindowManagerService mService;
    final Context mContext;
    final WindowManagerPolicy mPolicy;

    ArrayList<WindowStateAnimator> mWinAnimators = new ArrayList<WindowStateAnimator>();

    boolean mAnimating;

    /** Variables only intended to be valid within each pass through animate(). Does not contain
     * persistent state. */
    private class InnerLoopParams {
        boolean mTokenMayBeDrawn;
        boolean mForceHiding;
        WindowState mDetachedWallpaper = null;
        WindowState mWindowAnimationBackground;
        int mWindowAnimationBackgroundColor;
    }
    InnerLoopParams mInner = new InnerLoopParams();

    int mAdjResult;

    int mPendingLayoutChanges;

    /** Overall window dimensions */
    int mDw, mDh;

    /** Interior window dimensions */
    int mInnerDw, mInnerDh;

    /** Time of current animation step. Reset on each iteration */
    long mCurrentTime;

    /** Skip repeated AppWindowTokens initialization. Note that AppWindowsToken's version of this
     * is a long initialized to Long.MIN_VALUE so that it doesn't match this value on startup. */
    private int mTransactionSequence;

    /** The one and only screen rotation if one is happening */
    ScreenRotationAnimation mScreenRotationAnimation = null;

    // Window currently running an animation that has requested it be detached
    // from the wallpaper.  This means we need to ensure the wallpaper is
    // visible behind it in case it animates in a way that would allow it to be
    // seen. If multiple windows satisfy this, use the lowest window.
    WindowState mWindowDetachedWallpaper = null;

    DimSurface mWindowAnimationBackgroundSurface = null;

    int mBulkUpdateParams = 0;

    DimAnimator mDimAnimator = null;
    DimAnimator.Parameters mDimParams = null;

    static final int WALLPAPER_ACTION_PENDING = 1;
    int mPendingActions;

    WindowAnimator(final WindowManagerService service, final Context context,
            final WindowManagerPolicy policy) {
        mService = service;
        mContext = context;
        mPolicy = policy;
    }

    void hideWallpapersLocked(final WindowState w) {
        if ((mService.mWallpaperTarget == w && mService.mLowerWallpaperTarget == null)
                || mService.mWallpaperTarget == null) {
            for (final WindowToken token : mService.mWallpaperTokens) {
                for (final WindowState wallpaper : token.windows) {
                    final WindowStateAnimator winAnimator = wallpaper.mWinAnimator;
                    if (!winAnimator.mLastHidden) {
                        winAnimator.hide();
                        mService.dispatchWallpaperVisibility(wallpaper, false);
                        mPendingLayoutChanges |= WindowManagerPolicy.FINISH_LAYOUT_REDO_WALLPAPER;
                    }
                }
                token.hidden = true;
            }
        }
    }

    private void testWallpaperAndBackgroundLocked() {
        final WindowState detachedWallpaper = mInner.mDetachedWallpaper;
        if (mWindowDetachedWallpaper != detachedWallpaper) {
            if (WindowManagerService.DEBUG_WALLPAPER) Slog.v(TAG,
                    "Detached wallpaper changed from " + mWindowDetachedWallpaper
                    + " to " + detachedWallpaper);
            mWindowDetachedWallpaper = detachedWallpaper;
            mBulkUpdateParams |= SET_WALLPAPER_MAY_CHANGE;
        }

        if (mInner.mWindowAnimationBackgroundColor != 0) {
            // If the window that wants black is the current wallpaper
            // target, then the black goes *below* the wallpaper so we
            // don't cause the wallpaper to suddenly disappear.
            WindowState target = mInner.mWindowAnimationBackground;
            if (mService.mWallpaperTarget == target
                    || mService.mLowerWallpaperTarget == target
                    || mService.mUpperWallpaperTarget == target) {
                final int N = mService.mWindows.size();
                for (int i = 0; i < N; i++) {
                    WindowState w = mService.mWindows.get(i);
                    if (w.mIsWallpaper) {
                        target = w;
                        break;
                    }
                }
            }
            if (mWindowAnimationBackgroundSurface == null) {
                mWindowAnimationBackgroundSurface = new DimSurface(mService.mFxSession);
            }
            final int dw = mDw;
            final int dh = mDh;
            mWindowAnimationBackgroundSurface.show(dw, dh,
                    target.mWinAnimator.mAnimLayer - WindowManagerService.LAYER_OFFSET_DIM,
                    mInner.mWindowAnimationBackgroundColor);
        } else if (mWindowAnimationBackgroundSurface != null) {
            mWindowAnimationBackgroundSurface.hide();
        }
    }

    private void updateWindowsAppsAndRotationAnimationsLocked() {
        final ArrayList<AppWindowToken> appTokens = mService.mAnimatingAppTokens;
        int i;
        final int NAT = appTokens.size();
        for (i=0; i<NAT; i++) {
            final AppWindowAnimator appAnimator = appTokens.get(i).mAppAnimator;
            final boolean wasAnimating = appAnimator.animation != null
                    && appAnimator.animation != AppWindowAnimator.sDummyAnimation;
            if (appAnimator.stepAnimationLocked(mCurrentTime, mInnerDw, mInnerDh)) {
                mAnimating = true;
            } else if (wasAnimating) {
                // stopped animating, do one more pass through the layout
                mPendingLayoutChanges |= WindowManagerPolicy.FINISH_LAYOUT_REDO_WALLPAPER;
                if (WindowManagerService.DEBUG_LAYOUT_REPEATS) {
                    mService.debugLayoutRepeats("appToken " + appAnimator.mAppToken + " done",
                        mPendingLayoutChanges);
                }
                if (WindowManagerService.DEBUG_ANIM) Slog.v(TAG,
                        "updateWindowsApps...: done animating " + appAnimator.mAppToken);
            }
        }

        final int NEAT = mService.mExitingAppTokens.size();
        for (i=0; i<NEAT; i++) {
            final AppWindowAnimator appAnimator = mService.mExitingAppTokens.get(i).mAppAnimator;
            final boolean wasAnimating = appAnimator.animation != null
                    && appAnimator.animation != AppWindowAnimator.sDummyAnimation;
            if (appAnimator.stepAnimationLocked(mCurrentTime, mInnerDw, mInnerDh)) {
                mAnimating = true;
            } else if (wasAnimating) {
                // stopped animating, do one more pass through the layout
                mPendingLayoutChanges |= WindowManagerPolicy.FINISH_LAYOUT_REDO_WALLPAPER;
                if (WindowManagerService.DEBUG_LAYOUT_REPEATS) {
                    mService.debugLayoutRepeats("exiting appToken " + appAnimator.mAppToken
                        + " done", mPendingLayoutChanges);
                }
                if (WindowManagerService.DEBUG_ANIM) Slog.v(TAG,
                        "updateWindowsApps...: done animating exiting " + appAnimator.mAppToken);
            }
        }

        if (mScreenRotationAnimation != null && mScreenRotationAnimation.isAnimating()) {
            if (mScreenRotationAnimation.stepAnimationLocked(mCurrentTime)) {
                mAnimating = true;
            } else {
                mBulkUpdateParams |= SET_UPDATE_ROTATION;
                mScreenRotationAnimation.kill();
                mScreenRotationAnimation = null;
            }
        }
    }

    private void updateWindowsAndWallpaperLocked() {
        ++mTransactionSequence;

        ArrayList<WindowStateAnimator> unForceHiding = null;
        boolean wallpaperInUnForceHiding = false;

        for (int i = mWinAnimators.size() - 1; i >= 0; i--) {
            WindowStateAnimator winAnimator = mWinAnimators.get(i);
            WindowState win = winAnimator.mWin;
            final int flags = winAnimator.mAttrFlags;

            if (winAnimator.mSurface != null) {
                final boolean wasAnimating = winAnimator.mWasAnimating;
                final boolean nowAnimating = winAnimator.stepAnimationLocked(mCurrentTime);

                if (WindowManagerService.DEBUG_WALLPAPER) {
                    Slog.v(TAG, win + ": wasAnimating=" + wasAnimating +
                            ", nowAnimating=" + nowAnimating);
                }

                // If this window is animating, make a note that we have
                // an animating window and take care of a request to run
                // a detached wallpaper animation.
                if (nowAnimating) {
                    if (winAnimator.mAnimation != null) {
                        if ((flags & FLAG_SHOW_WALLPAPER) != 0
                                && winAnimator.mAnimation.getDetachWallpaper()) {
                            mInner.mDetachedWallpaper = win;
                        }
                        final int backgroundColor = winAnimator.mAnimation.getBackgroundColor();
                        if (backgroundColor != 0) {
                            final WindowState background = mInner.mWindowAnimationBackground;
                            if (background == null || (winAnimator.mAnimLayer <
                                    background.mWinAnimator.mAnimLayer)) {
                                mInner.mWindowAnimationBackground = win;
                                mInner.mWindowAnimationBackgroundColor = backgroundColor;
                            }
                        }
                    }
                    mAnimating = true;
                }

                // If this window's app token is running a detached wallpaper
                // animation, make a note so we can ensure the wallpaper is
                // displayed behind it.
                final AppWindowAnimator appAnimator =
                        win.mAppToken == null ? null : win.mAppToken.mAppAnimator;
                if (appAnimator != null && appAnimator.animation != null
                        && appAnimator.animating) {
                    if ((flags & FLAG_SHOW_WALLPAPER) != 0
                            && appAnimator.animation.getDetachWallpaper()) {
                        mInner.mDetachedWallpaper = win;
                    }
                    final int backgroundColor = appAnimator.animation.getBackgroundColor();
                    if (backgroundColor != 0) {
                        final WindowState background = mInner.mWindowAnimationBackground;
                        if (background == null || (winAnimator.mAnimLayer <
                                background.mWinAnimator.mAnimLayer)) {
                            mInner.mWindowAnimationBackground = win;
                            mInner.mWindowAnimationBackgroundColor = backgroundColor;
                        }
                    }
                }

                if (wasAnimating && !winAnimator.mAnimating && mService.mWallpaperTarget == win) {
                    mBulkUpdateParams |= SET_WALLPAPER_MAY_CHANGE;
                    mPendingLayoutChanges |= WindowManagerPolicy.FINISH_LAYOUT_REDO_WALLPAPER;
                    if (WindowManagerService.DEBUG_LAYOUT_REPEATS) {
                        mService.debugLayoutRepeats("updateWindowsAndWallpaperLocked 2",
                            mPendingLayoutChanges);
                    }
                }

                if (mPolicy.doesForceHide(win, win.mAttrs)) {
                    if (!wasAnimating && nowAnimating) {
                        if (WindowManagerService.DEBUG_ANIM ||
                                WindowManagerService.DEBUG_VISIBILITY) Slog.v(TAG,
                                "Animation started that could impact force hide: " + win);
                        mBulkUpdateParams |= SET_FORCE_HIDING_CHANGED;
                        mPendingLayoutChanges |= WindowManagerPolicy.FINISH_LAYOUT_REDO_WALLPAPER;
                        if (WindowManagerService.DEBUG_LAYOUT_REPEATS) {
                            mService.debugLayoutRepeats("updateWindowsAndWallpaperLocked 3",
                                mPendingLayoutChanges);
                        }
                        mService.mFocusMayChange = true;
                    }
                    if (win.isReadyForDisplay() && !winAnimator.isAnimating()) {
                        mInner.mForceHiding = true;
                    }
                    if (WindowManagerService.DEBUG_VISIBILITY) Slog.v(TAG,
                            "Force hide " + mInner.mForceHiding
                            + " hasSurface=" + win.mHasSurface
                            + " policyVis=" + win.mPolicyVisibility
                            + " destroying=" + win.mDestroying
                            + " attHidden=" + win.mAttachedHidden
                            + " vis=" + win.mViewVisibility
                            + " hidden=" + win.mRootToken.hidden
                            + " anim=" + win.mWinAnimator.mAnimation);
                } else if (mPolicy.canBeForceHidden(win, win.mAttrs)) {
                    final boolean changed;
                    if (mInner.mForceHiding && !winAnimator.isAnimating()) {
                        changed = win.hideLw(false, false);
                        if (WindowManagerService.DEBUG_VISIBILITY && changed) Slog.v(TAG,
                                "Now policy hidden: " + win);
                    } else {
                        changed = win.showLw(false, false);
                        if (WindowManagerService.DEBUG_VISIBILITY && changed) Slog.v(TAG,
                                "Now policy shown: " + win);
                        if (changed) {
                            if ((mBulkUpdateParams & SET_FORCE_HIDING_CHANGED) != 0
                                    && win.isVisibleNow() /*w.isReadyForDisplay()*/) {
                                if (unForceHiding == null) {
                                    unForceHiding = new ArrayList<WindowStateAnimator>();
                                }
                                unForceHiding.add(winAnimator);
                                if ((flags & FLAG_SHOW_WALLPAPER) != 0) {
                                    wallpaperInUnForceHiding = true;
                                }
                            }
                            if (mCurrentFocus == null || mCurrentFocus.mLayer < win.mLayer) {
                                // We are showing on to of the current
                                // focus, so re-evaluate focus to make
                                // sure it is correct.
                                mService.mFocusMayChange = true;
                            }
                        }
                    }
                    if (changed && (flags & FLAG_SHOW_WALLPAPER) != 0) {
                        mBulkUpdateParams |= SET_WALLPAPER_MAY_CHANGE;
                        mPendingLayoutChanges |= WindowManagerPolicy.FINISH_LAYOUT_REDO_WALLPAPER;
                        if (WindowManagerService.DEBUG_LAYOUT_REPEATS) {
                            mService.debugLayoutRepeats("updateWindowsAndWallpaperLocked 4",
                                mPendingLayoutChanges);
                        }
                    }
                }
            }

            final AppWindowToken atoken = win.mAppToken;
            if (atoken != null && (!atoken.allDrawn || atoken.mAppAnimator.freezingScreen)) {
                if (atoken.lastTransactionSequence != mTransactionSequence) {
                    atoken.lastTransactionSequence = mTransactionSequence;
                    atoken.numInterestingWindows = atoken.numDrawnWindows = 0;
                    atoken.startingDisplayed = false;
                }
                if ((win.isOnScreen() || winAnimator.mAttrType
                        == WindowManager.LayoutParams.TYPE_BASE_APPLICATION)
                        && !win.mExiting && !win.mDestroying) {
                    if (WindowManagerService.DEBUG_VISIBILITY ||
                            WindowManagerService.DEBUG_ORIENTATION) {
                        Slog.v(TAG, "Eval win " + win + ": isDrawn=" + win.isDrawnLw()
                                + ", isAnimating=" + winAnimator.isAnimating());
                        if (!win.isDrawnLw()) {
                            Slog.v(TAG, "Not displayed: s=" + winAnimator.mSurface
                                    + " pv=" + win.mPolicyVisibility
                                    + " mDrawState=" + winAnimator.mDrawState
                                    + " ah=" + win.mAttachedHidden
                                    + " th=" + atoken.hiddenRequested
                                    + " a=" + winAnimator.mAnimating);
                        }
                    }
                    if (win != atoken.startingWindow) {
                        if (!atoken.mAppAnimator.freezingScreen || !win.mAppFreezing) {
                            atoken.numInterestingWindows++;
                            if (win.isDrawnLw()) {
                                atoken.numDrawnWindows++;
                                if (WindowManagerService.DEBUG_VISIBILITY ||
                                        WindowManagerService.DEBUG_ORIENTATION) Slog.v(TAG,
                                        "tokenMayBeDrawn: " + atoken
                                        + " freezingScreen=" + atoken.mAppAnimator.freezingScreen
                                        + " mAppFreezing=" + win.mAppFreezing);
                                mInner.mTokenMayBeDrawn = true;
                            }
                        }
                    } else if (win.isDrawnLw()) {
                        atoken.startingDisplayed = true;
                    }
                }
            } else if (winAnimator.mDrawState == WindowStateAnimator.READY_TO_SHOW) {
                if (winAnimator.performShowLocked()) {
                    mPendingLayoutChanges |= WindowManagerPolicy.FINISH_LAYOUT_REDO_ANIM;
                    if (WindowManagerService.DEBUG_LAYOUT_REPEATS) {
                        mService.debugLayoutRepeats("updateWindowsAndWallpaperLocked 5",
                            mPendingLayoutChanges);
                    }
                }
            }
            final AppWindowAnimator appAnimator =
                    atoken == null ? null : atoken.mAppAnimator;
            if (appAnimator != null && appAnimator.thumbnail != null) {
                if (appAnimator.thumbnailTransactionSeq != mTransactionSequence) {
                    appAnimator.thumbnailTransactionSeq = mTransactionSequence;
                    appAnimator.thumbnailLayer = 0;
                }
                if (appAnimator.thumbnailLayer < winAnimator.mAnimLayer) {
                    appAnimator.thumbnailLayer = winAnimator.mAnimLayer;
                }
            }
        } // end forall windows

        // If we have windows that are being show due to them no longer
        // being force-hidden, apply the appropriate animation to them.
        if (unForceHiding != null) {
            for (int i=unForceHiding.size()-1; i>=0; i--) {
                Animation a = mPolicy.createForceHideEnterAnimation(wallpaperInUnForceHiding);
                if (a != null) {
                    final WindowStateAnimator winAnimator = unForceHiding.get(i);
                    winAnimator.setAnimation(a);
                    winAnimator.mAnimationIsEntrance = true;
                }
            }
        }
    }

    private void testTokenMayBeDrawnLocked() {
        // See if any windows have been drawn, so they (and others
        // associated with them) can now be shown.
        final ArrayList<AppWindowToken> appTokens = mService.mAnimatingAppTokens;
        final int NT = appTokens.size();
        for (int i=0; i<NT; i++) {
            AppWindowToken wtoken = appTokens.get(i);
            if (wtoken.mAppAnimator.freezingScreen) {
                int numInteresting = wtoken.numInterestingWindows;
                if (numInteresting > 0 && wtoken.numDrawnWindows >= numInteresting) {
                    if (WindowManagerService.DEBUG_VISIBILITY) Slog.v(TAG,
                            "allDrawn: " + wtoken
                            + " interesting=" + numInteresting
                            + " drawn=" + wtoken.numDrawnWindows);
                    wtoken.mAppAnimator.showAllWindowsLocked();
                    mService.unsetAppFreezingScreenLocked(wtoken, false, true);
                    if (WindowManagerService.DEBUG_ORIENTATION) Slog.i(TAG,
                            "Setting mOrientationChangeComplete=true because wtoken "
                            + wtoken + " numInteresting=" + numInteresting
                            + " numDrawn=" + wtoken.numDrawnWindows);
                    // This will set mOrientationChangeComplete and cause a pass through layout.
                    mPendingLayoutChanges |= WindowManagerPolicy.FINISH_LAYOUT_REDO_WALLPAPER;
                }
            } else if (!wtoken.allDrawn) {
                int numInteresting = wtoken.numInterestingWindows;
                if (numInteresting > 0 && wtoken.numDrawnWindows >= numInteresting) {
                    if (WindowManagerService.DEBUG_VISIBILITY) Slog.v(TAG,
                            "allDrawn: " + wtoken
                            + " interesting=" + numInteresting
                            + " drawn=" + wtoken.numDrawnWindows);
                    wtoken.allDrawn = true;
                    mPendingLayoutChanges |= PhoneWindowManager.FINISH_LAYOUT_REDO_ANIM;
                    if (WindowManagerService.DEBUG_LAYOUT_REPEATS) {
                        mService.debugLayoutRepeats("testTokenMayBeDrawnLocked",
                            mPendingLayoutChanges);
                    }

                    // We can now show all of the drawn windows!
                    if (!mService.mOpeningApps.contains(wtoken)) {
                        mAnimating |= wtoken.mAppAnimator.showAllWindowsLocked();
                    }
                }
            }
        }
    }

    private void performAnimationsLocked() {
        mInner.mTokenMayBeDrawn = false;
        mInner.mForceHiding = false;
        mInner.mDetachedWallpaper = null;
        mInner.mWindowAnimationBackground = null;
        mInner.mWindowAnimationBackgroundColor = 0;

        updateWindowsAndWallpaperLocked();
        if ((mPendingLayoutChanges & WindowManagerPolicy.FINISH_LAYOUT_REDO_WALLPAPER) != 0) {
            mPendingActions |= WALLPAPER_ACTION_PENDING;
        }

        if (mInner.mTokenMayBeDrawn) {
            testTokenMayBeDrawnLocked();
        }
    }

    synchronized void animate() {
        mPendingLayoutChanges = 0;
        mCurrentTime = SystemClock.uptimeMillis();
        mBulkUpdateParams = 0;
        boolean wasAnimating = mAnimating;
        mAnimating = false;
        if (WindowManagerService.DEBUG_WINDOW_TRACE) {
            Slog.i(TAG, "!!! animate: entry time=" + mCurrentTime);
        }

        // Update animations of all applications, including those
        // associated with exiting/removed apps
        Surface.openTransaction();

        try {
            updateWindowsAppsAndRotationAnimationsLocked();
            performAnimationsLocked();
            testWallpaperAndBackgroundLocked();

            // THIRD LOOP: Update the surfaces of all windows.

            if (mScreenRotationAnimation != null) {
                mScreenRotationAnimation.updateSurfaces();
            }

            final int N = mWinAnimators.size();
            for (int i = 0; i < N; i++) {
                mWinAnimators.get(i).prepareSurfaceLocked(true);
            }

            if (mDimParams != null) {
                mDimAnimator.updateParameters(mContext.getResources(), mDimParams, mCurrentTime);
            }
            if (mDimAnimator != null && mDimAnimator.mDimShown) {
                mAnimating |= mDimAnimator.updateSurface(isDimming(), mCurrentTime,
                        !mService.okToDisplay());
            }

            if (mService.mBlackFrame != null) {
                if (mScreenRotationAnimation != null) {
                    mService.mBlackFrame.setMatrix(
                            mScreenRotationAnimation.getEnterTransformation().getMatrix());
                } else {
                    mService.mBlackFrame.clearMatrix();
                }
            }

            if (mService.mWatermark != null) {
                mService.mWatermark.drawIfNeeded();
            }
        } catch (RuntimeException e) {
            Log.wtf(TAG, "Unhandled exception in Window Manager", e);
        } finally {
            Surface.closeTransaction();
        }

        if (mBulkUpdateParams != 0 || mPendingLayoutChanges != 0) {
            final WindowManagerService.AnimatorToLayoutParams animToLayout = mService.mAnimToLayout;
            synchronized (animToLayout) {
                animToLayout.mBulkUpdateParams = mBulkUpdateParams;
                animToLayout.mPendingLayoutChanges = mPendingLayoutChanges;
                animToLayout.mWindowDetachedWallpaper = mWindowDetachedWallpaper;
                mService.setAnimatorParameters();
            }
        }

        if (mAnimating) {
            mService.scheduleAnimationLocked();
        } else if (wasAnimating) {
            mService.requestTraversalLocked();
        }
        if (WindowManagerService.DEBUG_WINDOW_TRACE) {
            Slog.i(TAG, "!!! animate: exit mAnimating=" + mAnimating
                + " mBulkUpdateParams=" + Integer.toHexString(mBulkUpdateParams)
                + " mPendingLayoutChanges=" + Integer.toHexString(mPendingLayoutChanges));
        }
    }

    WindowState mCurrentFocus;
    void setCurrentFocus(final WindowState currentFocus) {
        mCurrentFocus = currentFocus;
    }

    void setDisplayDimensions(final int curWidth, final int curHeight,
                        final int appWidth, final int appHeight) {
        mDw = curWidth;
        mDh = curHeight;
        mInnerDw = appWidth;
        mInnerDh = appHeight;
    }

    void startDimming(final WindowStateAnimator winAnimator, final float target,
                      final int width, final int height) {
        if (mDimAnimator == null) {
            mDimAnimator = new DimAnimator(mService.mFxSession);
        }
        // Only set dim params on the highest dimmed layer.
        final WindowStateAnimator dimWinAnimator = mDimParams == null
                ? null : mDimParams.mDimWinAnimator;
        // Don't turn on for an unshown surface, or for any layer but the highest dimmed one.
        if (winAnimator.mSurfaceShown &&
                (dimWinAnimator == null || !dimWinAnimator.mSurfaceShown
                || dimWinAnimator.mAnimLayer < winAnimator.mAnimLayer)) {
            mService.mH.sendMessage(mService.mH.obtainMessage(SET_DIM_PARAMETERS,
                    new DimAnimator.Parameters(winAnimator, width, height, target)));
        }
    }

    // TODO(cmautner): Move into Handler
    void stopDimming() {
        mService.mH.sendMessage(mService.mH.obtainMessage(SET_DIM_PARAMETERS, null));
    }

    boolean isDimming() {
        return mDimParams != null;
    }

    boolean isDimming(final WindowStateAnimator winAnimator) {
        return mDimParams != null && mDimParams.mDimWinAnimator == winAnimator;
    }

    public void dump(PrintWriter pw, String prefix, boolean dumpAll) {
        if (mWindowDetachedWallpaper != null) {
            pw.print("  mWindowDetachedWallpaper="); pw.println(mWindowDetachedWallpaper);
        }
        if (mWindowAnimationBackgroundSurface != null) {
            pw.println("  mWindowAnimationBackgroundSurface:");
            mWindowAnimationBackgroundSurface.printTo("    ", pw);
        }
        if (mDimAnimator != null) {
            pw.println("  mDimAnimator:");
            mDimAnimator.printTo("    ", pw);
        } else {
            pw.println( "  no DimAnimator ");
        }
    }

    static class SetAnimationParams {
        final WindowStateAnimator mWinAnimator;
        final Animation mAnimation;
        final int mAnimDw;
        final int mAnimDh;
        public SetAnimationParams(final WindowStateAnimator winAnimator,
                                  final Animation animation, final int animDw, final int animDh) {
            mWinAnimator = winAnimator;
            mAnimation = animation;
            mAnimDw = animDw;
            mAnimDh = animDh;
        }
    }

    synchronized void clearPendingActions() {
        mPendingActions = 0;
    }
}