core/java/android/app/assist/AssistStructure.java

package android.app.assist;

import android.annotation.NonNull;
import android.annotation.Nullable;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.graphics.Matrix;
import android.graphics.Rect;
import android.net.Uri;
import android.os.BadParcelableException;
import android.os.Binder;
import android.os.Bundle;
import android.os.IBinder;
import android.os.LocaleList;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.PooledStringReader;
import android.os.PooledStringWriter;
import android.os.RemoteException;
import android.os.SystemClock;
import android.service.autofill.FillRequest;
import android.text.TextUtils;
import android.util.Log;
import android.util.Pair;
import android.view.View;
import android.view.View.AutofillImportance;
import android.view.ViewRootImpl;
import android.view.ViewStructure;
import android.view.ViewStructure.HtmlInfo;
import android.view.ViewStructure.HtmlInfo.Builder;
import android.view.WindowManager;
import android.view.WindowManagerGlobal;
import android.view.autofill.AutofillId;
import android.view.autofill.AutofillValue;

import com.android.internal.util.Preconditions;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 * <p>This API automatically creates assist data from the platform's
 * implementation of assist and autofill.
 *
 * <p>The structure is used for assist purposes when created by
 * {@link android.app.Activity#onProvideAssistData}, {@link View#onProvideStructure(ViewStructure)},
 * or {@link View#onProvideVirtualStructure(ViewStructure)}.
 *
 * <p>The structure is also used for autofill purposes when created by
 * {@link View#onProvideAutofillStructure(ViewStructure, int)},
 * or {@link View#onProvideAutofillVirtualStructure(ViewStructure, int)}.
 *
 * <p>For performance reasons, some properties of the assist data might only be available for
 * assist or autofill purposes. In those cases, a property's availability will be documented
 * in its javadoc.
 *
 * <p>To learn about using Autofill in your app, read the
 * <a href="/guide/topics/text/autofill">Autofill Framework</a> guides.
 */
public class AssistStructure implements Parcelable {
    static final String TAG = "AssistStructure";

    static final boolean DEBUG_PARCEL = false;
    static final boolean DEBUG_PARCEL_CHILDREN = false;
    static final boolean DEBUG_PARCEL_TREE = false;

    static final int VALIDATE_WINDOW_TOKEN = 0x11111111;
    static final int VALIDATE_VIEW_TOKEN = 0x22222222;

    boolean mHaveData;

    ComponentName mActivityComponent;
    private boolean mIsHomeActivity;
    private int mFlags;

    final ArrayList<WindowNode> mWindowNodes = new ArrayList<>();

    final ArrayList<ViewNodeBuilder> mPendingAsyncChildren = new ArrayList<>();

    SendChannel mSendChannel;
    IBinder mReceiveChannel;

    Rect mTmpRect = new Rect();

    boolean mSanitizeOnWrite = false;
    private long mAcquisitionStartTime;
    private long mAcquisitionEndTime;

    static final int TRANSACTION_XFER = Binder.FIRST_CALL_TRANSACTION+1;
    static final String DESCRIPTOR = "android.app.AssistStructure";

    /** @hide */
    public void setAcquisitionStartTime(long acquisitionStartTime) {
        mAcquisitionStartTime = acquisitionStartTime;
    }

    /** @hide */
    public void setAcquisitionEndTime(long acquisitionEndTime) {
        mAcquisitionEndTime = acquisitionEndTime;
    }

    /**
     * @hide
     * Set the home activity flag.
     */
    public void setHomeActivity(boolean isHomeActivity) {
        mIsHomeActivity = isHomeActivity;
    }

    /**
     * Returns the time when the activity started generating assist data to build the
     * AssistStructure. The time is as specified by {@link SystemClock#uptimeMillis()}.
     *
     * @see #getAcquisitionEndTime()
     * @return Returns the acquisition start time of the assist data, in milliseconds.
     */
    public long getAcquisitionStartTime() {
        ensureData();
        return mAcquisitionStartTime;
    }

    /**
     * Returns the time when the activity finished generating assist data to build the
     * AssistStructure. The time is as specified by {@link SystemClock#uptimeMillis()}.
     *
     * @see #getAcquisitionStartTime()
     * @return Returns the acquisition end time of the assist data, in milliseconds.
     */
    public long getAcquisitionEndTime() {
        ensureData();
        return mAcquisitionEndTime;
    }

    final static class SendChannel extends Binder {
        volatile AssistStructure mAssistStructure;

        SendChannel(AssistStructure as) {
            mAssistStructure = as;
        }

        @Override protected boolean onTransact(int code, Parcel data, Parcel reply, int flags)
                throws RemoteException {
            if (code == TRANSACTION_XFER) {
                AssistStructure as = mAssistStructure;
                if (as == null) {
                    return true;
                }

                data.enforceInterface(DESCRIPTOR);
                IBinder token = data.readStrongBinder();
                if (DEBUG_PARCEL) Log.d(TAG, "Request for data on " + as
                        + " using token " + token);
                if (token != null) {
                    if (DEBUG_PARCEL) Log.d(TAG, "Resuming partial write of " + token);
                    if (token instanceof ParcelTransferWriter) {
                        ParcelTransferWriter xfer = (ParcelTransferWriter)token;
                        xfer.writeToParcel(as, reply);
                        return true;
                    }
                    Log.w(TAG, "Caller supplied bad token type: " + token);
                    // Don't write anything; this is the end of the data.
                    return true;
                }
                //long start = SystemClock.uptimeMillis();
                ParcelTransferWriter xfer = new ParcelTransferWriter(as, reply);
                xfer.writeToParcel(as, reply);
                //Log.i(TAG, "Time to parcel: " + (SystemClock.uptimeMillis()-start) + "ms");
                return true;
            } else {
                return super.onTransact(code, data, reply, flags);
            }
        }
    }

    final static class ViewStackEntry {
        ViewNode node;
        int curChild;
        int numChildren;
    }

    final static class ParcelTransferWriter extends Binder {
        final boolean mWriteStructure;
        int mCurWindow;
        int mNumWindows;
        final ArrayList<ViewStackEntry> mViewStack = new ArrayList<>();
        ViewStackEntry mCurViewStackEntry;
        int mCurViewStackPos;
        int mNumWrittenWindows;
        int mNumWrittenViews;
        final float[] mTmpMatrix = new float[9];
        final boolean mSanitizeOnWrite;

        ParcelTransferWriter(AssistStructure as, Parcel out) {
            mSanitizeOnWrite = as.mSanitizeOnWrite;
            mWriteStructure = as.waitForReady();
            ComponentName.writeToParcel(as.mActivityComponent, out);
            out.writeInt(as.mFlags);
            out.writeLong(as.mAcquisitionStartTime);
            out.writeLong(as.mAcquisitionEndTime);
            mNumWindows = as.mWindowNodes.size();
            if (mWriteStructure && mNumWindows > 0) {
                out.writeInt(mNumWindows);
            } else {
                out.writeInt(0);
            }
        }

        void writeToParcel(AssistStructure as, Parcel out) {
            int start = out.dataPosition();
            mNumWrittenWindows = 0;
            mNumWrittenViews = 0;
            boolean more = writeToParcelInner(as, out);
            Log.i(TAG, "Flattened " + (more ? "partial" : "final") + " assist data: "
                    + (out.dataPosition() - start)
                    + " bytes, containing " + mNumWrittenWindows + " windows, "
                    + mNumWrittenViews + " views");
        }

        boolean writeToParcelInner(AssistStructure as, Parcel out) {
            if (mNumWindows == 0) {
                return false;
            }
            if (DEBUG_PARCEL) Log.d(TAG, "Creating PooledStringWriter @ " + out.dataPosition());
            PooledStringWriter pwriter = new PooledStringWriter(out);
            while (writeNextEntryToParcel(as, out, pwriter)) {
                // If the parcel is above the IPC limit, then we are getting too
                // large for a single IPC so stop here and let the caller come back when it
                // is ready for more.
                if (out.dataSize() > IBinder.MAX_IPC_SIZE) {
                    if (DEBUG_PARCEL) Log.d(TAG, "Assist data size is " + out.dataSize()
                            + " @ pos " + out.dataPosition() + "; returning partial result");
                    out.writeInt(0);
                    out.writeStrongBinder(this);
                    if (DEBUG_PARCEL) Log.d(TAG, "Finishing PooledStringWriter @ "
                            + out.dataPosition() + ", size " + pwriter.getStringCount());
                    pwriter.finish();
                    return true;
                }
            }
            if (DEBUG_PARCEL) Log.d(TAG, "Finishing PooledStringWriter @ "
                    + out.dataPosition() + ", size " + pwriter.getStringCount());
            pwriter.finish();
            mViewStack.clear();
            return false;
        }

        void pushViewStackEntry(ViewNode node, int pos) {
            ViewStackEntry entry;
            if (pos >= mViewStack.size()) {
                entry = new ViewStackEntry();
                mViewStack.add(entry);
                if (DEBUG_PARCEL_TREE) Log.d(TAG, "New stack entry at " + pos + ": " + entry);
            } else {
                entry = mViewStack.get(pos);
                if (DEBUG_PARCEL_TREE) Log.d(TAG, "Existing stack entry at " + pos + ": " + entry);
            }
            entry.node = node;
            entry.numChildren = node.getChildCount();
            entry.curChild = 0;
            mCurViewStackEntry = entry;
        }

        void writeView(ViewNode child, Parcel out, PooledStringWriter pwriter, int levelAdj) {
            if (DEBUG_PARCEL) Log.d(TAG, "write view: at " + out.dataPosition()
                    + ", windows=" + mNumWrittenWindows
                    + ", views=" + mNumWrittenViews
                    + ", level=" + (mCurViewStackPos+levelAdj));
            out.writeInt(VALIDATE_VIEW_TOKEN);
            int flags = child.writeSelfToParcel(out, pwriter, mSanitizeOnWrite, mTmpMatrix);
            mNumWrittenViews++;
            // If the child has children, push it on the stack to write them next.
            if ((flags&ViewNode.FLAGS_HAS_CHILDREN) != 0) {
                if (DEBUG_PARCEL_TREE || DEBUG_PARCEL_CHILDREN) Log.d(TAG,
                        "Preparing to write " + child.mChildren.length
                                + " children: @ #" + mNumWrittenViews
                                + ", level " + (mCurViewStackPos+levelAdj));
                out.writeInt(child.mChildren.length);
                int pos = ++mCurViewStackPos;
                pushViewStackEntry(child, pos);
            }
        }

        boolean writeNextEntryToParcel(AssistStructure as, Parcel out, PooledStringWriter pwriter) {
            // Write next view node if appropriate.
            if (mCurViewStackEntry != null) {
                if (mCurViewStackEntry.curChild < mCurViewStackEntry.numChildren) {
                    // Write the next child in the current view.
                    if (DEBUG_PARCEL_TREE) Log.d(TAG, "Writing child #"
                            + mCurViewStackEntry.curChild + " in " + mCurViewStackEntry.node);
                    ViewNode child = mCurViewStackEntry.node.mChildren[mCurViewStackEntry.curChild];
                    mCurViewStackEntry.curChild++;
                    writeView(child, out, pwriter, 1);
                    return true;
                }

                // We are done writing children of the current view; pop off the stack.
                do {
                    int pos = --mCurViewStackPos;
                    if (DEBUG_PARCEL_TREE) Log.d(TAG, "Done with " + mCurViewStackEntry.node
                            + "; popping up to " + pos);
                    if (pos < 0) {
                        // Reached the last view; step to next window.
                        if (DEBUG_PARCEL_TREE) Log.d(TAG, "Done with view hierarchy!");
                        mCurViewStackEntry = null;
                        break;
                    }
                    mCurViewStackEntry = mViewStack.get(pos);
                } while (mCurViewStackEntry.curChild >= mCurViewStackEntry.numChildren);
                return true;
            }

            // Write the next window if appropriate.
            int pos = mCurWindow;
            if (pos < mNumWindows) {
                WindowNode win = as.mWindowNodes.get(pos);
                mCurWindow++;
                if (DEBUG_PARCEL) Log.d(TAG, "write window #" + pos + ": at " + out.dataPosition()
                        + ", windows=" + mNumWrittenWindows
                        + ", views=" + mNumWrittenViews);
                out.writeInt(VALIDATE_WINDOW_TOKEN);
                win.writeSelfToParcel(out, pwriter, mTmpMatrix);
                mNumWrittenWindows++;
                ViewNode root = win.mRoot;
                mCurViewStackPos = 0;
                if (DEBUG_PARCEL_TREE) Log.d(TAG, "Writing initial root view " + root);
                writeView(root, out, pwriter, 0);
                return true;
            }

            return false;
        }
    }

    final class ParcelTransferReader {
        final float[] mTmpMatrix = new float[9];
        PooledStringReader mStringReader;

        int mNumReadWindows;
        int mNumReadViews;

        private final IBinder mChannel;
        private IBinder mTransferToken;
        private Parcel mCurParcel;

        ParcelTransferReader(IBinder channel) {
            mChannel = channel;
        }

        void go() {
            fetchData();
            mActivityComponent = ComponentName.readFromParcel(mCurParcel);
            mFlags = mCurParcel.readInt();
            mAcquisitionStartTime = mCurParcel.readLong();
            mAcquisitionEndTime = mCurParcel.readLong();
            final int N = mCurParcel.readInt();
            if (N > 0) {
                if (DEBUG_PARCEL) Log.d(TAG, "Creating PooledStringReader @ "
                        + mCurParcel.dataPosition());
                mStringReader = new PooledStringReader(mCurParcel);
                if (DEBUG_PARCEL) Log.d(TAG, "PooledStringReader size = "
                        + mStringReader.getStringCount());
                for (int i=0; i<N; i++) {
                    mWindowNodes.add(new WindowNode(this));
                }
            }
            if (DEBUG_PARCEL) Log.d(TAG, "Finished reading: at " + mCurParcel.dataPosition()
                    + ", avail=" + mCurParcel.dataAvail() + ", windows=" + mNumReadWindows
                    + ", views=" + mNumReadViews);
            mCurParcel.recycle();
            mCurParcel = null; // Parcel cannot be used after recycled.
        }

        Parcel readParcel(int validateToken, int level) {
            if (DEBUG_PARCEL) Log.d(TAG, "readParcel: at " + mCurParcel.dataPosition()
                    + ", avail=" + mCurParcel.dataAvail() + ", windows=" + mNumReadWindows
                    + ", views=" + mNumReadViews + ", level=" + level);
            int token = mCurParcel.readInt();
            if (token != 0) {
                if (token != validateToken) {
                    throw new BadParcelableException("Got token " + Integer.toHexString(token)
                            + ", expected token " + Integer.toHexString(validateToken));
                }
                return mCurParcel;
            }
            // We have run out of partial data, need to read another batch.
            mTransferToken = mCurParcel.readStrongBinder();
            if (mTransferToken == null) {
                throw new IllegalStateException(
                        "Reached end of partial data without transfer token");
            }
            if (DEBUG_PARCEL) Log.d(TAG, "Ran out of partial data at "
                    + mCurParcel.dataPosition() + ", token " + mTransferToken);
            fetchData();
            if (DEBUG_PARCEL) Log.d(TAG, "Creating PooledStringReader @ "
                    + mCurParcel.dataPosition());
            mStringReader = new PooledStringReader(mCurParcel);
            if (DEBUG_PARCEL) Log.d(TAG, "PooledStringReader size = "
                    + mStringReader.getStringCount());
            if (DEBUG_PARCEL) Log.d(TAG, "readParcel: at " + mCurParcel.dataPosition()
                    + ", avail=" + mCurParcel.dataAvail() + ", windows=" + mNumReadWindows
                    + ", views=" + mNumReadViews);
            mCurParcel.readInt();
            return mCurParcel;
        }

        private void fetchData() {
            Parcel data = Parcel.obtain();
            try {
                data.writeInterfaceToken(DESCRIPTOR);
                data.writeStrongBinder(mTransferToken);
                if (DEBUG_PARCEL) Log.d(TAG, "Requesting data with token " + mTransferToken);
                if (mCurParcel != null) {
                    mCurParcel.recycle();
                }
                mCurParcel = Parcel.obtain();
                try {
                    mChannel.transact(TRANSACTION_XFER, data, mCurParcel, 0);
                } catch (RemoteException e) {
                    Log.w(TAG, "Failure reading AssistStructure data", e);
                    throw new IllegalStateException("Failure reading AssistStructure data: " + e);
                }
            } finally {
                data.recycle();
            }
            mNumReadWindows = mNumReadViews = 0;
        }
    }

    final static class ViewNodeText {
        CharSequence mText;
        float mTextSize;
        int mTextStyle;
        int mTextColor = ViewNode.TEXT_COLOR_UNDEFINED;
        int mTextBackgroundColor = ViewNode.TEXT_COLOR_UNDEFINED;
        int mTextSelectionStart;
        int mTextSelectionEnd;
        int[] mLineCharOffsets;
        int[] mLineBaselines;
        String mHint;

        ViewNodeText() {
        }

        boolean isSimple() {
            return mTextBackgroundColor == ViewNode.TEXT_COLOR_UNDEFINED
                    && mTextSelectionStart == 0 && mTextSelectionEnd == 0
                    && mLineCharOffsets == null && mLineBaselines == null && mHint == null;
        }

        ViewNodeText(Parcel in, boolean simple) {
            mText = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(in);
            mTextSize = in.readFloat();
            mTextStyle = in.readInt();
            mTextColor = in.readInt();
            if (!simple) {
                mTextBackgroundColor = in.readInt();
                mTextSelectionStart = in.readInt();
                mTextSelectionEnd = in.readInt();
                mLineCharOffsets = in.createIntArray();
                mLineBaselines = in.createIntArray();
                mHint = in.readString();
            }
        }

        void writeToParcel(Parcel out, boolean simple, boolean writeSensitive) {
            TextUtils.writeToParcel(writeSensitive ? mText : "", out, 0);
            out.writeFloat(mTextSize);
            out.writeInt(mTextStyle);
            out.writeInt(mTextColor);
            if (!simple) {
                out.writeInt(mTextBackgroundColor);
                out.writeInt(mTextSelectionStart);
                out.writeInt(mTextSelectionEnd);
                out.writeIntArray(mLineCharOffsets);
                out.writeIntArray(mLineBaselines);
                out.writeString(mHint);
            }
        }
    }

    /**
     * Describes a window in the assist data.
     */
    static public class WindowNode {
        final int mX;
        final int mY;
        final int mWidth;
        final int mHeight;
        final CharSequence mTitle;
        final int mDisplayId;
        final ViewNode mRoot;

        WindowNode(AssistStructure assist, ViewRootImpl root, boolean forAutoFill, int flags) {
            View view = root.getView();
            Rect rect = new Rect();
            view.getBoundsOnScreen(rect);
            mX = rect.left - view.getLeft();
            mY = rect.top - view.getTop();
            mWidth = rect.width();
            mHeight = rect.height();
            mTitle = root.getTitle();
            mDisplayId = root.getDisplayId();
            mRoot = new ViewNode();

            ViewNodeBuilder builder = new ViewNodeBuilder(assist, mRoot, false);
            if ((root.getWindowFlags() & WindowManager.LayoutParams.FLAG_SECURE) != 0) {
                if (forAutoFill) {
                    final int viewFlags = resolveViewAutofillFlags(view.getContext(), flags);
                    view.onProvideAutofillStructure(builder, viewFlags);
                } else {
                    // This is a secure window, so it doesn't want a screenshot, and that
                    // means we should also not copy out its view hierarchy for Assist
                    view.onProvideStructure(builder);
                    builder.setAssistBlocked(true);
                    return;
                }
            }
            if (forAutoFill) {
                final int viewFlags = resolveViewAutofillFlags(view.getContext(), flags);
                view.dispatchProvideAutofillStructure(builder, viewFlags);
            } else {
                view.dispatchProvideStructure(builder);
            }
        }

        WindowNode(ParcelTransferReader reader) {
            Parcel in = reader.readParcel(VALIDATE_WINDOW_TOKEN, 0);
            reader.mNumReadWindows++;
            mX = in.readInt();
            mY = in.readInt();
            mWidth = in.readInt();
            mHeight = in.readInt();
            mTitle = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(in);
            mDisplayId = in.readInt();
            mRoot = new ViewNode(reader, 0);
        }

        int resolveViewAutofillFlags(Context context, int fillRequestFlags) {
            return (fillRequestFlags & FillRequest.FLAG_MANUAL_REQUEST) != 0
                        || context.isAutofillCompatibilityEnabled()
                    ? View.AUTOFILL_FLAG_INCLUDE_NOT_IMPORTANT_VIEWS : 0;
        }

        void writeSelfToParcel(Parcel out, PooledStringWriter pwriter, float[] tmpMatrix) {
            out.writeInt(mX);
            out.writeInt(mY);
            out.writeInt(mWidth);
            out.writeInt(mHeight);
            TextUtils.writeToParcel(mTitle, out, 0);
            out.writeInt(mDisplayId);
        }

        /**
         * Returns the left edge of the window, in pixels, relative to the left
         * edge of the screen.
         */
        public int getLeft() {
            return mX;
        }

        /**
         * Returns the top edge of the window, in pixels, relative to the top
         * edge of the screen.
         */
        public int getTop() {
            return mY;
        }

        /**
         * Returns the total width of the window in pixels.
         */
        public int getWidth() {
            return mWidth;
        }

        /**
         * Returns the total height of the window in pixels.
         */
        public int getHeight() {
            return mHeight;
        }

        /**
         * Returns the title associated with the window, if it has one.
         */
        public CharSequence getTitle() {
            return mTitle;
        }

        /**
         * Returns the ID of the display this window is on, for use with
         * {@link android.hardware.display.DisplayManager#getDisplay DisplayManager.getDisplay()}.
         */
        public int getDisplayId() {
            return mDisplayId;
        }

        /**
         * Returns the {@link ViewNode} containing the root content of the window.
         */
        public ViewNode getRootViewNode() {
            return mRoot;
        }
    }

    /**
     * Describes a single view in the assist data.
     */
    static public class ViewNode {
        /**
         * Magic value for text color that has not been defined, which is very unlikely
         * to be confused with a real text color.
         */
        public static final int TEXT_COLOR_UNDEFINED = 1;

        public static final int TEXT_STYLE_BOLD = 1<<0;
        public static final int TEXT_STYLE_ITALIC = 1<<1;
        public static final int TEXT_STYLE_UNDERLINE = 1<<2;
        public static final int TEXT_STYLE_STRIKE_THRU = 1<<3;

        int mId = View.NO_ID;
        String mIdPackage;
        String mIdType;
        String mIdEntry;

        // TODO: once we have more flags, it might be better to store the individual
        // fields (viewId and childId) of the field.
        AutofillId mAutofillId;
        @View.AutofillType int mAutofillType = View.AUTOFILL_TYPE_NONE;
        @Nullable String[] mAutofillHints;
        AutofillValue mAutofillValue;
        CharSequence[] mAutofillOptions;
        boolean mSanitized;
        HtmlInfo mHtmlInfo;
        int mMinEms = -1;
        int mMaxEms = -1;
        int mMaxLength = -1;
        @Nullable String mTextIdEntry;
        @AutofillImportance int mImportantForAutofill;

        // POJO used to override some autofill-related values when the node is parcelized.
        // Not written to parcel.
        AutofillOverlay mAutofillOverlay;

        int mX;
        int mY;
        int mScrollX;
        int mScrollY;
        int mWidth;
        int mHeight;
        Matrix mMatrix;
        float mElevation;
        float mAlpha = 1.0f;

        static final int FLAGS_DISABLED = 0x00000001;
        static final int FLAGS_VISIBILITY_MASK = View.VISIBLE|View.INVISIBLE|View.GONE;
        static final int FLAGS_FOCUSABLE = 0x00000010;
        static final int FLAGS_FOCUSED = 0x00000020;
        static final int FLAGS_SELECTED = 0x00000040;
        static final int FLAGS_ASSIST_BLOCKED = 0x00000080;
        static final int FLAGS_CHECKABLE = 0x00000100;
        static final int FLAGS_CHECKED = 0x00000200;
        static final int FLAGS_CLICKABLE = 0x00000400;
        static final int FLAGS_LONG_CLICKABLE = 0x00000800;
        static final int FLAGS_ACCESSIBILITY_FOCUSED = 0x00001000;
        static final int FLAGS_ACTIVATED = 0x00002000;
        static final int FLAGS_CONTEXT_CLICKABLE = 0x00004000;
        static final int FLAGS_OPAQUE = 0x00008000;

        // TODO: autofill data is made of many fields and ideally we should verify
        // one-by-one to optimize what's sent over, but there isn't enough flag bits for that, we'd
        // need to create a 'flags2' or 'autoFillFlags' field and add these flags there.
        // So, to keep thinkg simpler for now, let's just use on flag for all of them...
        static final int FLAGS_HAS_AUTOFILL_DATA = 0x80000000;
        static final int FLAGS_HAS_MATRIX = 0x40000000;
        static final int FLAGS_HAS_ALPHA = 0x20000000;
        static final int FLAGS_HAS_ELEVATION = 0x10000000;
        static final int FLAGS_HAS_SCROLL = 0x08000000;
        static final int FLAGS_HAS_LARGE_COORDS = 0x04000000;
        static final int FLAGS_HAS_CONTENT_DESCRIPTION = 0x02000000;
        static final int FLAGS_HAS_TEXT = 0x01000000;
        static final int FLAGS_HAS_COMPLEX_TEXT = 0x00800000;
        static final int FLAGS_HAS_EXTRAS = 0x00400000;
        static final int FLAGS_HAS_ID = 0x00200000;
        static final int FLAGS_HAS_CHILDREN = 0x00100000;
        static final int FLAGS_HAS_URL = 0x00080000;
        static final int FLAGS_HAS_INPUT_TYPE = 0x00040000;
        static final int FLAGS_HAS_LOCALE_LIST = 0x00010000;
        static final int FLAGS_ALL_CONTROL = 0xfff00000;

        int mFlags;

        String mClassName;
        CharSequence mContentDescription;

        ViewNodeText mText;
        int mInputType;
        String mWebScheme;
        String mWebDomain;
        Bundle mExtras;
        LocaleList mLocaleList;

        ViewNode[] mChildren;

        ViewNode() {
        }

        ViewNode(ParcelTransferReader reader, int nestingLevel) {
            final Parcel in = reader.readParcel(VALIDATE_VIEW_TOKEN, nestingLevel);
            reader.mNumReadViews++;
            final PooledStringReader preader = reader.mStringReader;
            mClassName = preader.readString();
            mFlags = in.readInt();
            final int flags = mFlags;
            if ((flags&FLAGS_HAS_ID) != 0) {
                mId = in.readInt();
                if (mId != View.NO_ID) {
                    mIdEntry = preader.readString();
                    if (mIdEntry != null) {
                        mIdType = preader.readString();
                        mIdPackage = preader.readString();
                    }
                }
            }

            if ((flags&FLAGS_HAS_AUTOFILL_DATA) != 0) {
                mSanitized = in.readInt() == 1;
                mAutofillId = in.readParcelable(null);
                mAutofillType = in.readInt();
                mAutofillHints = in.readStringArray();
                mAutofillValue = in.readParcelable(null);
                mAutofillOptions = in.readCharSequenceArray();
                final Parcelable p = in.readParcelable(null);
                if (p instanceof HtmlInfo) {
                    mHtmlInfo = (HtmlInfo) p;
                }
                mMinEms = in.readInt();
                mMaxEms = in.readInt();
                mMaxLength = in.readInt();
                mTextIdEntry = preader.readString();
                mImportantForAutofill = in.readInt();
            }
            if ((flags&FLAGS_HAS_LARGE_COORDS) != 0) {
                mX = in.readInt();
                mY = in.readInt();
                mWidth = in.readInt();
                mHeight = in.readInt();
            } else {
                int val = in.readInt();
                mX = val&0x7fff;
                mY = (val>>16)&0x7fff;
                val = in.readInt();
                mWidth = val&0x7fff;
                mHeight = (val>>16)&0x7fff;
            }
            if ((flags&FLAGS_HAS_SCROLL) != 0) {
                mScrollX = in.readInt();
                mScrollY = in.readInt();
            }
            if ((flags&FLAGS_HAS_MATRIX) != 0) {
                mMatrix = new Matrix();
                in.readFloatArray(reader.mTmpMatrix);
                mMatrix.setValues(reader.mTmpMatrix);
            }
            if ((flags&FLAGS_HAS_ELEVATION) != 0) {
                mElevation = in.readFloat();
            }
            if ((flags&FLAGS_HAS_ALPHA) != 0) {
                mAlpha = in.readFloat();
            }
            if ((flags&FLAGS_HAS_CONTENT_DESCRIPTION) != 0) {
                mContentDescription = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(in);
            }
            if ((flags&FLAGS_HAS_TEXT) != 0) {
                mText = new ViewNodeText(in, (flags&FLAGS_HAS_COMPLEX_TEXT) == 0);
            }
            if ((flags&FLAGS_HAS_INPUT_TYPE) != 0) {
                mInputType = in.readInt();
            }
            if ((flags&FLAGS_HAS_URL) != 0) {
                mWebScheme = in.readString();
                mWebDomain = in.readString();
            }
            if ((flags&FLAGS_HAS_LOCALE_LIST) != 0) {
                mLocaleList = in.readParcelable(null);
            }
            if ((flags&FLAGS_HAS_EXTRAS) != 0) {
                mExtras = in.readBundle();
            }
            if ((flags&FLAGS_HAS_CHILDREN) != 0) {
                final int NCHILDREN = in.readInt();
                if (DEBUG_PARCEL_TREE || DEBUG_PARCEL_CHILDREN) Log.d(TAG,
                        "Preparing to read " + NCHILDREN
                                + " children: @ #" + reader.mNumReadViews
                                + ", level " + nestingLevel);
                mChildren = new ViewNode[NCHILDREN];
                for (int i=0; i<NCHILDREN; i++) {
                    mChildren[i] = new ViewNode(reader, nestingLevel + 1);
                }
            }
        }

        int writeSelfToParcel(Parcel out, PooledStringWriter pwriter, boolean sanitizeOnWrite,
                float[] tmpMatrix) {
            // Guard used to skip non-sanitized data when writing for autofill.
            boolean writeSensitive = true;

            int flags = mFlags & ~FLAGS_ALL_CONTROL;

            if (mId != View.NO_ID) {
                flags |= FLAGS_HAS_ID;
            }
            if (mAutofillId != null) {
                flags |= FLAGS_HAS_AUTOFILL_DATA;
            }
            if ((mX&~0x7fff) != 0 || (mY&~0x7fff) != 0
                    || (mWidth&~0x7fff) != 0 | (mHeight&~0x7fff) != 0) {
                flags |= FLAGS_HAS_LARGE_COORDS;
            }
            if (mScrollX != 0 || mScrollY != 0) {
                flags |= FLAGS_HAS_SCROLL;
            }
            if (mMatrix != null) {
                flags |= FLAGS_HAS_MATRIX;
            }
            if (mElevation != 0) {
                flags |= FLAGS_HAS_ELEVATION;
            }
            if (mAlpha != 1.0f) {
                flags |= FLAGS_HAS_ALPHA;
            }
            if (mContentDescription != null) {
                flags |= FLAGS_HAS_CONTENT_DESCRIPTION;
            }
            if (mText != null) {
                flags |= FLAGS_HAS_TEXT;
                if (!mText.isSimple()) {
                    flags |= FLAGS_HAS_COMPLEX_TEXT;
                }
            }
            if (mInputType != 0) {
                flags |= FLAGS_HAS_INPUT_TYPE;
            }
            if (mWebScheme != null || mWebDomain != null) {
                flags |= FLAGS_HAS_URL;
            }
            if (mLocaleList != null) {
                flags |= FLAGS_HAS_LOCALE_LIST;
            }
            if (mExtras != null) {
                flags |= FLAGS_HAS_EXTRAS;
            }
            if (mChildren != null) {
                flags |= FLAGS_HAS_CHILDREN;
            }

            pwriter.writeString(mClassName);

            int writtenFlags = flags;
            if ((flags&FLAGS_HAS_AUTOFILL_DATA) != 0 && (mSanitized || !sanitizeOnWrite)) {
                // Remove 'checked' from sanitized autofill request.
                writtenFlags = flags & ~FLAGS_CHECKED;
            }
            if (mAutofillOverlay != null) {
                if (mAutofillOverlay.focused) {
                    writtenFlags |= ViewNode.FLAGS_FOCUSED;
                } else {
                    writtenFlags &= ~ViewNode.FLAGS_FOCUSED;
                }
            }

            out.writeInt(writtenFlags);
            if ((flags&FLAGS_HAS_ID) != 0) {
                out.writeInt(mId);
                if (mId != View.NO_ID) {
                    pwriter.writeString(mIdEntry);
                    if (mIdEntry != null) {
                        pwriter.writeString(mIdType);
                        pwriter.writeString(mIdPackage);
                    }
                }
            }

            if ((flags&FLAGS_HAS_AUTOFILL_DATA) != 0) {
                writeSensitive = mSanitized || !sanitizeOnWrite;
                out.writeInt(mSanitized ? 1 : 0);
                out.writeParcelable(mAutofillId, 0);
                out.writeInt(mAutofillType);
                out.writeStringArray(mAutofillHints);
                final AutofillValue sanitizedValue;
                if (writeSensitive) {
                    sanitizedValue = mAutofillValue;
                } else if (mAutofillOverlay != null && mAutofillOverlay.value != null) {
                    sanitizedValue = mAutofillOverlay.value;
                } else {
                    sanitizedValue = null;
                }
                out.writeParcelable(sanitizedValue,  0);
                out.writeCharSequenceArray(mAutofillOptions);
                if (mHtmlInfo instanceof Parcelable) {
                    out.writeParcelable((Parcelable) mHtmlInfo, 0);
                } else {
                    out.writeParcelable(null, 0);
                }
                out.writeInt(mMinEms);
                out.writeInt(mMaxEms);
                out.writeInt(mMaxLength);
                pwriter.writeString(mTextIdEntry);
                out.writeInt(mImportantForAutofill);
            }
            if ((flags&FLAGS_HAS_LARGE_COORDS) != 0) {
                out.writeInt(mX);
                out.writeInt(mY);
                out.writeInt(mWidth);
                out.writeInt(mHeight);
            } else {
                out.writeInt((mY<<16) | mX);
                out.writeInt((mHeight<<16) | mWidth);
            }
            if ((flags&FLAGS_HAS_SCROLL) != 0) {
                out.writeInt(mScrollX);
                out.writeInt(mScrollY);
            }
            if ((flags&FLAGS_HAS_MATRIX) != 0) {
                mMatrix.getValues(tmpMatrix);
                out.writeFloatArray(tmpMatrix);
            }
            if ((flags&FLAGS_HAS_ELEVATION) != 0) {
                out.writeFloat(mElevation);
            }
            if ((flags&FLAGS_HAS_ALPHA) != 0) {
                out.writeFloat(mAlpha);
            }
            if ((flags&FLAGS_HAS_CONTENT_DESCRIPTION) != 0) {
                TextUtils.writeToParcel(mContentDescription, out, 0);
            }
            if ((flags&FLAGS_HAS_TEXT) != 0) {
                mText.writeToParcel(out, (flags&FLAGS_HAS_COMPLEX_TEXT) == 0, writeSensitive);
            }
            if ((flags&FLAGS_HAS_INPUT_TYPE) != 0) {
                out.writeInt(mInputType);
            }
            if ((flags&FLAGS_HAS_URL) != 0) {
                out.writeString(mWebScheme);
                out.writeString(mWebDomain);
            }
            if ((flags&FLAGS_HAS_LOCALE_LIST) != 0) {
                out.writeParcelable(mLocaleList, 0);
            }
            if ((flags&FLAGS_HAS_EXTRAS) != 0) {
                out.writeBundle(mExtras);
            }
            return flags;
        }

        /**
         * Returns the ID associated with this view, as per {@link View#getId() View.getId()}.
         */
        public int getId() {
            return mId;
        }

        /**
         * If {@link #getId()} is a resource identifier, this is the package name of that
         * identifier.  See {@link android.view.ViewStructure#setId ViewStructure.setId}
         * for more information.
         */
        public String getIdPackage() {
            return mIdPackage;
        }

        /**
         * If {@link #getId()} is a resource identifier, this is the type name of that
         * identifier.  See {@link android.view.ViewStructure#setId ViewStructure.setId}
         * for more information.
         */
        public String getIdType() {
            return mIdType;
        }

        /**
         * If {@link #getId()} is a resource identifier, this is the entry name of that
         * identifier.  See {@link android.view.ViewStructure#setId ViewStructure.setId}
         * for more information.
         */
        public String getIdEntry() {
            return mIdEntry;
        }

        /**
         * Gets the id that can be used to autofill the view contents.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for autofill purposes.
         *
         * @return id that can be used to autofill the view contents, or {@code null} if the
         * structure was created for assist purposes.
         */
        @Nullable public AutofillId getAutofillId() {
            return mAutofillId;
        }

        /**
         * Gets the the type of value that can be used to autofill the view contents.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for autofill purposes.
         *
         * @return autofill type as defined by {@link View#getAutofillType()},
         * or {@link View#AUTOFILL_TYPE_NONE} if the structure was created for assist purposes.
         */
        public @View.AutofillType int getAutofillType() {
            return mAutofillType;
        }

        /**
         * Describes the content of a view so that a autofill service can fill in the appropriate
         * data.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for autofill purposes,
         * not for Assist - see {@link View#getAutofillHints()} for more info.
         *
         * @return The autofill hints for this view, or {@code null} if the structure was created
         * for assist purposes.
         */
        @Nullable public String[] getAutofillHints() {
            return mAutofillHints;
        }

        /**
         * Gets the the value of this view.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for autofill purposes,
         * not for assist purposes.
         *
         * @return the autofill value of this view, or {@code null} if the structure was created
         * for assist purposes.
         */
        @Nullable public AutofillValue getAutofillValue() {
            return mAutofillValue;
        }

        /** @hide **/
        public void setAutofillOverlay(AutofillOverlay overlay) {
            mAutofillOverlay = overlay;
        }

        /**
         * Gets the options that can be used to autofill this view.
         *
         * <p>Typically used by nodes whose {@link View#getAutofillType()} is a list to indicate
         * the meaning of each possible value in the list.
         *
         * <p>It's relevant when the {@link AssistStructure} is used for autofill purposes, not
         * for assist purposes.
         *
         * @return the options that can be used to autofill this view, or {@code null} if the
         * structure was created for assist purposes.
         */
        @Nullable public CharSequence[] getAutofillOptions() {
            return mAutofillOptions;
        }

        /**
         * Gets the {@link android.text.InputType} bits of this structure.
         *
         * @return bits as defined by {@link android.text.InputType}.
         */
        public int getInputType() {
            return mInputType;
        }

        /** @hide */
        public boolean isSanitized() {
            return mSanitized;
        }

        /**
         * Updates the {@link AutofillValue} of this structure.
         *
         * <p>Should be used just before sending the structure to the
         * {@link android.service.autofill.AutofillService} for saving, since it will override the
         * initial value.
         *
         * @hide
         */
        public void updateAutofillValue(AutofillValue value) {
            mAutofillValue = value;
            if (value.isText()) {
                if (mText == null) {
                    mText = new ViewNodeText();
                }
                mText.mText = value.getTextValue();
            }
        }

        /**
         * Returns the left edge of this view, in pixels, relative to the left edge of its parent.
         */
        public int getLeft() {
            return mX;
        }

        /**
         * Returns the top edge of this view, in pixels, relative to the top edge of its parent.
         */
        public int getTop() {
            return mY;
        }

        /**
         * Returns the current X scroll offset of this view, as per
         * {@link android.view.View#getScrollX() View.getScrollX()}.
         */
        public int getScrollX() {
            return mScrollX;
        }

        /**
         * Returns the current Y scroll offset of this view, as per
         * {@link android.view.View#getScrollX() View.getScrollY()}.
         */
        public int getScrollY() {
            return mScrollY;
        }

        /**
         * Returns the width of this view, in pixels.
         */
        public int getWidth() {
            return mWidth;
        }

        /**
         * Returns the height of this view, in pixels.
         */
        public int getHeight() {
            return mHeight;
        }

        /**
         * Returns the transformation that has been applied to this view, such as a translation
         * or scaling.  The returned Matrix object is owned by ViewNode; do not modify it.
         * Returns null if there is no transformation applied to the view.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for assist purposes,
         * not for autofill purposes.
         */
        public Matrix getTransformation() {
            return mMatrix;
        }

        /**
         * Returns the visual elevation of the view, used for shadowing and other visual
         * characterstics, as set by {@link ViewStructure#setElevation
         * ViewStructure.setElevation(float)}.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for assist purposes,
         * not for autofill purposes.
         */
        public float getElevation() {
            return mElevation;
        }

        /**
         * Returns the alpha transformation of the view, used to reduce the overall opacity
         * of the view's contents, as set by {@link ViewStructure#setAlpha
         * ViewStructure.setAlpha(float)}.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for assist purposes,
         * not for autofill purposes.
         */
        public float getAlpha() {
            return mAlpha;
        }

        /**
         * Returns the visibility mode of this view, as per
         * {@link android.view.View#getVisibility() View.getVisibility()}.
         */
        public int getVisibility() {
            return mFlags&ViewNode.FLAGS_VISIBILITY_MASK;
        }

        /**
         * Returns true if assist data has been blocked starting at this node in the hierarchy.
         */
        public boolean isAssistBlocked() {
            return (mFlags&ViewNode.FLAGS_ASSIST_BLOCKED) != 0;
        }

        /**
         * Returns true if this node is in an enabled state.
         */
        public boolean isEnabled() {
            return (mFlags&ViewNode.FLAGS_DISABLED) == 0;
        }

        /**
         * Returns true if this node is clickable by the user.
         */
        public boolean isClickable() {
            return (mFlags&ViewNode.FLAGS_CLICKABLE) != 0;
        }

        /**
         * Returns true if this node can take input focus.
         */
        public boolean isFocusable() {
            return (mFlags&ViewNode.FLAGS_FOCUSABLE) != 0;
        }

        /**
         * Returns true if this node currently had input focus at the time that the
         * structure was collected.
         */
        public boolean isFocused() {
            return (mFlags&ViewNode.FLAGS_FOCUSED) != 0;
        }

        /**
         * Returns true if this node currently had accessibility focus at the time that the
         * structure was collected.
         */
        public boolean isAccessibilityFocused() {
            return (mFlags&ViewNode.FLAGS_ACCESSIBILITY_FOCUSED) != 0;
        }

        /**
         * Returns true if this node represents something that is checkable by the user.
         */
        public boolean isCheckable() {
            return (mFlags&ViewNode.FLAGS_CHECKABLE) != 0;
        }

        /**
         * Returns true if this node is currently in a checked state.
         */
        public boolean isChecked() {
            return (mFlags&ViewNode.FLAGS_CHECKED) != 0;
        }

        /**
         * Returns true if this node has currently been selected by the user.
         */
        public boolean isSelected() {
            return (mFlags&ViewNode.FLAGS_SELECTED) != 0;
        }

        /**
         * Returns true if this node has currently been activated by the user.
         */
        public boolean isActivated() {
            return (mFlags&ViewNode.FLAGS_ACTIVATED) != 0;
        }

        /**
         * Returns true if this node is opaque.
         */
        public boolean isOpaque() { return (mFlags&ViewNode.FLAGS_OPAQUE) != 0; }

        /**
         * Returns true if this node is something the user can perform a long click/press on.
         */
        public boolean isLongClickable() {
            return (mFlags&ViewNode.FLAGS_LONG_CLICKABLE) != 0;
        }

        /**
         * Returns true if this node is something the user can perform a context click on.
         */
        public boolean isContextClickable() {
            return (mFlags&ViewNode.FLAGS_CONTEXT_CLICKABLE) != 0;
        }

        /**
         * Returns the class name of the node's implementation, indicating its behavior.
         * For example, a button will report "android.widget.Button" meaning it behaves
         * like a {@link android.widget.Button}.
         */
        public String getClassName() {
            return mClassName;
        }

        /**
         * Returns any content description associated with the node, which semantically describes
         * its purpose for accessibility and other uses.
         */
        public CharSequence getContentDescription() {
            return mContentDescription;
        }

        /**
         * Returns the domain of the HTML document represented by this view.
         *
         * <p>Typically used when the view associated with the view is a container for an HTML
         * document.
         *
         * <p><b>Warning:</b> an autofill service cannot trust the value reported by this method
         * without verifing its authenticity&mdash;see the "Web security" section of
         * {@link android.service.autofill.AutofillService} for more details.
         *
         * @return domain-only part of the document. For example, if the full URL is
         * {@code https://example.com/login?user=my_user}, it returns {@code example.com}.
         */
        @Nullable public String getWebDomain() {
            return mWebDomain;
        }

        /**
         * @hide
         */
        public void setWebDomain(@Nullable String domain) {
            if (domain == null) return;

            final Uri uri = Uri.parse(domain);
            if (uri == null) {
                // Cannot log domain because it could contain PII;
                Log.w(TAG, "Failed to parse web domain");
                return;
            }
            mWebScheme = uri.getScheme();
            mWebDomain = uri.getHost();
        }

        /**
         * Returns the scheme of the HTML document represented by this view.
         *
         * <p>Typically used when the view associated with the view is a container for an HTML
         * document.
         *
         * @return scheme-only part of the document. For example, if the full URL is
         * {@code https://example.com/login?user=my_user}, it returns {@code https}.
         */
        @Nullable public String getWebScheme() {
            return mWebScheme;
        }

        /**
         * Returns the HTML properties associated with this view.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for autofill purposes,
         * not for assist purposes.
         *
         * @return the HTML properties associated with this view, or {@code null} if the
         * structure was created for assist purposes.
         */
        @Nullable public HtmlInfo getHtmlInfo() {
            return mHtmlInfo;
        }

        /**
         * Returns the the list of locales associated with this view.
         */
        @Nullable public LocaleList getLocaleList() {
            return mLocaleList;
        }

        /**
         * Returns any text associated with the node that is displayed to the user, or null
         * if there is none.
         */
        public CharSequence getText() {
            return mText != null ? mText.mText : null;
        }

        /**
         * If {@link #getText()} is non-null, this is where the current selection starts.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for assist purposes,
         * not for autofill purposes.
         */
        public int getTextSelectionStart() {
            return mText != null ? mText.mTextSelectionStart : -1;
        }

        /**
         * If {@link #getText()} is non-null, this is where the current selection starts.
         * If there is no selection, returns the same value as {@link #getTextSelectionStart()},
         * indicating the cursor position.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for assist purposes,
         * not for autofill purposes.
         */
        public int getTextSelectionEnd() {
            return mText != null ? mText.mTextSelectionEnd : -1;
        }

        /**
         * If {@link #getText()} is non-null, this is the main text color associated with it.
         * If there is no text color, {@link #TEXT_COLOR_UNDEFINED} is returned.
         * Note that the text may also contain style spans that modify the color of specific
         * parts of the text.
         */
        public int getTextColor() {
            return mText != null ? mText.mTextColor : TEXT_COLOR_UNDEFINED;
        }

        /**
         * If {@link #getText()} is non-null, this is the main text background color associated
         * with it.
         * If there is no text background color, {@link #TEXT_COLOR_UNDEFINED} is returned.
         * Note that the text may also contain style spans that modify the color of specific
         * parts of the text.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for assist purposes,
         * not for autofill purposes.
         */
        public int getTextBackgroundColor() {
            return mText != null ? mText.mTextBackgroundColor : TEXT_COLOR_UNDEFINED;
        }

        /**
         * If {@link #getText()} is non-null, this is the main text size (in pixels) associated
         * with it.
         * Note that the text may also contain style spans that modify the size of specific
         * parts of the text.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for assist purposes,
         * not for autofill purposes.
         */
        public float getTextSize() {
            return mText != null ? mText.mTextSize : 0;
        }

        /**
         * If {@link #getText()} is non-null, this is the main text style associated
         * with it, containing a bit mask of {@link #TEXT_STYLE_BOLD},
         * {@link #TEXT_STYLE_BOLD}, {@link #TEXT_STYLE_STRIKE_THRU}, and/or
         * {@link #TEXT_STYLE_UNDERLINE}.
         * Note that the text may also contain style spans that modify the style of specific
         * parts of the text.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for assist purposes,
         * not for autofill purposes.
         */
        public int getTextStyle() {
            return mText != null ? mText.mTextStyle : 0;
        }

        /**
         * Return per-line offsets into the text returned by {@link #getText()}.  Each entry
         * in the array is a formatted line of text, and the value it contains is the offset
         * into the text string where that line starts.  May return null if there is no line
         * information.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for assist purposes,
         * not for autofill purposes.
         */
        public int[] getTextLineCharOffsets() {
            return mText != null ? mText.mLineCharOffsets : null;
        }

        /**
         * Return per-line baselines into the text returned by {@link #getText()}.  Each entry
         * in the array is a formatted line of text, and the value it contains is the baseline
         * where that text appears in the view.  May return null if there is no line
         * information.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for assist purposes,
         * not for autofill purposes.
         */
        public int[] getTextLineBaselines() {
            return mText != null ? mText.mLineBaselines : null;
        }

        /**
         * Gets the identifier used to set the text associated with this view.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for autofill purposes,
         * not for assist purposes.
         */
        @Nullable
        public String getTextIdEntry() {
            return mTextIdEntry;
        }

        /**
         * Return additional hint text associated with the node; this is typically used with
         * a node that takes user input, describing to the user what the input means.
         */
        public String getHint() {
            return mText != null ? mText.mHint : null;
        }

        /**
         * Return a Bundle containing optional vendor-specific extension information.
         */
        public Bundle getExtras() {
            return mExtras;
        }

        /**
         * Return the number of children this node has.
         */
        public int getChildCount() {
            return mChildren != null ? mChildren.length : 0;
        }

        /**
         * Return a child of this node, given an index value from 0 to
         * {@link #getChildCount()}-1.
         */
        public ViewNode getChildAt(int index) {
            return mChildren[index];
        }

        /**
         * Returns the minimum width in ems of the text associated with this node, or {@code -1}
         * if not supported by the node.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for autofill purposes,
         * not for assist purposes.
         */
        public int getMinTextEms() {
            return mMinEms;
        }

        /**
         * Returns the maximum width in ems of the text associated with this node, or {@code -1}
         * if not supported by the node.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for autofill purposes,
         * not for assist purposes.
         */
        public int getMaxTextEms() {
            return mMaxEms;
        }

        /**
         * Returns the maximum length of the text associated with this node node, or {@code -1}
         * if not supported by the node or not set.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for autofill purposes,
         * not for assist purposes.
         */
        public int getMaxTextLength() {
            return mMaxLength;
        }

        /**
         * Gets the {@link View#setImportantForAutofill(int) importantForAutofill mode} of
         * the view associated with this node.
         *
         * <p>It's only relevant when the {@link AssistStructure} is used for autofill purposes.
         */
        public @AutofillImportance int getImportantForAutofill() {
            return mImportantForAutofill;
        }
    }

    /**
     * POJO used to override some autofill-related values when the node is parcelized.
     *
     * @hide
     */
    static public class AutofillOverlay {
        public boolean focused;
        public AutofillValue value;
    }

    static class ViewNodeBuilder extends ViewStructure {
        final AssistStructure mAssist;
        final ViewNode mNode;
        final boolean mAsync;

        ViewNodeBuilder(AssistStructure assist, ViewNode node, boolean async) {
            mAssist = assist;
            mNode = node;
            mAsync = async;
        }

        @Override
        public void setId(int id, String packageName, String typeName, String entryName) {
            mNode.mId = id;
            mNode.mIdPackage = packageName;
            mNode.mIdType = typeName;
            mNode.mIdEntry = entryName;
        }

        @Override
        public void setDimens(int left, int top, int scrollX, int scrollY, int width, int height) {
            mNode.mX = left;
            mNode.mY = top;
            mNode.mScrollX = scrollX;
            mNode.mScrollY = scrollY;
            mNode.mWidth = width;
            mNode.mHeight = height;
        }

        @Override
        public void setTransformation(Matrix matrix) {
            if (matrix == null) {
                mNode.mMatrix = null;
            } else {
                mNode.mMatrix = new Matrix(matrix);
            }
        }

        @Override
        public void setElevation(float elevation) {
            mNode.mElevation = elevation;
        }

        @Override
        public void setAlpha(float alpha) {
            mNode.mAlpha = alpha;
        }

        @Override
        public void setVisibility(int visibility) {
            mNode.mFlags = (mNode.mFlags&~ViewNode.FLAGS_VISIBILITY_MASK) | visibility;
        }

        @Override
        public void setAssistBlocked(boolean state) {
            mNode.mFlags = (mNode.mFlags&~ViewNode.FLAGS_ASSIST_BLOCKED)
                    | (state ? ViewNode.FLAGS_ASSIST_BLOCKED : 0);
        }

        @Override
        public void setEnabled(boolean state) {
            mNode.mFlags = (mNode.mFlags&~ViewNode.FLAGS_DISABLED)
                    | (state ? 0 : ViewNode.FLAGS_DISABLED);
        }

        @Override
        public void setClickable(boolean state) {
            mNode.mFlags = (mNode.mFlags&~ViewNode.FLAGS_CLICKABLE)
                    | (state ? ViewNode.FLAGS_CLICKABLE : 0);
        }

        @Override
        public void setLongClickable(boolean state) {
            mNode.mFlags = (mNode.mFlags&~ViewNode.FLAGS_LONG_CLICKABLE)
                    | (state ? ViewNode.FLAGS_LONG_CLICKABLE : 0);
        }

        @Override
        public void setContextClickable(boolean state) {
            mNode.mFlags = (mNode.mFlags&~ViewNode.FLAGS_CONTEXT_CLICKABLE)
                    | (state ? ViewNode.FLAGS_CONTEXT_CLICKABLE : 0);
        }

        @Override
        public void setFocusable(boolean state) {
            mNode.mFlags = (mNode.mFlags&~ViewNode.FLAGS_FOCUSABLE)
                    | (state ? ViewNode.FLAGS_FOCUSABLE : 0);
        }

        @Override
        public void setFocused(boolean state) {
            mNode.mFlags = (mNode.mFlags&~ViewNode.FLAGS_FOCUSED)
                    | (state ? ViewNode.FLAGS_FOCUSED : 0);
        }

        @Override
        public void setAccessibilityFocused(boolean state) {
            mNode.mFlags = (mNode.mFlags&~ViewNode.FLAGS_ACCESSIBILITY_FOCUSED)
                    | (state ? ViewNode.FLAGS_ACCESSIBILITY_FOCUSED : 0);
        }

        @Override
        public void setCheckable(boolean state) {
            mNode.mFlags = (mNode.mFlags&~ViewNode.FLAGS_CHECKABLE)
                    | (state ? ViewNode.FLAGS_CHECKABLE : 0);
        }

        @Override
        public void setChecked(boolean state) {
            mNode.mFlags = (mNode.mFlags&~ViewNode.FLAGS_CHECKED)
                    | (state ? ViewNode.FLAGS_CHECKED : 0);
        }

        @Override
        public void setSelected(boolean state) {
            mNode.mFlags = (mNode.mFlags&~ViewNode.FLAGS_SELECTED)
                    | (state ? ViewNode.FLAGS_SELECTED : 0);
        }

        @Override
        public void setActivated(boolean state) {
            mNode.mFlags = (mNode.mFlags&~ViewNode.FLAGS_ACTIVATED)
                    | (state ? ViewNode.FLAGS_ACTIVATED : 0);
        }

        @Override
        public void setOpaque(boolean opaque) {
            mNode.mFlags = (mNode.mFlags & ~ViewNode.FLAGS_OPAQUE)
                    | (opaque ? ViewNode.FLAGS_OPAQUE : 0);
        }

        @Override
        public void setClassName(String className) {
            mNode.mClassName = className;
        }

        @Override
        public void setContentDescription(CharSequence contentDescription) {
            mNode.mContentDescription = contentDescription;
        }

        private final ViewNodeText getNodeText() {
            if (mNode.mText != null) {
                return mNode.mText;
            }
            mNode.mText = new ViewNodeText();
            return mNode.mText;
        }

        @Override
        public void setText(CharSequence text) {
            ViewNodeText t = getNodeText();
            t.mText = TextUtils.trimNoCopySpans(text);
            t.mTextSelectionStart = t.mTextSelectionEnd = -1;
        }

        @Override
        public void setText(CharSequence text, int selectionStart, int selectionEnd) {
            ViewNodeText t = getNodeText();
            t.mText = TextUtils.trimNoCopySpans(text);
            t.mTextSelectionStart = selectionStart;
            t.mTextSelectionEnd = selectionEnd;
        }

        @Override
        public void setTextStyle(float size, int fgColor, int bgColor, int style) {
            ViewNodeText t = getNodeText();
            t.mTextColor = fgColor;
            t.mTextBackgroundColor = bgColor;
            t.mTextSize = size;
            t.mTextStyle = style;
        }

        @Override
        public void setTextLines(int[] charOffsets, int[] baselines) {
            ViewNodeText t = getNodeText();
            t.mLineCharOffsets = charOffsets;
            t.mLineBaselines = baselines;
        }

        @Override
        public void setTextIdEntry(@NonNull String entryName) {
            mNode.mTextIdEntry = Preconditions.checkNotNull(entryName);
        }

        @Override
        public void setHint(CharSequence hint) {
            getNodeText().mHint = hint != null ? hint.toString() : null;
        }

        @Override
        public CharSequence getText() {
            return mNode.mText != null ? mNode.mText.mText : null;
        }

        @Override
        public int getTextSelectionStart() {
            return mNode.mText != null ? mNode.mText.mTextSelectionStart : -1;
        }

        @Override
        public int getTextSelectionEnd() {
            return mNode.mText != null ? mNode.mText.mTextSelectionEnd : -1;
        }

        @Override
        public CharSequence getHint() {
            return mNode.mText != null ? mNode.mText.mHint : null;
        }

        @Override
        public Bundle getExtras() {
            if (mNode.mExtras != null) {
                return mNode.mExtras;
            }
            mNode.mExtras = new Bundle();
            return mNode.mExtras;
        }

        @Override
        public boolean hasExtras() {
            return mNode.mExtras != null;
        }

        @Override
        public void setChildCount(int num) {
            mNode.mChildren = new ViewNode[num];
        }

        @Override
        public int addChildCount(int num) {
            if (mNode.mChildren == null) {
                setChildCount(num);
                return 0;
            }
            final int start = mNode.mChildren.length;
            ViewNode[] newArray = new ViewNode[start + num];
            System.arraycopy(mNode.mChildren, 0, newArray, 0, start);
            mNode.mChildren = newArray;
            return start;
        }

        @Override
        public int getChildCount() {
            return mNode.mChildren != null ? mNode.mChildren.length : 0;
        }

        @Override
        public ViewStructure newChild(int index) {
            ViewNode node = new ViewNode();
            mNode.mChildren[index] = node;
            return new ViewNodeBuilder(mAssist, node, false);
        }

        @Override
        public ViewStructure asyncNewChild(int index) {
            synchronized (mAssist) {
                ViewNode node = new ViewNode();
                mNode.mChildren[index] = node;
                ViewNodeBuilder builder = new ViewNodeBuilder(mAssist, node, true);
                mAssist.mPendingAsyncChildren.add(builder);
                return builder;
            }
        }

        @Override
        public void asyncCommit() {
            synchronized (mAssist) {
                if (!mAsync) {
                    throw new IllegalStateException("Child " + this
                            + " was not created with ViewStructure.asyncNewChild");
                }
                if (!mAssist.mPendingAsyncChildren.remove(this)) {
                    throw new IllegalStateException("Child " + this + " already committed");
                }
                mAssist.notifyAll();
            }
        }

        @Override
        public Rect getTempRect() {
            return mAssist.mTmpRect;
        }

        @Override
        public void setAutofillId(@NonNull AutofillId id) {
            mNode.mAutofillId = id;
        }

        @Override
        public void setAutofillId(@NonNull AutofillId parentId, int virtualId) {
            mNode.mAutofillId = new AutofillId(parentId, virtualId);
        }

        @Override
        public AutofillId getAutofillId() {
            return mNode.mAutofillId;
        }

        @Override
        public void setAutofillType(@View.AutofillType int type) {
            mNode.mAutofillType = type;
        }

        @Override
        public void setAutofillHints(@Nullable String[] hints) {
            mNode.mAutofillHints = hints;
        }

        @Override
        public void setAutofillValue(AutofillValue value) {
            mNode.mAutofillValue = value;
        }

        @Override
        public void setAutofillOptions(CharSequence[] options) {
            mNode.mAutofillOptions = options;
        }

        @Override
        public void setImportantForAutofill(@AutofillImportance int mode) {
            mNode.mImportantForAutofill = mode;
        }

        @Override
        public void setInputType(int inputType) {
            mNode.mInputType = inputType;
        }

        @Override
        public void setMinTextEms(int minEms) {
            mNode.mMinEms = minEms;
        }

        @Override
        public void setMaxTextEms(int maxEms) {
            mNode.mMaxEms = maxEms;
        }

        @Override
        public void setMaxTextLength(int maxLength) {
            mNode.mMaxLength = maxLength;
        }

        @Override
        public void setDataIsSensitive(boolean sensitive) {
            mNode.mSanitized = !sensitive;
        }

        @Override
        public void setWebDomain(@Nullable String domain) {
            mNode.setWebDomain(domain);
        }

        @Override
        public void setLocaleList(LocaleList localeList) {
            mNode.mLocaleList = localeList;
        }

        @Override
        public HtmlInfo.Builder newHtmlInfoBuilder(@NonNull String tagName) {
            return new HtmlInfoNodeBuilder(tagName);
        }

        @Override
        public void setHtmlInfo(@NonNull HtmlInfo htmlInfo) {
            mNode.mHtmlInfo = htmlInfo;
        }
    }

    private static final class HtmlInfoNode extends HtmlInfo implements Parcelable {
        private final String mTag;
        private final String[] mNames;
        private final String[] mValues;

        // Not parcelable
        private ArrayList<Pair<String, String>> mAttributes;

        private HtmlInfoNode(HtmlInfoNodeBuilder builder) {
            mTag = builder.mTag;
            if (builder.mNames == null) {
                mNames = null;
                mValues = null;
            } else {
                mNames = new String[builder.mNames.size()];
                mValues = new String[builder.mValues.size()];
                builder.mNames.toArray(mNames);
                builder.mValues.toArray(mValues);
            }
        }

        @Override
        public String getTag() {
            return mTag;
        }

        @Override
        public List<Pair<String, String>> getAttributes() {
            if (mAttributes == null && mNames != null) {
                mAttributes = new ArrayList<>(mNames.length);
                for (int i = 0; i < mNames.length; i++) {
                    final Pair<String, String> pair = new Pair<>(mNames[i], mValues[i]);
                    mAttributes.add(i, pair);
                }
            }
            return mAttributes;
        }

        @Override
        public int describeContents() {
            return 0;
        }

        @Override
        public void writeToParcel(Parcel parcel, int flags) {
            parcel.writeString(mTag);
            parcel.writeStringArray(mNames);
            parcel.writeStringArray(mValues);
        }

        @SuppressWarnings("hiding")
        public static final Creator<HtmlInfoNode> CREATOR = new Creator<HtmlInfoNode>() {
            @Override
            public HtmlInfoNode createFromParcel(Parcel parcel) {
                // Always go through the builder to ensure the data ingested by
                // the system obeys the contract of the builder to avoid attacks
                // using specially crafted parcels.
                final String tag = parcel.readString();
                final HtmlInfoNodeBuilder builder = new HtmlInfoNodeBuilder(tag);
                final String[] names = parcel.readStringArray();
                final String[] values = parcel.readStringArray();
                if (names != null && values != null) {
                    if (names.length != values.length) {
                        Log.w(TAG, "HtmlInfo attributes mismatch: names=" + names.length
                                + ", values=" + values.length);
                    } else {
                        for (int i = 0; i < names.length; i++) {
                            builder.addAttribute(names[i], values[i]);
                        }
                    }
                }
                return builder.build();
            }

            @Override
            public HtmlInfoNode[] newArray(int size) {
                return new HtmlInfoNode[size];
            }
        };
    }

    private static final class HtmlInfoNodeBuilder extends HtmlInfo.Builder {
        private final String mTag;
        private ArrayList<String> mNames;
        private ArrayList<String> mValues;

        HtmlInfoNodeBuilder(String tag) {
            mTag = tag;
        }

        @Override
        public Builder addAttribute(String name, String value) {
            if (mNames == null) {
                mNames = new ArrayList<>();
                mValues = new ArrayList<>();
            }
            mNames.add(name);
            mValues.add(value);
            return this;
        }

        @Override
        public HtmlInfoNode build() {
            return new HtmlInfoNode(this);
        }
    }

    /** @hide */
    public AssistStructure(Activity activity, boolean forAutoFill, int flags) {
        mHaveData = true;
        mActivityComponent = activity.getComponentName();
        mFlags = flags;
        ArrayList<ViewRootImpl> views = WindowManagerGlobal.getInstance().getRootViews(
                activity.getActivityToken());
        for (int i=0; i<views.size(); i++) {
            ViewRootImpl root = views.get(i);
            if (root.getView() == null) {
                Log.w(TAG, "Skipping window with dettached view: " + root.getTitle());
                continue;
            }
            mWindowNodes.add(new WindowNode(this, root, forAutoFill, flags));
        }
    }

    public AssistStructure() {
        mHaveData = true;
        mActivityComponent = null;
        mFlags = 0;
    }

    /** @hide */
    public AssistStructure(Parcel in) {
        mIsHomeActivity = in.readInt() == 1;
        mReceiveChannel = in.readStrongBinder();
    }

    /**
     * Helper method used to sanitize the structure before it's written to a parcel.
     *
     * <p>Used just on autofill.
     * @hide
     */
    public void sanitizeForParceling(boolean sanitize) {
        mSanitizeOnWrite = sanitize;
    }

    /** @hide */
    public void dump(boolean showSensitive) {
        if (mActivityComponent == null) {
            Log.i(TAG, "dump(): calling ensureData() first");
            ensureData();
        }
        Log.i(TAG, "Activity: " + mActivityComponent.flattenToShortString());
        Log.i(TAG, "Sanitize on write: " + mSanitizeOnWrite);
        Log.i(TAG, "Flags: " + mFlags);
        final int N = getWindowNodeCount();
        for (int i=0; i<N; i++) {
            WindowNode node = getWindowNodeAt(i);
            Log.i(TAG, "Window #" + i + " [" + node.getLeft() + "," + node.getTop()
                    + " " + node.getWidth() + "x" + node.getHeight() + "]" + " " + node.getTitle());
            dump("  ", node.getRootViewNode(), showSensitive);
        }
    }

    void dump(String prefix, ViewNode node, boolean showSensitive) {
        Log.i(TAG, prefix + "View [" + node.getLeft() + "," + node.getTop()
                + " " + node.getWidth() + "x" + node.getHeight() + "]" + " " + node.getClassName());
        int id = node.getId();
        if (id != 0) {
            StringBuilder sb = new StringBuilder();
            sb.append(prefix); sb.append("  ID: #"); sb.append(Integer.toHexString(id));
            String entry = node.getIdEntry();
            if (entry != null) {
                String type = node.getIdType();
                String pkg = node.getIdPackage();
                sb.append(" "); sb.append(pkg); sb.append(":"); sb.append(type);
                sb.append("/"); sb.append(entry);
            }
            Log.i(TAG, sb.toString());
        }
        int scrollX = node.getScrollX();
        int scrollY = node.getScrollY();
        if (scrollX != 0 || scrollY != 0) {
            Log.i(TAG, prefix + "  Scroll: " + scrollX + "," + scrollY);
        }
        Matrix matrix = node.getTransformation();
        if (matrix != null) {
            Log.i(TAG, prefix + "  Transformation: " + matrix);
        }
        float elevation = node.getElevation();
        if (elevation != 0) {
            Log.i(TAG, prefix + "  Elevation: " + elevation);
        }
        float alpha = node.getAlpha();
        if (alpha != 0) {
            Log.i(TAG, prefix + "  Alpha: " + elevation);
        }
        CharSequence contentDescription = node.getContentDescription();
        if (contentDescription != null) {
            Log.i(TAG, prefix + "  Content description: " + contentDescription);
        }
        CharSequence text = node.getText();
        if (text != null) {
            final String safeText = node.isSanitized() || showSensitive ? text.toString()
                    : "REDACTED[" + text.length() + " chars]";
            Log.i(TAG, prefix + "  Text (sel " + node.getTextSelectionStart() + "-"
                    + node.getTextSelectionEnd() + "): " + safeText);
            Log.i(TAG, prefix + "  Text size: " + node.getTextSize() + " , style: #"
                    + node.getTextStyle());
            Log.i(TAG, prefix + "  Text color fg: #" + Integer.toHexString(node.getTextColor())
                    + ", bg: #" + Integer.toHexString(node.getTextBackgroundColor()));
            Log.i(TAG, prefix + "  Input type: " + node.getInputType());
            Log.i(TAG, prefix + "  Resource id: " + node.getTextIdEntry());
        }
        String webDomain = node.getWebDomain();
        if (webDomain != null) {
            Log.i(TAG, prefix + "  Web domain: " + webDomain);
        }
        HtmlInfo htmlInfo = node.getHtmlInfo();
        if (htmlInfo != null) {
            Log.i(TAG, prefix + "  HtmlInfo: tag=" + htmlInfo.getTag()
                    + ", attr="+ htmlInfo.getAttributes());
        }

        LocaleList localeList = node.getLocaleList();
        if (localeList != null) {
            Log.i(TAG, prefix + "  LocaleList: " + localeList);
        }
        String hint = node.getHint();
        if (hint != null) {
            Log.i(TAG, prefix + "  Hint: " + hint);
        }
        Bundle extras = node.getExtras();
        if (extras != null) {
            Log.i(TAG, prefix + "  Extras: " + extras);
        }
        if (node.isAssistBlocked()) {
            Log.i(TAG, prefix + "  BLOCKED");
        }
        AutofillId autofillId = node.getAutofillId();
        if (autofillId == null) {
            Log.i(TAG, prefix + " NO autofill ID");
        } else {
            Log.i(TAG, prefix + "Autofill info: id= " + autofillId
                    + ", type=" + node.getAutofillType()
                    + ", options=" + Arrays.toString(node.getAutofillOptions())
                    + ", hints=" + Arrays.toString(node.getAutofillHints())
                    + ", value=" + node.getAutofillValue()
                    + ", sanitized=" + node.isSanitized()
                    + ", importantFor=" + node.getImportantForAutofill());
        }

        final int NCHILDREN = node.getChildCount();
        if (NCHILDREN > 0) {
            Log.i(TAG, prefix + "  Children:");
            String cprefix = prefix + "    ";
            for (int i=0; i<NCHILDREN; i++) {
                ViewNode cnode = node.getChildAt(i);
                dump(cprefix, cnode, showSensitive);
            }
        }
    }

    /**
     * Return the activity this AssistStructure came from.
     */
    public ComponentName getActivityComponent() {
        ensureData();
        return mActivityComponent;
    }

    /**
     * Called by Autofill server when app forged a different value.
     *
     * @hide
     */
    public void setActivityComponent(ComponentName componentName) {
        ensureData();
        mActivityComponent = componentName;
    }

    /** @hide */
    public int getFlags() {
        return mFlags;
    }

    /**
     * Returns whether the activity associated with this AssistStructure was the home activity
     * (Launcher) at the time the assist data was acquired.
     * @return Whether the activity was the home activity.
     * @see android.content.Intent#CATEGORY_HOME
     */
    public boolean isHomeActivity() {
        return mIsHomeActivity;
    }

    /**
     * Return the number of window contents that have been collected in this assist data.
     */
    public int getWindowNodeCount() {
        ensureData();
        return mWindowNodes.size();
    }

    /**
     * Return one of the windows in the assist data.
     * @param index Which window to retrieve, may be 0 to {@link #getWindowNodeCount()}-1.
     */
    public WindowNode getWindowNodeAt(int index) {
        ensureData();
        return mWindowNodes.get(index);
    }

    // TODO(b/35708678): temporary method that disable one-way warning flag on binder.
    /** @hide */
    public void ensureDataForAutofill() {
        if (mHaveData) {
            return;
        }
        mHaveData = true;
        Binder.allowBlocking(mReceiveChannel);
        try {
            ParcelTransferReader reader = new ParcelTransferReader(mReceiveChannel);
            reader.go();
        } finally {
            Binder.defaultBlocking(mReceiveChannel);
        }
    }

    /** @hide */
    public void ensureData() {
        if (mHaveData) {
            return;
        }
        mHaveData = true;
        ParcelTransferReader reader = new ParcelTransferReader(mReceiveChannel);
        reader.go();
    }

    boolean waitForReady() {
        boolean skipStructure = false;
        synchronized (this) {
            long endTime = SystemClock.uptimeMillis() + 5000;
            long now;
            while (mPendingAsyncChildren.size() > 0 && (now=SystemClock.uptimeMillis()) < endTime) {
                try {
                    wait(endTime-now);
                } catch (InterruptedException e) {
                }
            }
            if (mPendingAsyncChildren.size() > 0) {
                // We waited too long, assume none of the assist structure is valid.
                Log.w(TAG, "Skipping assist structure, waiting too long for async children (have "
                        + mPendingAsyncChildren.size() + " remaining");
                skipStructure = true;
            }
        }
        return !skipStructure;
    }

    /** @hide */
    public void clearSendChannel() {
        if (mSendChannel != null) {
            mSendChannel.mAssistStructure = null;
        }
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel out, int flags) {
        out.writeInt(mIsHomeActivity ? 1 : 0);
        if (mHaveData) {
            // This object holds its data.  We want to write a send channel that the
            // other side can use to retrieve that data.
            if (mSendChannel == null) {
                mSendChannel = new SendChannel(this);
            }
            out.writeStrongBinder(mSendChannel);
        } else {
            // This object doesn't hold its data, so just propagate along its receive channel.
            out.writeStrongBinder(mReceiveChannel);
        }
    }

    public static final Parcelable.Creator<AssistStructure> CREATOR
            = new Parcelable.Creator<AssistStructure>() {
        @Override
        public AssistStructure createFromParcel(Parcel in) {
            return new AssistStructure(in);
        }

        @Override
        public AssistStructure[] newArray(int size) {
            return new AssistStructure[size];
        }
    };
}