core/java/android/view/WindowContainerTransaction.java

/*
 * Copyright (C) 2019 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.view;

import android.annotation.NonNull;
import android.annotation.Nullable;
import android.app.WindowConfiguration;
import android.content.pm.ActivityInfo;
import android.content.res.Configuration;
import android.graphics.Rect;
import android.os.IBinder;
import android.os.Parcel;
import android.os.Parcelable;
import android.util.ArrayMap;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * Represents a collection of operations on some WindowContainers that should be applied all at
 * once.
 *
 * @hide
 */
public class WindowContainerTransaction implements Parcelable {
    private final ArrayMap<IBinder, Change> mChanges = new ArrayMap<>();

    // Flat list because re-order operations are order-dependent
    private final ArrayList<HierarchyOp> mHierarchyOps = new ArrayList<>();

    public WindowContainerTransaction() {}

    protected WindowContainerTransaction(Parcel in) {
        in.readMap(mChanges, null /* loader */);
        in.readList(mHierarchyOps, null /* loader */);
    }

    private Change getOrCreateChange(IBinder token) {
        Change out = mChanges.get(token);
        if (out == null) {
            out = new Change();
            mChanges.put(token, out);
        }
        return out;
    }

    /**
     * Resize a container.
     */
    public WindowContainerTransaction setBounds(IWindowContainer container, Rect bounds) {
        Change chg = getOrCreateChange(container.asBinder());
        chg.mConfiguration.windowConfiguration.setBounds(bounds);
        chg.mConfigSetMask |= ActivityInfo.CONFIG_WINDOW_CONFIGURATION;
        chg.mWindowSetMask |= WindowConfiguration.WINDOW_CONFIG_BOUNDS;
        return this;
    }

    /**
     * Notify activies within the hiearchy of a container that they have entered picture-in-picture
     * mode with the given bounds.
     */
    public WindowContainerTransaction scheduleFinishEnterPip(IWindowContainer container,
            Rect bounds) {
        Change chg = getOrCreateChange(container.asBinder());
        chg.mSchedulePipCallback = true;
        chg.mPinnedBounds = new Rect(bounds);
        return this;
    }

    /**
     * Sets whether a container or any of its children can be focusable. When {@code false}, no
     * child can be focused; however, when {@code true}, it is still possible for children to be
     * non-focusable due to WM policy.
     */
    public WindowContainerTransaction setFocusable(IWindowContainer container, boolean focusable) {
        Change chg = getOrCreateChange(container.asBinder());
        chg.mFocusable = focusable;
        chg.mChangeMask |= Change.CHANGE_FOCUSABLE;
        return this;
    }

    /**
     * Set the smallestScreenWidth of a container.
     */
    public WindowContainerTransaction setSmallestScreenWidthDp(IWindowContainer container,
            int widthDp) {
        Change cfg = getOrCreateChange(container.asBinder());
        cfg.mConfiguration.smallestScreenWidthDp = widthDp;
        cfg.mConfigSetMask |= ActivityInfo.CONFIG_SMALLEST_SCREEN_SIZE;
        return this;
    }

    /**
     * Reparents a container into another one. The effect of a {@code null} parent can vary. For
     * example, reparenting a stack to {@code null} will reparent it to its display.
     *
     * @param onTop When {@code true}, the child goes to the top of parent; otherwise it goes to
     *              the bottom.
     */
    public WindowContainerTransaction reparent(@NonNull IWindowContainer child,
            @Nullable IWindowContainer parent, boolean onTop) {
        mHierarchyOps.add(new HierarchyOp(child.asBinder(),
                parent == null ? null : parent.asBinder(), onTop));
        return this;
    }

    /**
     * Reorders a container within its parent.
     *
     * @param onTop When {@code true}, the child goes to the top of parent; otherwise it goes to
     *              the bottom.
     */
    public WindowContainerTransaction reorder(@NonNull IWindowContainer child, boolean onTop) {
        mHierarchyOps.add(new HierarchyOp(child.asBinder(), onTop));
        return this;
    }

    public Map<IBinder, Change> getChanges() {
        return mChanges;
    }

    public List<HierarchyOp> getHierarchyOps() {
        return mHierarchyOps;
    }

    @Override
    public String toString() {
        return "WindowContainerTransaction { changes = " + mChanges + " }";
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeMap(mChanges);
        dest.writeList(mHierarchyOps);
    }

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

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

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

    /**
     * Holds changes on a single WindowContainer including Configuration changes.
     *
     * @hide
     */
    public static class Change implements Parcelable {
        public static final int CHANGE_FOCUSABLE = 1;

        private final Configuration mConfiguration = new Configuration();
        private boolean mFocusable = true;
        private int mChangeMask = 0;
        private @ActivityInfo.Config int mConfigSetMask = 0;
        private @WindowConfiguration.WindowConfig int mWindowSetMask = 0;

        private boolean mSchedulePipCallback = false;
        private Rect mPinnedBounds = null;

        public Change() {}

        protected Change(Parcel in) {
            mConfiguration.readFromParcel(in);
            mFocusable = in.readBoolean();
            mChangeMask = in.readInt();
            mConfigSetMask = in.readInt();
            mWindowSetMask = in.readInt();
            mSchedulePipCallback = (in.readInt() != 0);
            if (mSchedulePipCallback ) {
                mPinnedBounds = new Rect();
                mPinnedBounds.readFromParcel(in);
            }
        }

        public Configuration getConfiguration() {
            return mConfiguration;
        }

        /** Gets the requested focusable value */
        public boolean getFocusable() {
            if ((mChangeMask & CHANGE_FOCUSABLE) == 0) {
                throw new RuntimeException("Focusable not set. check CHANGE_FOCUSABLE first");
            }
            return mFocusable;
        }

        public int getChangeMask() {
            return mChangeMask;
        }

        @ActivityInfo.Config
        public int getConfigSetMask() {
            return mConfigSetMask;
        }

        @WindowConfiguration.WindowConfig
        public int getWindowSetMask() {
            return mWindowSetMask;
        }

        /**
         * Returns the bounds to be used for scheduling the enter pip callback
         * or null if no callback is to be scheduled.
         */
        public Rect getEnterPipBounds() {
            return mPinnedBounds;
        }

        @Override
        public String toString() {
            final boolean changesBounds =
                    (mConfigSetMask & ActivityInfo.CONFIG_WINDOW_CONFIGURATION) != 0
                            && ((mWindowSetMask & WindowConfiguration.WINDOW_CONFIG_BOUNDS)
                                    != 0);
            final boolean changesSss =
                    (mConfigSetMask & ActivityInfo.CONFIG_SMALLEST_SCREEN_SIZE) != 0;
            StringBuilder sb = new StringBuilder();
            sb.append('{');
            if (changesBounds) {
                sb.append("bounds:" + mConfiguration.windowConfiguration.getBounds() + ",");
            }
            if (changesSss) {
                sb.append("ssw:" + mConfiguration.smallestScreenWidthDp + ",");
            }
            if ((mChangeMask & CHANGE_FOCUSABLE) != 0) {
                sb.append("focusable:" + mFocusable + ",");
            }
            sb.append("}");
            return sb.toString();
        }

        @Override
        public void writeToParcel(Parcel dest, int flags) {
            mConfiguration.writeToParcel(dest, flags);
            dest.writeBoolean(mFocusable);
            dest.writeInt(mChangeMask);
            dest.writeInt(mConfigSetMask);
            dest.writeInt(mWindowSetMask);

            dest.writeInt(mSchedulePipCallback ? 1 : 0);
            if (mSchedulePipCallback ) {
                mPinnedBounds.writeToParcel(dest, flags);
            }
        }

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

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

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

    /**
     * Holds information about a reparent/reorder operation in the hierarchy. This is separate from
     * Changes because they must be executed in the same order that they are added.
     */
    public static class HierarchyOp implements Parcelable {
        private final IBinder mContainer;

        // If this is same as mContainer, then only change position, don't reparent.
        private final IBinder mReparent;

        // Moves/reparents to top of parent when {@code true}, otherwise moves/reparents to bottom.
        private final boolean mToTop;

        public HierarchyOp(@NonNull IBinder container, @Nullable IBinder reparent, boolean toTop) {
            mContainer = container;
            mReparent = reparent;
            mToTop = toTop;
        }

        public HierarchyOp(@NonNull IBinder container, boolean toTop) {
            mContainer = container;
            mReparent = container;
            mToTop = toTop;
        }

        protected HierarchyOp(Parcel in) {
            mContainer = in.readStrongBinder();
            mReparent = in.readStrongBinder();
            mToTop = in.readBoolean();
        }

        public boolean isReparent() {
            return mContainer != mReparent;
        }

        @Nullable
        public IBinder getNewParent() {
            return mReparent;
        }

        @NonNull
        public IBinder getContainer() {
            return mContainer;
        }

        public boolean getToTop() {
            return mToTop;
        }

        @Override
        public String toString() {
            if (isReparent()) {
                return "{reparent: " + mContainer + " to " + (mToTop ? "top of " : "bottom of ")
                        + mReparent + "}";
            } else {
                return "{reorder: " + mContainer + " to " + (mToTop ? "top" : "bottom") + "}";
            }
        }

        @Override
        public void writeToParcel(Parcel dest, int flags) {
            dest.writeStrongBinder(mContainer);
            dest.writeStrongBinder(mReparent);
            dest.writeBoolean(mToTop);
        }

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

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

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