content: /*
   * Copyright (C) 2017 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.service.autofill;
  
  import static android.view.autofill.Helper.sDebug;
  
  import android.annotation.NonNull;
  import android.annotation.Nullable;
  import android.os.Parcel;
  import android.os.Parcelable;
  import android.util.Pair;
  import android.widget.RemoteViews;
  
  import com.android.internal.util.Preconditions;
  
  import java.util.ArrayList;
  
  /**
   * Defines actions to be applied to a {@link RemoteViews template presentation}.
   *
   *
   * <p>It supports 2 types of actions:
   *
   * <ol>
   *   <li>{@link RemoteViews Actions} to be applied to the template.
   *   <li>{@link Transformation Transformations} to be applied on child views.
   * </ol>
   *
   * <p>Typically used on {@link CustomDescription custom descriptions} to conditionally display
   * differents views based on user input - see
   * {@link CustomDescription.Builder#batchUpdate(Validator, BatchUpdates)} for more information.
   */
  public final class BatchUpdates implements Parcelable {
  
      private final ArrayList<Pair<Integer, InternalTransformation>> mTransformations;
      private final RemoteViews mUpdates;
  
      private BatchUpdates(Builder builder) {
          mTransformations = builder.mTransformations;
          mUpdates = builder.mUpdates;
      }
  
      /** @hide */
      @Nullable
      public ArrayList<Pair<Integer, InternalTransformation>> getTransformations() {
          return mTransformations;
      }
  
      /** @hide */
      @Nullable
      public RemoteViews getUpdates() {
          return mUpdates;
      }
  
      /**
       * Builder for {@link BatchUpdates} objects.
       */
      public static class Builder {
          private RemoteViews mUpdates;
  
          private boolean mDestroyed;
          private ArrayList<Pair<Integer, InternalTransformation>> mTransformations;
  
          /**
           * Applies the {@code updates} in the underlying presentation template.
           *
           * <p><b>Note:</b> The updates are applied before the
           * {@link #transformChild(int, Transformation) transformations} are applied to the children
           * views.
           *
           * <p>Theme does not work with RemoteViews layout. Avoid hardcoded text color
           * or background color: Autofill on different platforms may have different themes.
           *
           * @param updates a {@link RemoteViews} with the updated actions to be applied in the
           * underlying presentation template.
           *
           * @return this builder
           * @throws IllegalArgumentException if {@code condition} is not a class provided
           * by the Android System.
           */
          public Builder updateTemplate(@NonNull RemoteViews updates) {
              throwIfDestroyed();
              mUpdates = Preconditions.checkNotNull(updates);
              return this;
          }
  
          /**
           * Adds a transformation to replace the value of a child view with the fields in the
           * screen.
           *
           * <p>When multiple transformations are added for the same child view, they are applied
           * in the same order as added.
           *
           * <p><b>Note:</b> The transformations are applied after the
           * {@link #updateTemplate(RemoteViews) updates} are applied to the presentation template.
           *
           * @param id view id of the children view.
           * @param transformation an implementation provided by the Android System.
           * @return this builder.
           * @throws IllegalArgumentException if {@code transformation} is not a class provided
           * by the Android System.
           */
          public Builder transformChild(int id, @NonNull Transformation transformation) {
              throwIfDestroyed();
              Preconditions.checkArgument((transformation instanceof InternalTransformation),
                      "not provided by Android System: " + transformation);
              if (mTransformations == null) {
                  mTransformations = new ArrayList<>();
              }
              mTransformations.add(new Pair<>(id, (InternalTransformation) transformation));
              return this;
          }
  
          /**
           * Creates a new {@link BatchUpdates} instance.
           *
           * @throws IllegalStateException if {@link #build()} was already called before or no call
           * to {@link #updateTemplate(RemoteViews)} or {@link #transformChild(int, Transformation)}
           * has been made.
           */
          public BatchUpdates build() {
              throwIfDestroyed();
              Preconditions.checkState(mUpdates != null || mTransformations != null,
                      "must call either updateTemplate() or transformChild() at least once");
              mDestroyed = true;
              return new BatchUpdates(this);
          }
  
          private void throwIfDestroyed() {
              if (mDestroyed) {
                  throw new IllegalStateException("Already called #build()");
              }
          }
      }
  
      /////////////////////////////////////
      // Object "contract" methods. //
      /////////////////////////////////////
      @Override
      public String toString() {
          if (!sDebug) return super.toString();
  
          return new StringBuilder("BatchUpdates: [")
                  .append(", transformations=")
                      .append(mTransformations == null ? "N/A" : mTransformations.size())
                  .append(", updates=").append(mUpdates)
                  .append("]").toString();
      }
  
      /////////////////////////////////////
      // Parcelable "contract" methods. //
      /////////////////////////////////////
      @Override
      public int describeContents() {
          return 0;
      }
  
      @Override
      public void writeToParcel(Parcel dest, int flags) {
          if (mTransformations == null) {
              dest.writeIntArray(null);
          } else {
              final int size = mTransformations.size();
              final int[] ids = new int[size];
              final InternalTransformation[] values = new InternalTransformation[size];
              for (int i = 0; i < size; i++) {
                  final Pair<Integer, InternalTransformation> pair = mTransformations.get(i);
                  ids[i] = pair.first;
                  values[i] = pair.second;
              }
              dest.writeIntArray(ids);
              dest.writeParcelableArray(values, flags);
          }
          dest.writeParcelable(mUpdates, flags);
      }
      public static final @android.annotation.NonNull Parcelable.Creator<BatchUpdates> CREATOR =
              new Parcelable.Creator<BatchUpdates>() {
          @Override
          public BatchUpdates 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 Builder builder = new Builder();
              final int[] ids = parcel.createIntArray();
              if (ids != null) {
                  final InternalTransformation[] values =
                      parcel.readParcelableArray(null, InternalTransformation.class);
                  final int size = ids.length;
                  for (int i = 0; i < size; i++) {
                      builder.transformChild(ids[i], values[i]);
                  }
              }
              final RemoteViews updates = parcel.readParcelable(null);
              if (updates != null) {
                  builder.updateTemplate(updates);
              }
              return builder.build();
          }
  
          @Override
          public BatchUpdates[] newArray(int size) {
              return new BatchUpdates[size];
          }
      };
  }
  