OnItemVisibilityChangedDelegate.java

/*
 * Copyright 2020 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 androidx.car.app.model;

import android.annotation.SuppressLint;

import androidx.annotation.NonNull;
import androidx.car.app.OnDoneCallback;
import androidx.car.app.annotations.CarProtocol;

/**
 * A host-side delegate for sending
 * {@link androidx.car.app.model.ItemList.OnItemVisibilityChangedListener} events to the car app.
 */
@CarProtocol
public interface OnItemVisibilityChangedDelegate {
    /**
     * Notifies that the items in the list within the specified indices have become visible.
     *
     * <p>The start index is inclusive, and the end index is exclusive. For example, if only the
     * first item in a list is visible, the start and end indices would be 0 and 1,
     * respectively. If no items are visible, the indices will be set to -1.
     *
     * @param startIndex the index (inclusive) of the first visible element, or -1 if no items
     *                   are visible
     * @param endIndex   the index (exclusive) of the last visible element, or -1 if no items
     *                   are visible
     * @param callback   the {@link OnDoneCallback} to trigger when the client finishes handling
     *                   the event
     */
    // This mirrors the AIDL class and is not supported to support an executor as an input.
    @SuppressLint("ExecutorRegistration")
    void sendItemVisibilityChanged(int startIndex, int endIndex, @NonNull OnDoneCallback callback);
}