/*
 * Copyright 2014 Soichiro Kashima
 *
 * 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 com.github.ksoichiro.android.observablescrollview;

import android.view.ViewGroup;

/**
 * Provides common API for observable and scrollable widgets.
 */
public interface Scrollable {
    /**
     * Sets a callback listener.
     *
     * @param listener listener to set
     */
    void setScrollViewCallbacks(ObservableScrollViewCallbacks listener);

    /**
     * Scrolls vertically to the absolute Y.
     * Implemented classes are expected to scroll to the exact Y pixels from the top,
     * but it depends on the type of the widget.
     *
     * @param y vertical position to scroll to
     */
    void scrollVerticallyTo(int y);

    /**
     * Returns the current Y of the scrollable view.
     *
     * @return current Y pixel
     */
    int getCurrentScrollY();

    /**
     * Sets a touch motion event delegation ViewGroup.
     * This is used to pass motion events back to parent view.
     * It's up to the implementation classes whether or not it works.
     *
     * @param viewGroup ViewGroup object to dispatch motion events
     */
    void setTouchInterceptionViewGroup(ViewGroup viewGroup);
}