ObservableScrollView.java

/*
 * Copyright (C) 2014 Freddie (Musenkishi) Lust-Hed
 *
 * 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.musenkishi.wally.views;

import android.content.Context;
import android.util.AttributeSet;
import android.widget.ScrollView;

/**
 * An Observable ScrollView. With the included ScrollViewListener,
 * it's possible to be notified when the user scrolls the content.
 *
 * Created by Freddie (Musenkishi) Lust-Hed on 2014-09-29.
 */
public class ObservableScrollView extends ScrollView {

    private ScrollViewListener scrollViewListener = null;

    public interface ScrollViewListener {
        void onScrollChanged(ObservableScrollView scrollView, int x, int y, int oldx, int oldy);
    }

    public ObservableScrollView(Context context) {
        super(context);
    }

    public ObservableScrollView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public ObservableScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public void setScrollViewListener(ScrollViewListener scrollViewListener) {
        this.scrollViewListener = scrollViewListener;
    }

    @Override
    protected void onScrollChanged(int x, int y, int oldx, int oldy) {
        super.onScrollChanged(x, y, oldx, oldy);
        if(scrollViewListener != null) {
            scrollViewListener.onScrollChanged(this, x, y, oldx, oldy);
        }
    }

}