ObservableScrollView.java

/*
 * Copyright (C) 2014 Fastboot Mobile, LLC.
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation; either version 3 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
 * the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program;
 * if not, see <http://www.gnu.org/licenses>.
 */

package com.fastbootmobile.encore.app.ui;

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

/**
 * ScrollView that can be observed (ie. get a callback on scroll event)
 */
public class ObservableScrollView extends ScrollView {

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

    private ScrollViewListener mScrollListener = null;

    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 setOnScrollListener(ScrollViewListener scrollViewListener) {
        mScrollListener = scrollViewListener;
    }

    @Override
    public int computeVerticalScrollRange() {
        return super.computeVerticalScrollRange();
    }

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

}