NotifyingScrollView.java

package org.azavea.views;

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

public class NotifyingScrollView extends ScrollView {

    private OnScrollToBottomListener bottomListener = null;

    public interface OnScrollToBottomListener {
        void OnScrollToBottom();
    }

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

    public void setOnScrollToBottomListener(OnScrollToBottomListener listener) {
        bottomListener = listener;
    }

    public void onScrollToBottom() {
    }

    @Override
    protected void onScrollChanged(int l, int t, int oldl, int oldt) {
        // Grab the last child placed in the ScrollView, we need it to determinate the bottom position.
        View view = getChildAt(getChildCount() - 1);

        // Calculate the scrolldiff
        int diff = (view.getBottom() - (getHeight() + getScrollY()));

        if (diff == 0) {
            if (bottomListener != null) {
                bottomListener.OnScrollToBottom();
            }
        }

        super.onScrollChanged(l, t, oldl, oldt);
        this.onScrollToBottom();
    }
}