Centered ScrollView

CenteredScrollView

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

/**
 * Created by Dimitry Ivanov (noties.app@gmail.com) / macbook on 10/10/14.
 */
public class CenteredScrollView extends ScrollView {

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

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

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

    @Override
    public void onLayout(boolean changed, int l, int t, int r, int b) {

        final View child = getChildAt(0);

        if (child == null) {
            return;
        }

        final int childHeight = child.getMeasuredHeight();
        final boolean isSmaller = b - t > childHeight;

        if (!isSmaller) {
            child.layout(l, t, r, t + childHeight);
            return;
        }

        final int verticalOffset = ((b - t) - childHeight) / 2;
        child.layout(l, t + verticalOffset, r, b - verticalOffset);
    }

}