Android :: Modifying Android Seekbar Widget To Operate Vertically

I'm trying to get a vertical seekbar going with the emulator, but I'm sort of stuck. I can get the seekbar to display the way I want it to, and I can get the progress to do what I want, and I can modify the onTouchEvent to get the thumb to go vertically instead of horizontally. What I can't do is get the thumb to move outside of the default 29 horizontal pixels without using setThumbOffset(). This in itself isn't a problem. The problem is coming from the fact that I don't understand the thumb Offset at all -- I guess. I think I could (properly) resize the widget, which I am pretty sure I'm not doing right. Or maybe I could just use the thumb Offset if I could figure it out. Since I can calculate the progress correctly I thought I would just use a linear function of progress * (get Top() - get Bottom()) of the widget but that doesn't seem to do it. But I can't figure out what the offset is centered around. As a somewhat aside, I am really unsure if what I am doing in onSizeChanged() is sane or if it's going to bite me in the ass later
on. Here's the main.xml layout:
<?xml version="1.0" encoding="utf-8"?>
<Linear Layout xmlns:android="http://schemas.android.com/apk/res/android"
And the class (ignore the debugging junk):
import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.SeekBar;

public class Slide Bar extends Seek Bar {

private int oHeight = 320, oWidth = 29;
private int oProgress = -1, oOffset = -1;;
private float xPos = -1, yPos = -1;
private int top = -1, bottom = -1, left = -1, right = -1;
public Slide Bar(Context context) {
super(context);}