Custom Progressbar

public class CustomBar extends ProgressBar {

    Paint p = new Paint();
    int progress;
    public CustomBar(Context context) {
        super(context);
        p.setColor(Color.GREEN);
    }

    @Override
    protected synchronized void onDraw(Canvas canvas) {
        canvas.drawLine(0, 0, getWidth(), 0, p);
        canvas.drawLine(0, 0, 0, getHeight(), p);
        canvas.drawArc(new Rect(0, 0, getWidth(),  getHeight()), 40, true, p);
        /**
         * Whatever drawing is needed for your Layout
         * But make sure you use relative lenghts and heights
         * So you can reuse your Widget.
         * Also use the Progress Variable to draw the filled part
         * corresponding to getMax()
         */
    }

    protected void onValueChanged(){
        /**
         * Update your progress Variable and draw again
         */
        progress = getProgress();
        this.invalidate();
    }

    @Override
    public synchronized void setMax(int max) {
        onValueChanged();
        super.setMax(max);
    }

    @Override
    public synchronized void setProgress(int progress) {
        onValueChanged();
        super.setProgress(progress);
    }

    @Override
    public synchronized void setSecondaryProgress(int secondaryProgress) {
        onValueChanged();
        super.setSecondaryProgress(secondaryProgress);
    }
}