public void begin(){
    nextWidth = canvas.getWidth()*0.75;
    nextTop = canvas.getHeight()-STEP_HEIGHT;
}

public void onMouseClick(Location point){
    if ( nextWidth > 0) {
        new FilledRect(0, nextTop, 
                       nextWidth, STEP_HEIGHT, canvas);
        nextTop = nextTop - STEP_HEIGHT;
        nextWidth = nextWidth - STEP_WIDTH;
    }
}

public void onMouseClick(Location point){
    nextWidth = canvas.getWidth()*0.75;
    nextTop = canvas.getHeight()-STEP_HEIGHT;

    while ( nextWidth > 0) {
        new FilledRect(0, nextTop,
                       nextWidth, STEP_HEIGHT, canvas);
        nextTop = nextTop - STEP_HEIGHT;
        nextWidth = nextWidth - STEP_WIDTH;
    }
}