calculateContentArea( 0, 0, this.screenWidth, this.screenHeight );
	public void setPolishTicker( Ticker ticker)	{		this.ticker = ticker;		if (ticker == null) {			//this.screenHeight = this.originalScreenHeight;		} else {			ticker.screen = this;			// initialise ticker, so that subsequently ticker.itemHeight can be called:			ticker.getItemHeight(this.screenWidth, this.screenWidth );			//System.out.println("setTicker(): tickerHeight=" + tickerHeight );			//this.screenHeight = this.originalScreenHeight - tickerHeight;		}		//System.out.println("setTicker(): screenHeight=" + this.screenHeight + ", original=" + this.originalScreenHeight );		if (isShown()) {			repaint();		}	}