File	Doc	Category	Size	Date	Package
PixCanvas.java	API Doc	Example	2144	Fri Feb 11 22:30:06 GMT 2000	None

PixCanvas

• java.lang.Object
  • java.awt.Component
    • java.awt.Canvas

Fields Summary
Image	im
int	wid
int	ht

Constructors Summary
PixCanvas(int w, int h) Construct a PixCanvas, given a width and height setSize(wid=w, ht=h);
PixCanvas(String fn) Construct a PixCanvas, given an Image name setImage(fn); setSize(im.getWidth(this), im.getHeight(this));

Methods Summary
public java.awt.Dimension	getPreferredSize() Return how big we'd like to be. If image loaded, use its size. If not, use 200, 100 (why not?). if (im == null || im.getWidth(this) < 0 || im.getHeight(this) < 0) return new Dimension(200, 100); return new Dimension(im.getWidth(this), im.getHeight(this));
public void	paint(java.awt.Graphics g) Actually draw the Image onto the screen if (im == null) { g.setColor(Color.red); g.fillRect(0, 0, wid, ht); } else g.drawImage(im, 0, 0, this);
public void	setImage(java.lang.String fn) Set the image to a given filename if (fn == null) return; // Only the Application version of getImage shown here Image i = Toolkit.getDefaultToolkit().getImage(fn); setImage(i);
public void	setImage(java.awt.Image i) Set the image to a given Image object if (i == null) return; im = i; // ----- This part omitted from course notes for brevity ----- // Use a MediaTracker to show the "best"? way of waiting // for an image to load, and how to check for errors. MediaTracker mt = new MediaTracker(this); mt.addImage(im, 0); try { mt.waitForID(0); } catch(InterruptedException e) { throw new IllegalArgumentException( "Unexpected InterruptedException"); } if (mt.isErrorID(0)) { throw new IllegalArgumentException( "Couldn't load image"); } // Now that we know the image has been loaded, // it is safe to paint it onto the screen. // ----- End of part omitted from course notes for brevity ----- repaint();