Loading Images into Applets

Question

I've been having problems loading an image into an Applet. I've found that when the getImage() call is put into the init() method it loads the image fine, also implementing an imageUpdate call. However, now I'm trying to expand on this by putting it into a button click, it hangs indefinitely while waiting for the image to load.
Another interesting point I've noticed is that the Canvas subclass ImageSegmentSelector uses a PixelGrabber in its constructor to put the Image into a buffer - when this class is created from the imageUpdate() call, NOT the init() call, the grabPixels() call hangs indefinitely too!!
Any feedback, please,
Jonathan Pendrous
import java.applet.*;
import java.net.*;
import jmpendrous.util.*;
import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;
public class XplaneGlobalSceneryDownloader extends Applet implements ActionListener{
ImageSegmentSelector worldMap;
Image img;
URL url;
int longtitude = 36;
int latitude = 18;
boolean imageLoaded;
TextField t1, t2,t3;
Label l1,l2,l3;
Button b1;
Applet a1;
public void init() {
a1 = this;
l1 = (Label) add(new Label("Number of horizontal sections: "));
t1 = (TextField) add(new TextField("45",3));
l2 = (Label) add(new Label("Number of vertical sections: "));
t2 = (TextField) add(new TextField("45",3));
l3 = (Label) add(new Label("URL of image file: "));
t3 = (TextField) add(new TextField("file:///C:/java/work/xplane_project/source/world-landuse.GIF",60));
b1 = (Button) add(new Button("Load image"));
b1.addActionListener(this);
validate();
// THIS CODE WORKS FINE ...
/*try { url = new URL("file:///C:/java/work/xplane_project/source/world-landuse.GIF"); }
catch(MalformedURLException e) { System.exit(0);   }
img = getImage(url);
//int w=img.getWidth(this);
while(imageLoaded==false) { try { Thread.sleep(1000);   } catch(InterruptedException e) {System.exit(0);    } }
worldMap = new ImageSegmentSelector(this, img, longtitude, latitude);
add(worldMap);
//resize(worldMap.getWidth(), worldMap.getHeight());
validate();*/
//repaint();
//worldMap = new ImageSegmentSelector(this, img, longtitude, latitude);
//repaint();
public void actionPerformed(ActionEvent e) {
try { longtitude = Integer.parseInt(t1.getText()); } catch (NumberFormatException ex) {System.exit(0); }
try { latitude = Integer.parseInt(t2.getText()); } catch (NumberFormatException e2) {System.exit(0); }
try { url = new URL(t3.getText()); }
catch(MalformedURLException e3) { System.exit(0);   }
img = getImage(url);
//int w=img.getWidth(this);
while(imageLoaded==false)
{ try { Thread.sleep(1000);   } //KEEPS ON LOOPING
catch(InterruptedException e4) {System.exit(0);    } }
worldMap = new ImageSegmentSelector(a1, img, longtitude, latitude);
add(worldMap);
//resize(worldMap.getWidth(), worldMap.getHeight());
validate();
public boolean imageUpdate(Image i, int flags, int x, int y, int w, int h){
// THIS NEVER GETS CALLED AT ALL //
if (((flags & ImageObserver.WIDTH) != 0) && ((flags & ImageObserver.HEIGHT) != 0)) {
//worldMap = new ImageSegmentSelector(this, i, longtitude, latitude);
//add(worldMap);
//validate();
//repaint();
imageLoaded = true;
return false;
return true;
}

Answer 1

Sorry, thought this had been lost.
You can load a file if the applet itself is run from the local filesystem - it loads it fine from the init(), but not otherwise. But I haven't got the applet to run from a browser yet without crashing (it's OK in the IDE debugger), so that's the next step.