Image update problem (bug?)

Question

Within a canvas, which is placed in the center of a borderLayout, I am importing images via MediaTracker. I have a dialog and within this dialog, when an item is selected from a list, the image within the canvas ought to change when "ok' is clicked in the dialog.
The image only changes in two instances: (i am using obviously AWT)
1) when I have a repaint() after all the "if then" statements. This update only works if it is CONSTANTALLY updating. A simple loop-inforced single update does not work.
2) if I resize the screen manually, by closing it and re-opening it, or minimizing/maximizing it,..
I have wasted two days trying to solve this, and I admit defeat.
do any of you know what I am unawair of?

Answer 1

It's the repaint() part that seems to get me. Looking at your code up there, it seems that I would have the same issue with repainting after the image has loaded...??
Also, I noticed that after I change the image selected by its dialog pop-up, the image is repainted under where the dialog window was, and if I moved the dialod window around, the image repaints only under where the dialog window was.
here is the part that sticks:
class graphicsCanvas extends java.awt.Canvas
Image Europe,Iraq;
     public void paint (Graphics g)
          enviro = airEnviroDialog.Enviro;          
          if(enviro.equals("Random European Aerodrome"))
               Toolkit toolkit = Toolkit.getDefaultToolkit();
               Image Europe = getToolkit().createImage("EuropeBgnd.jpg");
               MediaTracker tracker = new MediaTracker(this);
               tracker.addImage(Europe,0);
               try
               tracker.waitForID(0);
               catch (InterruptedException e){}
               g.drawImage(Europe,1,100,550,500,this);
          else if(enviro.equals("Al Sahra airfield, Iraq"))
               Toolkit toolkit = Toolkit.getDefaultToolkit();
          Image Iraq = getToolkit().createImage("AlSahraAirfield.jpg");
          MediaTracker tracker = new MediaTracker(this);
          tracker.addImage(Iraq,1);
          try
          tracker.waitForID(1);
          catch (InterruptedException e){}
                         g.drawImage(Iraq,1,100,550,500,this);
          else if(enviro.equals("White Background"))
     g.drawRect(1,100,550,500);
          g.drawString("You chose "+ enviro,200,200);