Canvas dispose

[Praveen Nayak2]

Hi,

I use JSVGCanvas in an applet to show SVG diagrams. When the page is 
navigating away from the current page, I disposed the canvas in the applet 
stop method. I earlier had:
canvas.dispose();

I have many pages each with an applet in it, with the SVG diagram, and 
users can switch between these pages, sometimes quite rapidly. I noticed 
there was memory leaking away. I then included a call to stopProcessing, 
which improved things. So I now have
canvas.dispose();
canvas.stopProcessing();

1. Is this sufficient? 

Also, at times during navigation, I see errors such as these logged in the 
console (I believe if I navigate away before the SVG is rendered):
java.lang.NullPointerException
        at 
org.apache.batik.dom.events.EventListenerList.removeListener(Unknown 
Source)
        at 
org.apache.batik.dom.events.EventSupport.removeEventListenerNS(Unknown 
Source)
        at org.apache.batik.dom.AbstractNode.removeEventListenerNS(Unknown 
Source)
        at 
org.apache.batik.bridge.FocusManager.removeEventListeners(Unknown Source)
        at org.apache.batik.bridge.FocusManager.dispose(Unknown Source)
...
(or a null pointer exception at setGraphicsNode) Can these add to a leak, 
and can I handle these somehow?

Thanks,
Praveen