Re: Javascript to call applet function

From:
"Jaycuse" <jaycuse@gmail.com>
Newsgroups:
comp.lang.java.help
Date:
26 May 2006 05:54:30 -0700
Message-ID:
<1148648070.521346.296970@g10g2000cwb.googlegroups.com>
Hello,
I'm not a pro or anything (still new in the Java thing) but I was
wondering if there was a reason why in your constructor you have:

       GraphDraw g = new GraphDraw();

I think if you change that line to:

      g = new GraphDraw();

it should work. The reason why I think its still null at that point is
because that line Im talking about, your declaring a local g variable
in your constructor and not using your class variable g.

Like I said Im still new at this, so there might be something Im not
seeing. If so please dont hesitate to tell me :D

Jacques

dynaheir@hotmail.com wrote:

Hi,

I have a javascript function that adds a file to a graph viewer program
to display.

function addFile(File) {
   alert("called: " + File);
   document.applets[0].addFile(File);
}

The function definately calls the addFile() with the correct value and
the program is running but DrawGraph is null after initialisizing it in
the constructor. I used "alert" above to delay the call into the applet
to be sure it's fully loaded.

public class GraphViewer extends javax.swing.JApplet {
    GraphDraw g;

    public GraphViewer() {
       GraphDraw g = new GraphDraw();
       JScrollPane sp = new JScrollPane();
       sp.setViewportView(g);
       //sp.setVerticalScrollBarPolicy(sp.VERTICAL_SCROLLBAR_NEVER);
       add(sp, java.awt.BorderLayout.CENTER);
    }

    public void addFile(String fName) throws Exception {
        g.addLine(new GraphLine(fName));
    }
}

Does anybody know why g ()DrawGraph) would be null at this point?

Thanks in advance.

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