Question

I am currently working on a Swing Applet, and am having issues referencing my custom AWT Canvas component (very simple extended class) in other class functions, such as with any other component (i.e. button) normally created with Netbean (7.0)’s designer.

My custom canvas element I add here, I was sure this would be the appropriate place (especially after all other generated components were just created in the same area)

public void init() {
    try {
        java.awt.EventQueue.invokeAndWait(new Runnable() {
            public void run() {
                initComponents();

                CustomCanvas myCan = new CustomCanvas();
                myCan.setBounds(100, 100, 200, 200);
                getContentPane().add(myCan);
          ...

However, unlike the generated components, I cannot access them by name and cannot seem to access them through other means (this.myCan) either. I have set up a sample function that will handle a (generated) button on the Swing form to manipulate the previously instantiated myCan component:

private void btnManipCanvasActionPerformed(java.awt.event.ActionEvent evt) {
  //Essentially Was wanting to call something here such as myCan.getGraphics().setRect...
}

Do you know of a way to access myCan there? Am I supposed to place custom initializations of components in a different area so they can be publicly accessed?

Answer 1

Just make the canvas an instance variable, as (I guess) all the other components created by the Netbeans designer:

private CustomCanvas myCan;

public void init() {
try {
    java.awt.EventQueue.invokeAndWait(new Runnable() {
        public void run() {
            initComponents();

            myCan = new CustomCanvas();
            myCan.setBounds(100, 100, 200, 200);
            getContentPane().add(myCan);
            // ...