Multiple Canvas In Same JFrame

Could someone explain why the code below does not print in console?


canvasName=canvas1
canvasName=canvas2

But is printing:
canvasName=canvas2


That´s the code:

    public class JOGL2Setup_GLCanvas extends GLCanvas implements GLEventListener {

        private static String TITLE = "JOGL 2.0 Setup (GLCanvas)";
        private static final int CANVAS_WIDTH = 640;
        private static final int CANVAS_HEIGHT = 480;
        private static final int FPS = 60;
        private String canvasName;

        public JOGL2Setup_GLCanvas(String canvasName) {
            this();
            this.canvasName = canvasName;
        }



        public static void main(String[] args) {

            SwingUtilities.invokeLater(new Runnable() {

                public void run() {

                    // Create my two OpenGL Canvas
                    GLCanvas upperCanvas = new JOGL2Setup_GLCanvas("upperCanvas");
                    GLCanvas lowerCanvas = new JOGL2Setup_GLCanvas("lowerCanvas");

                    upperCanvas.setPreferredSize(new Dimension(CANVAS_WIDTH, CANVAS_HEIGHT));
                    lowerCanvas.setPreferredSize(new Dimension(CANVAS_WIDTH, CANVAS_HEIGHT));

                    final FPSAnimator upperCanvasAnimator = new FPSAnimator(upperCanvas, FPS, true);
                    final FPSAnimator lowerCanvasAnimator = new FPSAnimator(lowerCanvas, FPS, true);

                    final JFrame frame = new JFrame();


                    // Adding the canvases. Will be drawn one above the other because I just want to print messages in console.
                    frame.getContentPane().add(upperCanvas);
                    frame.getContentPane().add(lowerCanvas);

                    frame.addWindowListener(new WindowAdapter() {
                        @Override
                        public void windowClosing(WindowEvent e) {

                            new Thread() {
                                @Override
                                public void run() {
                                    // stop the world
                                    if (upperCanvasAnimator.isStarted() || lowerCanvasAnimator.isStarted()){
                                        upperCanvasAnimator.stop();
                                        lowerCanvasAnimator.stop();
                                    }
                                    System.exit(0);
                                }
                            }.start();
                        }
                    });
                    frame.setTitle(TITLE);
                    frame.pack();
                    frame.setVisible(true);

                    // Should start my two canvas
                    upperCanvasAnimator.start();// Should call init method for upperCanvas, am I right?
                    lowerCanvasAnimator.start();// Should call init method for lowerCanvas, am I right?
                }
            });
        }


        private GLU glu;  // for the GL Utility

        public JOGL2Setup_GLCanvas() {
            this.addGLEventListener(this);
        }

       
        public void init(GLAutoDrawable drawable) {
            GL2 gl = drawable.getGL().getGL2();
            glu = new GLU();                        
            gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
            gl.glClearDepth(1.0f);
            gl.glEnable(GL_DEPTH_TEST);
            gl.glDepthFunc(GL_LEQUAL);
            gl.glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
            gl.glShadeModel(GL_SMOOTH);

            // ....
        }

        // Should be called twice, am I right? One for upperCanvas and one for lowerCanvas? But is called once =(  
        public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {
            GL2 gl = drawable.getGL().getGL2();

            if (height == 0) height = 1;
            float aspect = (float)width / height;

            gl.glViewport(0, 0, width, height);

            gl.glMatrixMode(GL_PROJECTION);
            gl.glLoadIdentity();
            glu.gluPerspective(45.0, aspect, 0.1, 100.0);

            gl.glMatrixMode(GL_MODELVIEW);
            gl.glLoadIdentity();

            System.out.println(drawable);
        }

        public void display(GLAutoDrawable drawable) {
            GL2 gl = drawable.getGL().getGL2();
            gl.glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
            gl.glLoadIdentity();

            gl.glTranslatef(0.0f, 0.0f, -6.0f);
            gl.glBegin(GL_TRIANGLES);
            gl.glVertex3f(0.0f, 1.0f, 0.0f);
            gl.glVertex3f(-1.0f, -1.0f, 0.0f);
            gl.glVertex3f(1.0f, -1.0f, 0.0f);
            gl.glEnd();
        }

        public void dispose(GLAutoDrawable drawable) { }

        @Override
        public String toString() {
            return "canvasName="+this.canvasName;
        }
    }

Hi

Your code is poorly written, you mix up everything, you create a class that uselessly extends GLCanvas and that creates 2 canvases. System.exit(0) should be necessary only if you use Java Webstart. In my humble opinion, you should put the GLEventListener into a separate class and read some tutorials about Swing as your JFrame uses a BorderLayout by default then you should rather write:
frame.getContentPane().add(upperCanvas, BorderLayout.NORTH);
frame.getContentPane().add(lowerCanvas, BorderLayout.SOUTH);

Replace glu = new GLU();   by glu = GLU.createGLU(gl), otherwise your instance of GLU will support a tiny subset of GLU and throw unsupported operation exceptions whereas it is easy to avoid.

I wrote a simple example in which I put everything into the same class but I did it that way to keep it simple, it doesn't mean that it should be done in real programs:
https://gist.github.com/gouessej/3420e2b6f632efdddf98

There are some modern examples here:
http://jogamp.org/git/?p=jogl-demos.git;a=blob;f=src/demos/es2/RawGL2ES2demo.java;hb=HEAD
https://github.com/elect86/jogl-samples/blob/master/jogl-samples/src/helloTriangle/HelloTriangle.java

Hi Julien

Thanx for your reply.

I had extracted this code from a former tutorial and I tried to put the code the simplest I could to avoid a tiresome reading.

I´ll take a look at Swing and Layouts. There´s too many years since I used Swing apps for the last time.

I´ll check your example too.

Thanx again.

Set the BorderLayout give me the desired results.

Thanx

You're welcome. Don't forget to call GLU.createGLU(gl) instead of new GLU().