Best strategy to migrate a java applet?

Added by welton nascimento almost 8 years ago


Chrome is dropping out java applet support next month and I'm looking for viable alternative for a drawing applet we have here.

I took a look at figtree, but couldn't understand it very well.

My applet is a JPanel (as all applets are, I guess), with three JPanels and several subcomponents. As I said, is a specialized drawing app.

Right now, I was able to follow (or try to) figtree approach, creating a WPaintedWidget,

public class CroquiWebApplication extends WApplication{
    public CroquiWebApplication(WEnvironment env) {

        setTitle("Croqui Test");

        WVBoxLayout layout = new WVBoxLayout(getRoot());

        layout.addWidget(new CroquiWidget());

public class CroquiWidget extends WPaintedWidget {

    private MeuCroqui croqui;
    private WebGraphics2D graphics = new WebGraphics2D(new WPainter());

    public CroquiWidget(){
        croqui = new MeuCroqui(){
            private static final long serialVersionID = 1L;

            public void repaint() {

            public Graphics getGraphics() {
                return graphics;
        // this stub is needed to emulate the browser environment, as passing <applet> tag parameters to the applet.
        croqui.setStub(new MyAppletStub());

        // this is where the applet really runs.
        // croqui.init() is this:

//        public void init() {
//            //Take lots of parameters from emulated <applet> tag
//            Dados dados = new Dados();
//            Container container = this.getContentPane();
//            container.setLayout(new GridBagLayout());
//            GridBagConstraints c = new GridBagConstraints();
//            c.ipady = 0;
//            c.anchor = 10;
//            this.panelDesenho = new PanelDesenho(dados);
//            JPanel painel = new JPanel(new BorderLayout());
//            painel.setMaximumSize(new Dimension(950, 592));
//            painel.setMinimumSize(new Dimension(950, 592));
//            painel.setPreferredSize(new Dimension(950, 592));
//            painel.add(this.panelDesenho, "Center");
//            this.panelFerramentasInferior = new PanelFerramentasInferior(dados, this.panelDesenho);
//            painel.add(this.panelFerramentasInferior, "South");
//            this.panelFerramentasLateral = new PanelFerramentasLateral(dados, this.panelDesenho, this.panelFerramentasInferior);
//            painel.add(this.panelFerramentasLateral, "East");
//            container.add(painel, c);
//        }


    protected void paintEvent(WPaintDevice wPaintDevice) {
        WPainter wPainter = new WPainter(wPaintDevice);
        WebGraphics2D webGraphics2D = new WebGraphics2D(wPainter);

    protected void layoutSizeChanged(int width, int height) {
        super.layoutSizeChanged(width, height);
        croqui.setSize(width, height);


Right now, I am getting a blank screen and no errors on jetty console. As far as I can tell, by remote debugging it, the code is running just fine. It just is not being rendered, I think, or the panels are not being resized to the screen size.


1 - I can embed a this Applet inside a JFrame just fine, but I have to call Jframe.pack() and setVisible(true) to get things displayed. Shouldn't I set WApplication size? Or WPaintedWidget?

2 - I couldn't figure out how the applet is embedded inside the WPaintedWidget. When using a JFrame, I have to JFrame.add() it.

3 - Is it even possible? :)

Thanks for any help.

Replies (1)

RE: Best strategy to migrate a java applet? - Added by Koen Deforche almost 8 years ago


You'll only be able to recycle the painted part of your applet to integrate it into a WPaintedWidget, but will need to recreate the rest of of the UI using Wt widgets.