I am using Processing 3.0.1 and since we don't have (easy) access to the underlying AWT window, it seems impossible for me to start a new sketch (which I am using from withing a standalone Eclipse Java project) maximized.

I came closest with (the hacky):

private void maximized() {
    try {       
        final GLWindow window = (GLWindow) getSurface().getNative();
        window.getScreen().getDisplay().getEDTUtil().invoke(false, new Runnable() {
            @Override
            public void run() {
                window.setMaximized(true, true); // both horizontal and vertical
            }
        });
    } catch (Exception e) {
        System.err.println("Could not make window maximized");
    }
}

which I call inside setup() (it does not work inside settings() at all as there is no window yet).

It does start non-maximized, and after a short time the window is maximized, but this looks really not good and also is very non-portable since it depends on the JOGL renderer.

Since using fullScreen() inside settings() works perfectly, it would be great, if we had a maximized() method which can also be called in settings() and does the expected thing.