GWT中如何有固定位置面板？

Question

I have one big SimpleLayoutPanel which is located in RootLayoutPanel.get() and this is a constraint.

Now I want to place some extra panel and want it have position:fixed within browser screen. Is it possible?

I can set this style neither with setStyleName()/CSS, nor with DOM.setStyleAttribute(). In both cases my style is overrining by GWT's

Thanks

the code I succeeded

I used both root panels simultaneously

public void onModuleLoad() {

    SimpleLayoutPanel simpleLayoutPanel = new SimpleLayoutPanel();
    simpleLayoutPanel.setStyleName("SimpleLayoutPanel");

    DOM.setStyleAttribute(simpleLayoutPanel.getElement(), "backgroundColor", "blue");

    RootLayoutPanel rootLayoutPanel = RootLayoutPanel.get();
    rootLayoutPanel.add(simpleLayoutPanel);

    LayoutPanel layoutPanel = new LayoutPanel();
    layoutPanel.setStyleName("LayoutPanel");
    DOM.setStyleAttribute(layoutPanel.getElement(), "position", "fixed");
    DOM.setStyleAttribute(layoutPanel.getElement(), "bottom", "0px");
    DOM.setStyleAttribute(layoutPanel.getElement(), "height", "100px");
    DOM.setStyleAttribute(layoutPanel.getElement(), "width", "100px");
    DOM.setStyleAttribute(layoutPanel.getElement(), "backgroundColor", "red");

    RootPanel rootPanel = RootPanel.get();
    rootPanel.add(layoutPanel);


}

Answer 1

Both RootLayoutPanel and RootPanel can be used simultaneously.

I succeeded this way. The elements I need to receive resize events, have been put into RootLayoutPanel. And the elements I need to have positioned with fixed, have been put into RootLayout.

I found no way to put everything into one root panel flavour.

Answer 2

If I understood correctly you should be able to use the parent panel's add(Widget/Panel, int x, int y) method to specify exact location at pixel level. So if you have your Root panel called root, and want to add another panel somePanel at 100, 100, root.add(somePanel, 100, 100) should do the job.