Question

How may I block a gwt DisclosurePanel on the open state ?

I mean, how can I prevent this DisclosurePanel to close if the user click the header more than once ?

(My header is a textBox, I want the user to enter a text, and the panel should remain open if the user unfocus the textBox and focus newly by clicking it. The DisclosurePanel content has a “cancel” button that closes the panel)

Thank you very much.

I edit my question after 2 first answers: I would like to avoid to reopen the DisclosurePanel once closed to avoid flashing effect. I actually want to prevent the DisclosurePanel to close. Maybe sinkEvents can help me… if so, how? Thanks.

Answer 1

A NativePreviewHandler receives all events before they are fired to their handlers. By registering a nativePreviewHandler the first time your disclosurePanel is opened, you can cancel the click event. You can later decide to remove this handler by preventClose.removeHandler();

HandlerRegistration preventClose = null;
....
panel.addOpenHandler(new OpenHandler<DisclosurePanel>() {
    @Override
    public void onOpen(OpenEvent<DisclosurePanel> event) {
        if (preventClose == null){
            preventClose = Event.addNativePreviewHandler(new NativePreviewHandler() {
                @Override
                public void onPreviewNativeEvent(NativePreviewEvent event) {
                    if (event.getTypeInt()==Event.ONCLICK && event.getNativeEvent().getEventTarget() == panel.getHeader().getElement().cast()) 
                        event.cancel();
                }
            });
        }
    }
});