Overview of Handler in GWT

Question

Is there an overview about all handlers and their corresponding containers in GWT? Whenever I try to add a handler to a container, I have to check, whether the handler fires an event or not (the JavaDoc does not provide useful information about this). For example a ResizeHandler:

       SplitLayoutPanel splitLayoutPanel = new SplitLayoutPanel() {
            @Override
            public void onResize() {
                super.onResize();
                System.out.println("onResize");
            }           
        };

        splitLayoutPanel.addHandler(new ResizeHandler() {

            @Override
            public void onResize(ResizeEvent event) {

                System.out.println("resize");

            }
        }, ResizeEvent.getType());

Overwriting the onResize()-method (1. example) gives an information, if the splitter changes, but if I add a ResizeHandler (2. example), I do not get any call of the onResize-method. I don't understand why and don't find the documentation why the handler is not allowed in this container.

I search for an overview of all available handlers, together with their possible containers and event, when they will be fired.

Riley Lark Riley Lark · Accepted Answer · 2012-07-09T18:28:32

Usually there will be a more specific addHandler method. For example, Button has addClickHandler(ClickHandler). The interface that defines that method is HasClickHandlers, so you can look out for that, for example.

If the event doesn't have it's own addXyzHandler method, it probably won't be supported very well. In that case, it's usually pretty easy to subclass the widget and add support for that handler yourself.

Overview of Handler in GWT

2 Answers