Question

I have created a custom widget in GWT like:

public class Header extends Composite {
    private Button btnContribute;

    public Header() {
        btnContribute = new Button("Contribute");
    }
} //This is only a sample - in actual there are few bundled widgets

In my Entry point class I have used this custom widget as a north panel for my dockLayoutPanel as shown:

public class MyClass implements EntryPoint {
private DockLayoutPanel dockLayoutPanel;
private ScrollPanel contentScrollPanel;

private Header header; //My custom widget

public void onModuleLoad() {
    RootPanel rootPanel = RootPanel.get();

    dockLayoutPanel = new DockLayoutPanel(Unit.EM); 
    rootPanel.add(dockLayoutPanel, 20, 10);

    header = new Header();
    dockLayoutPanel.addNorth(header, 7.7);

    dockLayoutPanel.addSouth(new HTML("south"), 7.7);
    dockLayoutPanel.addWest(new HTML("west"), 7.7);

    contentScrollPanel = new ScrollPanel();
    dockLayoutPanel.add(contentScrollPanel);

    htmlContent = new HTML("content", true);
    contentScrollPanel.setWidget(htmlContent);
    htmlContent.setSize("100%", "100%");
}
}

I want to create a onClick event handler on the button in my custom widget ‘btnContribute’ such that it dynamically updates the ‘contentScrollPanel’, deletes the current content, and say loads a form in it.

The problem is that I when I try to create a event handler in my custom widget, I am unable to figure out as to how should I add and remove widgets from my entry point class..

Answer 1

Create getter in Header class ;

In your Entrypoint class add the handler like below :

header.getbtnContribute().addClickHandler(new ClickHandler() {
        @Override
        public void onClick(ClickEvent event) {
            //TODO
        }
    });