In GWTP how can TabLayoutPanel events be handled? - gwt

Question

I've followed Dani's GWTP Course but using TabLayoutPanel with presenters isn't covered.
I have a TabLayoutPanel with 3 tabs (each with a VerticalPanel on it). I've used #ProxyCodeSplit so that the code for each tab is loaded independently.
If in Eclipse, in GWT's Designer I add a handler for OnBeforeSelection then code is auto-added into my View. The View can then load up the appropriate presenter.
That doesn't feel like the right place for the code - but is it?
How are you handing different tabs within TabLayoutPanel and code splitting?

Answer 1

I think I've got this figured out.
In your presenter with the TabLayoutPanel (let's call it MainPresenter):
#ContentSlot public static final Type<RevealContentHandler<?>> SLOT_first = new Type<RevealContentHandler<?>>();
#ContentSlot public static final Type<RevealContentHandler<?>> SLOT_second = new Type<RevealContentHandler<?>>();
public interface MyView extends View {
public void setMainPresenter(MainPresenter presenter);
public TabLayoutPanel getTeamsPanel();
}
#Inject PlaceManager placeMananger;
#Inject FirstPresenter firstPresenter;
#Inject SecondPresenter secondPresenter;
#ProxyCodeSplit
public interface MyProxy extends Proxy<MainPresenter> {
}
#Inject
public MainPresenter(final EventBus eventBus, final MyView view,
final MyProxy proxy) {
super(eventBus, view, proxy);
view.setMainPresenter(this);
}
#Override
protected void revealInParent() {
RevealRootContentEvent.fire(this, this);
}
public void setTabContents(Integer tab) {
if (tab == 0) {
placeMananger.revealPlace(new PlaceRequest("first"));
} else if (tab == 1) {
placeMananger.revealPlace(new PlaceRequest("second"));
}
Then in your MainView implement the method setMainPresenter() to store a reference locally. Implement the usual setInSlot() and then add this tab handler:
#UiHandler("mainTabs")
void onMainTabsBeforeSelection(BeforeSelectionEvent<Integer> event) {
mainPresenter.setTabContents(event.getItem());
}
The handler will call MainPresenter each time the user changes tabs. setTabContents() will then call revealInParent() for the appropriate "tab" Presenter.