protected CloudCoderPage createPageForPageId(PageId pageId, String pageParams) {
CloudCoderPage page = createPageForPageId(pageId);
// Create a reasonable PageStack.
// (Note that we need to disable notifications while we do this,
// since we're not actually navigating pages.)
PageStack pageStack = session.get(PageStack.class);
pageStack.setNotifications(false);
page.initDefaultPageStack(pageStack);
pageStack.push(page.getPageId());
pageStack.setNotifications(true);
// Set initial page parameters (if any)
if (pageParams != null) {
page.setUrlFragmentParams(pageParams);
}
return page;
}
/** This is the entry point method. */
public void onModuleLoad() {
theInstance = this;
GWT.log("loading, fragment name is " + Window.Location.getHash());
session = new Session();
pageStack = new PageStack();
session.add(pageStack);
subscriptionRegistrar = new DefaultSubscriptionRegistrar();
// Subscribe to PAGE_CHANGE events in the PageStack
pageStack.subscribe(PageStack.Event.PAGE_CHANGE, this, subscriptionRegistrar);
// Subscribe to all Session events
session.subscribeToAll(Session.Event.values(), this, subscriptionRegistrar);
// Go to whatever initial page is appropriate.
createInitialPage();
}
@Override
public void eventOccurred(Object key, Publisher publisher, Object hint) {
// This is where we monitor for events that indicate page changes.
// The PageStack makes this pretty straightforward.
if (key == PageStack.Event.PAGE_CHANGE) {
PageId current = session.get(PageStack.class).getTop();
changePage(createPageForPageId(current));
} else if (key == Session.Event.LOGOUT) {
// On logout, go back to the LoginPage, then
// clear the Session and PageStack,
// add the PageStack back to the Session.
// We clear the Session after navigating away from the
// current page, because some pages
// (e.g., CoursesAndProblemsPage3) add a memento to the
// Session to save UI context information.
changePage(new LoginPage());
session.clear();
pageStack.clear();
session.add(pageStack);
}
}
@Override
public void initDefaultPageStack(PageStack pageStack) {
pageStack.push(PageId.COURSES_AND_PROBLEMS);
pageStack.push(PageId.USER_ADMIN);
}