i need your help. i´m trying to add a menubar to my application to switch the single views.
therefor i´m using the navigator api.
my plan was to add the menubar to a view and only change the following layout deppending which button in the menubar is pressed.
the menubar is shown but there is no button (“do something”)
here my code:
protected void init(VaadinRequest vaadinRequest) {
...
//Navigator
// Create a navigator to control the views
navigator = new Navigator(UI.getCurrent(), new VerticalLayout());
// Create and register the views
navigator.addView("View3", new View3());
navigator.addView("View4", new View4());
...
public class View3 extends VerticalLayout implements View {
public View3() {
setSizeFull();
Button button = new Button("do something",
new Button.ClickListener() {
@Override
public void buttonClick(ClickEvent event) {
System.out.println("blabla");
}
});
addComponent(button);
setComponentAlignment(button, Alignment.MIDDLE_CENTER);
}
@Override
public void enter(ViewChangeEvent event) {
Notification.show("View3 entered");
}
}
navigator = new Navigator(UI.getCurrent(), new VerticalLayout());
Navigator controls a component container such as a UI, Panel, or a layout like VerticalLayout. But you need to add the layout to the UI.
Moreover, as you want to use the menu made from buttons that you use to display something in the view area, they should not be part of the view area, as you have in your view class.
You seem to have taken your view class from the LoginView in the Navigator section in the book. Notice that in that example, the navigator controls the entire UI content, not a view area in the UI, as would probably be in your case.
The MainView class in the example is one way to do what you are looking for, although there the view fills the entire UI and the view area is controlled manually within the view by using view parameters.
public static enum VIEWS {
View1, View2, View3, View4, View5
};
....
//Navigator
// Create a navigator to control the views
navigator = new Navigator(this, this);
// Create and register the views
navigator.addView(VIEWS.Main.toString(), new MainView());
navigator.navigateTo(VIEWS.Main.toString());
...
}
public class MainView extends VerticalLayout implements View {
private MenuBar menu;
VerticalLayout vl = new VerticalLayout();
public MainView() {
//Menubar
MenuBar.Command mycommand = new MenuBar.Command() {
public void menuSelected(MenuItem selectedItem) {
getUI().getNavigator().navigateTo(MAIN + "/" +selectedItem.getText());
}
};
menu = new MenuBar();
menu.setWidth("100%");
for(VIEWS v :VIEWS.values()){
menu.addItem(v.toString(), null, mycommand);
}
addComponent(menu);
addComponent(vl);
}
@Override
public void enter(ViewChangeEvent event) {
System.out.println(event.getParameters());
if(event.getParameters() == null ||
event.getParameters().isEmpty()){
// Throw Exception
} else if (event.getParameters().equals(VIEWS.View1.toString())){
vl.addComponent(new View1());
} else if (event.getParameters().equals(VIEWS.View2.toString())){
vl.addComponent(new View2());
} else if (event.getParameters().equals(VIEWS.View3.toString())){
vl.addComponent(new View3());
} else if (event.getParameters().equals(VIEWS.View4.toString())){
vl.addComponent(new View4());
} else if (event.getParameters().equals(VIEWS.View5.toString())){
vl.addComponent(new View5());
} else {
//Throw Exception
}
}
I can’t say if all the details work, but roughly yes, that’s one way to do it.
As I noted earlier, if you have just one top-level view there, the MainView, you might want to organize the navigation differently. In the other approach, you would have the menu in the UI’s content, and have the navigator control a layout to insert different views into it. Unfortunately, I don’t have a ready example of this approach.
Sampler’s navigation example demonstrates yet another approach, but unfortunately its source code may be a bit difficult to grasp, as there’s no UI class in the example code.
I use similar approach to write the jdal sample. However, the views and button bar are defined in Spring application context definition file instead code:
