如何在 Eclipse e4 应用程序的菜单/工具栏中创建切换/收音机项目？

Question

What is the canonical way of creating a menu item that implements a toggle or radio state in an eclipse e4 rcp application?

It seems such a basic thing, but all the documentation I found relies on e3 API and creates dependencies to org.eclipse.ui, which is not allowed in e4.

Answer 1

One possible way that I use for a radio button menu which saves the radio button state in the part class.

I use multiple Direct Menu Item entries with the type set to Radio .

I set a Tag value (on the supplementary page of the menu item) to the value I want to associate with the menu item.

I use the same handler for all of the menu items.

In the handler I inject the MPart and the MItem :

@Execute
public void execute(final MPart part, final MItem mitem)
{
  // Only take action on the selected radio item

  if (!mitem.isSelected())
    return;

  // The tag value specifying the radio state

  String tag = mitem.getTags().get(0);

  // Get the part class

  MyPart myPart = (MyPart)part.getObject();

  // tell the part about the state change

  myPart.setState(tag);
}

Instead of the MPart you could also use any class that is in the Eclipse Context - such as one declared as @Creatable and @Singleton .