Strange syntax for instantiating an inner class

Question

I didn\'t imagine that I would encounter radically new syntax in Java anymore at this stage, but lo and behold, I just encountered something:

The exact context a

Answer 1

You actually can do that, but you have to declare ClickEvent as static inside Button, and then you shouldn't have any problem using you sintax:

buttonClick(new Button.ClickEvent(button));

Basically static makes the class ClickEvent belong directly to the class Button instead of a specific instance(i.e. new Button()) of Button.

---

Following @Jon Skeet example:

// Button.java
class Button
{

    public static class ClickEvent
    {
        public ClickEvent(Button b)
        {
            System.out.println("Instance: " + this.toString());
        }
    }
}

// Test.java
public class Test
{
    public static void main(String[] args)
    {
        Button button = new Button();
        buttonClick(new Button.ClickEvent(button));
    }

    public static void buttonClick (Button.ClickEvent ce) {
    }
}