public class TestEvent extends Event implements EventCancellable { private boolean isCancelled; private String data; // can be whatever public TestEvent(String data) { this.data = data; } public String getData() { return data; } @Override public boolean isCancelled() { return this.isCancelled; } @Override public void setCancelled(boolean cancelled) { this.isCancelled = cancelled; } }

public class SomeListener implements EventListener { // will be invoked @HandleEvent public void onTestEvent(TestEvent event) { System.out.println("Data: " + event.getData()); } // will not be invoked public void onNotInvokedTestEvent(TestEvent event) { System.out.println("Data: " + event.getData()); } }

// create the handler and listener instances EventHandler handler = new EventHandler(); ListenerTest testListener = new ListenerTest(); // register the listener handler.registerEvents(testListener); // make sure data is not overridden yet Assert.assertEquals("None", testListener.getData()); Assert.assertEquals(0, testListener.getTimesRan()); // call the test event handler.callEvent(new TestEvent("New data")); // data should now be what was passed into the TestEvent constructor Assert.assertNotEquals("None", testListener.getData()); Assert.assertEquals("New data", testListener.getData()); Assert.assertEquals(1, testListener.getTimesRan()); // unregister the listener handler.unregisterEvents(testListener); // call the test event, this should not change the data now handler.callEvent(new TestEvent("Different data")); Assert.assertNotEquals("Different data", testListener.getData()); Assert.assertEquals(1, testListener.getTimesRan());