In iOS events bubble up from child to parent view by default, but in Android you have to explicitly say so. For example if we have a parentview that adds a childview that has a button in it. After clicking the button, the childview fires a "logout" event on the button. The parent view listens for this event on the child view (so not on the button).

// From the parent view
var childView = Alloy.createController("childView").getView();
childView.addEventListener("logout", function() {
  console.log("Received the logout event from the childView!");
});
$.container.add(childView);

In the childView we fire the logout event from the button:

// From the childView
var button = Ti.UI.createButton({
  title : "Logout"
});
button.addEventListener("click", function() {
  button.fireEvent("logout", {
    bubbles : true
  });
});
$.container.add(button);