Events Controllers extend BackBone.Events and as such can dispatch events.

gistfile1.xml

<!--
Events
Controllers extend BackBone.Events and as such can dispatch events.
For example, our index view could also require another controller to deliver the label and listen to an event:
-->
app/views/index.xml
<Alloy>
    <Window class="container">
        <Require id="label" src="label" onNotify="doSomething" />
    </Window>
</Alloy>
<!--
The view of the required label-controller would listen to the click event of the label itself:
-->
app/views/label.xml
*/

<Alloy>
    <Label id="label" onClick="passClick">Hello, World</Label>
</Alloy>
<!--
And that label-controller would in turn fire the notify event on itself so the index controller will receive it:
-->

x.js

 // app/controllers/label.js

function passClick(e) {
    $.trigger('notify');
}