Much of Titanium is built around the concept of event-driven programming. If you have ever written code in Visual Basic, C#, Java or any number of event-driven, object-orientated languages, this concept will already be familiar to you.
Each time a user interacts with a part of your application's interface, or types something in a TextField, an event occurs. The event is simply the action the user took (for example, a tap, a scroll, or a key press on the virtual keyboard) and where it took place (for example, on a button, or in this TextField). Additionally, some events can indirectly cause other events to fire. For example, when the user selects a menu item that opens a window, it causes another event—the opening of the window.
There are basically two fundamental types of events in Titanium; those you define yourself (a custom event), and those already defined by the Titanium API (a button click event is a good example).
In the following recipes, we will explore...