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 other event-driven, object-orientated language, this concept will 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. An event is simply an action that the user took (for example, a tap, scroll, or key press on the keyboard) and the object in which it took place (for example, on a button, or in a particular TextField). Additionally, some events can indirectly cause some 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 two fundamental types of events in Titanium: those that you define yourself (a custom event) and those already defined by the Titanium API (a button click event is a good example of this).
In the following recipes, we will explore...