The Graphics Composer Event Manager provides a GUI interface to manage all of the events associated with a graphics application. In a general sense, an event is an action or occurrence that is processed by software using an “event handler”. Button pushes or keystrokes are widely recognized and handled events. Events related to a touch screen are commonly called “gestures”. This GUI allows the assignment of actions to events associated with graphics widgets and to events outside of the graphics library. Under the Graphics Composer Event Manager tab there are two sub-tabs, one for “Events” and a second for “Macros”.

The following table summarizes the difference between "events" and "macros" and provides examples of each instance of source to destination:

Differences Between Events and Macros

“Events” under the first tab are generated from within graphics widgets and can manipulate the properties of screen widgets or set semaphores that engage with the rest of the application. “Macros” are executed outside of graphics widgets by other parts of the application. “Macros” allow the application to change widget properties or behavior. 

Both “Events” and “Macros” event handlers can be built using collections of “Template” actions or using “Custom” developer-provided code. Most widget properties have an associated Template action that can be used to manipulate that property in an event handler (either “Event” or “Macro”). For more information on properties and related actions, see the discussion on the Properties Window below. 

To explore these capabilities, let’s look at the Aria Quickstart project after the completion of the Adding Event to a Graphics Application Quick Start Guide.