The TLcyFormatBarAddOn provides one menu item or tool bar item that controls the presence of a container for ALcyFormatBar instances, located at the bottom of a map component. Layer selection in a ILcyGenericMapComponent is monitored, and the format bar that matches the format of the selected layer is displayed in the container.

An ALcyFormatBar is a Swing component that provides tools to manipulate the layers of the format. Manipulation can mean anything here. A typical use consists of making buttons available for drawing new domain objects, and adding them into the layer and its model.

A number of existing addons show their respective tool bars inside an ALcyFormatBar. They include the TLcyDrawingAddOn, the TLcyMS2525bAddOn, and the TLcyAPP6AAddOn.

If the menu bar or toolbar item is activated and no ALcyFormatBar can be created for any layer in the map with an ALcyFormatBarFactory, an attempt is made to create a new layer for this purpose. To do so, a ALcyDefaultModelDescriptorFactory is used to create an ILcdModelDescriptor. If multiple factories are available, the end user is asked to select one. With the ILcdModelDescriptor, an ILcdModel is created using an ILcdModelFactory. A layer for that model is created using a layer factory and added to the map, for example, a ILcdGXYLayerFactory is used for an ILcyMapComponent

The ALcyFormatBarFactory objects, ALcyDefaultModelDescriptorFactory objects, ILcdModelFactory objects and layer factories are all retrieved using the ILcyLucyEnv method getServices. As such, they must be registered using addService.