Action Basics

To make an application respond to a user action (e.g., pressing an accelerator key) the corresponding action handler should be defined within the source code.

 

Action View

An action view is any widget/element appearing to be the graphical representation of an action defined in a source code with an action handler.

The connection between the action and the view associated with it is established by the runtime system.

 

The appearance and behavior of an action view can be modified by the developer at different application levels. Besides the text, comment and action view image, one have a possibility to define key accelerators triggering an action (up to four) and to modify an action view behaviour under certain circumstances setting values to its optional attributes.

 

Globally, the views of the predefined actions are predetermined in the SystemActionDefaults.fm2 file. If any of these action view attributes is assigned to a certain action within an application development, merging takes place.

 

Context Action

A context action is the currently available (at runtime) action which can be triggered.

 

Context Action View

A context action view is the graphical representation of a context action. Its attributes can be defined at different application levels (.4gl, .fm2, server configuration file, etc.), and are merged at runtime to create the final view of the context action.

 

To find out which actions are created automatically (are defined on the system level) in which context, please, see List of Predefined Actions.

 

Action Toolbar

If the source code of an application does not explicitly define the form of an action view (for example, a button or a top menu item widget), an action toolbar containing the action toolbar buttons is created automatically. Depending on the user preferences it may appear on top or on in right of a form: an action toolbar location is defined by the Toolbar Location property ('top' by default), which in its turn can be influenced by the Compatibilty Mode property setting.

As the action toolbar content depends on the context, it is dynamically changed on the course of an application execution depending on it.