EiffelVision Library Reference Manual

EiffelVision 2 is a platform-independent Graphical User Interface (GUI) library that allows easy, simultaneous development of Windowed applications for both Windows- & Unix-based platforms. Heavily relying on the EiffelBase library, EiffelVision 2 has been designed primarily with ease of use in mind. By reusing EiffelBase structures, existing, as well as new Eiffel users will find EiffelVision to be surprising intuitive and easy to use. In very little time, users will be producing professional Windowed application skeletons which will run on a multitude of platforms with no change of source code.

The EiffelVision 2 library includes the following interface clusters:

• The kernel cluster includes classes that are key to an EiffelVision 2 application. The most important class in this cluster is EV_APPLICATION which is the main entry point for all EiffelVision 2 applications.

• The widgets cluster contains classes used to create EiffelVision 2 widgets. Widgets are the visible objects that the user sees and interacts with in the application. Examples of widgets are windows, buttons and labels.

• The items cluster includes the classes needed to create items. Items are widgets that can only be contained within a certain type of widget. Example: EV_LIST widgets may only contain objects of type EV_LIST_ITEM . Items provide an abstract way of dealing with an item-widget's internal data structures and provide, in many cases, the same functionality that a widget does.

• The events cluster contains classes that allow for user-initiated events, such as the clicking of a button to be dealt with via the use of a linked list of agents (EV_ACTION_SEQUENCE). An Agent can be thought of as an object that encapsulates a certain procedure. When a user clicks a button on the screen, the corresponding EV_BUTTON object has its pointer_button_press_actions fired, and this, in turn, fires all of the agents held within this list, thus calling all of the procedures represented by the agents. Every widget and item has a number of ACTION_SEQUENCE objects, each of which are linked to a certain type of event. To link any number of different procedure calls with an event, it is only necessary to extend the action-sequence list associated with that event, with agents representing those calls.

• The properties cluster contains classes that allow for the customization of Vision 2 widgets and items. Classes such as EV_COLORIZABLE and EV_FONTABLE contain routines that allow for (respectively) color and font to be altered for a widget.

• The support cluster includes classes that provide more professional touches to an application, whether these are keyboard shortcuts (EV_ACCELERATOR_LIST) or graphical output (EV_GRAPHICAL_FORMAT) for drawable widgets such as EV_PIXMAP .

• The figures cluster allows for the projection of two-dimensional shapes (figures) onto an EV_DRAWABLE or printer via the use of an EV_PROJECTOR .

To see differences between released versions of EiffelVision, click Here