Design Specification

Figure 3.4 shows the class GUI interface having a one to one compositional relationship with the class Virtual Environment. The latter of which holds the information and methods necessary to deal with the animation and maintain the integrity of the virtual world, whilst the former holds the application interface data and methods.

This segregation of functionality falls in line with the natural way in which the requirements were split, and also conforms to the object oriented methodology by using the encapsulation of related methods in the two separate classes.

Figure 3.4: Class diagram for the animation module

The GUI Interface class should create and manage the application window and its elements. This is reflected by the attributes of the class as there is a widget for each of the following desired application elements:

• Main window - the constructor must set the size, and connect the menu's and accelerator keys together.
• Menu bar - the menu bar and its associated menus.
• Dialogue box - the subwindow to which the recognised phrases, system messages and errors will be sent.
• Status bar - enabling display of the latest action performed by the application such as connecting to ViaVoice or enabling or disabling of the microphone.

The display area shall be created as a member of the GUI interface object and be an instantiation of the virtual environment class. It shall have the following members:

• World - the internal representation of the virtual environment.
• Model - the internal representation of the agent over which the user shall have control
• Current heading - in a general architecture this would be stored as a three dimensional vector, but since this application shall assume that movement is only allowed in two degrees of freedom (namely movement on the x-z plane, and rotation about the y-axis), only two of the values are needed.
• Current position - three dimensional co-ordinates of the current location of the agent.