View

A Triarc Process is a headless process running without a user interface. While indicators may be added to the Handle Messages.vi for debugging, this is not recommended for implementing a user interface. The derived View class adds a user interface to the process. This VI should be used to implement a user interface component and complex user interfaces are typically composed from multiple small views inserted in sub panels.

Anatomy of a View

The View class adds a VI called View.vi and provides methods for showing and hiding the panel of the View.vi. The API also provides a method for getting a reference to the View.vi, which may be used to insert the View into a subpanel. The API is shown below.

There are two requiremetns that the framework asserts on the View.vi and it is important that these are fulfilled. The first is that the View.vi reports a refrence to the VI when it is started using the provided framework method. The second requirement is that the View.vi stops when the Stop message is broadcasted. This is demonstrated below. These requirements are tested in the unit test created with the class when the class is created from the New Triarc Process menu item.

Communicating between the Process and the View

The View.vi and Handle Messages.vi runs concurrently and in separate VIs with some given communcation channels.

When a user interacts with the view, the view may call any API method on the process to send messages to the process loop. As the View.vi belongs to the process, the API may even be privately scoped.

Communicating from hte Handle Messages.vi in the process loop to the View.vi is typically done using broadcasts. Broadcast messages are sent from the process loop and handled by the View.vi to update the user interface.

Another way of updating the user interface is to send references from the View.vi to indicators and then update these indicators using property nodes in the Handle Messages.vi.