Chapter 15

Extending Viola

Extending viola

Why, how...

For developers who want to modify, or add, Viola code. This section intends to encourage others to contribute code to viola. Some of this material should be documented in the code itself.

15.1 Creating assistance applications

Point out that assistance applications, like the builder stack, is just another stack configured in certain way. Discuss how this provides a flexible way for building stack tools that help to build stacks.

For the application scriptor, explain the internals of these applications. Explain why these stacks need to be ``locked'', or non-selectable... Discuss guidelines for creating, or customizing, assistance application.

15.2 How viola's inheritance scheme works

Explain viola's single inheritance algorithm. ?

15.3 How to add new command/method

People may want to, for the same reasons why HyperCard XCMDs are necessary. It's also useful to point out ways to get around this need, by using either the socket or tty facilities...

15.4 How to add new slots

Show procedure in adding new slots. In some cases this is necessary knowledge in adding a new method.

Point out some things to watch out for (due to the single inheritance algorithm).