Protos

Introduction to Protos

Consider a button on the Newton as a perfect proto candidate. Everything from its visual characteristics--its rectangular frame, rounded corners, and text string (such as "Press Me")--to its particular behavior--it does something when you tap on it--screams for protoing.

The Newton design team wisely decided that you should not have to reinvent this type of button, so they provided protos and, in this case, a protoTextButton. When you want a button in an application, you just draw out a template that protos from protoTextButton, and you get all of the proto's button characteristics without any extra work. Your job as the programmer is to add the specialized components: what happens when you tap on the button, where the button is located, and so on. Further, because a great number of protos have been built into the Newton ROM, you get to use them without paying a price in much additional memory space. And just in case the Newton designers forgot some really useful proto on the ROM, they gave you the ability to design your own custom protos.

But enough fanfare--let's get down to the mechanics of protos, how they work, how you use them, and how you create them.

Kinds of Protos
Proto Nuts and Bolts
Protos and Template Size
Protos Provide Template Reuse
Protos Reduce Application Size
Protos Increase Maintainability
Protos Can Be Shared between Projects

An online version of Programming for the Newton using Macintosh, 2nd ed. ©1996, 1994, Julie McKeehan and Neil Rhodes.

Last modified: 1 DEC 1996