TweetFollow Us on Twitter

Oct 98 Factory Floor

Volume Number: 14 (1998)
Issue Number: 10
Column Tag: From The Factory Floor

A PowerPlant Update

by Greg Dow and Dave Mark, ©1998 by Metrowerks, Inc., all rights reserved

This month's column is the start of a series on PowerPlant. We'll start off with a short interview with the godfather of PowerPlant, Greg Dow. Look for more on PowerPlant in next month's column.

Gregory Dow pretends to be the creator and chief architect of PowerPlant at Metrowerks. In reality, he is the sock puppet of a stuffed pink bear named Snuffles, who enjoys watching television, doing backflips, and casino gambling.

Dave: How would you suggest someone get started learning PowerPlant?

Greg: The best way to learn PowerPlant is to come up with an idea for a program that you'd like to write and then begin reading The PowerPlant Book which comes with CodeWarrior. While reading the first few chapters of the book and performing the code exercises, think about how the concepts apply to your program.

After you absorb the basic concepts, create a new project for your program using one of the PowerPlant stationery projects. As you read about features in the book, try implementing them in your project. Also, concurrently read the first few chapters of the manual for Constructor, which is the visual editor for PowerPlant. If you're too impatient to finish the entire book, at least read enough to reach the point where you can build menus and windows, and add code to respond to menu selections and manipulate views.

As you continue to work on your program, look at the sample PowerPlant projects on the CodeWarrior reference CD and at the PowerPlant Contributed Class Archives on the Metrowerks web site: http://www.metrowerks.com

Very often, someone else has already done something similar to what you want to do.

Finally, participate in the Usenet newsgroup comp.sys.mac.oop.powerplant. Follow the discussions, ask your own questions, and answer other's questions if you can. John C. Daub, one of the PowerPlant programmers at Metrowerks, and I read every message on this newsgroup and frequently answer questions.

Dave: Tell me about some of the more recent additions that have made PowerPlant easier to use.

Greg: The LString class provides many routines for creating and manipulating the Pascal-style strings (the first byte is a length count) used by the Mac Toolbox. For example, it can concatenate strings, find substrings within a string, and load strings from resources.

Based on some recent postings on the PowerPlant newsgroup, I just added new functions for converting between strings and floating point numbers. These conversion routines use the Toolbox's StringToExtended and ExtendedToString functions, which have flexible formatting options that account for country-based differences such as the currency symbol and whether to use a comma or period for the decimal point.

The LRadioGroupView and LTabGroupView classes are replacements for the old LRadioGroup and LTabGroup classes. As the names imply, the new classes are views, which makes them easier to create in the Constructor visual editor. I wrote the old classes before Constructor existed, so I didn't consider the problems of dealing with non-visual elements.

Another improvement is a set of debugging classes that John Daub wrote. These classes help stress test a program and provide diagnostic information while a program is running. For example, you can have a debugging window which dynamically displays the chain of command and visual hierarchy.

Dave: How did Mac OS 8 affect PowerPlant?

Greg: Mac OS 8 introduced many changes to the standard Mac interface. The platinum appearance makes traditional controls such as buttons and check boxes look gray and puffy. And there are many new controls, progress bars, sliders, and buttons containing graphics.

PowerPlant already had versions of most of these controls based on the Apple Grayscale Appearance (AGA). Apple published the AGA specification in technical notes for developers, giving pixel-level detail on how to draw each visual element. Robin Mair wrote PowerPlant classes for these visual elements, mostly for internal use by Metrowerks for the interface of the CodeWarrior IDE (integrated development environment). Unfortunately, the Mac OS 8 versions of the visual elements did not follow the AGA specification.

Whenever Apple introduces new OS features, I need to decide how to support them in PowerPlant and whether to have backward compatibility. Backward compatibility means supporting the same or similar features on older versions of the OS.

In this case, it meant implementing all the new Mac OS 8 visual elements with code that runs on System 7. The goal was to allow PowerPlant users to write programs that look and work the same on System 7 and Mac OS 8. So, we made the AGA classes obsolete, and wrote new ones that have the Mac OS 8 look and feel. We call these the GA (Grayscale Appearance) implementations.

At the same time, we wrote classes that create the controls using the new Toolbox calls in Mac OS 8. We call these the AM (Appearance Manager) implementations.

To make a program that runs on both System 7 and Mac OS 8, a programmer can always use the GA version, or can use the hybrid approach of performing a runtime check and using the AM version if the machine supports it. The hybrid approach has more code, but has the advantage of tracking changes that Apple makes to the new Toolbox calls in future versions of Mac OS.

Dave: What about PowerPlant and Carbon?

Greg: Carbon will support a subset of the current Toolbox. Fortunately, PowerPlant does not use many Toolbox calls that Carbon won't support. Typical PowerPlant programs are over 90% Carbon-compatible according to Apple's Carbon Dater program. As Apple provides more details, we will make PowerPlant 100% Carbon-compatible.

One thing that you can do now to prepare for Carbon is to use Navigation Services instead of Standard File to present the dialogs that ask a user to open or save a file. I just finshed adding Navigation Services support to PowerPlant. You can read about Navigation Services by downloading the SDK (software development kit) from Apple's web site at http://developer.apple.com/sdk/.

Dave: What do you see as the next big directional change for PowerPlant?

Greg: Presently, PowerPlant view layouts are static. There is no built-in mechanism for creating, rearranging, and resizing views based on content or runtime conditions. Future versions of PowerPlant will have better support for changing program appearance and behavior at runtime.

As part of this runtime adaptability, visual editing will be part of the framework itself. By attaching special editor objects, you'll be able to directly manipulate visual elements while a program is running.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

ExpanDrive 6.1.8 - Access cloud storage...
ExpanDrive builds cloud storage in every application, acts just like a USB drive plugged into your Mac. With ExpanDrive, you can securely access any remote file server directly from the Finder or... Read more
ExpanDrive 6.1.8 - Access cloud storage...
ExpanDrive builds cloud storage in every application, acts just like a USB drive plugged into your Mac. With ExpanDrive, you can securely access any remote file server directly from the Finder or... Read more
DiskCatalogMaker 7.2.7 - Catalog your di...
DiskCatalogMaker is a simple disk management tool which catalogs disks. Simple, light-weight, and fast Finder-like intuitive look and feel Super-fast search algorithm Can compress catalog data for... Read more
DiskCatalogMaker 7.2.7 - Catalog your di...
DiskCatalogMaker is a simple disk management tool which catalogs disks. Simple, light-weight, and fast Finder-like intuitive look and feel Super-fast search algorithm Can compress catalog data for... Read more
Iridient Developer 3.2.1 - Powerful imag...
Iridient Developer (was RAW Developer) is a powerful image-conversion application designed specifically for OS X. Iridient Developer gives advanced photographers total control over every aspect of... Read more
BusyContacts 1.2.7 - Fast, efficient con...
BusyContacts is a contact manager for OS X that makes creating, finding, and managing contacts faster and more efficient. It brings to contact management the same power, flexibility, and sharing... Read more
MegaSeg 6.0.5 - Professional DJ and radi...
MegaSeg is a complete solution for pro audio/video DJ mixing, radio automation, and music scheduling with rock-solid performance and an easy-to-use design. Mix with visual waveforms and Magic... Read more
BusyContacts 1.2.7 - Fast, efficient con...
BusyContacts is a contact manager for OS X that makes creating, finding, and managing contacts faster and more efficient. It brings to contact management the same power, flexibility, and sharing... Read more
MegaSeg 6.0.5 - Professional DJ and radi...
MegaSeg is a complete solution for pro audio/video DJ mixing, radio automation, and music scheduling with rock-solid performance and an easy-to-use design. Mix with visual waveforms and Magic... Read more
Iridient Developer 3.2.1 - Powerful imag...
Iridient Developer (was RAW Developer) is a powerful image-conversion application designed specifically for OS X. Iridient Developer gives advanced photographers total control over every aspect of... Read more

Latest Forum Discussions

See All

The best deals on the App Store this wee...
A new week means new discounts on the App Store. This week's deals run the gamut of action-adventure titles, puzzle games, and one of the best narrative adventure series out there. If you're looking to fill out your mobile gaming library on a... | Read more »
What you need to know about Animal Cross...
We hope you've been hard at work on collecting all of those holiday items in Animal Crossing: Pocket Camp, because you're about to get a whole new list of fun things to do as the game receives its first big update sometime soon. There are a lot of... | Read more »
Reigns: Her Majesty guide - how to use e...
Ruling a kingdom isn't easy--doubly so for a queen whose every decision is questioned by the other factions seeking a slice of power. Reigns: Her Majesty builds on the original game's swipey tactics, adding items that you can use to move the story... | Read more »
The best new games we played this week -...
Friday has crept up on us once again, so it's time to honor the best new games we've played over the past few days. This past week was a pretty exciting one, with the debut of lots of beautiful new indies and some familiar faces returning to the... | Read more »
Portal Knights guide- beginner tips and...
Portal Knights is finally making the jump to iOS and Android, and it's already climbing the ranks to become the next big MMO experience on mobile. This sprawling sandbox game will let you pursue any adventure you wish, whether you want to sling... | Read more »
Reigns: Her Majesty guide - how to swipe...
Reigns: Her Majesty is storming the App Store this week, bringing more tinder-esque kingdom building to eager players everywhere. If you've played the original Reigns, you'll know that leading a kingdom is never easy. It's a careful balancing act... | Read more »
Getting Over It (Games)
Getting Over It 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: A game I madeFor a certain kind of person To hurt them. • Climb up an enormous mountain with nothing but a hammer and a pot.•... | Read more »
Reigns: Her Majesty (Games)
Reigns: Her Majesty 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »
Pocket Legends Adventures guide - how to...
Pocket Legends Adventures is a fun action adventure RPG that takes control when you want it to, but also opens itself for player input, too, if you're looking to tkae a more active role in combat. Regardless of play style, the game can be quite... | Read more »
Portal Knights (Games)
Portal Knights 1.2.4 Device: iOS Universal Category: Games Price: $4.99, Version: 1.2.4 (iTunes) Description: Craft your adventure. Forge your hero. Become the ultimate Portal Knight! | Read more »

Price Scanner via MacPrices.net

Green Monday deal: 15″ 2.8GHz MacBook Pro on...
B&H Photo has the 15″ 2.8GHz Space Gray MacBook Pro on sale for $250 off MSRP for today only as part of their Green Monday/Holiday sale. Shipping is free, and B&H charges sales tax for NY... Read more
Green Monday sale: B&H offers 12″ Apple i...
B&H Photo has 12″ iPad Pros on sale for up to $150 off MSRP as part of their Green Monday/Holiday sale. Shipping is free, and B&H charges sales tax in NY & NJ only: – 12″ 64GB WiFi iPad... Read more
Holiday deal: 21″ and 27″ Apple iMacs on sale...
MacMall has 2017 21″ and 27″ Apple iMacs on sale for up to $200 off MSRP. Shipping is free: – 21″ 2.3GHz iMac: $999 $100 off MSRP – 21″ 3.0GHz iMac: $1199 $100 off MSRP – 21″ 3.4GHz iMac: $1379 $120... Read more
Holiday deal: Apple Mac minis for up to $150...
MacMall has Mac minis on sale for up to $100 off MSRP, each including free shipping: – 1.4GHz Mac mini: $399 $100 off MSRP – 2.6GHz Mac mini: $599 $100 off MSRP – 2.8GHz Mac mini: $949 $50 off MSRP... Read more
Beats by Dr. Dre – BeatsX Earphones on sale f...
Best Buy has BeatsX Earphones on sale for $109, $40 off, on their online store. Sale price for online orders only. Choose free store pickup, if available, or choose free shipping. Read more
10″ 64GB WiFi Apple iPad Pros on sale for $59...
MacMall has 10.5″ 64GB Apple iPad Pros on sale for $599 including free shipping. That’s $50 off MSRP and among the lowest prices available for these iPads from any Apple reseller. Read more
15″ 2.2GHz MacBook Pros on sale for $200-$300...
B&H Photo has the 15″ 2.2GHz MacBook Pro available for $200 off MSRP including free shipping plus NY & NJ sales tax only: – 15″ 2.2GHz MacBook Pro (MJLQ2LL/A): $1799 $200 off MSRP Apple has... Read more
Holiday sale: 15″ MacBook Pros for $200-$420...
MacMall has 15″ MacBook Pros on sale for $220-$300 off MSRP, each including free shipping: – 15″ 2.8GHz MacBook Pro Space Gray (MPTR2LL/A): $2179, $220 off MSRP – 15″ 2.8GHz MacBook Pro Silver (... Read more
Holiday sale: 13″ MacBook Airs for up to $150...
B&H Photo has 13″ MacBook Airs on sale for $100 off MSRP as part of their Holiday sale. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 13″ 1.8GHz/128GB MacBook... Read more
The best Holiday sale prices on 13″ MacBook P...
B&H Photo has 13″ MacBook Pros on sale this weekend, with models available for $100-$150 off MSRP. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 13-inch 2.3GHz... Read more

Jobs Board

*Apple* Retail - Multiple Positions - Apple,...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Information Security - Security Data...
# Apple Information Security - Security Data Analyst Job Number: 113119545 Austin, Texas, United States Posted: 10-Nov-2017 Weekly Hours: 40.00 **Job Summary** This Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.