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

Adobe Acrobat Reader 20.012.20048 - View...
Adobe Acrobat Reader allows users to view PDF documents. You may not know what a PDF file is, but you've probably come across one at some point. PDF files are used by companies and even the IRS to... Read more
Adobe Acrobat DC 20.012.20048 - Powerful...
Acrobat DC is available only as a part of Adobe Creative Cloud, and can only be installed and/or updated through Adobe's Creative Cloud app. Adobe Acrobat DC with Adobe Document Cloud services is... Read more
Box Sync 4.0.8009 - Online synchronizati...
Box Sync gives you a hard-drive in the Cloud for online storage. Note: You must first sign up to use Box. What if the files you need are on your laptop -- but you're on the road with your iPhone? No... Read more
Daylite 2020.36.1 - Dynamic business org...
Daylite helps businesses organize themselves with tools such as shared calendars, contacts, tasks, projects, notes, and more. Enable easy collaboration with features such as task and project... Read more
Catalina Cache Cleaner 15.0.6 - Clear ca...
Catalina Cache Cleaner is an award-winning general-purpose tool for macOS X. CCC makes system maintenance simple with an easy point-and-click interface to many macOS X functions. Novice and expert... Read more
Final Cut Pro X 10.4.10 - Professional v...
Final Cut Pro X is a professional video editing solution. Completely redesigned from the ground up, Final Cut Pro adds extraordinary speed, quality, and flexibility to every part of the post-... Read more
Civilization VI 1.3.4 - Next iteration o...
Civilization® VI is the award-winning experience. Expand your empire across the map, advance your culture, and compete against history’s greatest leaders to build a civilization that will stand the... Read more
iTubeDownloader 6.5.23 - Easily download...
iTubeDownloader is a powerful-yet-simple YouTube downloader for the masses. Because it contains a proprietary browser, you can browse YouTube like you normally would. When you see something you want... Read more
iMovie 10.1.16 - Edit personal videos an...
With an all-new design, Apple iMovie lets you enjoy your videos like never before. Browse your clips more easily, instantly share your favorite moments, and create beautiful HD movies and Hollywood-... Read more
macOS Catalina 10.15.7 - An Operating Sy...
macOS Catalina gives you more of everything you love about Mac. Experience three all-new media apps: Apple Music, Apple TV, and Apple Podcasts. Locate a missing Mac with the new Find My app. And now... Read more

Latest Forum Discussions

See All

Distract Yourself With These Great Mobil...
There’s a lot going on right now, and I don’t really feel like trying to write some kind of pithy intro for it. All I’ll say is lots of people have been coming together and helping each other in small ways, and I’m choosing to focus on that as I... | Read more »
BTS Universe Story, the social game that...
Netmarble's highly anticipated social game, BTS Universe Story, is available now for iOS and Android. It's the second collaboration between the hugely successful mobile developer and the K-pop superstars following BTS World. [Read more] | Read more »
The 5 Best Mobile Games Like Hades
Supergiant Games finally released Hades upon the world this week, and we’re loving it. The game plays to all of the studio’s strengths while still retaining a strong sense of identity. It also just so happens to play rather well using the Steam... | Read more »
A Year of Apple Arcade: The Good, The Ba...
Apple Arcade has persisted for just over a year at this point, and although that means I've been busy ranking and re-ranking every game on the service for just about as long, I haven't done much reflection on the service as a whole. [Read more] | Read more »
Animal Restaurant anniversary event team...
Animal idle simulator Animal Restaurant is celebrating its first-year anniversary with a crossover event with popular YouTube series Aaron’s Animals. [Read more] | Read more »
Raziel: Dungeon Arena is a hack 'n...
Raziel: Dungeon Arena is available now on mobile and will appeal to fans of both comic books and old school dungeon crawlers. Not only will you hack 'n' slash your way through mobs of enemies but there's also fully-narrated animated comic to enjoy... | Read more »
Steam Link Spotlight - Hades
Steam Link Spotlight is a feature where we look at PC games that play exceptionally well using the Steam Link app. Our last entry was on Disco Elysium. Read about how it plays using Steam Link over here. | Read more »
Microsoft has acquired ZeniMax Media and...
In the latest of a series of blockbuster moves, Microsoft has now acquired Zenimax Media and its subsidiary, Bethesda Softworks, for $7.5 billion. [Read more] | Read more »
Infinity Mechs is an upcoming idle game...
Indie developer SkullStar studio has announced an upcoming idle mech game called Infinity Mechs. It draws inspiration from the mobile game Iron Saga and has been officially licensed by Game Duchy. It's set to launch for both iOS and Android on... | Read more »
PUBG Mobile Lite's latest update se...
PUBG Mobile Lite, the streamlined version of the popular battle royale that's designed to work on less powerful devices, sees the return of a popular game variant today, Survive Till Dawn mode. It arrives as part of the 0.19.0 content update. [... | Read more »

Price Scanner via MacPrices.net

Clearance 8-core iMac Pro available for $3819...
Apple has Certified Refurbished, clearance, 27″ 3.2GHz 8-Core iMac Pros available $3819 including free shipping. Their price is $1180 off the original MSRP of new models. A standard Apple one-year... Read more
How The Upcoming Mac Transition To Apple Sili...
FEATURE: 09.25.20 – Apple’s plan to transition all of its desktop and notebook computers away from Intel processors to Apple silicon, chips designed by the company itself, has been eclipsed by the... Read more
New low price! Apple Watch SE for only $269
B&H Photo is reporting limited stock of Apple’s new Apple Watch SE GPS models for $10 off MSRP and including free shipping. Their $269 price for the 40mm model is the lowest price we’ve seen so... Read more
Lowest price anywhere: New 13″ 2.0GHz MacBook...
Amazon has new 2020 13″ 2.0GHz/512GB MacBook Pros with 10th generation Intel processors back in stock on sale today for $200 off Apple’s MSRP. Shipping is free. Be sure to purchase the MacBook Pro... Read more
Apple Pro Display XDR with Nano-Texture Glass...
Amazon Apple Premier Partner GatorTec has the Apple Pro Display XDR with Nano-Texture Glass on sale for $5599 shipped, on Amazon. Their price is $400 off Apple’s MSRP, and it’s the cheapest price... Read more
Get a 2019 13″ MacBook Air for only $779 toda...
Apple has clearance, Certified Refurbished, 2019 13″ 1.6GHz/128GB MacBook Airs available again for $779. Each MacBook features a new outer case, comes with a standard Apple one-year warranty, and is... Read more
2020 11″ iPad Pros on sale today for $50-$75...
Apple reseller Expercom has new 2020 11″ Apple iPad Pros on sale for $50-$75 off MSRP, with prices starting at $749. These are the same iPad Pros sold by Apple in their retail and online stores: – 11... Read more
Apple has restocked 2020 13″ MacBook Airs sta...
Apple has restocked Certified Refurbished 2020 13″ MacBook Airs starting at only $849 and up to $200 off the cost of new Airs. Each MacBook features a new outer case, comes with a standard Apple one-... Read more
Apple’s new 8th generation 10.2″ iPads are on...
Amazon is discounting new 2020 8th generation 10.2″ Apple iPads by up to $35 off MSRP with prices starting at only $299. Shipping is free. These are the same iPads sold by Apple in their retail and... Read more
Today on Woot: Apple refurbished 16″ MacBook...
Amazon-owned Woot has Apple refurbished 16″ MacBook Pros available today for up to $605 off the cost of new models. Shipping is free for Prime members: – 16″ 6-Core MacBook Pros: $1874.99 $525 off... Read more

Jobs Board

Freelance *Apple* Technology Journalist - V...
…freelance basis. Valnet Inc. is looking for journalists with strong knowledge of Apple technology for our website MakeUseOf.com MakeUseOf is one of the largest Read more
*Apple* Certified Macintosh Technician - Exc...
Apple Certified Macintosh Technician Summary Title: Apple Certified Macintosh Technician ID:350 Department:All Location:Bethesda, MD Description Apple Read more
Security Officer ($23.00/Hourly) - *Apple*...
**Security Officer \($23\.00/Hourly\) \- Apple Store** **Description** About NMS Built on a culture of safety and integrity, NMSdelivers award\-winning, integrated Read more
Security Officer ($23.00/Hourly) - *Apple*...
**Security Officer \($23\.00/Hourly\) \- Apple Store** **Description** About NMS Built on a culture of safety and integrity, NMSdelivers award\-winning, integrated Read more
*Apple* Certified Macintosh Technician - Exc...
Apple Certified Macintosh Technician Summary Title: Apple Certified Macintosh Technician ID:350 Department:All Location:Falls Church, VA Description Apple Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.