TweetFollow Us on Twitter

Apr 96 Factory Floor
Volume Number:12
Issue Number:4
Column Tag:From The Factory Floor

From the Factory Floor

By Dave Mark

In this month’s Factory Floor, we’ll meet Greg Dow. Greg designed and wrote PowerPlant, the next generation framework from Metrowerks. Before we get to the interview, I wanted to take a sec and thank Jim Trudeau for all his help in putting this interview together. Cognac and cigars on me at WWDC, Jim!

Dave: Greg, since not all of our readers have a background in object programming, let’s start things off by defining a few terms. What is the difference between a class library and a framework?

Greg: People often use the terms interchangeably. However, I think of a class library as a collection of utilities and a framework as a structure for building programs.

With a class library, you are in control. You design the program structure and use library classes where convenient. For example, you can use the ANSI C++ streams class library to handle file I/O.

With a framework, the framework is in control. You usually start with a “do nothing” program provided by the framework and add your own code. The framework calls your code at the appropriate time.

PowerPlant is a framework, but it also has families of utility classes that you can use independently.

Dave: Why would a C programmer want to move to C++ and PowerPlant? What are the advantages?

Greg: Using PowerPlant lets you build upon code written by other programmers. It’s code that you don’t have to write yourself. PowerPlant classes handle mundane tasks such as menu and window management, as well as more advanced features such as Apple events and threads. By not having to start from scratch, you have more time to concentrate on the unique features of your program.

Another big advantage is Constructor, which lets you graphically lay out the visual elements of your PowerPlant programs. PowerPlant can create a window and its contents from information edited in Constructor, so it’s possible to create a program that displays items such as scrolling pictures, text, and buttons without ever writing a line of code.

Dave: Once someone has learned the basics of C++ and object programming, how do they pick up on PowerPlant?

Greg: The first thing everyone should do is read The PowerPlant Book, which is part of the Inside PowerPlant for CW8 manual that comes with CW8. This book, written by Jim Trudeau, is an excellent guide to understanding and using PowerPlant.

After that, they should start using PowerPlant. Look over the sample programs. Run the samples and use the source debugger to single-step through some of the code to follow the flow of control. For example, set a breakpoint in the main event loop, then hit a key and follow the resulting sequence of calls to see how PowerPlant handles it.

Finally, talk with other people who use PowerPlant by getting a modem and an Internet account. Read the Usenet newsgroup comp.sys.mac.programmer.codewarrior. (A new group, comp.sys.oop.powerplant, will probably form soon.) Metrowerks also has an active forum on America Online. And join the PowerPlant Dream Team.

Dave: What exactly is the PowerPlant Dream Team? What do they do? How do you go about joining?

Greg: The PowerPlant Dream Team is an organization of developers interested in learning PowerPlant in a team-based environment. It started as a study group formed by Stephen Jovanovic, but has grown to over 200 people. A small subset of the PP Dream Team wrote an LNewTextEdit class that supports styled text and drag-and-drop editing. Very cool. To find out more about the PP Dream Team, visit their Web page at: http://petrified.cic.net/powerplant-dt/

Dave: Tell me about the PowerPlant architecture.

Greg: One of my favorite toys is Lego™ blocks. You can build complex structures by combining simple parts. PowerPlant follows this approach by using a mixin architecture, where the base classes are relatively simple, and subclasses use multiple inheritance to combine features.

For example, the EditField class multiply inherits from Pane (so it can draw and handle mouse clicks), Commander (so it can handle keystrokes and menu commands), and Periodical (so it gets time during the event loop to flash the insertion point).

I also tried to eliminate dependencies between classes so that you can use them separately. In particular, PowerPlant is not just an application framework. You can use PowerPlant to build code resources such as HyperCard XCMDs and control panels, or even integrate PowerPlant classes into existing procedural programs.

Dave: What is your favorite part of PowerPlant?

Greg: Other than the overall design, my favorite feature of PowerPlant is the Drag Manager support. Drag and drop is cool, and it’s one of the better implemented features in the Mac OS. The API is clean and simple. It took me only two days (and three classes) to implement all the basic support.

Dave: Tell me about your life before Metrowerks.

Greg: I have a Bachelor’s degree from MIT in chemical engineering, and I spent a few years at UC Berkeley working on a Ph.D., also in chemical engineering, that I never completed. My thesis research was computer modeling of coal gasification reactors, and I did a lot of scientific programming in FORTRAN.

During that time, I became more interested in programming than in chemical engineering, so I started taking computer science classes. In July 1987, I bought my first personal computer, a Mac SE. A few months later, I dropped out of school to devote my time to learning Mac programming.

One of my first projects was writing a generic application shell. I kept tinkering with this shell, and it eventually turned into version 1.0 of the THINK Class Library (TCL), which Symantec shipped with THINK C in July 1989.

Dave: How did you get hooked up with Metrowerks? Did Greg Galanos recruit you? Was the company already building CodeWarrior when you started work on PowerPlant?

Greg: My first contact with Metrowerks was actually with Jean Belanger, sometime before the MacWorld Expo in January 1992. I lead the Programmers Group at BMUG (Berkeley Macintosh Users Group), and Jean called up looking for some volunteers to staff his booth at the show. At the time, Metrowerks was selling Pascal and Modula 2 compilers for the education market.

I never actually met anyone from Metrowerks then, but a year later John McEnerney asked me if I was interested in writing a new C++ framework for some little Canadian company. John is the PowerPC Compiler Architect for Metrowerks, and he worked at Symantec when I wrote TCL 1.0.

I met with Greg Galanos and started working on PowerPlant in March 1993. Codewarrior as we know it did not exist. There was a prototype C compiler and environment. It fit on a floppy disk.

Dave: A lot of people ask about cross-platform development using PowerPlant. I know that the Microsoft Foundation Classes (MFC) are the de facto standard on the Windows side. What’s the best way to get a PowerPlant-based application ported to run under Windows?

Greg: I know that a lot of people are interested in developing programs that run on both the Mac and Windows. However, PowerPlant is a Mac-only framework. Metrowerks has no intention of developing a Windows version of PowerPlant.

To port code to Windows, I recommend that people investigate Mac2Win from Altura Software. The Mac2Win libraries emulate the Mac Toolbox on Windows. Metrowerks is using these libraries to port portions of the CodeWarrior environment to Windows.

Dave: What are your future plans for PowerPlant?

Greg: My future work with PowerPlant will concentrate on three major areas: (1) Visual programming; (2) OpenDoc; and (3) Copland.

Right now, you can specify the static layout of interface elements using PowerPlant Constructor. Future versions of Constructor will let you specify runtime relationships between objects. For example, adding Attachments to Panes and linking Broadcasters to Listeners.

If you know what you’re doing, you can use PowerPlant today to develop both OpenDoc parts and OpenDoc container applications. In fact, a few programmers (besides me) have already done so. However, it’s not easy. Future versions of PowerPlant will make it as easy to create an OpenDoc part as it is to create a stand-alone application.

Copland, the next major version of the Mac OS, will provide many new capabilities and interface elements. I intend to keep PowerPlant on the leading edge of Mac development by supporting these new features as soon as possible.

 
AAPL
$524.75
Apple Inc.
-6.95
MSFT
$39.69
Microsoft Corpora
-0.30
GOOG
$526.94
Google Inc.
-7.87

MacTech Search:
Community Search:

Software Updates via MacUpdate

MacFamilyTree 7.1.6 - Create and explore...
MacFamilyTree gives genealogy a facelift: it's modern, interactive, incredibly fast, and easy to use. We're convinced that generations of chroniclers would have loved to trade in their genealogy... Read more
EtreCheck 1.9.9 - For troubleshooting yo...
EtreCheck is a simple little app to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support... Read more
TeamViewer 9.0.28116 - Establish remote...
TeamViewer gives you remote control of any computer or Mac over the Internet within seconds, or can be used for online meetings. Find out why more than 200 million users trust TeamViewer! Free for... Read more
Viber 4.1.0 - Send messages and make cal...
Viber lets you send free messages and make free calls to other Viber users, on any device and network, in any country! Viber syncs your contacts, messages and call history with your mobile device,... Read more
Apple iOS 7.1.1 - The latest version of...
The latest version of iOS can be downloaded through iTunes. Apple iOS 7 brings an all-new design and all-new features. Simplicity Simplicity is often equated with minimalism. Yet true simplicity is... Read more
1Password 4.3 - Powerful password manage...
1Password is a password manager that uniquely brings you both security and convenience. It is the only program that provides anti-phishing protection and goes beyond password management by adding Web... Read more
Lens Blur 1.3.0 - True out-of-focus boke...
Let Lens Blur transform your existing photo into true SLR-quality out-of-focus bokeh effect! Everyone needs a gorgeous personalized background for a social profile, blog, Web/UI design, presentation... Read more
VMware Fusion 6.0.3 - Run Windows apps a...
VMware Fusion allows you to create a Virtual Machine on your Mac and run Windows (including Windows 8.1) and Windows software on your Mac. Run your favorite Windows applications alongside Mac... Read more
BitTorrent Sync 1.3.93 - Sync files secu...
BitTorrent Sync allows you to sync unlimited files between your own devices, or share a folder with friends and family to automatically sync anything. File transfers are encrypted. Your information... Read more
Tweetbot 1.5.1 - Popular iOS twitter cli...
Tweetbot is a full-featured OS X Twitter client with a lot of personality. Whether it's the meticulously-crafted interface, sounds and animation, or features like multiple timelines and column views... Read more

Latest Forum Discussions

See All

Leo's Fortune (Games)
Leo's Fortune 1.0.2 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.2 (iTunes) Description: Leo’s Fortune is a platform adventure game where you hunt down the cunning and mysterious thief that stole your gold.... | Read more »
iOOTP Baseball 2014 Edition Review
iOOTP Baseball 2014 Edition Review By Carter Dotson on April 23rd, 2014 Our Rating: :: SOLID CONTRACTUniversal App - Designed for iPhone and iPad The long-running baseball simulator returns to mobile with a much-improved entry in... | Read more »
148Apps Live on Twitch: Soccer Rally 2 w...
Soccer Rally 2 from IceFlame Games officially releases on Thursday, bringing perhaps the most realistic car soccer action to the App Store since the original released. David Deacon of IceFlame Games will join us on our Twitch channel to talk about... | Read more »
NightCap Pro Review
NightCap Pro Review By Jennifer Allen on April 23rd, 2014 Our Rating: :: NIGHT TIME SNAPPINGUniversal App - Designed for iPhone and iPad Taking photos in low light conditions has always been tricky, but NightCap Pro has just made... | Read more »
Plague Inc. has Mutated Yet Again – We’r...
Plague Inc. has Mutated Yet Again – We’re All Doomed Even More than Usual Posted by Rob Rich on April 23rd, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Intake from Cipher Prime Coming to iPad...
Cipher Prime’s Inake is coming to iPad on May 1, as exclusively revealed yesterday on our Twitch channel. | Read more »
Gusto Email App Review
Gusto Email App Review By Jennifer Allen on April 23rd, 2014 Our Rating: :: POWERFUL SEARCHINGiPhone App - Designed for the iPhone, compatible with the iPad Focusing on making it easy to browse files and photos attached to your... | Read more »
New Update Adds Two More Cars to Fishlab...
New Update Adds Two More Cars to Fishlabs’ Sports Car Challenge 2 Posted by Rob Rich on April 23rd, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
What’s Up with Readdle? – The Verge Exam...
What’s Up with Readdle? | Read more »
Knight Saves Queen Review
Knight Saves Queen Review By Jennifer Allen on April 23rd, 2014 Our Rating: :: PUZZLING MASH UPUniversal App - Designed for iPhone and iPad Mixing up puzzle elements with Chess-based sensibilities is a fun move for this simplistic... | Read more »

Price Scanner via MacPrices.net

iPad Sales “Lull” A Reality Correction Of Unm...
I have lots of time for Jean-Louis Gassée, the former Apple Computer executive (1981 to 1990) who succeeded Steve Jobs as head of Macintosh development when the latter was dismissed in 1985. Mr.... Read more
Apple Makes OS X Betas Available To All – Wit...
Apple’s OS X Beta Seed Program, which lets you install the latest pre-release builds, try it out, and submit your feedback, is now open to anyone who wants to sign on rather than to developers and... Read more
Apple Releases iOS 7.1.1 Update
The latest iOS 7.1.1 update contains improvements, bug fixes and security updates, including: • Further improvements to Touch ID fingerprint recognition • Fixes a bug that could impact keyboard... Read more
Logitech Announces Thinner, Lighter, More Fle...
Logitech has announced an update to its Ultrathin for iPad Air, iPad mini and iPad mini with Retina display, improving the flexibility and design of its award-winning predecessor with an even thinner... Read more
Logitech Introduces Hinge, Big Bang and Turna...
Logitech has announced expansion of its tablet product line with three new cases – the Logitech Hinge, the Logitech Big Bang and the Logitech Turnaround – each for the iPad Air, iPad mini and iPad... Read more
WaterField’s Rough Rider Leather Messenger Ba...
WaterField Designs have announced the new 15-inch size of their popular Rough Rider leather messenger bag, a vintage-looking bag that combines Old West charm and ruggedness with distinctly modern... Read more
New Mac Pro on sale, save $100 on the 4-Core...
J&R has the new 4-Core Mac Pro in stock today and on sale for $2899 including free shipping plus NY sales tax only. Their price is $100 off MSRP, and it’s the lowest price available for this... Read more
Apple refurbished iMacs available for up to $...
The Apple Store has Apple Certified Refurbished 2013 iMacs available for up to $300 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free. - 27″ 3.4GHz iMac – $1699... Read more
Updated iPad Price Trackers
We’ve updated our iPad Price Tracker and our iPad mini Price Tracker with the latest information on prices and availability from Apple and other resellers. Using a mobile device? We’ve also updated... Read more
Everything You Wanted To Know And Probably Mo...
Macworld UK’s Lou Hattersley takes a look inside Apple’s A7 System On Chip (SoC) , noting that its processor module is much more powerful than other smartphone chipsets. He notes that the A7 was a... Read more

Jobs Board

*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
Position Opening at *Apple* - Apple (United...
…customers purchase our products, you're the one who helps them get more out of their new Apple technology. Your day in the Apple Store is filled with a range of Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Inc. Research Data Specialist - Appl...
…of Worldwide Market Research & Intelligence. The team is responsible for conducting Apple branded consumer market research. It is also responsible for analyzing data Read more
*Apple* Automotive Parts Department position...
Apple Automotive is one of the fastest growing dealer…and it shows. Consider making the switch to the Apple Automotive Group today! At Apple Automotive, we Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.