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:

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.


Community Search:
MacTech Search:

Software Updates via MacUpdate

Tweetbot 2.1 - Popular Twitter client. (...
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
MacPilot 8.0 - Enable over 1,200 hidden...
MacPilot gives you the power of UNIX and the simplicity of Macintosh, which means a phenomenal amount of untapped power in your hands! Use MacPilot to unlock over 1,200 features, and access them all... Read more
Typinator 6.7 - Speedy and reliable text...
Typinator turbo-charges your typing productivity. Type a little. Typinator does the rest. We've all faced projects that require repetitive typing tasks. With Typinator, you can store commonly used... Read more
Adobe Lightroom 6.2 - Import, develop, a...
Adobe Lightroom is available as part of Adobe Creative Cloud for as little as $9.99/month bundled with Photoshop CC as part of the photography package. Lightroom 6 is also available for purchase as a... Read more
ForeverSave 2.1.4 - Universal auto-save...
ForeverSave auto-saves all documents you're working on while simultaneously doing backup versioning in the background. Lost data can be quickly restored at any time. Losing data, caused by... Read more
VueScan 9.5.27 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more
AirPort Utility 6.3.6 - Set up and manag...
Note: Most recent release available only within OS X 10.11 El Capitan update. Use AirPort Utility to set up and manage your Wi-Fi network and AirPort base stations, including AirPort Express, AirPort... Read more
Quicksilver 1.3.1 - Application launcher...
Quicksilver is a light, fast and free Mac application that gives you the power to control your Mac with keystrokes alone. Quicksilver allows you to find what you need quickly and easily, then act... Read more
Tidy Up (Five Users) 4.1.5 - Find duplic...
Tidy Up is a complete duplicate finder and disk-tidiness utility. With Tidy Up you can search for duplicate files and packages by the owner application, content, type, creator, extension, time... Read more
Mellel 3.4.3 - The word processor of cho...
Mellel is the leading word processor for OS X and has been widely considered the industry standard since its inception. Mellel focuses on writers and scholars for technical writing and multilingual... Read more

Swords & Crossbones: An Epic Pirate...
Swords & Crossbones: An Epic Pirate Story 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: | Read more »
Camel Up (Games)
Camel Up 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: | Read more »
The Martian: Bring Him Home (Games)
The Martian: Bring Him Home 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Based on the best selling novel and critically acclaimed film, THE MARTIAN tells the story of Astronaut Mark... | Read more »
This Week at 148Apps: September 21-30, 2...
Leap Into Fall With 148Apps How do you know what apps are worth your time and money? Just look to the review team at 148Apps. We sort through the chaos and find the apps you're looking for. The ones we love become Editor’s Choice, standing out above... | Read more »
Tweetbot 4 for Twitter (Social Networki...
Tweetbot 4 for Twitter 4.0 Device: iOS Universal Category: Social Networking Price: $4.99, Version: 4.0 (iTunes) Description: *** 50% off for a limited time. *** | Read more »
Mori (Games)
Mori 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Stop, rewind and unwind with Mori. Time is always running, take a moment to take control. Mori is an action puzzle game about infinitely... | Read more »
100 Years' War (Games)
100 Years' War 1.0 Device: iOS Universal Category: Games Price: $3.99, Version: 1.0 (iTunes) Description: | Read more »
Tower in the Sky (Games)
Tower in the Sky 0.0.60 Device: iOS Universal Category: Games Price: $1.99, Version: 0.0.60 (iTunes) Description: | Read more »
hocus. (Games)
hocus. 1.0.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0.0 (iTunes) Description: New, polished, mind-bending, minimal puzzle game with dozens of levels and extra-ordinary design Features:- Beautifully crafted... | Read more »
Mos Speedrun 2 (Games)
Mos Speedrun 2 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Mos is back, in her biggest and most exciting adventure ever! Wall-jump to victory through 30 mysterious, action packed levels... | Read more »

Price Scanner via

13-inch 2.5GHz MacBook Pro (refurbished) avai...
Apple has Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.5GHz MacBook Pros... Read more
27-inch 3.2GHz iMac on sale for $1689, save $...
Adorama has the 27″ 3.2GHz iMac on sale for $1689 including free shipping plus NY & NJ sales tax only. Their price is $110 off MSRP. Read more
12-inch Retina MacBooks on sale for up to $12...
B&H Photo has 12″ Retina MacBooks in stock today and on sale for up to $120 off MSRP. B&H will include free shipping, and there is NY sales tax only: - 12″ 1.1GHz Gray Retina MacBook: $1224 $... Read more
Tablets Shaping Up for Growth in 2016 – Strat...
Observing that Apple, Samsung, and Microsoft have refocused what tablet computers can do, market analysis firm Strategy Analytics believes there is immense opportunity for new and replacement sales... Read more
Apple Interbrand’s Number One Most Valuable G...
Apple and Google hold aced #1 and #2 spots respectively in Interbrand’s 2015 Best Global Brands Report, leading all tech brands that now comprise more than a third of the entire rankings value.... Read more
Apple offering refurbished 2015 13-inch Retin...
Apple is offering Certified Refurbished 2015 13″ Retina MacBook Pros for up to $270 (15%) off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: -... Read more
Apple refurbished 2015 MacBook Airs available...
Apple has Certified Refurbished 2015 11″ and 13″ MacBook Airs (the latest models), available for up to $180 off the cost of new models. An Apple one-year warranty is included with each MacBook, and... Read more
Adobe Photoshop Elements 14 Gets Haze Removal...
The latest iteration of Adobe’s powerful consumer image editing appliction Photoshop Elements 14 analyzes your photo and removes background haze, so your shot looks sharp all the way to the horizon... Read more
Apple refurbished 15-inch Retina MacBook Pros...
Apple has Certified Refurbished 2015 15″ Retina MacBook Pros available for up to $380 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: - 15″ 2... Read more
21-inch iMacs on sale for up to $120 off MSRP
B&H Photo has 21″ iMacs on sale for up to $100 off MSRP including free shipping plus NY sales tax only: - 21″ 1.4GHz iMac: $1029.99 $70 off - 21″ 2.7GHz iMac: $1229 $70 off - 21″ 2.9GHz iMac: $... Read more

Jobs Board

Touch Validation Design (EE) - *Apple* Watc...
**Job Summary** Help launch next-generation Touch Technologies in Apple products. The Touch Technology team develops cutting-edge Touch solutions and technologies that Read more
WW Sales Strategy & Program Manager, *Ap...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
*Apple* TV Product Design Internship (Spring...
…the mechanical design effort associated with creating world-class products with the Apple TV PD Group. Responsibilities will include working closely with manufacturing, Read more
Product Design Engineer - *Apple* Watch - A...
**Job Summary** Product Design Engineer - WATCH ( Apple Watch) Be an integral part of a small and visible team of world-class Mechanical Engineers making Apple 's Read more
Senior Software System App Engineer, *Apple*...
**Job Summary** The Apple Watch system application team is looking for great software engineers who are comfortable working across all levels of the software stack. From Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.