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
$100.96
Apple Inc.
-0.83
MSFT
$47.52
Microsoft Corpora
+0.84
GOOG
$596.08
Google Inc.
+6.81

MacTech Search:
Community Search:

Software Updates via MacUpdate

Audio Hijack Pro 2.11.3 - Record and enh...
Audio Hijack Pro drastically changes the way you use audio on your computer, giving you the freedom to listen to audio when you want and how you want. Record and enhance any audio with Audio Hijack... Read more
Airfoil 4.8.9 - Send audio from any app...
Airfoil allows you to send any audio to AirPort Express units, Apple TVs, and even other Macs and PCs, all in sync! It's your audio - everywhere. With Airfoil you can take audio from any... Read more
WhatRoute 1.13.0 - Geographically trace...
WhatRoute is designed to find the names of all the routers an IP packet passes through on its way from your Mac to a destination host. It also measures the round-trip time from your Mac to the... Read more
Chromium 37.0.2062.122 - Fast and stable...
Chromium is an open-source browser project that aims to build a safer, faster, and more stable way for all Internet users to experience the web. FreeSMUG-Free OpenSource Mac User Group build is... Read more
Attachment Tamer 3.1.14b9 - Take control...
Attachment Tamer gives you control over attachment handling in Apple Mail. It fixes the most annoying Apple Mail flaws, ensures compatibility with other email software, and allows you to set up how... Read more
Duplicate Annihilator 5.0 - Find and del...
Duplicate Annihilator takes on the time-consuming task of comparing the images in your iPhoto library using effective algorithms to make sure that no duplicate escapes. Duplicate Annihilator detects... Read more
jAlbum Pro 12.2 - Organize your digital...
jAlbum Pro has all the features you love in jAlbum, but comes with a commercial license. With jAlbum, you can create gorgeous custom photo galleries for the Web without writing a line of code!... Read more
jAlbum 12.2 - Create custom photo galler...
With jAlbum, you can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly, with pro results Simply drag and drop photos into groups, choose a design... Read more
Quicken 2015 2.0.4 - Complete personal f...
Quicken 2015 helps you manage all your personal finances in one place, so you can see where you're spending and where you can save. Quicken automatically categorizes your financial transactions,... Read more
iMazing 1.0 - Complete iOS device manage...
iMazing (formerly DiskAid) is the ultimate iOS device manager with capabilities far beyond what iTunes offers. With iMazing and your iOS device (iPhone, iPad, or iPod), you can: Copy music to and... Read more

Latest Forum Discussions

See All

View Source – HTML, JavaScript and CSS...
View Source – HTML, JavaScript and CSS 1.0 Device: iOS Universal Category: Utilities Price: $.99, Version: 1.0 (iTunes) Description: View Source is an app plus an iOS 8 Safari extension that makes it easy to do one key web developer... | Read more »
Avenged Sevenfold’s Hail To The King: De...
Avenged Sevenfold’s Hail To The King: Deathbat is Coming to iOS on October 16th Posted by Jessica Fisher on September 19th, 2014 [ permalink ] Just in time for Halloween, on October 16 Avenged Sevenfold will be launching | Read more »
Talisman Has Gone Universal – Can Now be...
Talisman Has Gone Universal – Can Now be Played on the iPhone Posted by Jessica Fisher on September 19th, 2014 [ permalink ] | Read more »
Tap Army Review
Tap Army Review By Jennifer Allen on September 19th, 2014 Our Rating: :: SHOOT EM ALLUniversal App - Designed for iPhone and iPad Mindless but fun, Tap Army is a lane-based shooter that should help you relieve some stress.   | Read more »
Monsters! Volcanoes! Loot! Epic Island f...
Monsters! Volcanoes! Loot! | Read more »
Plunder Pirates: Tips, Tricks, Strategie...
Ahoy There, Seadogs: Interested in knowing our thoughts on all this plundering and pirating? Check out our Plunder Pirates Review! Have you just downloaded the rather enjoyable pirate-em-up Plunder Pirates and are in need of some assistance? Never... | Read more »
Goat Simulator Review
Goat Simulator Review By Lee Hamlet on September 19th, 2014 Our Rating: :: THE GRUFFEST OF BILLY GOATSUniversal App - Designed for iPhone and iPad Unleash chaos as a grumpy goat in this humorous but short-lived casual game.   | Read more »
A New and Improved Wunderlist is Here fo...
A New and Improved Wunderlist is Here for iOS 8 Posted by Jessica Fisher on September 19th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Evernote Update for iOS 8 Adds Web Clipp...
Evernote Update for iOS 8 Adds Web Clipping, Quick Notes, and More Posted by Ellis Spice on September 19th, 2014 [ permalink ] | Read more »
Apple Names Ultimate Productivity Bundl...
Apple Names Ultimate Productivity Bundle by Readdle as the Essential Bundle on the App Store Posted by Jessica Fisher on September 19th, 2014 [ permalink | Read more »

Price Scanner via MacPrices.net

iFixIt Tears Down iPhone 6; Awards Respectabl...
iFixit notes that even the smaller 4.7″ iPhone 6 is a giant among iPhones; so big that Apple couldn’t fit it into the familiar iPhone form factor. In a welcome reversal of a recent trend to more or... Read more
Phone 6 Guide – Tips Book For Both iPhone 6...
iOS Guides has announced its latest eBook: iPhone 6 Guide. Brought to you by the expert team at iOS Guides, and written by best-selling technology author Tom Rudderham, iPhone 6 Guide is packed with... Read more
How to Upgrade iPhone iPad to iOS 8 without D...
PhoneClean, a iPhone cleaner utility offered by iMobie Inc., reveals a solution for upgrading iPhone and iPad to iOS 8 without deleting photos, apps, the new U2 album or anything. Thanks to more than... Read more
Inpaint 6 – Photo Retouching Tool Gets Faster...
TeoreX has announced Inpaint 6, a simple retouching tool for end users that helps remove scratches, watermarks, and timestamps as well as more complex objects like strangers, unwanted elements and... Read more
Worldwide PC Monitor Market Sees Growth in To...
Worldwide PC monitor shipments totaled 32.5 million units in the second quarter of 2014 (2Q14), a year-over-year decline of -2.9%, according to the International Data Corporation (IDC) Worldwide... Read more
Updated Price Trackers
We’ve updated our Mac Price Trackers with the latest information on prices, bundles, and availability on systems from Apple’s authorized internet/catalog resellers: - 15″ MacBook Pros - 13″ MacBook... Read more
Mac Pros available for up to $260 off MSRP
Adorama has Mac Pros on sale for up to $260 off MSRP. Shipping is free, and Adorama charges sales tax in NY & NJ only: - 4-core Mac Pro: $2839.99, $160 off MSRP - 6-core Mac Pro: $3739.99, $260... Read more
13-inch 2.6GHz/256GB Retina MacBook Pros avai...
B&H Photo has the 13″ 2.6GHz/256GB Retina MacBook Pro on sale for $1379 including free shipping plus NY sales tax only. Their price is $120 off MSRP. Read more
Previous-generation 15-inch 2.0GHz Retina Mac...
B&H Photo has leftover previous-generation 15″ 2.0GHz Retina MacBook Pros now available for $1599 including free shipping plus NY sales tax only. Their price is $400 off original MSRP. B&H... Read more
21″ 2.7GHz iMac available for $1179, save $12...
Adorama has 21″ 2.7GHz Hawell iMacs on sale for $1179.99 including free shipping. Their price is $120 off MSRP. NY and NJ sales tax only. Read more

Jobs Board

Position Opening at *Apple* - Apple (United...
**Job Summary** At the Apple Store, you connect business professionals and entrepreneurs with the tools they need in order to put Apple solutions to work in their Read more
Position Opening at *Apple* - Apple (United...
**Job Summary** The Apple Store is a retail environment like no other - uniquely focused on delivering amazing customer experiences. As an Expert, you introduce people Read more
Position Opening at *Apple* - Apple (United...
**Job Summary** As businesses discover the power of Apple computers and mobile devices, it's your job - as a Solutions Engineer - to show them how to introduce these Read more
Position Opening at *Apple* - Apple (United...
…Summary** As a Specialist, you help create the energy and excitement around Apple products, providing the right solutions and getting products into customers' hands. You Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.