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.

 
AAPL
$102.50
Apple Inc.
+0.25
MSFT
$45.43
Microsoft Corpora
+0.55
GOOG
$571.60
Google Inc.
+2.40

MacTech Search:
Community Search:

Software Updates via MacUpdate

Path Finder 6.5.5 - Powerful, award-winn...
Path Finder is a file browser that combines the familiar Finder interface with the powerful utilities and innovative features. Just a small selection of the Path Finder 6 feature set: Dual pane... Read more
QuarkXPress 10.2.1 - Desktop publishing...
With QuarkXPress, you can communicate in all the ways you need to -- and always look professional -- in print and digital media, all in a single tool. Features include: Easy to Use -- QuarkXPress is... Read more
Skype 6.19.0.450 - Voice-over-internet p...
Skype allows you to talk to friends, family and co-workers across the Internet without the inconvenience of long distance telephone charges. Using peer-to-peer data transmission technology, Skype... Read more
VueScan 9.4.41 - 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
Cloud 3.0.0 - File sharing from your men...
Cloud is simple file sharing for the Mac. Drag a file from your Mac to the CloudApp icon in the menubar and we take care of the rest. A link to the file will automatically be copied to your clipboard... Read more
LibreOffice 4.3.1.2 - Free Open Source o...
LibreOffice is an office suite (word processor, spreadsheet, presentations, drawing tool) compatible with other major office suites. The Document Foundation is coordinating development and... Read more
SlingPlayer Plugin 3.3.20.505 - Browser...
SlingPlayer is the screen interface software that works hand-in-hand with the hardware inside the Slingbox to make your TV viewing experience just like that at home. It features an array of... Read more
Get Lyrical 3.8 - Auto-magically adds ly...
Get Lyrical auto-magically add lyrics to songs in iTunes. You can choose either a selection of tracks, or the current track. Or turn on "Active Tagging" to get lyrics for songs as you play them.... Read more
Viber 4.2.2 - 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
Cocktail 7.6 - General maintenance and o...
Cocktail is a general purpose utility for OS X that lets you clean, repair and optimize your Mac. It is a powerful digital toolset that helps hundreds of thousands of Mac users around the world get... Read more

Latest Forum Discussions

See All

Rhonna Designs Magic (Photography)
Rhonna Designs Magic 1.0 Device: iOS Universal Category: Photography Price: $1.99, Version: 1.0 (iTunes) Description: Want to sprinkle *magic* on your photos? With RD Magic, you can add colors, filters, light leaks, bokeh, edges,... | Read more »
This Week at 148Apps: August 25-29, 2014
Shiny Happy App Reviews   | Read more »
Qube Kingdom – Tips, Tricks, Strategies,...
Qube Kingdom is a tower defense game from DeNA. You rally your troops – magicians, archers, knights, barbarians, and others – and fight against an evil menace looking to dominate your kingdom of tiny squares. Planning a war isn’t easy, so here are a... | Read more »
Qube Kingdom Review
Qube Kingdom Review By Nadia Oxford on August 29th, 2014 Our Rating: :: KIND OF A SQUARE KINGDOMUniversal App - Designed for iPhone and iPad Qube Kingdom has cute visuals, but it’s a pretty basic tower defense game at heart.   | Read more »
Fire in the Hole Review
Fire in the Hole Review By Rob Thomas on August 29th, 2014 Our Rating: :: WALK THE PLANKUniversal App - Designed for iPhone and iPad Seafoam’s Fire in the Hole looks like a bright, 8-bit throwback, but there’s not enough booty to... | Read more »
Alien Creeps TD is Now Available Worldwi...
Alien Creeps TD is Now Available Worldwide Posted by Ellis Spice on August 29th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Dodo Master Review
Dodo Master Review By Jordan Minor on August 29th, 2014 Our Rating: :: NEST EGGiPad Only App - Designed for the iPad Dodo Master is tough but fair, and that’s what makes it a joy to play.   | Read more »
Motorsport Manager Review
Motorsport Manager Review By Lee Hamlet on August 29th, 2014 Our Rating: :: MARVELOUS MANAGEMENTUniversal App - Designed for iPhone and iPad Despite its depth and sense of tactical freedom, Motorsport Manager is one of the most... | Read more »
Motorsport Manager – Beginner Tips, Tric...
The world of Motorsport management can be an unforgiving and merciless one, so to help with some of the stress that comes with running a successful race team, here are a few hints and tips to leave your opponents in the dust. | Read more »
CalPal Update Brings the App to 2.0, Add...
CalPal Update Brings the App to 2.0, Adds Lots of New Stuff Posted by Ellis Spice on August 29th, 2014 [ permalink ] | Read more »

Price Scanner via MacPrices.net

Apple now offering refurbished 21-inch 1.4GHz...
The Apple Store is now offering Apple Certified Refurbished 21″ 1.4GHz iMacs for $929 including free shipping plus Apple’s standard one-year warranty. Their price is $170 off the cost of new models,... Read more
Save $50 on the 2.5GHz Mac mini, on sale for...
B&H Photo has the 2.5GHz Mac mini on sale for $549.99 including free shipping. That’s $50 off MSRP, and B&H will also include a free copy of Parallels Desktop software. NY sales tax only. Read more
Save up to $300 on an iMac with Apple refurbi...
The Apple Store has Apple Certified Refurbished iMacs available for up to $300 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free. These are the best prices on... Read more
The Rise of Phablets
Carlisle & Gallagher Consulting Group, a businesses and technology consulting firm focused solely on the financial services industry, has released an infographic depicting the convergence of... Read more
Bad Driver Database App Allows Good Drivers t...
Bad Driver Database 1.4 by Facile Group is a new iOS and Android app that lets users instantly input and see how many times a careless, reckless or just plain stupid driver has been added to the... Read more
Eddy – Cloud Music Player for iPhone/iPad Fre...
Ukraine based CapableBits announces the release of Eddy, its tiny, but smart and powerful cloud music player for iPhone and iPad that allows users to stream or download music directly from cloud... Read more
A&D Medical Launches Its WellnessConnecte...
For consumers and the healthcare providers and loved ones who care for them, A&D Medical, a leader in connected health and biometric measurement devices and services, has launched its... Read more
Anand Lal Shimpi Retires From AnandTech
Anand Lal Shimpi, whose AnandTech Website is famous for its meticulously detailed and thoroughgoing reviews and analysis, is packing it in. Lal Shimpi, who founded the tech site at age 14 in 1997,... Read more
2.5GHz Mac mini, Apple refurbished, in stock...
The Apple Store has Apple Certified Refurbished 2.5GHz Mac minis available for $509, $90 off MSRP. Apple’s one-year warranty is included, and shipping is free. Read more
13-inch 2.5GHz MacBook Pro on sale for $999,...
B&H Photo has the 13″ 2.5GHz MacBook Pro on sale for $999.99 including free shipping plus NY sales tax only. Their price is $100 off MSRP. Read more

Jobs Board

*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
*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
*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
*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
Senior Event Manager, *Apple* Retail Market...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global event strategy. Delivering an overarching brand story; in-store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.