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

Parallels Desktop 13.3.0 - Run Windows a...
Parallels allows you to run Windows and Mac applications side by side. Choose your view to make Windows invisible while still using its applications, or keep the familiar Windows background and... Read more
Bookends 13.0.6 - Reference management a...
Bookends is a full-featured bibliography/reference and information-management system for students and professionals. Bookends uses the cloud to sync reference libraries on all the Macs you use.... Read more
macOS 10.13.3 Supplemental Update 1.0 -...
macOS High Sierra Supplemental Update includes security improvements to Safari and WebKit to mitigate the effects of Spectre. Version 1.0: Update fixes an issue where using certain character... Read more
Chromium 64.0.3282.167 - 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. Version 64.0.3282.167: [806388] High CVE-2018-6056:... Read more
Chromium 64.0.3282.167 - 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. Version 64.0.3282.167: [806388] High CVE-2018-6056:... Read more
Parallels Desktop 13.3.0 - Run Windows a...
Parallels allows you to run Windows and Mac applications side by side. Choose your view to make Windows invisible while still using its applications, or keep the familiar Windows background and... Read more
Bookends 13.0.6 - Reference management a...
Bookends is a full-featured bibliography/reference and information-management system for students and professionals. Bookends uses the cloud to sync reference libraries on all the Macs you use.... Read more
macOS 10.13.3 Supplemental Update 1.0 -...
macOS High Sierra Supplemental Update includes security improvements to Safari and WebKit to mitigate the effects of Spectre. Version 1.0: Update fixes an issue where using certain character... Read more
ffWorks 1.0.6 - Convert multimedia files...
ffWorks (was iFFmpeg), focused on simplicity, brings a fresh approach to the use of FFmpeg, allowing you to create ultra-high-quality movies without the need to write a single line of code on the... Read more
Adobe Acrobat 18.011.20035 - Powerful PD...
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

Latest Forum Discussions

See All

Check out these 5 games that are a lot l...
So you're in love with Minecraft, but you're looking for something else to play as well? You've come to the right place then, because this list is all about games that are a bit like Minecraft. Some of them, more than others. [Read more] | Read more »
Our top 5 characters from casual RPG Cre...
Creature Quest definitely lives up to its name with a host of collectible creatures based on fantasy tales and world mythologies. To celebrate Creature Quest’s first birthday, we’re going to lay out what we think are the five best characters in the... | Read more »
Around the Empire: What have you missed...
Did you know that Steel Media has a whole swathe of other sites dedicated to all aspects of mobile gaming? Sure you'll get the very best iPhone news, reviews, and opinions right here at 148Apps, but we don't want you missing out on a single piece... | Read more »
All the best games on sale for iPhone an...
Oh hi there, and welcome to our round-up of the best games that are currently on sale for iPhone and iPad. You thought I didn't see you there, did you, skulking behind the bushes? Trust me though, the bushes aren't where the best deals are. The... | Read more »
The Battle of Polytopia Guide - How to H...
A new update just released for The Battle of Polytopia (formerly Super Tribes), which introduces online multiplayer. For all the fans of Midjiwan’s lite take on Civilization, this is certainly welcome news, but playing online isn’t as easy and... | Read more »
Here are the very best mobile games to p...
It's Valentine's Day! Did you get loads of cards and chocolates and other tacky, simple expressions of human affection? Did you send out tat because you find it almost impossible to express emotion unless there's a section dedicated to it at your... | Read more »
Florence (Games)
Florence 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Florence is an interactive storybook from the award-winning lead designer of Monument Valley about the heart-racing highs and... | Read more »
Purrfect Date (Games)
Purrfect Date 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Cats are a lil’ like marmite. Either you absolutely head-over-heels love’ em, or… nahhh, who are we kidding?! Everyone... | Read more »
More monsters to collect and evolve in C...
A laid-back mix of RPG and TCG, Creature Quest is all about building your deck, evolving your creatures and winning in battle. It’s the creation of VC Mobile, set up by Might and Magic producer Jon Van Caneghem. There are elements of that classic... | Read more »
Check out this awesome hands-on with the...
Well, PlayerUnknown's Battlegrounds has come out on mobile. This isn't a clone, this isn't a riff on the battleroyale mechanics of the game, it's the official mobile port by Tencent. But there's a little bit of a hitch. [Read more] | Read more »

Price Scanner via MacPrices.net

Apple refurbished Mac minis in stock again st...
Apple has restocked Certified Refurbished Mac minis starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: – 1.4GHz Mac mini: $419 $80 off MSRP – 2.6GHz Mac... Read more
Tuesday MacBook Deals: $250 off 15″ 2.9GHz Ma...
Adorama has the Silver 15″ 2.9GHz Apple MacBook Pro on sale today for $250 off MSRP. Shipping is free, and Adorama charges sales tax for residents in NY & NJ only: – 15″ 2.9GHz Silver MacBook Pro... Read more
Save up to $350 with these Apple Certified Re...
Apple has a full line of Certified Refurbished iMacs available for up to $350 off original MSRP. Apple’s one-year warranty is standard, and shipping is free. The following models are available: – 27... Read more
B&H offers $200 discount on Silver 15″ Ma...
B&H Photo has Silver 15″ Apple MacBook Pros on sale for $200 off MSRP. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 15″ 2.8GHz Touch Bar MacBook Pro Silver (... Read more
12″ Apple iPad Pro Sale of the Year! Models u...
B&H Photo has 12″ #iPad Pros on sale for up to $150 off MSRP. Shipping is free, and B&H charges sales tax in NY & NJ only: – 12″ 64GB WiFi iPad Pro: $719 $80 off MSRP – 12″ 256GB WiFi... Read more
Deals on 32GB 9″ iPads: Up to $50 off MSRP, s...
B&H Photo has 2017 9.7″ 32GB iPads on sale for $299 including free shipping plus NY & NJ sales tax only. Their price is $30 off MSRP, and it’s currently the lowest price available for these... Read more
15″ 2.2GHz Retina MacBook Pro available for o...
Apple has Certified Refurbished 15″ 2.2GHz Retina MacBook Pros available for $1699. That’s $300 off MSRP for this model, and it’s the lowest price available for a 15″ MacBook Pro currently offered by... Read more
13″ 3.1GHz/256GB Silver Touch Bar MacBook Pro...
Amazon has the Silver 13″ 3.1GHz/256GB Touch Bar MacBook Pro (MPXX2LL/A) on sale for $1649.99 including free shipping. Their price is $150 off MSRP, and it’s the lowest price available for a new 13″... Read more
Saturday Sale: Amazon offers 13″ 1.8GHz/256GB...
Amazon has the 13″ 1.8GHz/256B Apple MacBook Air on sale today for $250 off MSRP including free shipping: – 13″ 1.8GHz/256GB MacBook Air (MQD42LL/A): $949.99, $250 off MSRP Their price is the lowest... Read more
Roundup of Apple Certified Refurbished 12″ Ma...
Apple has Certified Refurbished 2017 12″ Retina MacBooks available for $200-$240 off the cost of new models. Apple will include a standard one-year warranty with each MacBook, and shipping is free.... Read more

Jobs Board

*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Strategist, *Apple* Media Products, Content...
# Strategist, Apple Media Products, Content and Marketing Job Number: 113399632 Santa Clara Valley, California, United States Posted: 20-Feb-2018 Weekly Hours: 40.00 Read more
*Apple* Store Leader - Retail District Manag...
Job Description:Job SummaryAs more and more people discover Apple , they visit our retail stores seeking ways to incorporate our products into their lives. It's your Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.