TweetFollow Us on Twitter

Nov 98 Factory Floor

Volume Number: 14 (1998)
Issue Number: 11
Column Tag: From The Factory Floor

A PowerPlant Update, Part 2

by John Daub and Dave Mark, ©1998 by Metrowerks, Inc., all rights reserved.

This month's column is the second installment in our series on PowerPlant. Last month we spoke with the godfather of PowerPlant, Greg Dow. This month, we'll hear from John Daub, another key member of the PowerPlant team.

Dave: What are your thoughts on getting started with PowerPlant?

John: I think what Greg Dow said in last month's Factory Floor provided a good starting point, from a coding perspective. I've found a few concepts that are not exactly coding related, but have helped me (and others) not only get started in PowerPlant, but also follow through. These still help me every day.

1. Lay a good foundation - Many people starting out with PowerPlant start knowing little and desiring to accomplish a lot. The enthusiasm is commendable, but do not let this enthusiasm turn into impatience. I've seen too many beginners desire to write the next great Killer App over a weekend, expect PowerPlant to do it all for them, then get frustrated and give up because of impatience, unrealistic expectations of PowerPlant, and/or unrealistic goals. That's a shame.

Make a good assessment of where your skills currently are and where they need to be to accomplish the goals you set for yourself. Then fill in the gaps along that route and set out.

To work with PowerPlant, you need to know the C++ programming language, and knowing how to get around the Mac OS Toolbox is certainly beneficial.

If you do not know C++, you should pick up a good book on the language and learn it first. There are many at your local bookstore, and there are some on the CodeWarrior CD as well.

Although PowerPlant does hide many of the details of the OS from the user, sooner or later you will find yourself needing to deal directly with the OS. That's not as scary as it might sound, and the more familiar you are with the Mac OS Toolbox, the less scary it will certainly seem. You should at least be familiar with basic concepts like event loops and dispatching; basic managers like Windows, Dialogs, Menus, Controls; basic memory management; etc. There are many good books on Mac programming at your local bookstore (and on the CodeWarrior CD).

After you've laid yourself a good foundation, then start to work with PowerPlant.

I know... that's a lot of background work and could take you some weeks or even months before you touch PowerPlant at all... and you want to start writing apps now! I do understand this excitement. I believe you should still take the time to lay a good foundation for yourself, but tinkering around and getting your hands dirty can be a lot of fun as well. Just remember that you tend to go further building a house upon rock than upon sand.

2. Be honest - Not only with others, but mostly with yourself. Learning PowerPlant isn't easy, but it's not difficult either.

One of the most difficult parts of learning PowerPlant is knowing when you've truly mastered some concept or technique. When will you know if you've mastered it? You'll know (don't you hate answers like that? :)

And if you aren't certain, if you doubt your understanding of a concept, perhaps you do not fully understand it. It's best to be honst with yourself and take the time to go back and see. Maybe you didn't know it and now you know better. Maybe you did and through reduncancy you've fostered some learning.

Or maybe you thought you did but corrected yourself, or picked up on a finer point that you missed the first time around.

Never let your ego get in the way of learning.

3. Read, Ask, Do - Read everything that you can. Books, documentation, magazines, websites, FAQs, newsgroup archives, and most importantly here, source code. You learn a lot. Just read, and reread, and reread again.

Ask questions whenever you are not certain of something. If someone is going to look down on you for asking a question, they've got a problem they need to get over. And keep asking until you fully understand. The only dumb question is the one never asked.

Do. Write code, write apps. So what if there are a zillon text editors on the market. Write the zillion-and-one editor. The more you write code, the more you'll learn. Experience teaches us a great deal that we cannot learn any other way.

4. Spend time in the debugger - The debugger is a great place for the beginner to learn. If you start out at main and then Step Into every single line of code watching what goes on, examining variables, monitoring flow, you will learn a great deal about how PowerPlant works. It can also help you see how the pieces of PowerPlant all fit together to form an application. And as well, it can help you learn how to debug, which is a necessary part of development.

5. Be patient and don't give up - I don't believe that anything worth having in life comes easy. Same holds true for PowerPlant. Like I said before, learning PowerPlant isn't easy, but it isn't difficult either. If you hit a frustating problem that you just can't solve, keep at it. Maybe leave it for a while to clear your head, but don't totally quit. Ask someone else for a fresh perspective. Try to find a different angle from which to approach the problem. Some of the biggest joys come from solving the worst problems.

Hang in there. If you don't know what I mean yet, you definitely will sooner or later.

6. There is no such thing as a mistake, so long as you learn from it - So the app crashed. So it totally trashed your machine and now it won't boot. So what! Have you learned something from this (aside from "Yea, don't do that!")? In the beginning, you will probably crash more than run. Take the time to understand why your code failed and what you (or someone else perhaps) did wrong. Learn from it, grow from it.

And last, but most of all, have fun.

Dave: What are some of the PowerPlant classes you've work on?

John: I've written some examples and sundry code for PowerPlant, like LTextEditView, LCMAttachment (Contextual Menu support for PowerPlant), and some Grayscale implementations ("GA Imps", part of the Appearance Classes). I've also worked on larger projects like the Cursor Classes (provides cursor support, including animated cursors. I'm hoping to revamp this for Pro 5) and Debugging Classes.

Dave: Cool, debugging classes. What do they do?

John: The Debugging Classes are a set of tools that hope to make your life a bit easier and your code more robust and stable. They help you stress test, sanity check, view information, and a host of other features.

One of the most visible features of the Debugging Classes is the Debug Menu, provided by LDebugMenuAttachment (see Figure 1).

Figure 1. The Debug menu, provided by the PowerPlant class LDebugMenuAttachment.

To gain this menu and its functionality within your own project is very simple: just add the attachment to your application object like this:

     void
     CMyApp::Initialize()
     {
          LApplication::Initialize();

          #if PP_DEBUG
               mDebugMenuAttachment =
                    new LDebugMenuAttachment(...);
               AddAttachment(mDebugMenuAttachment);
          #endif
     }

That's all! Using the Debugging Classes and the Debug Menu isn't just as simple as that, but it is fairly close.

The menu is generated on the fly (so it should be relatively painless to add to existing as well as new projects), and it allows you to perform actions such as breaking into a debugger; performing compactions, purges, and/or scrambles to your heap; validate your PPob's; modify the behavior of gDebugThrow and gDebugSignal at runtime (typically you'd have to recompile to do this); and consume memory to simulate low-memory conditions.

One of the very useful parts of the menu are the displays of pane and commander hierarchies on the fly. I know being able to display the commander chain has helped many people solve their commander problems already. A big thanx to Greg Bolsinga (our Class Wrangler Wrangler) for the original code to LCommanderTree.

One additional behavior of the menu is how it allows you to work with Metrowerks utilities, such as ZoneRanger and DebugNew, and third-party utilities, such as QC, at runtime. Turn QC tests on and off, generate a DebugNew log, clear all DebugNew leaks, whatever you'd like to do. Normally to change these behaviors you would have to recompile; but now they have an interface and can be accessed at runtime. Much handier.

The other portion of the Debugging Classes provides macros and utilities for use within your code. These build upon the core debugging functionality in PowerPlant (Assert_, ThrowIfOSErr_, ThrowIfMemFail_, etc.) to help you sanity check and ensure your code will be solid.

And just like the core macros, when you turn debugging off in PowerPlant, the Debugging Classes macros are redefined to minimal implementations.

For example, to find a pane by ID, you typically do this:

   CSomePane *thePane = dynamic_cast<CSomePane*>
                        (theWindow->FindPaneByID(kPaneID));
   ThrowIfNil_(thePane);

That's a lot of code to have to type. Plus, although the dynamic_cast is technically correct, it's not *really* necessary here: after your initial debugging run to ensure you set your code and PPob correctly, you are pretty much guarenteed that looking for kPaneID will return the proper object (unless someone fouls up your PPob). Furthermore, the nil check isn't needed since you should have no problem obtaining a proper and valid pointer.

With all of this in mind, you can reduce the typing, the code bloat, and runtime overhead (of the RTTI and the nil check) by using DebugFindPaneByID_.

   CSomePane *thePane = DebugFindPaneByID_( theWindow, 
                                    kPaneID, CSomePane);

That's all there is to it.

In debug builds, the macro will expand to ensure theWindow is not nil, then perform the FindPaneByID and dynamic_cast just the same as the original code. It will check for nil and signal if there is failure. So you have all of the original functionality, and a lot less typing.

In release builds, the macro reduces to a simple call to FindPaneByID, static_cast'ing the return result. A lot less overhead (no RTTI, no nil checks) and a lot less code for releases, but still the sanity and robustness needed for development.

Of course, if you do need to determine the proper object type on the fly, i.e. you need the dynamic_cast because the pane type is unknown at compile time and/or could vary at runtime, then by all means do use the previous method to FindPaneByID() so you do not lose the dynamic_cast when the macro is turned off.

Dave: What's going on with Constructor?

John: As of this writing, Constructor is in maintenance mode and I am the maintainer. We are not working on any major improvements. The forthcoming RAD tools (and some future PowerPlant developments) will supersede Constructor in form and function.

I am not adverse to fixing bugs or adding features; in fact I have a list for each category and would like to work to make the lists shorter. However, RAD at Metrowerks is now the top priority, so major changes to Constructor probably will not be happening.

We will continue to ship a Constructor with CodeWarrior for a good long while, as there are many legacy projects that will continue to need and utilize Constructor. We will ship Constructor until we have a complete and viable replacement.

Dave: What other programming things do you do?

John: Aside from my work at Metrowerks, I try to stay involved in the Mac OS development community. I've contributed to the WASTE project, do a little informal (non-profit) consulting work here and there, and write some classes for PowerPlant that I distribute on my own.

Some people ask me why I write PowerPlant classes outside of my regular PowerPlant work, or why my outside classes are not rolled into PowerPlant officially. Most of the things I write in my own time are experiments, tinkering, or just something that doesn't fit into the scope of "PowerPlant proper". They're still useful (many people love my CURLPushButton class), but not something that really fits within the core PowerPlant scope.

Currently (at the time of this writing) I'm looking at WT++, a new all C++ text engine from Timothy Paustian (author of CWASTEEdit and WebWarrior). It's pretty neat. And I'm also getting more serious with Linux.

Dave: Any parting comments?

John: I always welcome input and feedback from our users. If you have any comments or criticisms about any of the topics discussed here or about PowerPlant in general, do feel free to drop me a line.

I'm hoping to be able to find some time in the near future to write some more in-depth articles for MacTech, about getting started, the debugging classes, or some other topics. If readers have any input as to what they might like to see, in terms of some future articles on PowerPlant, drop a line to editor@mactech.com and CC me. I cannot promise anything (any of you with children know how life can be sometimes :-) but I'll certainly see what I can do.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

FontExplorer X Pro 7.1.3 - Font manageme...
FontExplorer X Pro is optimized for professional use; it's the solution that gives you the power you need to manage all your fonts. Now you can more easily manage, activate and organize your... Read more
DiskCatalogMaker 8.2.5 - Catalog your di...
DiskCatalogMaker is a simple disk management tool which catalogs disks. Simple, light-weight, and fast Finder-like intuitive look and feel Super-fast search algorithm Can compress catalog data for... Read more
Skim 1.5.12 - PDF reader and note-taker...
Skim is a PDF reader and note-taker for OS X. It is designed to help you read and annotate scientific papers in PDF, but is also great for viewing any PDF file. Skim includes many features and has a... Read more
rekordbox 6.1.0.0030 - Professional DJ m...
rekordbox is the best way of preparing and managing your tracks, be it at home, in the studio, or even on the plane! It allows you to import music from other music-management software using the... Read more
iExplorer 4.4.0 - View and transfer file...
iExplorer is an iPhone browser for Mac lets you view the files on your iOS device. By using a drag and drop interface, you can quickly copy files and folders between your Mac and your iPhone or... Read more
OmniGraffle 7.17.5 - Create diagrams, fl...
OmniGraffle helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use Graffle to... Read more
Apple Configurator 2.13.1 - Configure an...
Apple Configurator makes it easy to deploy iPad, iPhone, iPod touch, and Apple TV devices in your school or business. Use Apple Configurator to quickly configure large numbers of devices connected to... Read more
OmniGraffle Pro 7.17.5 - Create diagrams...
OmniGraffle Pro helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use... Read more
FoldersSynchronizer 5.1.6 - Synchronize...
FoldersSynchronizer is a popular and useful utility that synchronizes and backs-up files, folders, disks and boot disks. On each session you can apply special options like Timers, Multiple Folders,... Read more
Adobe After Effects 17.1.4 - Create prof...
After Effects is available as part of Adobe Creative Cloud for $52.99/month (or $20.99/month for a single app license). The new, more connected After Effects can make the impossible possible. Get... Read more

Latest Forum Discussions

See All

Infinity Mechs is an upcoming idle game...
Indie developer SkullStar studio has announced an upcoming idle mech game called Infinity Mechs. It draws inspiration from the mobile game Iron Saga and has been officially licensed by Game Duchy. It's set to launch for both iOS and Android on... | Read more »
PUBG Mobile Lite's latest update se...
PUBG Mobile Lite, the streamlined version of the popular battle royale that's designed to work on less powerful devices, sees the return of a popular game variant today, Survive Till Dawn mode. It arrives as part of the 0.19.0 content update. [... | Read more »
Matchy Catch, Jyamma Games’ new hyper-ca...
Matchy Catch is a new hyper-casual puzzler from Jyamma Games, the Italian studio behind the Pong-inspired puzzle-adventure Hi-Ball Rush. It’s only the developer’s second game for iOS and Android devices, but it promises to be every bit as fun and... | Read more »
Among Us! Imposter Guide - How to be a s...
Among Us! continues to be getting a lot of play in these parts, and since our first guide we've learned a thing or two about the game. This is especially true regarding the imposter role, as its a relatively rare opportunity that we've now put... | Read more »
Paladin's Story is an upcoming fant...
Paladin's Story is an upcoming fantasy RPG with an off-kilter sense of humour that's heading for iOS and Android. It will officially launch for both on September 16th though the game is already available on Google Play in Early Access. [Read more... | Read more »
Among Us! Guide - Tips for the uninitiat...
| Read more »
A Pretty Odd Bunny is a stealth-platform...
A Pretty Odd Bunny is a stealth-platformer from two-man team AJ Ordaz and René Rivera. It follows the story of a red-eyed rabbit who is allergic to carrots and instead has a penchant for devouring pigs. It's available now for Android devices. [... | Read more »
Apple Arcade: Ranked - Top 25 [Updated 9...
In case you missed it, I am on a quest to rank every Apple Arcade game there is. [Read more] | Read more »
The 5 Best Mobile Games Like Tony Hawk...
Tony Hawk’s Pro Skater 1+2 dropped last week, meaning you can get remastered versions of two of the most iconic “sports” games ever made and experience some of the highest watermarks set in games of generations’ past. [Read more] | Read more »
Bouncing Box is a challenging platformer...
In platformers, we often spend a large amount of time mindless destroying boxes by jumping onto or into them, whatever makes them splinter apart. Bouncing Box from developer The K Brothers aims to give those poor destructible cubes a chance to be... | Read more »

Price Scanner via MacPrices.net

Price drop! Get a 44mm Apple Watch Series 5 G...
Amazon has dropped their price on the 44mm Apple Watch Series 5 GPS + Cellular by $100 to $429 shipped. That’s $100 off Apple’s original MSRP for this model. For the latest prices and sales, see our... Read more
Verizon offers $200 discount on new Apple Wat...
Verizon will take up to $200 off the purchase of a new GPS + Cellular Apple Watch Series 6 or Apple Watch SE with select trade-in and the purchase of a new iPhone with service. The fine print: “Get... Read more
Verizon offers $250 discount on new 8th gener...
Verizon will take up to $250 off the price of an 8th generation 2020 Apple Cellular iPad with select trade-ins and a new iPhone purchase. Plus get Apple News+ free for 6 months. The fine print: “Save... Read more
Apple’s Implementation Of COVID-19 Exposure...
NEWS: 09.18.20 – The latest effort by Apple to embed exposure notifications for COVID-19 contact tracing right into its mobile operating system has some iPhone users weary of being exposed to... Read more
Here’s how to get a 16″ MacBook Pro for $300...
B&H Photo has new 16″ MacBook Pros on sale today for $250-$300 off Apple’s MSRP, starting at $2099. Expedited shipping is free to many addresses in the US: – 2019 16″ 2.6GHz 6-Core MacBook Pro... Read more
Apple has Certified Refurbished 16″ MacBook P...
Apple has Certified Refurbished 2019 16″ MacBook Pros available for up to $420 off the cost of new models, starting at $2039. Each model features a new outer case, shipping is free, and an Apple 1-... Read more
Price drops! Apple reseller B&H drops App...
B&H Photo has dropped prices on Apple Watch Series 5 models by $50-$70 off Apple’s original MSRP. Shipping is free. These are the same Apple Watch models sold by Apple in their retail and online... Read more
Apple extends their 2020 Back-to-School promo...
As part of their Back to School promotion for 2020, Apple will include one free pair Apple AirPods (with charging case) with the purchase of a MacBook Air, MacBook Pro, iMac, iMac Pro (Mac Pro and... Read more
Apple 7.9″ iPad minis are on sale today for $...
Amazon has new 7.9″ 64GB WiFi iPad minis on sale today for $50 off Apple’s MSRP, each including free shipping. Prices start at $349. These are the same iPad minis sold by Apple in their retail and... Read more
Lowest price anywhere! New 16″ 6-core MacBook...
Expercom has the Silver 16″ 6-core MacBook Pro back on sale for a limited time for $2079 shipped. Their price is $320 off Apple’s MSRP for this model, and it’s the cheapest price currently available... Read more

Jobs Board

Platform - Workplace Eng - *Apple* Enterpri...
MORE ABOUT THIS JOB We are looking for an Apple Platform Engineer who will bring a unique engineering skill set, support, clarity, organization and above all else, Read more
*Apple* Certified Repair Technician - Utah S...
…selected candidate will work in the USU Campus Store Tech Department as an Apple Certified Repair Technician and floor associate. This position is for both summer Read more
Senior Data Engineer - *Apple* - Theorem, L...
Job Summary Apple is seeking an experienced, detail-minded data engineeringconsultant to join our worldwide business development and strategy team. If you are Read more
Desktop Support Technician - A+, *Apple* -...
Desktop Support Technician - A+, Apple **Ref No.:** 20-01604 **Location:** Miami, Florida **e** at http://www.excell.com/ **X** at http://www.excell.com/ **cell** at Read more
Tier 2 Technical Support Analyst - ( *Apple*...
…Analystiless than/strong>who will analyze and determine user software needs on all Apple devices (first support contact), Windows devices, and support printers in Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.