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

Chromium 75.0.3770.142 - 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 75.0.3770.142: Release notes were... Read more
Viber 11.1.0 - Send messages and make fr...
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, so... Read more
Wireshark 3.0.3 - Network protocol analy...
Wireshark is one of the world's foremost network protocol analyzers, and is the standard in many parts of the industry. It is the continuation of a project that started in 1998. Hundreds of... Read more
DEVONthink Pro 3.0beta4 - Knowledge base...
DEVONthink Pro is your essential assistant for today's world, where almost everything is digital. From shopping receipts to important research papers, your life often fills your hard drive in the... Read more
Adobe Creative Cloud 4.9.0.512 - Access...
Adobe Creative Cloud costs $20.99/month for a single app, or $52.99/month for the entire suite. Introducing Adobe Creative Cloud desktop applications, including Adobe Photoshop CC and Illustrator CC... Read more
SketchUp 19.1.174 - Create 3D design con...
SketchUp is an easy-to-learn 3D modeling program that enables you to explore the world in 3D. With just a few simple tools, you can create 3D models of houses, sheds, decks, home additions,... Read more
ClamXav 3.0.12 - Virus checker based on...
ClamXav is a popular virus checker for OS X. Time to take control ClamXAV keeps threats at bay and puts you firmly in charge of your Mac’s security. Scan a specific file or your entire hard drive.... Read more
BetterTouchTool 3.151 - Customize multi-...
BetterTouchTool adds many new, fully customizable gestures to the Magic Mouse, Multi-Touch MacBook trackpad, and Magic Trackpad. These gestures are customizable: Magic Mouse: Pinch in / out (zoom)... Read more
FontExplorer X Pro 6.0.9 - 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
Dropbox 77.4.131 - Cloud backup and sync...
Dropbox is an application that creates a special Finder folder that automatically syncs online and between your computers. It allows you to both backup files and keeps them up-to-date between systems... Read more

Latest Forum Discussions

See All

Upcoming visual novel Arranged shines a...
If you’re in the market for a new type of visual novel designed to inform and make you think deeply about its subject matter, then Arranged by Kabuk Games could be exactly what you’re looking for. It’s a wholly unique take on marital traditions in... | Read more »
TEPPEN guide - The three best decks in T...
TEPPEN’s unique take on the collectible card game genre is exciting. It’s just over a week old, but that isn’t stopping lots of folks from speculating about the long-term viability of the game, as well as changes and additions that will happen over... | Read more »
Intergalactic puzzler Silly Memory serve...
Recently released matching puzzler Silly Memory is helping its fans with their intergalactic journeys this month with some very special offers on in-app purchases. In case you missed it, Silly Memory is the debut title of French based indie... | Read more »
TEPPEN guide - Tips and tricks for new p...
TEPPEN is a wild game that nobody asked for, but I’m sure glad it exists. Who would’ve thought that a CCG featuring Capcom characters could be so cool and weird? In case you’re not completely sure what TEPPEN is, make sure to check out our review... | Read more »
Dr. Mario World guide - Other games that...
We now live in a post-Dr. Mario World world, and I gotta say, things don’t feel too different. Nintendo continues to squirt out bad games on phones, causing all but the most stalwart fans of mobile games to question why they even bother... | Read more »
Strategy RPG Brown Dust introduces its b...
Epic turn-based RPG Brown Dust is set to turn 500 days old next week, and to celebrate, Neowiz has just unveiled its biggest and most exciting update yet, offering a host of new rewards, increased gacha rates, and a brand new feature that will... | Read more »
Dr. Mario World is yet another disappoin...
As soon as I booted up Dr. Mario World, I knew I wasn’t going to have fun with it. Nintendo’s record on phones thus far has been pretty spotty, with things trending downward as of late. [Read more] | Read more »
Retro Space Shooter P.3 is now available...
Shoot-em-ups tend to be a dime a dozen on the App Store, but every so often you come across one gem that aims to shake up the genre in a unique way. Developer Devjgame’s P.3 is the latest game seeking to do so this, working as a love letter to the... | Read more »
Void Tyrant guide - Guildins guide
I’ve still been putting a lot of time into Void Tyrant since it officially released last week, and it’s surprising how much stuff there is to uncover in such a simple-looking game. Just toray, I finished spending my Guildins on all available... | Read more »
Tactical RPG Brown Dust celebrates the s...
Neowiz is set to celebrate the summer by launching a 2-month long festival in its smash-hit RPG Brown Dust. The event kicks off today, and it’s divided into 4 parts, each of which will last two weeks. Brown Dust is all about collecting, upgrading,... | Read more »

Price Scanner via MacPrices.net

Verizon is offering a 50% discount on iPhone...
Verizon is offering 50% discounts on Apple iPhone 8 and iPhone 8 Plus models though July 24th, plus save 50% on activation fees. New line required. The fine print: “New device payment & new... Read more
Get a new 21″ iMac for under $1000 today at t...
B&H Photo has new 21″ Apple iMacs on sale for up to $100 off MSRP with models available starting at $999. These are the same iMacs offered by Apple in their retail and online stores. Shipping is... Read more
Clearance 2017 15″ 2.8GHz Touch Bar MacBook P...
Apple has Certified Refurbished 2017 15″ 2.8GHz Space Gray Touch Bar MacBook Pros available for $1809. Apple’s refurbished price is currently the lowest available for a 15″ MacBook Pro. An standard... Read more
Clearance 12″ 1.2GHz MacBook on sale for $899...
Focus Camera has clearance 12″ 1.2GHz Space Gray MacBooks available for $899.99 shipped. That’s $400 off Apple’s original MSRP. Focus charges sales tax for NY & NJ residents only. Read more
Get a new 2019 13″ 2.4GHz 4-Core MacBook Pro...
B&H Photo has new 2019 13″ 2.4GHz MacBook Pros on sale for up to $150 off Apple’s MSRP. Overnight shipping is free to many addresses in the US: – 2019 13″ 2.4GHz/256GB 6-Core MacBook Pro Silver... Read more
AirPods with Wireless Charging Case now on sa...
Amazon has extended their Prime Day savings on Apple AirPods by offering AirPods with the Wireless Charging case for $169.99. That’s $30 off Apple’s MSRP, and it’s the cheapest price available for... Read more
New 2019 15″ MacBook Pros on sale for $200 of...
B&H Photo has the new 2019 15″ 6-Core and 8-Core MacBook Pros on sale for $200 off Apple’s MSRP. Overnight shipping is free to many addresses in the US: – 2019 15″ 2.6GHz 6-Core MacBook Pro Space... Read more
Amazon drops prices, now offers clearance 13″...
Amazon has new dropped prices on clearance 13″ 2.3GHz Dual-Core non-Touch Bar MacBook Pros by $200 off Apple’s original MSRP, with prices now available starting at $1099. Shipping is free. Be sure to... Read more
2018 15″ MacBook Pros now on sale for $500 of...
Amazon has dropped prices on select clearance 2018 15″ 6-Core MacBook Pros to $500 off Apple’s original MSRP. Prices now start at $1899 shipped: – 2018 15″ 2.2GHz Touch Bar MacBook Pro Silver: $1899.... Read more
Price drop! Clearance 12″ 1.2GHz Silver MacBo...
Amazon has dropped their price on the recently-discontinued 12″ 1.2GHz Silver MacBook to $849.99 shipped. That’s $450 off Apple’s original MSRP for this model, and it’s the cheapest price available... Read more

Jobs Board

Best Buy *Apple* Computing Master - Best Bu...
**696259BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Store Associates **Location Number:** 001076-Temecula-Store **Job Description:** The Read more
Business Development Manager, *Apple* Globa...
Business Development Manager, Apple Global Tampa, FL, US Requisition Number:73805 As a Global Apple Business Development Manager at Insight, you proactively Read more
*Apple* Systems Architect/Engineer, Vice Pre...
…its vision to be the world's most trusted financial group. **Summary:** Apple Systems Architect/Engineer with strong knowledge of products and services related to Read more
*Apple* IOS Systems Engineer - Randstad (Uni...
Apple IOS Systems Engineer **job details:** + location:Irvine, CA + salary:$45 - $55 per hour + date posted:Tuesday, July 16, 2019 + job type:Temp to Perm + Read more
Business Development Manager, *Apple* Globa...
Business Development Manager, Apple Global Tampa, FL, US Requisition Number:73805 As a Global Apple Business Development Manager at Insight, you proactively Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.