TweetFollow Us on Twitter

January 92 - Postcard from Windows Land - Is Windows object-oriented?

Postcard from Windows Land - Is Windows object-oriented?

James Plamondon

When the Microsoft gang started writing Windows back in the mid-eighties, they were all excited about object programming. They, like Apple, toured Xerox PARC and saw what Xerox was doing with bit-mapped displays, windows, mice, and so on. Microsoft, like Apple, thought this stuff was going to be the wave of the future-so they went home and started working on a cool object-oriented operating system.

Then reality hit. Their target platform, the standard IBM PC of their day, was totally unable to handle the strain of a truly object-oriented system. So, like Apple, Microsoft compromised, and wrote a procedural operating system with an object-oriented flavor.

For whatever reason, however, Windows was unsuccessful throughout its development-until around the time Microsoft's OS/2 deal with IBM fell through-whereas the Mac OS was the star at Apple from soon after its inception. So the Windows operating system is only now beginning to flower, as the Mac OS did about four years ago.

What's amazing to me is how fast Windows is moving. Whereas Apple took ages to bring out System 7, Microsoft is bringing out Windows 3.1 just 18 months (roughly) after 3.0 hit the shelves. And Windows 3.1 should really be called Windows 4; it is a really big improvement over Windows 3.0 (which has sold over five million copies in the last year, so it's no slouch, either).

But is Windows object-oriented? Absolutely not-if, by "object-oriented," you mean written in an object programming language. Given Windows' origins and history, it couldn't be. Smalltalk and Simula were the only decent object programming languages available at the product's inception, and neither would give adequate performance on their target system. So Microsoft did the best it could under the restraints it was under at the time. And in at least one way, Microsoft did a better job than Apple.

Windows, true to its name, has a real windowing system; the Mac does not. This should come as no surprise to MacApp programmers; one of the most important benefits MacApp provides to Mac programmers is-you guessed it-a windowing system, in the form of MacApp views. [A Windows "window" is equivalent to a MacApp "view;" a MacApp "window" is equivalent to a Windows "frame window."] It is considerably easier to write an application framework for Windows than for the Mac, because a Windows framework could use the native windowing system. Zillions of lines of code could be saved.

On the Mac, when you create a window, you get a pointer to a data structure. This data structure is completely dumb. There's no way to call its methods or send it messages. In Windows, on the other hand, one can define a window class, and associate with this class a number of attributes and-importantly-a window procedure (WinProc). When you create a window, you must specify the class of the window. The window reference you get back is a unique window identifier, but it's completely "blind." You can't use it as a pointer to get at its data directly. Instead, you have to "send the window a message" to act on it.

"Sending the window a message" works just like "sending a message" to a Mac CDEF, WDEF, or other code resource. You call a procedure with an integer argument that indicates which message you're sending, and a couple of other arguments that can hold additional data. (Before you snort in disdain at the notion of using integral message discriminators, think about MacApp's use of command numbers in TEvtHandler.DoMenuCommand().)

So, Windows does a better job of data abstraction and encapsulation, at least with regard to window data structures. But is this abstraction and encapsulation enough to make it object-oriented?

Well, maybe not-but there's more. Having defined a window class, one can "subclass" the window class. Now, before you get all excited, let me admit that it's not "real" subclassing, using the definition used by object programming languages. But it's not a bad simulation.

Let's say you want to write a variation of the standard Windows "edit" control-to validate its entries as dates, perhaps. You would need to get a copy of the "edit" class' class info (by calling GetClassInfo()), and modify the resulting copy to use your new class name ("edit_date"). Also, you would save off the class info's pointer to the "edit" class' WinProc, and store the "edit_date" class' WinProc pointer in its place (in the copy). Then, you would call RegisterClass() to tell Windows that the window class existed.

Having done this, you can then create a window of class "edit_date" by telling Windows to do so. It will respond by handing you back a unique window identifier. From then on, both Windows and your application will interact with the window by sending it messages. Messages are sent to the window by calling the Windows function SendMessage() with the window ID as the first argument, or by calling other Windows functions that eventually call SendMessage().

SendMessage()'s prototype is roughly as follows:

long SendMessage(HWND hWnd, short wMsg, short wParam, long lParam);

[This prototype has been simplified for ease of understanding by the MacApp audience. The correct prototype is "LONG FAR PASCAL MyWinProc(HWND hWnd, WORD wMsg, WORD wParam, LONG lParam)."]

"hWnd" is the unique window ID. When SendMessage() is called on a given window, the window's WinProc is called. The WinProc's prototype is almost the same as that of SendMessage(); calling SendMessage() can be viewed as a polymorphic call to a window's message procedure.

The WinProc typically contains a huge switch statement (in Pascal, case statement) that forwards the message to the appropriate message handler (much like TApplication.DispatchEvent()). And, since you carefully saved off the standard Windows "edit" window class' WinProc pointer before calling RegisterClass(), you can call it from within your "edit_date" window class' WinProc-much like calling the inherited implementation of a method in an OOP language. It ain't pretty, but it works.

So, maybe Windows is object-oriented, and maybe it's not. Maybe, as a friend of mine said recently, object-orientation is not a binary, yes-or-no quality, but rather a continuum. If so, then Windows is certainly "more object-oriented" than the Mac OS, while being "less object-oriented" than MacApp.

The answer to the question may be irrelevant. It is relevant, though, that your MacApp experience will put you way ahead of the game in Windows programming. MacApp software development tools are on the cutting edge, while those for Windows are still blunt instruments, suitable only for beating code into submission.

But the bottom line remains the same: Windows is selling at an incredible rate, and will be a significant force in the microcomputer industry for years to come. By learning to program in Windows, you will be assuring your financial security for at least the next decade.

As the old saying goes, in the land of the blind, the one-eyed man is King; and with Windows selling at an incredible rate, the Land of the Blind is expanding rapidly. We MacAppers know how to wring the most out of an even vaguely-object-oriented system; you can see the opportunity this presents to us, even with one eye shut.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

BetterTouchTool 2.305 - 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
calibre 3.8.0 - Complete e-book library...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital librarian... Read more
Carbon Copy Cloner 5.0.2 - Easy-to-use b...
Carbon Copy Cloner backups are better than ordinary backups. Suppose the unthinkable happens while you're under deadline to finish a project: your Mac is unresponsive and all you hear is an ominous,... Read more
Evernote 6.12.3 - Create searchable note...
Evernote allows you to easily capture information in any environment using whatever device or platform you find most convenient, and makes this information accessible and searchable at anytime, from... Read more
Default Folder X 5.1.6 - Enhances Open a...
Default Folder X attaches a toolbar to the right side of the Open and Save dialogs in any OS X-native application. The toolbar gives you fast access to various folders and commands. You just click on... Read more
Geekbench 4.1.2 - Measure processor and...
Geekbench provides a comprehensive set of benchmarks engineered to quickly and accurately measure processor and memory performance. Designed to make benchmarks easy to run and easy to understand,... Read more
GraphicConverter 10.5 - $39.95
GraphicConverter is an all-purpose image-editing program that can import 200 different graphic-based formats, edit the image, and export it to any of 80 available file formats. The high-end editing... Read more
Dropbox 35.4.20 - Cloud backup and synch...
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 keep them up-to-date between systems... Read more
XMind 8 Update 4 - Popular mind mapping...
XMind is the most popular mind mapping tool. Millions of people use XMind to clarify thinking, manage complex information, run brainstorming and get work organized. It couldn't be easier to get... Read more
Safari Technology Preview 11.1 - The new...
Safari Technology Preview contains the most recent additions and improvements to WebKit and the latest advances in Safari web technologies. And once installed, you will receive notifications of... Read more

The best new games we played this week -...
It's pretty much been one big release after another. We were privy to a bunch of surprises this week, with a lot of games we'd been waiting for quite some time dropping unexpectedly. We hope you're free this weekend, because there is a lot for... | Read more »
Stormbound: Kingdom Wars guide - how to...
Stormbound: Kingdom Wars is an excellent new RTS turned card battler out now on iOS and Android. Lovers of strategy will get a lot of enjoyment out of Stormbound's chess-like mechanics, and it's cardbased units are perfect for anyone who loves the... | Read more »
The best AR apps and games on iOS right...
iOS 11 has officially launched, and with it comes Apple's ARKit, a helpful framework that makes it easier than ever for developers to create mobile AR experiences. To celebrate the occassion, we're featuring some of the best AR apps and games on... | Read more »
Phoenix Wright: Ace Attorney - Spirit of...
Phoenix Wright: Ace Attorney - Spirit of Justice 1.00.00 Device: iOS Universal Category: Games Price: $.99, Version: 1.00.00 (iTunes) Description: ************************************************※IMPORTANT※・Please read the “When... | Read more »
Kpressor (Utilities)
Kpressor 1.0.0 Device: iOS Universal Category: Utilities Price: $4.99, Version: 1.0.0 (iTunes) Description: The ultimate ZIP compression application for iPhone and iPad. - Full integration of iOS 11 with support for multitasking.-... | Read more »
Find out how you can save £35 and win a...
Nothing raises excitement like a good competition, and we’re thrilled to announce our latest contest. We’ll be sending one lucky reader and a friend to the Summoners War World Arena Championship at Le Comedia in Paris on October 7th. It’s the... | Read more »
Another Lost Phone: Laura's Story...
Another Lost Phone: Laura's Story 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Another Lost Phone is a game about exploring the social life of a young woman whose phone you have just... | Read more »
The Witness (Games)
The Witness 1.0 Device: iOS Universal Category: Games Price: $9.99, Version: 1.0 (iTunes) Description: You wake up, alone, on a strange island full of puzzles that will challenge and surprise you. You don't remember who you are, and... | Read more »
Egg, Inc. guide - how to build your gold...
Egg, Inc.'s been around for some time now, but don't you believe for one second that this quirky clicker game has gone out of style. The game keeps popping up on Reddit and other community forums thanks to the outlandish gameplay (plus, the... | Read more »
The best deals on the App Store this wee...
Good news, everyone! Your favorite day of the week has arrived at last -- it's discount roundup day! This fine Wednesday evening we're gathering up the hottest deals on the App Store. We've got action platformers, we've got puzzle games, we've got... | Read more »

Price Scanner via MacPrices.net

Apple Offering Up To $455 Credit Toward iPhon...
iPhone 8 and 8 Plus are now available at the Apple Store, and you can receive up to $375 credit toward a new iPhone purchase when you trade in your eligible smartphone. Photo Courtesy Apple Just... Read more
AnyTrans Offers iOS Users Three Ways For Movi...
iMobie Inc. today announceed AnyTrans v6.0.1, which now can help iOS users move all data to iPhone 8/8 Plus seamlessly. The software is available both on Mac and Windows and fully able to move all... Read more
Snag a 13-inch 2.3GHz MacBook Pro for $100 of...
B&H Photo has 2017 13″ 2.3GHz MacBook Pros in stock today and on sale for $100 off MSRP, each including free shipping plus NY & NJ sales tax only: – 13-inch 2.3GHz/128GB Space Gray MacBook... Read more
Verizon offers new iPhone 8 for $100-$300 off...
Verizon is offering the new iPhone 8 for up to $300 off MSRP with an eligible trade-in: • $300 off: iPhone 6S/6S Plus/7/7 Plus, Google Pixel XL, LG G6, Moto Z2 Force, Samsung Galaxy S7/S7 edge/S8/S8... Read more
Apple Refurbished 2017 13-inch MacBook Pros a...
Apple has Certified Refurbished 2017 13″ Touch Bar MacBook Pros in stock today and available for $200-$300 off MSRP. A standard Apple one-year warranty is included with each MacBook, and shipping is... Read more
OWC USB-C Travel Dock with 5 Ports Connectivi...
OWC have announced the new OWC USB-C Travel Dock, the latest addition to their line of connectivity solutions. The USB-C Travel Dock lets you connect its integrated USB-C cable to a Mac or PC laptop... Read more
Pelican Products, Inc. Unveils Cases For All...
Pelican Products, Inc. has announced the launch of its full line of cases including Voyager, Adventurer, Protector, Ambassador, Interceptor (for the Apple iPhone 8 and 8 Plus backwards compatible... Read more
$100 off new 2017 13-inch MacBook Airs
B&H Photo has 2017 13″ MacBook Airs on sale today for $100 off MSRP including free shipping. B&H charges NY & NJ sales tax only: – 13″ 1.8GHz/128GB MacBook Air (MQD32LL/A): $899, $100 off... Read more
Apple restocks Certified Refurbished 13-inch...
Apple has Certified Refurbished 2015 13″ MacBook Airs available starting at $719 and 2016 models available starting at $809. An Apple one-year warranty is included with each MacBook, and shipping is... Read more
Is iPhone X Really The Future Of The Smartpho...
Should iPhone X even be called a telephone? It does of course support telephony and texting, but its main feature set is oriented to other things. It is also debatable whether it makes any rational... Read more

Jobs Board

Development Operations and Site Reliability E...
Development Operations and Site Reliability Engineer, Apple Payment Gateway Job Number: 57572631 Santa Clara Valley, California, United States Posted: Jul. 27, 2017 Read more
Specialist - Retail Customer Services and Sal...
The position listed below is not with Tennessee Interviews but with Apple , Inc. Tennessee Interviews is a private organization that works in collaboration with Read more
Specialist - Retail Customer Services and Sal...
The position listed below is not with South Carolina Interviews but with Apple , Inc. South Carolina Interviews is a private organization that works in collaboration Read more
Behavior Technician with *Apple* Consulting...
The position listed below is not with Washington Interviews but with APPLE CONSULTING Washington Interviews is a private organization that works in collaboration Read more
Infection Control RN with *Apple* Rehab - A...
The position listed below is not with Georgia Interviews but with Apple Rehab Georgia Interviews is a private organization that works in collaboration with Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.