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

Vivaldi 1.7.735.46 - An advanced browser...
Vivaldi is a browser for our friends. In 1994, two programmers started working on a web browser. Our idea was to make a really fast browser, capable of running on limited hardware, keeping in mind... Read more
HandBrake 1.0.3 - Versatile video encode...
HandBrake is a tool for converting video from nearly any format to a selection of modern, widely supported codecs. Features Supported Sources VIDEO_TS folder, DVD image or real DVD (unencrypted... Read more
Slack 2.5.1 - Collaborative communicatio...
Slack is a collaborative communication app that simplifies real-time messaging, archiving, and search for modern working teams. Version 2.5.1: New The way we load teams you don't view often has been... Read more
BBEdit 11.6.4 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
BBEdit 11.6.4 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
beaTunes 4.6.12 - Organize your music co...
beaTunes is a full-featured music player and organizational tool for music collections. How well organized is your music Library? Are your artists always spelled the same way? Any R.E.M. vs REM?... Read more
Tinderbox 7.0.1 - Store and organize you...
Tinderbox is a personal content management assistant. It stores your notes, ideas, and plans. It can help you organize and understand them. And Tinderbox helps you share ideas through Web journals... Read more
FotoMagico 5.4 - Powerful slideshow crea...
FotoMagico lets you create professional slideshows from your photos and music with just a few, simple mouse clicks. It sports a very clean and intuitive yet powerful user interface. High image... Read more
Direct Mail 4.3.9 - Create and send grea...
Direct Mail is an easy-to-use, fully-featured email marketing app purpose-built for OS X. It lets you create and send great looking email campaigns. Start your newsletter by selecting from a gallery... Read more
Tinderbox 7.0.1 - Store and organize you...
Tinderbox is a personal content management assistant. It stores your notes, ideas, and plans. It can help you organize and understand them. And Tinderbox helps you share ideas through Web journals... Read more

The best sales on the App Store this wee...
The App Store has quite an exciting lineup of discount games this week that range across a variety of genres. It's a great opportunity to catch up on some of the premium games you may have been holding off on -- and some you can even grab for free... | Read more »
The best new games we played this week
Ah, here we are again at the close of another busy week. Don't rest too easy, though. We had a lot of great new releases in mobile games this week, and now you're going to have to spend all weekend playing them. That shouldn't be too much of a... | Read more »
Rollercoaster Tycoon Touch Guide: How to...
| Read more »
Rabbids Crazy Rush Guide: How to unlock...
The Rabbids are back in a new endless running adventure, Rabbids Crazy Rush. It's more ridiculous cartoon craziness as you help the little furballs gather enough fuel (soda) to get to the moon. Sure, it's a silly idea, but everyone has dreams --... | Read more »
Tavern Guardians (Games)
Tavern Guardians 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Tavern Guardians is a Hack-and-Slash action game played in the style of a match-three. You can experience high pace action... | Read more »
Slay your way to glory in idle RPG Endle...
It’s a golden age for idle games on the mobile market, and those addictive little clickers have a new best friend. South Korean developer Ekkorr released Endless Frontier last year, and players have been idling away the hours in the company of its... | Read more »
Tiny Striker: World Football Guide - How...
| Read more »
Good news everyone! Futurama: Worlds of...
Futurama is finding a new home on mobile in TinyCo and Fox Interactive's new game, Futurama: Worlds of Tomorrow. They're really doing it up, bringing on board Futurama creator Matt Groening along with the original cast and writers. TinyCo wants... | Read more »
MUL.MASH.TAB.BA.GAL.GAL (Games)
MUL.MASH.TAB.BA.GAL.GAL 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: ENDLESS UPGRADES. CONSTANT DANGER. ANCIENT WISDOM. BOUNCY BALLS. Launch Sale, 40% OFF for a very limited time!!! MUL.... | Read more »
Dungeon Rushers (Games)
Dungeon Rushers 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Dungeon Rushers is a 2D tactical RPG combining dungeon crawler’s gameplay and turn based fights. Manage your team, loot dusty... | Read more »

Price Scanner via MacPrices.net

12-inch 1.2GHz Retina MacBooks on sale for $2...
Newegg has the 12″ 1.2GHz Space Gray Retina MacBook (sku MLH82LL/A) on sale for $1349.99 including free shipping. Their price is $250 off MSRP, and it’s the lowest price available for this model.... Read more
13-inch MacBook Airs on sale for $100 off MSR...
B&H Photo has 13″ MacBook Airs on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 1.6GHz/128GB MacBook Air (MMGF2LL/A): $899 $100 off MSRP - 13″ 1.6GHz/... Read more
9-inch 32GB Silver iPad Pro on sale for $549,...
B&H Photo has the 9.7″ 32GB Silver Apple iPad Pro on sale for $549 for a limited time. Shipping is free, and B&H charges NY sales tax only. Their price is $50 off standard MSRP for this model... Read more
13-inch 2.0GHz Apple MacBook Pros on sale for...
B&H has the non-Touch Bar 13″ 2.0GHz MacBook Pros in stock today and on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.0GHz MacBook Pro Space Gray (... Read more
15-inch Touch Bar MacBook Pros on sale for up...
B&H Photo has the new 2016 15″ Apple Touch Bar MacBook Pros in stock today and on sale for up to $150 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.7GHz Touch Bar... Read more
12-inch Retina MacBooks on sale for $1150, $1...
B&H has 12″ 1.1GHz Retina MacBooks on sale for $150 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 12″ 1.1GHz Space Gray Retina MacBook: $1149 $150 off MSRP - 12″ 1.1GHz... Read more
Apple restocks refurbished 11-inch MacBook Ai...
Apple has Certified Refurbished 11″ MacBook Airs (the latest models recently discontinued by Apple), available for up to $170 off original MSRP. An Apple one-year warranty is included with each... Read more
Apple Park Opens to Employees in April With T...
Apple has announced that Apple Park, the company’s new 175-acre campus, will be ready for employees to begin occupying in April. The process of moving more than 12,000 people will take over six... Read more
Manhattan Neighbors for Safer Telecommunicati...
A new education and advocacy group focused on cell phone and wireless risks, Manhattan Neighbors for Safer Telecommunications, launched today at http://www.ManhattanNeighbors.org. Manhattan... Read more
Portable Dual DisplayPort Monitor Dock Enable...
IOGEAR has announced the launch of its USB-C Dual DisplayPort Monitor Portable Dock (GUC3CMST). The dock enables users to easily connect two DisplayPort monitors to a USB-C or Thunderbolt 3 laptop to... Read more

Jobs Board

*Apple* Wireless Lead - T-ROC - The Retail O...
…of knowledge in wireless sales and activations to the Beautiful and NEW APPLE Experiencestore within MACYS. THIS role, APPLE Wireless Lead, isbrandnewas MACYS Read more
Manager *Apple* Systems Administration - Pu...
Req ID 3315BR Position Title Manager, Apple Systems Administration Job Description The Manager of Apple Systems Administration oversees the administration and 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
*Apple* Retail - Multiple Positions- Chicago...
SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
Manager *Apple* Systems Administration - Pu...
Req ID 3315BR Position Title Manager, Apple Systems Administration Job Description The Manager of Apple Systems Administration oversees the administration and Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.