TweetFollow Us on Twitter

May 93 - WAMADA Notes

WAMADA Notes

John MacVeigh

The February WAMADA meeting was held a week late to avoid conflicting with MADACON. As a result, members who traveled to San Diego had a chance to report on the latest news from the conference. It will suffice to say that no one leapt for the phone to change their current development plans. The expected release of another MacApp update was the piece of news most immediately useful to our members. Component Software seems to be off to a good start with their plan to involve third parties in the enhancement of Component Workshop™. This could become a key weapon in their upcoming battle for market share with Symantec's Think C++. Bedrock is still on the horizon, and the viability of a single framework which provides a "native" look and feel on more than one platform remains barely tested. At the 50,000 foot level (a common Apple metaphor for "the big picture") the concept of writing frameworks to encapsulate your application's knowledge is the latest programming paradigm. Dave Wilson was the most public advocate of this idea, Taligent the most subtle.

Threads and Asynchronicity

The second part of the February meeting focused on ways of providing multiple execution paths in MacApp applications. Yvon Perreault of Cactus Inc. (a large-format color printing company) presented some sample code for the use of Apple's Threads package to provide asynchronous polling of PPC I/O completion calls. One "gotcha" with using threads is that segments can not be unloaded while a thread is executing, and since the main program is also a thread, MacApp's auto-unload feature had to be disabled.

Phil Flack of McDonnell Douglas Aerospace showed his code which provides event handling while the mouse is held down in controls. This was used to allow the monitoring of real-time devices which can transmit data to the Mac at any time. Phil overrode Button, CheckBox and Radio controls to set the control's action proc to a function which calls PollEvent during tracking. The key "trick" to making this work is to call Focus after PollEvent has returned. If the routine which is calling PollEvent is performing drawing, you need to also save off and restore the visRgn, clipRgn, and state of the fUpdating flag during the call.

Phil and coworker Mark Gerl also showed some code for a TEventHandler class called TTimedHandler which serves as an intermediary for TBehaviors on the application's idle chain. Since TBehaviors are not descended from TEventHandler, they can not directly be part of the idle chain. By using a TTimedHandler, a TBehavior can indirectly add itself to the idle chain. The TTimedHandler just passes the DoIdle call through to the TBehavior. Lastly, they described how the use of a state machine within idle methods can be used to break up processing of lengthy tasks without destroying the responsiveness of the user interface.

Affiliate Matters

The March WAMADA meeting fell four days after the infamous blizzard of '93, and squarely on Saint Patrick's Day. As a result, attendance also fell. Still, almost a dozen attendees gathered and, to start the meeting, tackled the subject of becoming an official MADA affiliate. The chief concern was that an admittance charge for non-members would drive people away, rather than encourage them to pay for membership. This lead to a discussion on how to structure MADA's fees and benefits. One proposed benefit of becoming an official affiliate is that we would receive a small share of the profits from MADA products sold at meetings. Since this is an inconvenient way to purchase software, it was suggested that a member's affiliation be recorded when they sign up, and that the affiliate get a cut from any MADA purchase which they made. Electronic access to bulletin boards is a common and often essential part of our jobs, so it was suggested that MADA establish a board on one or more of the commercial systems and limit access to members only. (Using existing systems removes the costs of billing and some administration from MADA, and provides the most widespread service). Also suggested was a more staggered fee structure, where a higher fee gains you increasing access to MADA's benefits, namely: printed information, books and software, on-line services, meetings and conferences. The question of where affiliate meetings fell in this list of services was left unanswered. Since the board member writing the affiliates rules (Leslie Jeffries) is also in charge of WAMADA, we agreed that becoming an affiliate was a good thing to do, but we wanted to see a more complete design of the implementation before making a formal declaration (typical OO programmers, huh?).

Mitem View

Our March speaker was Dan Corenzwit of Mitem Corporation. Mitem makes MitemView™, a communications product which people often associate exclusively with HyperCard. While HyperCard is the original interface for MitemView, it is no longer the only one. Now in its fourth generation, MitemView can make use of HyperCard, 4D, and C++. Note that I said "make use of" rather than "be used by". This is because Mitem considers MitemView (MV) to be a framework rather than a library. Dan credits Dave Wilson's session at MADACON for putting the difference in perspective. A library provides services which your application must determine how and when to call. A framework provides functionality that calls your application's additions at the appropriate time.

In the case of MV the functionality provided is the ability to recognize the arrival of messages and associated data from remote machines (usually mainframes) and then call your code to handle the message and its data. Its primary market is people who need to use "legacy" applications (all those mainframe COBOL applications which communicate with hardwired terminals) on their micros. Dan explained that MV views the remote system as a non-sequential, non-deterministic state machine and attempts to linearize the complexity of moving between states. MV works asynchronously (hmmm, I see a trend here!). It accepts input from a variety of communication services (SNA, TCP/IP, etc.) examines the "presentation" of the data (sort of a generalized terminal emulation) and matches incoming patterns with pre-built messages which it then sends to you. MV is able to update itself on the fly, from information provided by the sender, if a new configuration is needed to handle changes in the presentation.

To support MacApp, Mitem provides several C++ classes, along with code which is installed in your application as resources. The MV communication objects are not part of the target chain. This allows interactions with the remote machine to work in parallel with user interface activity. When MV recognizes a pattern it sends your code a message in the form of a message name. This name is turned into a method call by way of a registration table which your application builds. The result is that your application becomes a sort of way station between two users: the person running it, and the remote machine sending in data.

In combination with the previous month's discussion of handling asynchronous I/O, I found the asynchronous nature of MitemView its most interesting feature. Dan showed that responding to messages from MV in the proper order can improve response time, by taking the remote machine's processing time into account. As operating systems (including the Mac's) move towards providing multi-threading and multi-processing services, those of us who long ago became comfortable with event-based programming will have to take the next step to working with these new services. Thinking back to MADACON, I don't recall many vendors touting multi-threading as a factor in the design of their frameworks (SmalltalkAgents is the only exception that comes to mind). Let's hope this changes as fast as the new OSs change.

If you're in the D.C. area, and interested in object oriented programming, give WAMADA a visit. We meet every third Wednesday at McDonnell Douglas in Tyson's Corner, Virginia, beginning around 7:15 p.m. For a map, send a message to JEFFRIES.L on AppleLink, or call Leslie at (301) 340-5126 during business hours (EST).

 
AAPL
$98.38
Apple Inc.
-0.64
MSFT
$43.89
Microsoft Corpora
-0.09
GOOG
$585.61
Google Inc.
-4.99

MacTech Search:
Community Search:

Software Updates via MacUpdate

Drive Genius 3.2.4 - Powerful system uti...
Drive Genius is an OS X utility designed to provide unsurpassed storage management. Featuring an easy-to-use interface, Drive Genius is packed with powerful tools such as a drive optimizer, a... Read more
Vitamin-R 2.15 - Personal productivity t...
Vitamin-R creates the optimal conditions for your brain to work at its best by structuring your work into short bursts of distraction-free, highly focused activity alternating with opportunities for... Read more
Toast Titanium 12.0 - The ultimate media...
Toast Titanium goes way beyond the very basic burning in the Mac OS and iLife software, and sets the standard for burning CDs, DVDs, and now Blu-ray discs on the Mac. Create superior sounding audio... Read more
OS X Yosemite Wallpaper 1.0 - Desktop im...
OS X Yosemite Wallpaper is the gorgeous new background image for Apple's upcoming OS X 10.10 Yosemite. This wallpaper is available for all screen resolutions with a source file that measures 5,418... Read more
Acorn 4.4 - Bitmap image editor. (Demo)
Acorn is a new image editor built with one goal in mind - simplicity. Fast, easy, and fluid, Acorn provides the options you'll need without any overhead. Acorn feels right, and won't drain your bank... Read more
Bartender 1.2.20 - Organize your menu ba...
Bartender lets you organize your menu bar apps. Features: Lets you tidy your menu bar apps how you want. See your menu bar apps when you want. Hide the apps you need to run, but do not need to... Read more
TotalFinder 1.6.2 - Adds tabs, hotkeys,...
TotalFinder is a universally acclaimed navigational companion for your Mac. Enhance your Mac's Finder with features so smart and convenient, you won't believe you ever lived without them. Tab-based... Read more
Vienna 3.0.0 RC 2 :be5265e: - RSS and At...
Vienna is a freeware and Open-Source RSS/Atom newsreader with article storage and management via a SQLite database, written in Objective-C and Cocoa, for the OS X operating system. It provides... Read more
VLC Media Player 2.1.5 - Popular multime...
VLC Media Player is a highly portable multimedia player for various audio and video formats (MPEG-1, MPEG-2, MPEG-4, DivX, MP3, OGG, ...) as well as DVDs, VCDs, and various streaming protocols. It... Read more
Default Folder X 4.6.7 - 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... Read more

Latest Forum Discussions

See All

Note Review
Note Review By Jennifer Allen on July 29th, 2014 Our Rating: :: TOO SIMPLEiPhone App - Designed for the iPhone, compatible with the iPad Note is a note taking app that’s a little too short on features to be worth its asking price... | Read more »
Chainsaw Warrior Goes on Sale & Ther...
Chainsaw Warrior Goes on Sale & There’s a Chance to Win a Copy of the Original Board Game Posted by Jennifer Allen on July 29th, 2014 [ permalink | Read more »
It Came From Canada: Tiny Tower Vegas
If you go to a casino, you might make a lot of money. If you run a casino, you’re guaranteed to make a lot of money. The choice seems pretty obvious. So while waiting for your shady real estate deals to move forward, get prepared with Tiny Tower... | Read more »
Z Hunter Review
Z Hunter Review By Lee Hamlet on July 29th, 2014 Our Rating: :: RIGHT ON TARGETUniversal App - Designed for iPhone and iPad While it might not necessarily break new ground, Z Hunter has enough tricks up its sleeve to ensure that... | Read more »
Huge Update Comes To Duet, Adding 48 New...
Huge Update Comes To Duet, Adding 48 New Stages Posted by Jennifer Allen on July 29th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Sharknado: The Video Game Available Now....
Sharknado: The Video Game Available Now. Seriously. Posted by Rob Rich on July 29th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Frog Orbs 2 Review
Frog Orbs 2 Review By Nadia Oxford on July 29th, 2014 Our Rating: :: THIS MAGIC IS A TAD MONOTONOUS Universal App - Designed for iPhone and iPad Frog Orbs 2 is repetitive, but younger players should enjoy it nonetheless.   | Read more »
Puzzix Review
Puzzix Review By Jennifer Allen on July 29th, 2014 Our Rating: :: NICE IDEAUniversal App - Designed for iPhone and iPad A little like Tetris, Puzzix is all about piecing together blocks and watching them vanish. It could do with... | Read more »
Cannonball eMail is Now Live – Works Wit...
Cannonball eMail is Now Live – Works With Gmail, Yahoo, Outlook, Hotmail, and AOL Posted by Jessica Fisher on July 29th, 2014 [ permalink ] | Read more »
To The End Review
To The End Review By Lee Hamlet on July 29th, 2014 Our Rating: :: A VICIOUS CYCLEUniversal App - Designed for iPhone and iPad To The End will test players’ patience, timing, and dedication as they try to navigate all 13 levels in... | Read more »

Price Scanner via MacPrices.net

WaterField Unveils 15″ Outback Solo & 13″...
Hard on the heels of Apple’s refreshed MacBook Pro Retina laptops announcement, WaterField Designs has unveiled a 15-inch version of the waxed-canvas and leather Outback Solo and a 13-inch version of... Read more
New Roxio Toast 12 Delivers Digital Media Pow...
Roxio Toast 12 is a hub for sharing digital media to virtually any platform or device. has introduced two new additions to its Roxio Toast product family – Roxio Toast 12 Titanium and Roxio Toast 12... Read more
The lowest prices on leftover Retina MacBook...
Best Buy has dropped prices on leftover 13″ and 15″ Retina MacBook Pros by up to $300 off original MSRP on their online store for a limited time. Choose free local store pickup (if available) or free... Read more
Apple Updates MacBook Pro with Retina Display...
Apple today updated its MacBook Pro with Retina display with faster processors and double the amount of memory in both entry-level configurations. MacBook Pro with Retina display features a Retina... Read more
Up to $250 price drop on leftover 15-inch Mac...
B&H Photo has dropped prices on 2013 15″ Retina MacBook Pros by as much as $250 off original MSRP. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.3GHz Retina MacBook Pro: $2349... Read more
Updated MacBook Pro Price Trackers
We’ve updated our MacBook Pro Price Trackers with the latest information on prices, bundles, and availability on the new 2014 models from Apple’s authorized internet/catalog resellers as well as... Read more
Apple updates MacBook Pros with slightly fast...
Apple updated 13″ and 15″ Retina MacBook Pros today with slightly faster Haswell processors. 13″ models now ship with 8GB of RAM standard, while 15″ MacBook Pros ship with 16GB across the board. Most... Read more
Apple drops price on 13″ 2.5GHz MacBook Pro b...
The Apple Store has dropped their price for the 13″ 2.5GHz MacBook Pro by $100 to $1099 including free shipping. Read more
Apple drops prices on refurbished 2013 MacBoo...
The Apple Store has dropped prices on Apple Certified Refurbished 13″ and 15″ 2013 MacBook Pros, with model now available starting at $929. Apple’s one-year warranty is standard, and shipping is free... Read more
iOS 8 and OS X 10.10 To Support DuckDuckGo As...
Writing for Quartz, Dan Frommer reports that Apple’s forthcoming iOS 8 and OS X 10.10 operating systems version updates will allow users to select DuckDuckGo as their default search engine. He notes... Read more

Jobs Board

Sr Software Lead Engineer, *Apple* Online S...
Sr Software Lead Engineer, Apple Online Store Publishing Systems Keywords: Company: Apple Job Code: E3PCAK8MgYYkw Location (City or ZIP): Santa Clara Status: Full Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
Sr. Product Leader, *Apple* Store Apps - Ap...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.