TweetFollow Us on Twitter

Nov 91 Letters
Volume Number:7
Issue Number:11
Column Tag:Letters

Strip Printing

By Kirk Chase, Editor

Larry Resestein at August BAMADA

James Plamondon

Fourth Wednesday of the month at 7PM, in the Mountain View Room of Apple’s City Center Four building, at 20450 Steven’s Creek Boulevard, Cupertino

Larry Rosenstein, MacApp wizard, was the speaker at the August BAMADA meeting where he discussed a few ideas from his book, C++ Programming with MacApp. First, he discussed filtered commands, which are described in detail in Chapter 25 of his book. The goal of the filtered command mechanism is to reduce the amount of information that one must maintain in order to undo or redo a command.

Larry gave the example of a styled text document, containing hundreds of different style runs (a little bold Times, some 9-point Zapf Chancery, a dash of italic Courier, etc. -- a real ransom-note document). If the user selected all of the document’s styled text, and set it to plain Geneva 12, saving the previous state of the document -- with all of its different styles -- could take a lot of space; in the worst case, you might have to save off the entire document.

Filtered commands solve this problem. Instead of saving the pre-change data, and then altering the document in accordance with the command, the command just installs a filter into each affected piece of data which makes it LOOK as if it has been changed. In the example above, each style run object would be filtered to look like it was plain Geneva 12. To undo the command, the filter is simply removed; to redo it, the filter is reapplied.

The mechanics of the approach are beyond the scope of this summary; besides, you can find them in Larry’s excellent book. Suffice it to say that the use of such commands simplifies the implementation of Undo/Redo significantly, and reduces the storage costs associated with it, at the cost of slightly slower data access times.

After Larry shined his light on filtered commands, he moved on to streaming. Streaming is also discussed in his book (in Chapter 22), and is a major feature of MacApp 3.0. By using streams for data I/O, one can handle input and output more abstractly; one can stream to a file or to the clipboard with equal ease.

The basic idea is that the TStream class is responsible for reading and writing bytes, or aggregates of bytes, from and to “something.” TStream’s subclasses implement the abstract methods that do the reading an writing. For example, a TFileStream would implement reading and writing to a file, while a THandleStream would implement reading and writing to a memory block. A TCountingStream wouldn’t read or write anything -- it would just count the bytes that it was told to write; this is particularly useful when trying to find out if there’s enough room on a disk to hold a file, before you actually write it out (via a TFileStream).

Larry’s book describes streaming in much more detail than this, of course, and you’ll want to look into it, as streams are used extensively in MacApp 3.0.

Article missing

MacTutor

Due to an oversight on our part, the last part of Brendan Murphy's article on Modeless SFDialogs was missing. Here is a reprint of that final section.

Conclusion

After reading this article there are probably a lot of unanswered questions. These questions are left to the reader as an exercise (I always hated that in college). I’m not going to produce a Think C version or a MacApp version. I leave this honor to some hearty soul out there. I will release a maintenance version if enough bugs or deficiencies are brought to my attention. My hope for this piece of software is that it will someday be incorporated into Apple’s system software (7.x or 8.x) and thus make this article a moot exercise for future programmers.

In the future, I plan to write more articles on TCL and perhaps MacApp. I am already “cooking up” some ideas to remove some of the short comings of TCL, but I have not yet decided which idea to pursue. Half the battle is coming up with the idea and half the battle is sticking with the idea and half the battle is implementing the idea. Yes, that adds up to 3/2 which goes to show that anything worth doing, is more work than you thought.

A Problem Stripping

Deborah E. Meadow

Cormetrics Medical Systems, Inc.

61 Barnes Park Road North

Wallingford, CT 06492-0333

(203) 265-5631

Now that the title has caught your attention, here is somthing interesting. While a the Boston MacWorld, Deborah Meadow approached me with an unsual problem. From the above address, you can see that she works for a medical group. Her problem involves printing. Some things such as EKG strips are printed in a continuous fashion, i.e. they are not spooled by the page as Mac printing is usually done. What she would like is help in creating, hopefully, a general purpose driver to do real-time, strip printing. If you have an idea, please get in touch with her at the above address.

Cheshire Keeps on Smiling

Cheshire Grin Productions Ltd.

2145 Sherobee Rd., Ste. 43

Mississauga, Ontario, Canada L5A 3G8

Cheshire Grin has just added two new additions to their Stack Enhancers product. The first addition is the Browser Palette. This allows the user/developer to navigate cards quickly and do card management, such as renaming cards; its immediate benefit is navigation for incomplete stacks. The second addition to Stack Enhancers is the Search Palette. This palette allows you to search for text on a particular stack-great for keeping a list of cards that meet the search criterea. Contact Cheshire Grin for more information.

Prospective International Software Developers

The Software Toolworks

60 Leveroni Court

Novato, CA 94949

(415) 883-3000

Planning on making a trip overseas to a trade show or just curious about the world around you? The Software Toolworks has the product for you, World Atlas. This product puts the atlas on your computer. It comes complete with over 250 detailed maps in either black & white or color. There is also a database covering information such as population, climate, national holidays, and travel documents. Sort of a one stop shop in world travel information.

BitMap Error

Kirk Chase

MacTutor

I would like to point out an error in some code published in MacTutor, November 1990 ("Special Effects") and June 1991 ("Kolorize Your B&W Application"). Basically the code in question is the offscreen bitmap allocation function used in both articles. The offending line in the procedure NewBitMap is

bm->baseAddr=NewPtr(bm->rowBytes *(long (r->right - r->left));

This assumes a height the same size as the width. Correct it to the following:

bm->baseAddr=NewPtr(bm->rowBytes *(long (r->bottom - r->top));

Thanks to Randy Frank for pointing this out.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Skim 1.4.29 - 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
FontExplorer X Pro 6.0.2 - 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
1Password 6.7.1 - Powerful password mana...
1Password is a password manager that uniquely brings you both security and convenience. It is the only program that provides anti-phishing protection and goes beyond password management by adding Web... Read more
Vivaldi 1.9.818.44 - 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
Vivaldi 1.9.818.44 - 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
Skim 1.4.29 - 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
1Password 6.7.1 - Powerful password mana...
1Password is a password manager that uniquely brings you both security and convenience. It is the only program that provides anti-phishing protection and goes beyond password management by adding Web... Read more
FontExplorer X Pro 6.0.2 - 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
VOX 2.8.24 - Music player that supports...
VOX just sounds better! The beauty is in its simplicity, yet behind the minimal exterior lies a powerful music player with a ton of features and support for all audio formats you should ever need.... Read more
OmniPlan 3.7.1 - Robust project manageme...
With OmniPlan, you can create logical, manageable project plans with Gantt charts, schedules, summaries, milestones, and critical paths. Break down the tasks needed to make your project a success,... Read more

Latest Forum Discussions

See All

Fire Emblem Heroes event announces new m...
As reported yesterday, Nintendo was gearing up a live press event for their popular mobile game,Fire Emblem Heroes. While the stream revealed a lot of new things, the event was entirely in Japanese. Luckily we have a rundown of what was announced... | Read more »
Best games we played this week
Another week, another slate of new mobile games. Although there weren't as many big name releases as last week, there were plenty of unique video game titles that came out that's sure to keep you interested over the weekend. Everything from classic... | Read more »
Olli by Tinrocket (Photography)
Olli by Tinrocket 1.0 Device: iOS iPhone Category: Photography Price: $2.99, Version: 1.0 (iTunes) Description: Get drawn in with Olli by TinrocketOlli instantly turns your everyday moments into hand-drawn art and animations. • Watch... | Read more »
Penarium (Games)
Penarium 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: | Read more »
Fire Emblem Heroes is way more profitabl...
Profits for Nintendo's mobile game Fire Emblem Heroes are apparently impressive enough to beat out other Nintendo titles likeSuper Mario Run, despite having 10 times fewer downloads. [Read more] | Read more »
Classic series Robot Unicorn Attack 3 no...
The classic Adult Swim browser game, Robot Unicorn Attack, branched off into a series of popular mobile games. Now, the latest entry into the series, Robot Unicorn Attack 3, is available for iOS and Android mobile devices. [Read more] | Read more »
Sudoku Sweeper (Games)
Sudoku Sweeper 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: A minimalist mashup of Minesweeper and Sudoku. Logic puzzle perfection. Every row, column and zone contains a bomb and one of... | Read more »
Under Leaves (Games)
Under Leaves 1.0.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0.0 (iTunes) Description: Journey into the forest, the jungle or the depths of the deep blue sea. Find chestnuts for the pigs, a caterpillar for the... | Read more »
Ninja Pizza Girl (Games)
Ninja Pizza Girl 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: In the not-so-distant future, rampart traffic congestion has resulted in only one way to deliver pizzas across town in thirty... | Read more »
SCRAP (Games)
SCRAP 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: That day, for no apparent reason, SCRAP decided to wake up and run. He had to, because his activation was a mistake the "Factory" could... | Read more »

Price Scanner via MacPrices.net

15-inch 2.7GHz Space Gray Touch Bar MacBook P...
B&H Photo has the 15″ 2.7GHz Space Gray Touch Bar MacBook Pro in stock today and on sale for $2599…$200 off MSRP. Shipping is free, and B&H charges NY & NJ sales tax only: - 15″ 2.7GHz... Read more
13-inch 2.9GHz/256GB Space Gray Touch Bar Mac...
B&H Photo has the 13″ 2.9GHz/256GB Space Gray Touch Bar MacBook Pro in stock today and on sale for $150 off MSRP including free shipping plus NY & NJ sales tax only: - 13″ 2.9GHz/256GB Touch... Read more
21-inch iMacs on sale for up to $151 off MSRP
B&H Photo has 21″ iMacs on sale for up to $151 off MSRP, each including free shipping plus NY sales tax only: - 21″ 3.1GHz iMac 4K: $1348 $151 off MSRP - 21″ 2.8GHz iMac: $1199.99 $100 off MSRP... Read more
Weekend deal: Up to $420 off new MacBook Pros...
Apple has Certified Refurbished 2016 15″ and 13″ MacBook Pros available for $230 to $420 off original MSRP. An Apple one-year warranty is included with each model, and shipping is free: - 15″ 2.6GHz... Read more
Price drop: 15-inch 2.2GHz Retina MacBook Pro...
Amazon has dropped their price on 15″ 2.2GHz Retina MacBook Pros (MJLQ2LL/A) to $1709.99 including free shipping. Their price is $290 off MSRP for this model. Note that stock may sell out quickly at... Read more
2.8GHz Mac mini on sale for $899, save $100
B&H Photo has the 2.8GHz Mac mini (model number MGEQ2LL/A) on sale for $899 including free shipping plus NY & NJ sales tax only. Their price is $100 off MSRP. Read more
Check Apple prices on any device with the iTr...
MacPrices is proud to offer readers a free iOS app (iPhones, iPads, & iPod touch) and Android app (Google Play and Amazon App Store) called iTracx, which allows you to glance at today’s lowest... Read more
New System Clock for macOS by B-Eng Now Avail...
Fehraltorf, Switzerland based B-Eng has announced the release and immediate availability of System Clock, the company’s new system monitor and information app developed exclusively for macOS. System... Read more
DEVONtechnologies Celebrates 15th Anniversary...
DEVONtechnologies celebrates its 15th company anniversary with a 30% discount on all its software products from May 1st through 5th, 2017. In spring 2002, DEVONtechnologies opened its website and... Read more
WaterField Designs Invites Customers to Help...
San Francisco based WaterField Designs invites customers and air travelers to participate in developing the next generation in-flight travel case, the Air Porter. Frustrated with limited legroom,... Read more

Jobs Board

*Apple* Mac Computer Technician - GeekHampto...
…complex computer issues over the phone and in person? GeekHampton, Long Island's Apple Premium Service Provider, is looking for you! Come work with our crew Read more
*Apple* Mobile Master - Best Buy (United Sta...
**501505BR** **Job Title:** Apple Mobile Master **Location Number:** 000849-Gurnee-Store **Job Description:** **What does a Best Buy Apple Mobile Master do?** At Read more
Best Buy *Apple* Computing Master - Best Bu...
**498428BR** **Job Title:** Best Buy Apple Computing Master **Location Number:** 000293-Rockville-Store **Job Description:** **What does a Best Buy Apple Read more
*Apple* Mac Computer Technician - GeekHampto...
…complex computer issues over the phone and in person? GeekHampton, Long Island's Apple Premium Service Provider, is looking for you! Come work with our crew Read more
*Apple* Retail - Multiple Positions- Chicago...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.