TweetFollow Us on Twitter

June 96 - Print Hints: The Top 10 Printing Crimes Revisited

Print Hints: The Top 10 Printing Crimes Revisited

DAVE POLASCHEK

They say some things never change. Although it's been four years since Pete "Luke" Alexander wrote about the top 10 printing crimes in develop, people are still committing some of the same crimes. There are also a few new crimes to add to the list. So, here they are, the updated top 10 printing crimes (ordered on a combined frequency and hideousness scale):


    10. Having insufficient free memory at print time.

    9. Coloring outside the lines.

    8. Misusing the PostScriptHandle picture comment.

    7. Calling PrintDefault or PrValidate before PrOpen.

    6. Avoiding the print dialogs, especially PrJobDialog.

    5. Accessing undocumented fields in the print record.

    4. Not checking error return values.

    3. Making low-level Printing Manager calls.

    2. Not using QuickDraw GX print dialogs if QuickDraw GX is present.

    1. Adding printing to your application last.

Now let's look at how to avoid these crimes. The solutions are relatively easy.

SOLVING THE PRINTING CRIMES

10. Having insufficient free memory at print time.

Some printer drivers use a lot of memory. When a driver runs out of memory, the results are usually pretty bad, so you should give printer drivers as much memory as possible. Unfortunately, memory requirements vary from driver to driver, so it's hard to predict how much memory a driver will need.

Solution: Unload all unneeded code and resources before printing.

9. Coloring outside the lines.

Many applications draw outside the printable area of the page when printing. This can happen if the user has extended objects beyond the printable area. Drawing unneeded objects causes extra work for the driver and the printer, which affects performance. In some cases, the driver also needs to allocate extra memory to hold the objects or the enclosing rectangle.

Solution: Draw only the portions of objects that will appear on the page. This can be determined by looking at the rPage field in the printer information record (which is in the prInfo field of the print record).

8. Misusing the PostScriptHandle picture comment.

The PostScriptHandle picture comment is designed to add PostScript (TM) code to a page containing QuickDraw graphics. It's not designed to send multiple pages of pre-generated PostScript code to a printer (for that, you need to use the Pap.WorkStation.o library).

Solution: Use the PostScriptHandle picture comment only to draw a self-contained image, which will be added to any QuickDraw graphics already on the page. If the PostScript code needs to change the graphics state, it should save and restore the state. Think of the picture comment as a way to include an EPS image, with all the restrictions placed on EPS by Adobe (TM) (as specified in Appendix H of the PostScript Language Reference Manual, second edition). The PostScript code should be compatible with both Level 1 and Level 2 PostScript, and you should include a QuickDraw version of the graphic so that your users can print to a non-PostScript printer.

    For more information on how to use the PostScriptHandle picture comment, see Technote 1032, "Mixing QuickDraw & PostScript Printing from Your App: Some Gotchas," and Appendix B of Inside Macintosh: Imaging With QuickDraw.*

7. Calling PrintDefault or PrValidate before PrOpen.

The documentation for the Printing Manager (Chapter 9 of Inside Macintosh: Imaging With QuickDraw) mentions that you need to call PrOpen before calling any other Printing Manager functions. Unfortunately, the descriptions for PrintDefault and PrValidate don't repeat this warning.

Solution: Always call PrOpen before calling any other Printing Manager calls.

6. Avoiding the print dialogs, especially PrJobDialog.

Some applications try to avoid print dialogs because either user interaction isn't possible or the developer thinks the user will make a mistake. Because all of the many options for the current drivers, most notably LaserWriter 8, cannot be stored in the print record, you need to call PrJobDialog so that the driver can read in the options from where they're stored (usually in the preferences file). If you don't call PrJobDialog, the driver can't set up the print record correctly, and you might not get the output you expected. The solution should be to call PrJobMerge, but in many drivers PrJobMerge does a less than perfect job.

Solution: Call PrJobDialog before printing to set up your print record correctly, or use QuickDraw GX, which supports dialog-free printing.

5. Accessing undocumented fields in the print record.

Many of the fields in the print record are undocumented or documented as private. Printer drivers can use these fields however they choose. What works for one driver might cause another to crash or to print zillions of pages you don't want.

Solution: Use only the fields in the print record that are documented as public in Chapter 9 of Inside Macintosh: Imaging With QuickDraw.

4. Not checking error return values.

After any call to a Printing Manager function, you should check PrError. If you're calling PrGeneral, you should also check the iError field in the TGnlData structure. Be aware that newer drivers return errors that older drivers didn't. For example, PrStlDialog in LaserWriter 8 can return an error if the preferences file is missing or corrupted; many applications don't check for this error, and later crash when they've pushed the driver completely off the cliff.

Solution: Always check and handle printing errors. See the Macintosh Technical Note "A Printing Loop That Cares..." (PR 10) and the article "Meet PrGeneral" in develop Issue 3.

3. Making low-level Printing Manager calls.

The low-level Printing Manager routines, such as PrDrvrOpen, are obsolete and unsupported.

Solution: Never call the low-level routines.

2. Not using QuickDraw GX print dialogs if QuickDraw GX is present.

When you call the classic Printing Manager functions and QuickDraw GX is active, the user gets the old-style "compatibility dialogs," which lack many of the features that are provided in the QuickDraw GX print dialogs. There are two problems with this: the user doesn't have access to all of the QuickDraw GX features; and when some applications call the QuickDraw GX print dialog functions and others don't, two very different printing experiences are presented to the user.

Solution: Call the QuickDraw GX print dialog functions in your print loop if QuickDraw GX is present. For help, see the article "Adding QuickDraw GX Printing to QuickDraw Applications" in develop Issue 19. The complete documentation can be found in Inside Macintosh: QuickDraw GX Printing.

1. Adding printing to your application last.

Four years later, this is still the number-one printing crime. A lot of developers leave printing until near the end of the product development cycle. When problems are encountered, Developer Technical Support gets messages like: "My application can't print, and I've got to ship today. Please answer as soon as possible."

Solution: Hook up your print loop as early as possible. As you add each new feature to your application, print a page or two. Make sure that things are still working as expected. When you take this approach, any features that cause printing problems get noticed early, and you'll have time to fix them.

A CLOSING NOTE

If you're committing any of the crimes on this list, your customers are probably seeing things they don't like when they print. This list is also far from comprehensive, as people continue to find new and unique ways to abuse the Macintosh print architecture.

Looking ahead, printing will be changing in a big way. Mac OS 8 will use QuickDraw GX as the printing model. As changes occur, there will be Technotes, develop articles, and other sources of information. So keep your eyes open, and remember, don't commit too many printing crimes. Crime doesn't pay.

DAVE POLASCHEK supports printing and font-related issues in Apple's Developer Technical Support group. Dave was last seen wandering the halls muttering, "This will all be better in Mac OS 8" and laughing maniacally.*

Thanks to Pete "Luke" Alexander, Paul Danbold, Dave Hersey, and Jim Zandee for reviewing this column.

 
AAPL
$103.30
Apple Inc.
+0.80
MSFT
$45.09
Microsoft Corpora
-0.34
GOOG
$577.33
Google Inc.
+5.73

MacTech Search:
Community Search:

Software Updates via MacUpdate

TextSoap 7.4.0 - Flexible text editing u...
TextSoap is for people who work with text. TextSoap effortlessly cleans up text from endlessly different formats. Wash away unwanted characters, spaces, tabs. Fix paragraphs with hard returns at the... Read more
NetShade 6.0.2 - Browse privately using...
NetShade is an Internet security tool that conceals your IP address on the web. NetShade routes your Web connection through either a public anonymous proxy server, or one of NetShade's own dedicated... Read more
Mac DVDRipper Pro 5.0 - Copy, backup, an...
Mac DVDRipper Pro is the DVD backup solution that lets you protect your DVDs from scratches, save your batteries by reading your movies from your hard disk, manage your collection with just a few... Read more
pwSafe 3.1 - Secure password management...
pwSafe provides simple and secure password management across devices and computers. pwSafe uses iCloud to keep your password databases backed-up and synced between Macs and iOS devices. It is... Read more
StatsBar 1.8 - Monitor system processes...
StatsBar gives you a comprehensive and detailed analysis of the following areas of your Mac: CPU usage Memory usage Disk usage Network and bandwidth usage Battery power and health (MacBooks only)... Read more
Path Finder 6.5.5 - Powerful, award-winn...
Path Finder is a file browser that combines the familiar Finder interface with the powerful utilities and innovative features. Just a small selection of the Path Finder 6 feature set: Dual pane... Read more
QuarkXPress 10.2.1 - Desktop publishing...
With QuarkXPress, you can communicate in all the ways you need to -- and always look professional -- in print and digital media, all in a single tool. Features include: Easy to Use -- QuarkXPress is... Read more
Skype 6.19.0.450 - Voice-over-internet p...
Skype allows you to talk to friends, family and co-workers across the Internet without the inconvenience of long distance telephone charges. Using peer-to-peer data transmission technology, Skype... Read more
Capo 3.1.2 - Slow down and learn to play...
Capo lets you slow down your favorite songs so you can hear the notes and learn how they are played. With Capo, you can quickly tab out your songs atop a highly-detailed OpenCL-powered spectrogram... Read more
VueScan 9.4.41 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more

Latest Forum Discussions

See All

Modern Combat 5 Gets a Major Multiplayer...
Modern Combat 5 Gets a Major Multiplayer Update Posted by Jessica Fisher on September 2nd, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Alien Creeps TD Review
Alien Creeps TD Review By Jennifer Allen on September 2nd, 2014 Our Rating: :: EXPENSIVE DEFENSESUniversal App - Designed for iPhone and iPad Alien Creeps TD would be a fun if unremarkable Tower Defense game, but its heavy focus on... | Read more »
The Journey Down: Chapter Two Review
The Journey Down: Chapter Two Review By Jennifer Allen on September 2nd, 2014 Our Rating: :: DARK YET ENTICINGUniversal App - Designed for iPhone and iPad It’s a little dark, in every sense of the word, but The Journey Down:... | Read more »
Function Space, a Social Network App for...
Function Space, a Social Network App for Science, Launches on iOS Posted by Ellis Spice on September 2nd, 2014 [ permalink ] | Read more »
Stupidfast – How Taylor Martinez Switche...
How do you make an Endless Running game more than just another Endless Running game? By adding real life prizes to it, of course! That’s the thinking behind StupidFast: a game designed for football enthusiasts, and the brainchild of former college... | Read more »
Little Raiders: Robin’s Revenge Review
Little Raiders: Robin’s Revenge Review By Jennifer Allen on September 2nd, 2014 Our Rating: :: CASUAL RAIDINGUniversal App - Designed for iPhone and iPad Combining simple combat with village building is a potent combination for... | Read more »
Treasure Tombs: Ra Deal Coming from Bulk...
Treasure Tombs: Ra Deal Coming from Bulkypix and Dark Tonic This Fall Posted by Jessica Fisher on September 2nd, 2014 [ permalink ] Dark Tonic and | Read more »
Pirate Bash Review
Pirate Bash Review By Nadia Oxford on September 2nd, 2014 Our Rating: :: BAD PIRATES, GOOD TIMESUniversal App - Designed for iPhone and iPad Pirate Bash’s turn-based battles add an intriguing twist to a typical physics game.   | Read more »
Tiny Tower Vegas Review
Tiny Tower Vegas Review By Jennifer Allen on September 2nd, 2014 Our Rating: :: STEADY DEVELOPMENTUniversal App - Designed for iPhone and iPad Build a huge tower again but Vegas-style in Tiny Tower Vegas.   | Read more »
The Manhattan Project Review
The Manhattan Project Review By Andrew Fisher on September 2nd, 2014 Our Rating: :: ROCKET SCIENCEUniversal App - Designed for iPhone and iPad The Manhattan Project offers a great Euro-style gameplay experience, but it is totally... | Read more »

Price Scanner via MacPrices.net

Apple refurbished iPads available for up to $...
Apple is offering Certified Refurbished iPad Airs for up to $140 off MSRP. Apple’s one-year warranty is included with each model, and shipping is free. Stock tends to come and go with some of these... Read more
Are We Now In The Post-Post-PC Era?
A longtime and thoroughgoing laptop aficionado, I was more than a little dismayed by Steve Jobs’s declaration back in 2010 when he sprang the iPad on an unsuspecting world. that we’d entered a “post-... Read more
PC Outlook Improves, But 2014 Shipments Still...
According to the International Data Corporation (IDC) Worldwide Quarterly PC Tracker, worldwide PC shipments are expected to fall by -3.7 percent in 2014. To hat’s actually an improvement from the... Read more
IDC Lowers Tablet Sales Projections for 2014...
Following a second consecutive quarter of softer than expected demand, International Data Corporation (IDC) has lowered its worldwide tablet plus 2-in-1 forecast for 2014 to 233.1 million units. The... Read more
Apple now offering refurbished 21-inch 1.4GHz...
The Apple Store is now offering Apple Certified Refurbished 21″ 1.4GHz iMacs for $929 including free shipping plus Apple’s standard one-year warranty. Their price is $170 off the cost of new models,... Read more
Save $50 on the 2.5GHz Mac mini, on sale for...
B&H Photo has the 2.5GHz Mac mini on sale for $549.99 including free shipping. That’s $50 off MSRP, and B&H will also include a free copy of Parallels Desktop software. NY sales tax only. Read more
Save up to $300 on an iMac with Apple refurbi...
The Apple Store has Apple Certified Refurbished iMacs available for up to $300 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free. These are the best prices on... Read more
The Rise of Phablets
Carlisle & Gallagher Consulting Group, a businesses and technology consulting firm focused solely on the financial services industry, has released an infographic depicting the convergence of... Read more
Bad Driver Database App Allows Good Drivers t...
Bad Driver Database 1.4 by Facile Group is a new iOS and Android app that lets users instantly input and see how many times a careless, reckless or just plain stupid driver has been added to the... Read more
Eddy – Cloud Music Player for iPhone/iPad Fre...
Ukraine based CapableBits announces the release of Eddy, its tiny, but smart and powerful cloud music player for iPhone and iPad that allows users to stream or download music directly from cloud... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
Senior Event Manager, *Apple* Retail Market...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global event strategy. Delivering an overarching brand story; in-store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.