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.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Garmin Express 4.0.18.0 - Manage your Ga...
Garmin Express is your essential tool for managing your Garmin devices. Update maps, golf courses and device software. You can even register your device. Update maps Update software Register your... Read more
jAlbum Pro 12.6.4 - Organize your digita...
jAlbum Pro has all the features you love in jAlbum, but comes with a commercial license. With jAlbum, you can create gorgeous custom photo galleries for the Web without writing a line of code!... Read more
jAlbum 12.6.4 - Create custom photo gall...
With jAlbum, you can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly, with pro results Simply drag and drop photos into groups, choose a design... Read more
Microsoft Remote Desktop 8.0.16 - Connec...
With Microsoft Remote Desktop, you can connect to a remote PC and your work resources from almost anywhere. Experience the power of Windows with RemoteFX in a Remote Desktop client designed to help... Read more
Spotify 1.0.4.90. - Stream music, create...
Spotify is a streaming music service that gives you on-demand access to millions of songs. Whether you like driving rock, silky R&B, or grandiose classical music, Spotify's massive catalogue puts... Read more
djay Pro 1.1 - Transform your Mac into a...
djay Pro provides a complete toolkit for performing DJs. Its unique modern interface is built around a sophisticated integration with iTunes and Spotify, giving you instant access to millions of... Read more
Vivaldi 1.0.118.19 - Lightweight browser...
Vivaldi browser. 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 that users are... Read more
Stacks 2.6.11 - New way to create pages...
Stacks is a new way to create pages in RapidWeaver. It's a plugin designed to combine drag-and-drop simplicity with the power of fluid layout. Features: Fluid Layout: Stacks lets you build pages... Read more
xScope 4.1.3 - Onscreen graphic measurem...
xScope is powerful set of tools that are ideal for measuring, inspecting, and testing on-screen graphics and layouts. Its tools float above your desktop windows and can be accessed via a toolbar,... Read more
Cyberduck 4.7 - FTP and SFTP browser. (F...
Cyberduck is a robust FTP/FTP-TLS/SFTP browser for the Mac whose lack of visual clutter and cleverly intuitive features make it easy to use. Support for external editors and system technologies such... Read more

This Week at 148Apps: April 20-24, 2015
The Apps of April How do you know what apps are worth your time and money? Just look to the review team at 148Apps. We sort through the chaos and find the apps you're looking for. The ones we love become Editor’s Choice, standing out above the many... | Read more »
Discover Your Reflexes With Minimalist G...
Discover O, BYOF Studios, may look simple at first with its' color matching premise and swipe controls, but as you speed up the task becomes more daunting. [Read more] | Read more »
Here's Another Roundup of Notable A...
Now that the Apple Watch is publically available (kind of), even more apps and games have been popping up for it. Some of them are updates to existing software, others are brand new. The main thing is that they're all for the Apple Watch, and if you... | Read more »
Use Batting Average and the Apple Watch...
Batting Average, by Pixolini, is designed to help you manage your statistics. Every time you go to bat, you can use your Apple Watch to track  your swings, strikes, and hits. [Read more] | Read more »
Celebrate Studio Pango's 3rd Annive...
It is time to party, Pangoland pals! Studio Pango is celebrating their 3rd birthday and their gift to you is a new update to Pangoland. [Read more] | Read more »
Become the World's Most Important D...
Must Deliver, by cherrypick games, is a top-down endless-runner witha healthy dose of the living dead. [Read more] | Read more »
SoundHound + LiveLyrics is Making its De...
SoundHound Inc. has announced that SoundHound + LiveLyrics, will be one of the first third-party apps to hit the Apple Watch. With  SoundHound you'll be able to tap on your watch and have the app recognize the music you are listening to, then have... | Read more »
Adobe Joins the Apple Watch Lineup With...
A whole tidal wave of apps are headed for the Apple Watch, and Adobe has joined in with 3 new ways to enhance your creativity and collaborate with others. The watch apps pair with iPad/iPhone apps to give you total control over your Adobe projects... | Read more »
Z Steel Soldiers, Sequel to Kavcom'...
Kavcom has released Z Steel Soldiers, which continues the story of the comedic RTS originally created by the Bitmap Brothers. [Read more] | Read more »
Seene Lets You Create 3D Images With You...
Seene, by Obvious Engineering, is a 3D capture app that's meant to allow you to create visually stunning 3D images with a tap of your finger, and then share them as a 3D photo, video or gif. [Read more] | Read more »

Price Scanner via MacPrices.net

Final day for Best Buy’s 4 Day Sale: Up to $3...
Best Buy has the new 2015 13″ 1.6GHz/128GB MacBook Air on sale for $799.99 through April 27th. That’s $200 off MSRP, and it’s the lowest price available for this new model from any reseller. Choose... Read more
College Student Deals: Additional $50 off Mac...
Take an additional $50 off all MacBooks and iMacs at Best Buy Online with their College Students Deals Savings, valid through May 9, 2015. Anyone with a valid .EDU email address can take advantage of... Read more
Save up to $300 on a new Mac, $30 on an iPad,...
Purchase a new Mac or iPad at The Apple Store for Education and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free,... Read more
Zoho Business Apps for Apple Watch Put Select...
Pleasanton, California based Zoho has launched Zoho Business Apps for Apple Watch, a line of apps that extends Zoho business applications to let users perform select functions from an Apple Watch.... Read more
Universal Stylus Initiative Launched to Creat...
OEMs, stylus and touch controller manufacturers have announced the launch of Universal Stylus Initiative (USI), a new organization formed to develop and promote an industry specification for an... Read more
Amazon Shopping App for Apple Watch
With the new Amazon shopping app for Apple Watch, Amazon customers with one of the wearable devices can simply tap the app on the watch to purchase items in seconds, or save an idea for later. The... Read more
Mac Pros on sale for up to $260 off MSRP
B&H Photo has Mac Pros on sale for up to $260 off MSRP. Shipping is free, and B&H charges sales tax in NY only: - 3.7GHz 4-core Mac Pro: $2799, $200 off MSRP - 3.5GHz 6-core Mac Pro: $3719.99... Read more
Apple refurbished Time Capsules available for...
The Apple Store has certified refurbished Time Capsules available for $100 off MSRP. Apple’s one-year warranty is included with each Time Capsule, and shipping is free: - 2TB Time Capsule: $199, $100... Read more
Intel Compute Stick: A New Mini-Computing For...
The Intel Compute Stick, a new pocket-sized computer based on a quad-core Intel Atom processor running Windows 8.1 with Bing, is available now through Intel Authorized Dealers across much of the... Read more
Heal to Launch First One-Touch House Call Doc...
Santa Monica, California based Heal, a pioneer in on-demand personal health care services — will offer the first one-touch, on-demand house call doctor app for the Apple Watch. Heal’s Watch app,... Read more

Jobs Board

*Apple* iOS Specialist - TCML (United States...
AppleiOS Specialist Senior Apple /iOS Administrator/Engineer responsible for configuration and distribution of desktop, laptop and mobile devices to State Employees Read more
*Apple* Client Systems Solution Specialist -...
…drive revenue and profit in assigned sales segment and/or region specific to the Apple brand and product sets. This person will work directly with CDW Account Managers 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* Support Technician IV - Jack Henry a...
Job Description Jack Henry & Associates is seeking an Apple Support Technician. This position while acting independently, ensures the proper day-to-day control of Read more
*Apple* Client Systems Solution Specialist -...
…drive revenue and profit in assigned sales segment and/or region specific to the Apple brand and product sets. This person will work directly with CDW Account Managers Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.