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Q80900: Windows 3.1 Application Compatibility (part 5 of 7)

Article: Q80900
Product(s): Microsoft Windows Software Development Kit
Version(s): 3.1
Operating System(s): 
Keyword(s): kb16bitonly
Last Modified: 07-FEB-2002

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The information in this article applies to:

- Microsoft Windows Software Development Kit (SDK) 3.1 
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SUMMARY
=======

Application Compatibility Document for Windows 3.1:

Due to the amount of information in this document, it has been broken into seven
pieces. To find all seven pieces of this document and the Windows 3.1
Compatibility Test checklist, query this knowledge base on the words:

  prod(winsdk) and 31compattest

      TrueType
--------

Although Windows version 3.1 includes support that seamlessly integrates TrueType
fonts into existing applications, problems with fonts can occur for Windows
version 3.0 applications that assume bitmap fonts are always available, that
Helv and Tms Rmn are always available, and that font sizes are limited. Be sure
to thoroughly check fonts in your application, including files and dialogs.
Also, because TrueType provides more fonts at more sizes and in more styles,
Windows version 3.1 may consume both printer and global memory faster than
Windows version 3.0 did. Check your applications with systems and printers that
have limited memory.

HELV AND TMS RMN FONTS:

MS Sans Serif replaces Helv, and MS Serif replaces Tms Rmn. To support Windows
version 3.0 applications that use the Helv and Tms Rmn fonts, the
[FontSubstitutes] section in the WIN.INI file maps Helv to MS Sans Serif and Tms
Rmn to MS Serif by default. It also maps Times to Times New Roman and Helvetica
to Arial.

Potential Problem:

Applications that hard code a search for Helv or Tms Rmn may encounter
difficulties after not finding these fonts.

Test:

Examine your application code and be sure there are no dependencies on the font
names Helv and Tms Rmn.

FONT ENUMERATION:

Applications should test to ensure that TrueType fonts are enumerated correctly
and that they encounter no unexpected font mapping, such as might occur when a
TrueType font substitutes for another font and line spacing changes and/or the
position of text in documents is recalculated.

Windows continues to support and is fully backward compatible with ATM, Facelift,
and Intellifont for Windows. Applications using these other font technologies
should encounter no problems.

TRUETYPE ONLY CHECKED:

Windows version 3.0 applications may behave unexpectedly if the user has set the
"Show Only TrueType Fonts in Applications" check box using the Control Panel.

Potential Problem:

An application may fail to locate any fonts if only TrueType fonts are present.

Test:

In the Control Panel, choose Fonts, select TrueType, and enable "Show Only
TrueType Fonts in Applications."

- Check the font dialog boxes in your application. It should list all the
  TrueType fonts and should not list non-TrueType fonts.

FONT SIZES:

TrueType supports a wide variety of sizes for all TrueType fonts. In Windows
version 3.1, an application usually gets the requested size if it requests a
very small or very large font.

Potential Problem:

An application that checks for the smallest or largest font by setting the
nHeight parameter in CreateFont to an extreme value will not get the expected
results.

Test:

Check fonts in dialog boxes, tool bars, and sample files for your application. Be
sure they are all readable.

FONTSUBSTITUTES:

The [FontSubstitutes] section may cause the GetTextFace function to return a face
name that the EnumFonts function does not enumerate. This is done so that an
application that asks for Helv (and expects Helv) gets a font named Helv.

Potential Problem:

An application that expects matching face names from the EnumFonts and
GetTextFace functions may encounter mismatches.

Test:

Check the application code and be sure there are no dependencies on GetTextFace
and EnumFonts matching.

ABC-SPACED FONTS:

Potential Problem:

ABC-spaced fonts can lead to misplaced cursors, highlights that do not encompass
all the text on a line, "pieces" of characters left behind after screen updates,
and unexpected clipping of fonts on printers (when a character goes outside the
printable area).

Tests:

1. Create a document in your application that contains characters close to the
  edge of the screen and the printable margins. Scroll the document, checking
  for characters (or pieces of characters) left behind.

2. Highlight text. Be sure the highlight encompasses all characters and that no
  part of any character (especially the first and last characters) is left out.

3. Print the document. Be sure that no characters are clipped at the edges of
  the printable region.

THIRD-PARTY TYPE MANAGER PROBLEMS:

Potential Problem:

Be sure to try your application with ATM, Facelift, or Intellifont for Windows
fonts installed. Do not install more that one of these font managers at a time.
Skip this test if your application does not work with these font managers under
Windows version 3.0a.

Tests:

1. Create a document under Windows version 3.0a using a type manager (such as
  ATM), bitmap, and device fonts. Look at the document under Windows version
  3.1, and be sure the screen appears the same.

2. Print the document with Windows versions 3.0a and 3.1, and be sure the output
  is identical.

FONT ENUMERATION:

Windows version 3.0 applications sometimes create multiple instances of a single
font or font family. In particular, some applications handle fonts that a
nonraster printer enumerates as different from fonts enumerated for the display,
even if the names are the same. TrueType fonts with the same name are identical
regardless of the output device. Some Windows version 3.0 applications assume
that scalable fonts cannot be available on nonscaling devices. In such cases,
the applications intentionally enumerate a single size for every TrueType font
even though other sizes are available. Furthermore, some applications assume
that bold, italic, and bold italic are always simulated from regular fonts. This
is not true with TrueType fonts.

Potential Problem:

An application may create multiple instances of the same font.

Tests:

1. If your application assumes that scalable fonts could not print on
  nonscalable devices, such as a PCL printer, it will have problems enumerating
  fonts. Check the font dialog boxes and sizes listed for TrueType fonts. Many
  sizes for each TrueType font should be listed.

2. TrueType fonts are shipped in regular, bold, italic, and bold italic. This
  can cause problems for applications that assume styles were always simulated.
  Check the font dialog boxes to be sure that each font is listed only once.

3. TrueType fonts appear for both printer and screen. This causes problems for
  applications that assume printer and screen fonts are always different.
  Select a nonraster printer (for example, PCL) and check the font dialog boxes
  to be sure each font is listed only once.

MIXING DEVICE, BITMAP, AND TRUETYPE FONTS:

In Windows version 3.1, some fonts, such as the Symbol font, may be supported by
a TrueType font, a GDI bitmap font, and a device-specific font. Applications can
get unexpected results when printing waterfalls. For example, a Symbol waterfall
to a dot matrix printer intermixes the Symbol bitmap with TrueType Symbol.
Because no Symbol font is designed for dot matrix resolution, the results can be
spectacularly unattractive.

Potential Problem:

Printing may mix device, bitmap, and TrueType fonts causing unacceptable output.

Test:

Create a document with a nonscalable printer installed, using a device font and a
TrueType font. Both fonts must have the same name. Print.

DESKTOP PUBLISHING AND INTERNATIONAL CHARACTERS:

Windows version 3.1 includes 22 new international and desktop publishing
characters. Unfortunately, these new characters appear only in TrueType fonts;
the bitmap fonts do not have them.

Potential Problem:

Changing to a bitmap font causes the new characters to appear as "blots." Some
applications may remap the character code range (128 to 159).

Tests:

1. Use a TrueType font to create a document using the desktop publishing and
  international characters. Be sure the characters appear correctly on the
  screen.

2. Select a bitmap font, and then change to a TrueType font. Be sure the
  characters still appear correctly.

3. Print the document. Be sure the printout is correct.

4. Using the Char Map application in the Accessories group of Program Manager,
  use a TrueType font to copy the desktop publishing characters to the
  clipboard and paste them into your application. Be sure the characters appear
  correctly.

NOTE: The desktop publishing characters will not be available to dialog boxes
that use bitmap fonts exclusively (such as the Find and Replace dialog boxes).

TEXT ROTATION:

Although Windows version 3.0 can rotate vector and device fonts, under certain
mapping modes it rotates these fonts differently. For compatibility, Windows
version 3.1 also rotates fonts differently. However, an application can override
this default behavior and direct Windows version 3.1 to rotate all fonts the
same by setting the CLIP_LH_ANGLES bit in the lfClipPrecision member of the
LOGFONT structure. When this bit is set, Windows version 3.1 rotates all fonts
using the same left-hand rule as Windows version 3.0 uses to rotate device
fonts.

OTHER CONSIDERATIONS:

- Some applications do not request point sizes correctly. For bitmap fonts, the
  results are acceptable because only these fonts have a limited range of sizes
  available. For TrueType fonts, output can be unacceptable because any size
  requested is available.

- Applications sometimes set the tmCharWidth to request specific fonts, but
  Windows now stretches or compresses a TrueType font to match the requested
  width. Some applications make assumptions that work for bitmaps in many cases
  but that lead to squashed or clipped lines with TrueType fonts.

- Windows version 3.1 adds 13 or more fonts to the default list. Some
  applications may break when more fonts of more types in more styles are
  enumerated. They do not have test cases that can account for the additional
  fonts.

Additional query words: 3.10

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Keywords          : kb16bitonly 
Technology        : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK310
Version           : :3.1

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