Q152136: HOWTO: Know if Large/Small Font Is in Use Under Win95/98/Me/NT

Article: Q152136
Product(s): Microsoft Visual Basic for Windows
Version(s): 4.0,5.0,6.0
Operating System(s): 
Keyword(s): kbprint kbAPI kbPrinting kbSDKWin32 kbVBp kbVBp400 kbVBp500 kbVBp600 kbGrpDSVB kbDSuppo
Last Modified: 07-SEP-2001

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The information in this article applies to:

- Microsoft Visual Basic Learning Edition for Windows, versions 6.0, 5.0 
- Microsoft Visual Basic Professional Edition for Windows, versions 6.0, 5.0 
- Microsoft Visual Basic Enterprise Edition for Windows, versions 6.0, 5.0 
- Microsoft Visual Basic Control Creation Edition for Windows, version 5.0 
- Microsoft Visual Basic Standard Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0 
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SUMMARY
=======

Determining whether Windows 95, Windows 98, Windows Me, or Windows NT 3.51 is
using large or small fonts can be done from Visual Basic through Windows API
calls. The API that retrieves information about the physical font selected for a
device context is GetTextMetrics().

MORE INFORMATION
================

The theory of determining whether a large or small font is used under Windows
95, Windows 98, Windows Me, or Windows NT 3.51 is based on the assumption that
the Windows display driver uses the default value VGASYS.FON for Small Fonts and
8514SYS.FON for Large Fonts. If the user changes the default system font
manually to any other value, this theory will not apply.

Step-by-Step Example
--------------------

1. Get the handle of the Desktop window.

2. Get the Device Context for the entire Desktop window (including borders,
  scroll bars, captions, menus, and so on).

3. Set the mapping mode to pixels.

4. Get the size of the system font.

5. Reset the mapping mode to its original setting.

6. Release the device context obtained through a call to GetWindowDC.

If the system font is more than 16 pixels high, then large fonts are being used.

Sample Code
-----------

     '** TYPES **
     Type TEXTMETRIC
       tmHeight As Integer
       tmAscent As Integer
       tmDescent As Integer
       tmInternalLeading As Integer
       tmExternalLeading As Integer
       tmAveCharWidth As Integer
       tmMaxCharWidth As Integer
       tmWeight As Integer
       tmItalic As String * 1
       tmUnderlined As String * 1
       tmStruckOut As String * 1
       tmFirstChar As String * 1
       tmLastChar As String * 1
       tmDefaultChar As String * 1
       tmBreakChar As String * 1
       tmPitchAndFamily As String * 1
       tmCharSet As String * 1
       tmOverhang As Integer
       tmDigitizedAspectX As Integer
       tmDigitizedAspectY As Integer
     End Type

     '** Win32 API DECLARATIONS **
     Declare Function GetTextMetrics Lib "gdi32" Alias "GetTextMetricsA" _
      (ByVal hdc As Long, lpMetrics As TEXTMETRIC) As Long
     Declare Function GetDesktopWindow Lib "user32" () As Long
     Declare Function GetWindowDC Lib "user32" (ByVal hwnd As Long) As Long
     Declare Function ReleaseDC Lib "user32" (ByVal hwnd As Long, ByVal hdc _
      As Long) As Long
     Declare Function SetMapMode Lib "gdi32" (ByVal hdc As Long, ByVal _
     nMapMode As Long) As Long

     '** CONSTANTS **
     Global Const MM_TEXT = 1

     '** Function **
     Public Function gbl_GetFontRes$()
     Dim hdc, hwnd, PrevMapMode As Long
     Dim tm As TEXTMETRIC

       ' Set the default return value to small fonts
       gbl_GetFontRes$ = "VGA"

       ' Get the handle of the desktop window
       hwnd = GetDesktopWindow()

       ' Get the device context for the desktop
       hdc = GetWindowDC(hwnd)
       If hdc Then
         ' Set the mapping mode to pixels
         PrevMapMode = SetMapMode(hdc, MM_TEXT)

         ' Get the size of the system font
         GetTextMetrics hdc, tm

         ' Set the mapping mode back to what it was
         PrevMapMode = SetMapMode(hdc, PrevMapMode)

         ' Release the device context
         ReleaseDC hwnd, hdc

         ' If the system font is more than 16 pixels high,
         ' then large fonts are being used
         If tm.tmHeight > 16 Then gbl_GetFontRes$ = "8514"
       End If

     End Function

Additional query words:

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Keywords          : kbprint kbAPI kbPrinting kbSDKWin32 kbVBp kbVBp400 kbVBp500 kbVBp600 kbGrpDSVB kbDSupport 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500Search kbVB500 kbVB600 kbVB400Search kbVB400 kbZNotKeyword3
Version           : :4.0,5.0,6.0
Issue type        : kbhowto

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