Q129208: Pixel Replaces Foxel as Default Scale Value in Design Mode

Article: Q129208
Product(s): Microsoft FoxPro
Version(s): WINDOWS:3.0
Operating System(s): 
Keyword(s): kbcode kbvfp
Last Modified: 12-FEB-2000

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 3.0 
-------------------------------------------------------------------------------

SUMMARY
=======

In earlier releases of FoxPro, the default scale value has been the Foxel. The
definition of a foxel is:

  A foxel is equivalent to the average height and width of a character based on
  the current font of the form in which an object is contained. Foxels are
  useful when developing cross-platform applications for character-based and
  graphical platforms.

Beginning with Visual FoxPro, the default value for the Form and Class designer
is the pixel. As documented in the online Help file, the definition of a pixel
is:

  The smallest element that can be displayed on a screen or printer. Pixels are
  screen-dependent.

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

The ramifications for this can be significant. When designing a new class or
form, the default measurement unit is now the pixel. Because a pixel is
significantly smaller than a foxel, screens and all objects placed on them will
likely be mis-aligned unless the correct measurement unit is chosen.

The Scalemode property can be found on the Form Layout properties tab or it can
be accessed by code in a program. Visual FoxPro supports two entries for this
property:

  0 - Foxels
  3 - Pixels

In general, you should design forms and classes using the foxel measurement when
your application is intended to be used across platforms or when the font
metrics are likely to change (small to large fonts, for example). To ensure that
you are using the correct measurement, you will need to set it explicitly. The
following code demonstrates how to do it:

      * Demonstration of pixel versus Foxel scale modes. *
      *--------------------------------------------------*
      PUBLIC MyForm
      MyForm = CREATEOBJECT("MyForm")     && To instance an new object

      MyForm.Show                         && To Show

      DEFINE CLASS myform AS form
         scalemode = 0  && Foxels
         ADD OBJECT cmd1 as commandbutton WITH ;
                top = 10, ;
                left = 10
      ENDDEFINE

      *End code definition

With this definition, the button should appear in the lower third of the form. If
you change the scalemode to 3, the button will be moved to the upper left corner
of the screen. Again, if scalemode is not set to 0, this will have the same
effect as explicitly setting the scalemode to 3.

Alternatively, in a form, you can set this by going to the Form Layout properties
tab and choosing the appropriate value.

Additional query words: foxels pixels xplatform crossplat 3.00

======================================================================
Keywords          : kbcode kbvfp 
Technology        : kbVFPsearch kbAudDeveloper kbVFP300
Version           : WINDOWS:3.0

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1986-2002.