docs/doxygen/overviews/font.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        font.h
   3 // Purpose:     topic overview
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows license
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /*!
  10
  11  @page overview_font wxFont overview
  12
  13  Class: #wxFont, #wxFontDialog
  14
  15  A font is an object which determines the appearance of text, primarily
  16  when drawing text to a window or device context. A font is determined by
  17  the following parameters (not all of them have to be specified, of course):
  18
  19  @beginDefList
  20  @itemdef{Point size, This is the standard way of referring to text size.}
  21  @itemdef{Family,
  22           Supported families are:
  23            @b wxDEFAULT, @b wxDECORATIVE, @b wxROMAN, @b wxSCRIPT, @b wxSWISS, @b wxMODERN.
  24            @b wxMODERN is a fixed pitch font; the others are either fixed or variable pitch.}
  25  @itemdef{Style, The value can be @b wxNORMAL, @b wxSLANT or @b wxITALIC.}
  26  @itemdef{Weight, The value can be @b wxNORMAL, @b wxLIGHT or @b wxBOLD.}
  27  @itemdef{Underlining, The value can be @true or @false.}
  28  @itemdef{Face name,
  29           An optional string specifying the actual typeface to be used. If @NULL,
  30           a default typeface will chosen based on the family.}
  31  @itemdef{Encoding,
  32           The font encoding (see @b wxFONTENCODING_XXX
  33           constants and the @ref fontencoding_overview for more
  34           details)}
  35  @endDefList
  36
  37  Specifying a family, rather than a specific typeface name, ensures a degree of
  38  portability across platforms because a suitable font will be chosen for the
  39  given font family, however it doesn't allow to choose a font precisely as the
  40  parameters above don't suffice, in general, to identify all the available fonts
  41  and this is where using the native font descriptions may be helpful - see
  42  below.
  43
  44  Under Windows, the face name can be one of the installed fonts on the user's
  45  system. Since the choice of fonts differs from system to system, either choose
  46  standard Windows fonts, or if allowing the user to specify a face name, store
  47  the family name with any file that might be transported to a different Windows
  48  machine or other platform.
  49
  50  @note There is currently a difference between the appearance
  51        of fonts on the two platforms, if the mapping mode is anything other than
  52        wxMM_TEXT. Under X, font size is always specified in points. Under MS
  53        Windows, the unit for text is points but the text is scaled according to the
  54        current mapping mode. However, user scaling on a device context will also
  55        scale fonts under both environments.
  56
  57
  58
  59  @section overview_font_nativeinfo Native font information
  60
  61  An alternative way of choosing fonts is to use the native font description.
  62  This is the only acceptable solution if the user is allowed to choose the font
  63  using the #wxFontDialog because the selected font cannot
  64  be described using only the family name and so, if only family name is stored
  65  permanently, the user would almost surely see a different font in the program
  66  later.
  67
  68  Instead, you should store the value returned by wxFont::GetNativeFontInfoDesc and pass
  69  it to wxFont::SetNativeFontInfo later to recreate exactly the same font.
  70
  71  Note that the contents of this string depends on the platform and shouldn't be
  72  used for any other purpose (in particular, it is not meant to be shown to the
  73  user). Also please note that although the native font information is currently
  74  implemented for Windows and Unix (GTK+ and Motif) ports only, all the methods
  75  are available for all the ports and should be used to make your program work
  76  correctly when they are implemented later.
  77
  78 */
  79