docs/doxygen/overviews/font.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        font.h
   3 // Purpose:     topic overview
   4 // Author:      wxWidgets team
   5 // Licence:     wxWindows licence
   6 /////////////////////////////////////////////////////////////////////////////
   7
   8 /**
   9
  10 @page overview_font wxFont Overview
  11
  12 @tableofcontents
  13
  14 A font is an object which determines the appearance of text, primarily when
  15 drawing text to a window or device context. A font is determined by the
  16 following parameters (not all of them have to be specified, of course):
  17
  18 @beginDefList
  19 @itemdef{Point size, This is the standard way of referring to text size.}
  20 @itemdef{Family,
  21         Supported families are:
  22         @b wxDEFAULT, @b wxDECORATIVE, @b wxROMAN, @b wxSCRIPT, @b wxSWISS, @b wxMODERN.
  23         @b wxMODERN is a fixed pitch font; the others are either fixed or variable pitch.}
  24 @itemdef{Style, The value can be @b wxNORMAL, @b wxSLANT or @b wxITALIC.}
  25 @itemdef{Weight, The value can be @b wxNORMAL, @b wxLIGHT or @b wxBOLD.}
  26 @itemdef{Underlining, The value can be @true or @false.}
  27 @itemdef{Face name,
  28         An optional string specifying the actual typeface to be used. If @NULL,
  29         a default typeface will chosen based on the family.}
  30 @itemdef{Encoding,
  31         The font encoding (see @b wxFONTENCODING_XXX
  32         constants and the @ref overview_fontencoding for more details)}
  33 @endDefList
  34
  35 Specifying a family, rather than a specific typeface name, ensures a degree of
  36 portability across platforms because a suitable font will be chosen for the
  37 given font family, however it doesn't allow to choose a font precisely as the
  38 parameters above don't suffice, in general, to identify all the available fonts
  39 and this is where using the native font descriptions may be helpful - see
  40 below.
  41
  42 Under Windows, the face name can be one of the installed fonts on the user's
  43 system. Since the choice of fonts differs from system to system, either choose
  44 standard Windows fonts, or if allowing the user to specify a face name, store
  45 the family name with any file that might be transported to a different Windows
  46 machine or other platform.
  47
  48 @see wxFont, wxFontDialog
  49
  50 @note There is currently a difference between the appearance of fonts on the
  51       two platforms, if the mapping mode is anything other than wxMM_TEXT.
  52       Under X, font size is always specified in points. Under MS Windows, the
  53       unit for text is points but the text is scaled according to the current
  54       mapping mode. However, user scaling on a device context will also scale
  55       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 */