[Pythoncard-users] fonts - day one

[Kevin A. <al...@se...>]

If you know anything about fonts, programming issues around fonts,
cross-platform font issues, wxPython font issues, cascading style sheets
(CSS), etc. or just have some opinions on what you want in terms of font
support, please contribute to this thread on the list. Fonts are not a
speciality of mine, so if I end up doing this one alone we're gonna have to
refactor many times ;-)

The time has come to add font support to all the widgets in PythonCard.
Since the prototype is based on wxPython, we're going to be limited by what
can be done with the wxWindows/wxPython library and we're going to be
further limited by what is going to work across platforms. Rowland and I
avoided adding MS Windows-specific features to any of the existing widgets,
and fonts should be handled the same way. This is also the time to start
looking at wrapping wxSTC (Scintilla) for styled text support, though I'm
still unclear on how the wxTE_RICH style for wxTextCtrl relates to wxSTC if
at all.

I encourage everyone to at least read the wxFont overview in the
wxWindows/wxPython documentation, but I'm going to include it at the end of
this message in case you don't know where to look. Other relevant sections
include: Font encoding overview, Unicode support in wxWindows, wxFont class,
wxFontDialog, and just about any other topic in the wxWindows docs with
'Font' in the name.

I don't want to use the wxWindows constants directly for font families, but
will probably use some equivelant mapping initially. I definitely want to
support basic style sheets, so that an app can define a fontStyleSheet and
then set the font for a widget simply by referring to the named
fontStyleSheet. This isn't going to be a full web CSS-like capability, but
we can borrow some of the ideas from CSS.

platform-specific features
In the future, we will probably have a some kind of setting so that if you
wanted to write a PythonCard app that uses platform-specific features the
framework will let you do so, but then make appropriate warnings when the
app is being written and run. So, if there is some feature that is
platform-specific that you want, you can still bring it up and it will get
posted into the feature requests.

ka
---

wxFont overview
Class: wxFont

A font is an object which determines the appearance of text, primarily when
drawing text to a window or device context. A font is determined by the
following parameters (not all of them have to be specified, of course):

Point size  This is the standard way of referring to text size.
Family  Supported families are: wxDEFAULT, wxDECORATIVE, wxROMAN, wxSCRIPT,
wxSWISS, wxMODERN. wxMODERN is a fixed pitch font; the others are either
fixed or variable pitch.
Style  The value can be wxNORMAL, wxSLANT or wxITALIC.
Weight  The value can be wxNORMAL, wxLIGHT or wxBOLD.
Underlining  The value can be TRUE or FALSE.
Face name  An optional string specifying the actual typeface to be used. If
NULL, a default typeface will chosen based on the family.
Encoding  The font encoding (see wxFONTENCODING_XXX constants and the font
overview for more details)


Specifying a family, rather than a specific typeface name, ensures a degree
of portability across platforms because a suitable font will be chosen for
the given font family.

Under Windows, the face name can be one of the installed fonts on the user's
system. Since the choice of fonts differs from system to system, either
choose standard Windows fonts, or if allowing the user to specify a face
name, store the family id with any file that might be transported to a
different Windows machine or other platform.



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Note: There is currently a difference between the appearance of fonts on the
two platforms, if the mapping mode is anything other than wxMM_TEXT. Under
X, font size is always specified in points. Under MS Windows, the unit for
text is points but the text is scaled according to the current mapping mode.
However, user scaling on a device context will also scale fonts under both
environments.