RE: [Pythoncard-users] How about CSS for Layout

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

> From: Peter Cleaveland
>
> I just started reading the list, and I noticed the discussion of "sizers"
> to control the GUI appearance. I can sure see the cross platform
> differences in widget rendering. What are sizers?  (They sound like
> something from the Java AWT - but I'm just guessing.)  It's clear

Yes, Java AWT and Swing support sizers as part of the layout manager.
Originally, there was just the grid bag layout, but now Java supports box
layout as well. HTML tables are another form of sizer layout. You can read
up on sizers in the wxWindows documentation that came with your wxPython
installation. In the "Classes by category" section look under 'Window
layout' and then look at wxSizer, wxGridSizer, wxFlexGridSizer, etc.
Everyone that wants to contribute ideas or code should read those sections.

I haven't done much with "sizers" myself and in fact started reading up on
the various forms today. It would be great if somebody can correct me where
I made a mistake in my description above or better yet provide more insight
into what wxWindows/wxPython does right or wrong with regards to sizers.
After we are happy with our Font implementation I will be getting more into
sizers. I already have an idea how we might implement them so that their
description would be relatively easy to grasp.

> Perhaps PythonCard could borrow some of the CSS syntax.  Specifying
> font-family as a list of requested fonts, falling to default if none are
> available.  Font-size and box/containment properties (border, padding,
> margin, etc.) could be in pixels, but the actual width and height of most
> things could fall where they may.

Last week the font discussion centered around CSS-like syntax for the font
family and facename. I didn't implement it yet because I'm still thinking
about how the user (programmer) will need to manipulate the fonts in real
programs versus initialization. At a minimum, there will always be a default
family that must be specified: serif, sansSerif, monospace.

CSS is too complicated for us to implement a complete-CSS syntax and I'm not
sure that most of it applies anyway. I am much more interested in something
like TABLE for our sizers, but done with Python lists and dictionaries
instead of using tags like <TABLE> <TR> <TD> ... and then implementing dot
notation to reference individual elements. However, I've only thought about
this for a little while and my initial thoughts on the matter could be
either too limited or difficult to implement or both.

There is actually quite a lot of work going into the wxHTML control for
wxWindows and even in the upcoming wxWindows/wxPython 2.3.2 it will be much
more capable than the one available today. We won't be able to do a GUI
layout editor that uses HTML, that is simply too complicated, but we will
probably be able to support the use of HTML with embedded widgets for
layouts sometime in the future if somebody wants to go that route. The
layout capabilities won't be as advanced as what you can pull off with say
Internet Explorer today, but if you're careful you will be able to do quite
a lot and probably share layout between web pages and PythonCard apps. I
keep reminding myself about Zope and how Zope and PythonCard might
complement each other for just this type of cross-platform (web and desktop)
work.

ka