Re: [Tile-dev] modified themes for labelframes

[Joe E. <jen...@fl...>]

Jeff Hobbs wrote:

> I'm porting more stuff to OS X, and finding that the alternate
> grouping controls (essentially labelframes) might be nice to
> have.  See:
>
> http://developer.apple.com/documentation/UserExperience/Conceptual/
>    OSXHIGuidelines/XHIGLayout/chapter_19_section_4.html
>
> We should be able to reproduce these in styles, but the current
> labelframe drawing disallows that.  It has a -borderwidth, but
> that is ignored for anything but adjusting the label inset (at
> size 0, it still draws the border, Windows and OS X).
>
> On OS X it seems that for drawing themed groupboxes, there is
> only the one API func.  So I'm wondering ... is this an
> instance of something tile styles should support,

In principal, yes, this ought to be possible with custom styles,
but it will be necessary to define a few new elements, and the 
labelframe layout algorithm needs to be generalized a bit more.

> Essentially, I want the option:
> 	labelframe .foo -style whitespace|bordered|separator

You can almost get the "Whitespace" style with:

    style default Flat.TLabelframe -relief flat -borderwidth 0

This doesn't work at present, because the [ttk::labelframe]
has non-NULL defaults for -relief and -borderwidth, which will 
take precedence.  I'm starting to think that these should be removed 
altogether (-relief in particular; Tk's standard set of -relief values
don't map onto platform-native border styles very well).  At the 
very least, they should be NULL by default so that custom styles 
will work.

([ttk::label]s have the same problem wrt. custom styles.  This
will be fixed in 0.7 when we drop attempted BWidget compatibility.)

For the "separator" style, it might work to define a
Separator.TLabelframe.border element that only draws one edge
of the border. 

Another groupbox style we ought to support is the BWidget
PanelFrame, where the label appears in a shaded box that
extends across the top of the frame.  This isn't possible
with the current layout algorithm, but it might work if
the "-labelanchor" option were extended to allow things like
"nwe" in addition to "n", "nw", and "ne".

Then there's things like "disclosure boxes" (commonly used
for e.g., "Show/Hide Advanced Options" sections in dialog boxes).
I think this is currently doable as a snidget, using a custom
[ttk::checkbox] as the -labelwidget.

See also: #1117281, which may be tangentially relevant.

And lastly: Under OSX, the groupbox background gets successively
darker depending on the nesting level.  Tile can't handle this
at all right now (this is The Background Problem.)


Other ideas?


--Joe English

  jen...@fl...