Tests rely on Helvetica

[PurpleMyst]

Most of the tests in tests/test_font.py rely on the font Helvetica being present.

This is not the case for all *nix installations, although admittedly it is the case for most Linux personal computers.

A fix for this is to utilize a program such as xlsfonts to figure out which fonts are installed and choose one with a correct min/max size bound.

[Akuli]

xlsfonts output lines don't seem to be the same thing as Tk's font families. On this system, one of the output lines is 10x20, but I get this:

>>> f = teek.Font(('10x20', 12, ''))
>>> f.family     # seems to be a fallback
'DejaVu Sans'
>>> f = teek.Font(('asdasjfioajsf', 12, ''))
>>> f.family
'DejaVu Sans'
>>> 

A better solution might be to pick a font family from the teek.Font.families list:

>>> teek.Font.families()
['Latin Modern Mono Slanted', 'MathJax_Caligraphic', ..., 'DejaVu Sans', ...]

Something like random.choice(teek.Font.families()) wouldn't be good, because then the tests might fail sometimes and succeed at other times, but something like min(teek.Font.families()) for the alphabetically first font might work.

[Akuli]

@PurpleMyst, does teek.Font.families() contain Helvetica on the system where the Helvetica tests didn't work? For me, the asserts in this code don't fail:

>>> for family in teek.Font.families():
...     font = teek.Font((family, 42, ''))
...     assert font.family == family
...     assert font.size == 42
... 
>>> 

[codetent]

Is it a problem if Helvetica is not installed? If the given font family does not exist on the system, the most closely matching native font is selected by tk.

Besides, it would be a better solution to use TkDefaultFont instead of Helvetica because this is the font family which is used by tkinter for the tests.

@Akuli if the font is not installed on the system, it is not in the list obtained by teek.Font.families().

[Akuli]

The problem is that when Tk selects the most closely matching font, it may differ from the font passed to teek.Font so much that the font size comes out as different. (*) Myst had a situation where teek.Font(('Helvetica', 12)).size was not 12. However, teek.Font(('utopia', 12)).size was 12 on that system. I guess anything else from teek.Font.families() would have worked too, and if that's true, then the tests should be changed to use something like that.

TkDefaultFont is not actually a font family; it is a name of a named font. Code like teek.Font(('TkDefaultFont', 12)) is "wrong", but it works nicely anyway because Tk looks for a font family called TkDefaultFont, and doesn't find it, then falls back to whatever the default font family is. The correct TkDefaultFont code would be teek.Font('TkDefaultFont') or teek.NamedFont('TkDefaultFont'). Notice that no size can be specified here, because again, TkDefaultFont is not a font family.

(*) Edit: This is because teek's .size property uses font actual documented in font(3tk) to look up the family and size. I thought this would be a good idea when I made this. I can add a separate .actual() method or something if it's not a good idea after all.

[Akuli]

this is now fixed in #11