CSS does not do exponents, so printing numbers close to 0 as 1.234e-15
does not work.
Also up the accuracy to 17 digits because that's what everyone else
uses.
This commit is still way too big, but I couldn't make it smaller.
It transitions the old CSS parser to the new parser. CSS parsing is now
tokenized, everything else is probably still buggy.
This is just lots of renaming.
The interface remains private, so the public API does not change, apart
from removing the definition of the Interface object to avoid
subclassing.
Fixes a couple bugs...
- Pixel font sizes in css would render as point sizes.
- For em font sizes, where the parent size was set and not default, we would
incorrectly convert a pixel value from points to pixels.
We'll always grab the default font size in pixels so we don't keep confusing
things.
Worth noting that gtk css font-size will still behave differently than the
web. Pango interprets font-size differently.
This requires adding code to do math on number values:
gtk_css_number_value_multiply()
and
gtk_css_number_value_try_add()
were added to achieve that.
Some tests are included.
GtkCssNumberValue is now a base class for numbers.
Actual numbers are now implemented in GtkCssDimensionValue. The name is
borrowed from the CSS spec, so there.
