CSS supports blend modes, in which a series of layers are
merged together according to the given operation or set of
operations.
Support for blend modes landed on Cairo, which exposes all
the commons and also the exquisites blend modes available.
Adding support for blend modes, then, is just a matter of
using the available Cairo operations.
This patch adds the background-blend-mode CSS enum property,
and adapts the background rendering code to blend the backgrounds
using the available blend modes when they're set.
https://bugzilla.gnome.org/show_bug.cgi?id=768305
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.
The values can be:
"requested" - the style as requested
"regular" - use a regular full-color icon
"symbolic" - use a symbolic icon
The property defaults to "requested", so no changes should be seen
unless CSS overrides it.
It is also inherited, so that using this CSS
.toolbar { -gtk-icon-style: symbolic; }
is enough to force the whole toolbar to use symbolic icons.
We now support the keywords (like xx-small, medium, larger, smaller...)
and I've changed the default value to be "medium".
This required some shuffling of the "get default font size" code. But
all is well now.
