Ideally we'd make this property inaccessible to Web content style sheets, but
that seems hard since view-source and plain text documents seem to load in a
context that's very similar to Web content as far as the style system is
concerned. It doesn't matter much since it's quite safe and unlikely to be
discovered or used by anyone.
--HG--
extra : rebase_source : 009aafc992afd07fd76a9026afe0f6994b4b214a
This adds an nsStyleVariables on which computed variable values
will be stored. We don't actually have any properties assigned to
nsStyleVariables; eCSSPropertyExtra_Variables which we added earlier
isn't a real property. To avoid compiler errors for gVariableFlags
being a zero length array, we stick a dummy entry in there.
nsRuleNode::ComputeVariablesData does nothing for the moment.
nsStyleVariable nsChangeHint calculations always return 0, as later
we will compare the actual properties that reference variables to
see what changes are required for them.
Patch co-authored by Emmanuele Bassi <ebassi@gmail.com>
This defines a CSSVariableDeclarations class that holds a set of
variable declarations. This is at the specified value stage, so values
can either be 'initial', 'inherit' or a token stream (which is what you
normally have). The variables are stored in a hash table. Although
it's a bit of a hack, we store 'initial' and 'inherit' using special
string values that can't be valid token streams (we use "!" and ";").
Declaration objects now can have two CSSVariableDeclarations objects
on them, to store normal and !important variable declarations. So that
we keep preserving the order of declarations on the object, we inflate
mOrder to store uint32_ts, where values from eCSSProperty_COUNT onwards
represent custom properties. mVariableOrder stores the names of the
variables corresponding to those entries in mOrder.
We also add a new nsCSSProperty value, eCSSPropertyExtra_variable, which
is used to represent any custom property name.
nsCSSProps::LookupProperty can return this value.
The changes to nsCSSParser are straightforward. Custom properties
are parsed and checked for syntactic validity (e.g. "var(a,)" being
invalid) and stored on the Declaration. We use nsCSSScanner's
recording ability to grab the unparsed CSS string corresponding to
the variable's value.
