Add an implementation of CSS `contain: style`. This introduces two new
data structures, the ContainStyleScope and ContainStyleScopeManager.
ContainStyleScope manages one `contain: style` "world" which has its own
counter and quote lists. The contents of these lists depend on their
parent scopes, but are not affected by their children.
ContainStyleScopeManager manages a tree of scopes starting at a root
scope which is outside of any `contain: style` element.
Scopes are stored in a hash table that is keyed off of the nsIContent
which establishes the `contain: style` scope. When modifying quote or
content lists, the ContainStyleScopeManager is responsible for finding
the appropriate `contain: style` scope to modify.
Perhaps the most complex part of this is that counters and quotes have
read access to the state of counters and quotes that are in ancestor
`contain: style` scopes. In the case of counters, USE nodes that are at
the beginning of counter lists might have a counter scope that starts in
an ancestor `contain: style` scope. When nsCounterNode::SetScope() is
called, the code may look upward in the `contain: style` scope tree to
find the start of the counter scope. In the case of quotes, the first
node in the quote list must look for the state of quotes in ancestor
`contain: style` scopes.
Differential Revision: https://phabricator.services.mozilla.com/D149508
Add an implementation of CSS `contain: style`. This introduces two new
data structures, the ContainStyleScope and ContainStyleScopeManager.
ContainStyleScope manages one `contain: style` "world" which has its own
counter and quote lists. The contents of these lists depend on their
parent scopes, but are not affected by their children.
ContainStyleScopeManager manages a tree of scopes starting at a root
scope which is outside of any `contain: style` element.
Scopes are stored in a hash table that is keyed off of the nsIContent
which establishes the `contain: style` scope. When modifying quote or
content lists, the ContainStyleScopeManager is responsible for finding
the appropriate `contain: style` scope to modify.
Perhaps the most complex part of this is that counters and quotes have
read access to the state of counters and quotes that are in ancestor
`contain: style` scopes. In the case of counters, USE nodes that are at
the beginning of counter lists might have a counter scope that starts in
an ancestor `contain: style` scope. When nsCounterNode::SetScope() is
called, the code may look upward in the `contain: style` scope tree to
find the start of the counter scope. In the case of quotes, the first
node in the quote list must look for the state of quotes in ancestor
`contain: style` scopes.
Differential Revision: https://phabricator.services.mozilla.com/D149508
Emilio Cobos Álvarez