Since StViewport uses the value of the StAdjustment to create its custom
paint volume, ClutterActors newly introduced proper caching of paint
volumes doesn't get notifed about changes to that paint volume and will
simply reuse the cached old one.
So make use of the newly introduced
clutter_actor_invalidate_paint_volume() method to make sure ClutterActor
will ask for the paint volume again on the next paint.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1484>
This property controls whether the viewport clips the content to its own
allocation or not. This will be necessary in special modes that we want to
render past the viewport inside a scrollview.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1630>
When scrolled, the container's allocation is smaller than the allocation
of the content. To account for that, commit 2717ca9d08 added the
additional size reported by the layout manager to the content allocation.
However as it did so unconditionally, we now allow children to extend
outside the parent even when *not* scrolled, which breaks any constraints
set on the container (like "width" or "max-height").
Fix this by only extending the child allocation in scrollable dimensions.
https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/2491
St has the regular abstractions to handle actors that are bigger
than their parent could handle: StScrollable, StScrollView, and
StAdjustment.
However, the only StScrollable implementation available currently
is StBoxLayout, which forces a ClutterBoxLayout as the layout
manager (and relies on it not being unset).
Introduce StViewport, which is a minimal StScrollable implementation
that doesn't rely on any specific layout manager.
https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/929
