Previously, this was used because we didn't have access to the current
view and `EventContext` was an element-only abstraction. Now that the
`EventContext` wraps the current view's `ViewContext` we can simply check
for the view's focus and avoid querying ancestors.
During `layout`, we now pass a mutable reference to the element's
parent view. This is a recursive process that causes the view to
be removed from `AppContext` and then re-inserted back into it once
the layout is complete.
As such, querying parent views during `layout` does not work as such
views will have been removed from `AppContext` and not yet re-inserted
into it. This caused a bug in `KeystrokeLabel`, which used the `keystrokes_for_action`
method to query its ancestors to determine their type id and keymap context.
Now, any time a view notifies, we will cache its keymap context so that
we don't need to query the parent view during `layout`.
This is achieved by moving `available_actions` into `AsyncAppContext` (where
we know no view/window is on the stack) and `keystrokes_for_action` into `LayoutContext`
where we'll fetch the previous frame's ancestors and notify the current view if those
change after we perform a layout.
Previously, `debug_elements` was available on `WindowContext`. If that
method was called while having a borrow out to a view, it would panic because
the view would already have been borrowed.
By moving it to an `AsyncAppContext` we ensure the method can't be called while
a view is being used.
This avoids an invitation to hold strong view handles across async await
points, which is a common source of leaks.
Co-Authored-By: Nathan Sobo <nathan@zed.dev>
Multi-element are now generic over any drawable child, which can be converted
into an element.
Co-Authored-By: Nathan Sobo <nathan@zed.dev>
Co-Authored-By: Max Brunsfeld <max@zed.dev>
This is redundant because when creating a window we will receive
an activation event if the window was effectively focused. And if
it wasn't, we shouldn't call `focus_in`.
Mikayla Maki
Antonio Scandurra
