This moves Servo closer to the focus parts of the HTML specification.
The behavior should be the same as before, but now the code in `script`
matches the structure of the specification.
The main goal is to set us up for:
- Firing focus events in the right order on nested documents
- A proper implementation of the unfocusing steps.
Testing: This should not change behavior so is covered by existing
tests.
Signed-off-by: Martin Robinson <mrobinson@fastmail.fm>
Co-authored-by: Martin Robinson <mrobinson@fastmail.fm>
Make Servo match the focus bits of the HTML specification a bit more by
storing a `FocusableArea` as the currently focused thing in a
`Document` instead of an optional `Element`. There is always a focused
area of a `Document`, defaulting to the viewport. This is important to
support the case of focused navigables and image maps parts in the
future.
Some focus chain debugging code has been removed as the focus chain
concept needs to be reworked to match the specification more closely.
Testing: This should not change behavior so existing tests should
suffice.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
This continues the work to split up the large DOM structs. In this case
we create a helper struct to store focus-related state much like
`DocumentEventHandler`.
Testing: This is mostly code motion, so should be covered by existing
tests.
Fixes: #43720
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
`DocumentOrShadowRoot#activeElement` should return retargeted results.
What that means is that if the DOM anchor of the `Document`'s focused
focusable area is within a shadow root, `Document#activeElement` should
return the shadow host. This change implements that behavior, properly
returning the `activeElement` from both `Document` and `ShadowRoot`.
Testing: This causes a decent number of WPT tests and subtests to start
passing. One subtest starts to fail, because it uses the `autofocus`
attribute
which we do not yet support.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
When navigating to a fragment the specification says to run the focusing
steps. This is possible now that the focusing steps are properly
exposed. This change also adds support for the fallback option, which is
used when the focus target is not associated with a focuable area. In
this case the fallback is to focus the viewport.
Testing: This change adds a new WPT for this behavior, which was
seemingly not tested before.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
`HTMLOrSVGElement#focus` specifies the "scroll into view" steps should
be run after focusing. This was happening implicitly as part of the
`Document`'s implementation of the "focusing steps." That behavior is
not in the specification, so this change moves the scrolling call to
where it is specified. Along with making the code match the
specification, this change simplifies it as well.
Testing: This should not modify behavior, so existing tests should
suffice.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
For years Servo has had the concept of a focus transaction which was
used only to allow falling back to focusing the viewport when focusing a
clicked element failed. As this concept isn't part of the specification,
this change removes it.
Instead, a `FocusableArea` (a specification concept) is passed to
the `Document` focusing code. A `FocusableArea` might also be the
`Document`'s viewport.
As part of this change, some focus-related methods are moved to `Node`
from `Element` as the `Document` is not an `Element`. This brings the
code closer to implementing the "focusing steps" from the specification.
Testing: This should not change behavior and is thus covered by existing
tests.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
