Struct DocumentFocusHandler 

pub(crate) struct DocumentFocusHandler {
    window: Dom<Window>,
    focused_element: MutNullableDom<Element>,
    focus_sequence: Cell<FocusSequenceNumber>,
    has_focus: Cell<bool>,
}

The DocumentFocusHandler is a structure responsible for handling and storing data related to focus for the Document. It exists to decrease the size of the Document. structure.

Fields

window: Dom<Window>

The Window element for this DocumentFocusHandler.

focused_element: MutNullableDom<Element>

The element that currently has focus in the Document.

focus_sequence: Cell<FocusSequenceNumber>

The last sequence number sent to the constellation.

has_focus: Cell<bool>

Indicates whether the container is included in the top-level browsing context’s focus chain (not considering system focus). Permanently true for a top-level document.

Implementations

impl DocumentFocusHandler

pub(crate) fn new(window: &Window, has_focus: bool) -> Self

pub(crate) fn has_focus(&self) -> bool

pub(crate) fn focused_element(&self) -> Option<DomRoot<Element>>

Return the element that currently has focus. If None is returned the viewport itself has focus.

pub(crate) fn set_focused_element(&self, new_element: Option<&Element>)

Set the element that currently has focus and update the focus state for both the previously set element (if any) and the new one, as well as the new one. This will not do anything if the new element is the same as the previous one. Note that this will not fire any focus events. If that is necessary the DocumentFocusHandler::focus should be used.

pub fn focus_sequence(&self) -> FocusSequenceNumber

Get the last sequence number sent to the constellation.

Received focus-related messages with sequence numbers less than the one returned by this method must be discarded.

fn increment_fetch_focus_sequence(&self) -> FocusSequenceNumber

Generate the next sequence number for focus-related messages.

pub(crate) fn handle_container_unfocus(&self, can_gc: CanGc)

Update the local focus state accordingly after being notified that the document’s container is removed from the top-level browsing context’s focus chain (not considering system focus).

pub(crate) fn focus( &self, focus_operation: FocusOperation, focus_initiator: FocusInitiator, can_gc: CanGc, )

Reassign the focus context to the element that last requested focus during this transaction, or the document if no elements requested it.

fn fire_focus_event( &self, focus_event_type: FocusEventType, event_target: &EventTarget, related_target: Option<&EventTarget>, can_gc: CanGc, )

https://html.spec.whatwg.org/multipage/#fire-a-focus-event

pub(crate) fn perform_focus_fixup_rule(&self, can_gc: CanGc)

https://html.spec.whatwg.org/multipage/#focus-fixup-rule

For each doc of docs, if the focused area of doc is not a focusable area, then run the focusing steps for doc’s viewport, and set doc’s relevant global object’s navigation API’s focus changed during ongoing navigation to false.

TODO: Handle the “focus changed during ongoing navigation” flag.

Trait Implementations

impl MallocSizeOf for DocumentFocusHandler

fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize

Measure the heap usage of all descendant heap-allocated structures, but not the space taken up by the value itself.

impl Traceable for DocumentFocusHandler

unsafe fn trace(&self, tracer: *mut JSTracer)

Trace self.