Struct TextSurfaces 

pub struct TextSurfaces { /* private fields */ }

A cloneable view of one tree’s registered text surfaces.

Taken once, with BuildContext::text_surfaces, and held by whatever needs to ask the question later — a view-model refreshed from a frame tick has no &WidgetTree to consult, which is precisely when it needs the answer.

Implementations

impl TextSurfaces

pub fn focused(&self) -> Option<Rc<dyn TextSurface>>

The text-editing widget that currently holds the keyboard focus.

None when focus is elsewhere — or nowhere — which is exactly what a host needs in order to know that a text chord is safe to route itself.

pub fn focused_is_text_surface(&self) -> bool

Is the keyboard focus inside a widget that edits text? The cheap half of focused, for a host that only needs to decide whether to step aside.

pub fn is_read_only(&self, owner: WidgetId) -> bool

Does the widget registered under owner refuse edits?

false for a widget that edits nothing — the question is only asked of text surfaces, and a node that is not one is not read-only, it is simply not text. Read by the hit-test slop pass, which must never re-attribute a press to a surface that would ignore it.

pub fn set_empty_history_passes_on(&self, on: bool)

Make every text widget of this tree decline Undo when it has nothing to undo, and Redo when it has nothing to redo, so the intent goes on to an ancestor’s action — the application’s own history — instead of stopping at a widget that would do nothing with it. See the module documentation.

Off by default. Applies to RichTextEditor, TextInputField and the fields built on it, and CodeEditor, from the next command they receive; set it once, from the root’s build. The widgets ask their document at the moment the command runs, never a cached can_undo, so a keystroke typed a moment earlier is always undone where it was typed.

pub fn empty_history_passes_on(&self) -> bool

Whether a text widget with nothing to undo (or redo) passes the command on. See set_empty_history_passes_on.

pub fn focus_signal(&self) -> Signal<Option<WidgetId>>

The signal to react to. A host mirroring “can undo” into a menu row re-reads when focus moves.

Trait Implementations

impl Clone for TextSurfaces

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TextSurfaces

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.