Struct TextArea 

pub struct TextArea {
    pub value: String,
    pub placeholder: String,
    pub focused: bool,
    pub width: Option<f32>,
    pub height: f32,
    pub font_size: Option<f32>,
    pub radius: f32,
    /* private fields */
}

A multi-line, wrapped, virtualized-paint text field (D116 Step 4).

Built entirely on the same D116 core TextInput uses — Transaction/ Selection/Command/EditController are unchanged; TextLayoutSnapshot already models “a list of visual lines” so TextArea just populates one LineLayout per WRAPPED line instead of TextInput’s single entry. Click/drag/double/triple-click dispatch in engine.rs is untouched — it only ever talks to editable.layout, never knows which widget it’s looking at.

New in this widget: word-wrapping (wrap_char_ranges below), Enter inserts a real newline (engine.rs, gated on multiline), Up/Down cross wrapped lines with goal-column memory (TextEditState::goal_x), and vertical scrolling via the same zero-wiring rosace_scroll::ScrollController ListView/ScrollView use (D101) — wheel events mutate the controller’s atoms directly, never the render tree, so there’s no !Sync/!Send wall to work around here the way click dispatch has.

Paint is virtualized: every visual line’s geometry is computed each frame (needed for correct click-anywhere/goal-column behavior), but only lines intersecting the current viewport actually emit paint commands — a large document’s PAINT cost stays bounded even though its LAYOUT cost does not yet (a named follow-up, not this step’s exit bar).

Fields

value: String

placeholder: String

focused: bool

width: Option<f32>

height: f32

font_size: Option<f32>

None = read from the active theme’s typography.body_medium (D127 “environment” track — see Checkbox::resolved_font_size’s doc for the reasoning).

radius: f32

Implementations

impl TextArea

pub fn new() -> Self

pub fn value(self, v: impl Into<String>) -> Self

pub fn placeholder(self, p: impl Into<String>) -> Self

pub fn focused(self) -> Self

pub fn width(self, w: f32) -> Self

pub fn height(self, h: f32) -> Self

pub fn background(self, c: Color) -> Self

See TextInput::background — same seam, same contract.

pub fn border(self, c: Color) -> Self

See TextInput::border — same seam, same contract.

pub fn focus_color(self, c: Color) -> Self

See TextInput::focus_color — same seam, same contract.

pub fn on_change(self, f: impl Fn(String) + Send + Sync + 'static) -> Self

pub fn controller(self, c: EditController) -> Self

pub fn spans( self, f: impl Fn(&str, Option<(usize, usize)>) -> Vec<Span> + Send + Sync + 'static, ) -> Self

See TextInput::spans — same seam, same contract (D116 Step 5).

pub fn cursor_style(self, s: CursorStyle) -> Self

See TextInput::cursor_style — same seam, same contract.

pub fn field(self, f: FormField) -> Self

See TextInput::field — same seam, same contract (D116 Step 8).

pub fn filters(self, filters: Vec<InputFilter>) -> Self

See TextInput::filters — same seam, same contract.

pub fn no_scrollbar(self) -> Self

Hide the vertical scroll-position thumb (see ScrollView::no_scrollbar — same convention). Content still scrolls; only the indicator is gone.

pub fn scrollbar_color(self, c: Color) -> Self

Trait Implementations

impl Default for TextArea

fn default() -> Self

Returns the “default value” for a type.

impl Widget for TextArea

fn layout(&self, ctx: &LayoutCtx<'_>) -> Size

Measure under ctx.constraints and return a size within them.

fn paint(&self, ctx: &mut PaintCtx<'_>)

Record draw commands for ctx.rect.

fn children(&self) -> Children<'_>

Declare this widget’s children. Drives every default below.

fn flex_factor(&self) -> f32

Flex weight inside Row/Column. Wrappers are transparent by default.

fn into_element(self) -> Element

where Self: Sized + 'static,

Wrap this widget in an Element so it can be returned from Component::build().