Struct TabBarLayout 

pub struct TabBarLayout {
    pub bar_width: f32,
    pub bar_height: f32,
    pub visible_tabs: Vec<VisibleTab>,
    pub visible_segments: Vec<VisibleSegment>,
    pub scroll_left: Option<Rect>,
    pub scroll_right: Option<Rect>,
    pub hit_regions: Vec<(Rect, TabBarHit)>,
    pub resolved_scroll_offset: usize,
}

Fully-resolved tab-bar layout. Backends iterate visible_tabs / visible_segments for painting; call Self::hit_test for clicks.

Writing resolved_scroll_offset back

When a frame paints with a stale TabBar.scroll_offset (e.g. after a window resize or a jump to a tab that wasn’t previously visible), the layout corrects it. The backend should write resolved_scroll_offset back to the app’s stored scroll state so the next frame starts coherent. See TabBar::layout docs for the two-pass-paint pattern.

Fields

bar_width: f32

Total bar width in the measurer’s unit (copied from input).

bar_height: f32

Total bar height in the measurer’s unit (copied from input).

visible_tabs: Vec<VisibleTab>

Tabs that made it onto the bar, left-to-right as drawn.

visible_segments: Vec<VisibleSegment>

Right-aligned segments that fit, drawn left-to-right starting from their resolved left edge.

scroll_left: Option<Rect>

Left scroll-arrow rectangle, present iff resolved_scroll_offset > 0 and scroll_arrow_width > 0.0.

scroll_right: Option<Rect>

Right scroll-arrow rectangle, present iff tabs extend beyond the visible area and scroll_arrow_width > 0.0.

hit_regions: Vec<(Rect, TabBarHit)>

Ordered hit-region list. hit_test walks this from the start and returns the first containing region. More-specific regions (close buttons) come before containing regions (tab bodies).

resolved_scroll_offset: usize

Scroll offset actually used. May differ from TabBar.scroll_offset if the input was stale.

Implementations

impl TabBarLayout

pub fn hit_test(&self, x: f32, y: f32) -> TabBarHit

Test which clickable region (if any) contains point (x, y). Returns TabBarHit::Empty when no region matches.

pub fn tab_center(&self, tab_idx: usize) -> Option<(f32, f32)>

Center point of tab tab_idx’s full bounds (label + close button), in this layout’s own bar-relative coordinate space — the same space visible_tabs[].bounds uses (origin at the bar’s top-left, not the target surface). None if tab_idx isn’t in visible_tabs, i.e. it’s scrolled out of view behind the bar’s scroll_offset.

Backends that cache a TabBarLayout per WidgetId at paint time add the cached bar rect’s own (x, y) origin to this to get an absolute screen point — see TuiDriver::tab_center / GtkDriver::tab_center, which every tab bar needs since every tab paints the same label-independent chrome and find() can’t disambiguate tab 3’s target from tab 0’s the way it can for uniquely-labeled text.

pub fn tab_close_center(&self, tab_idx: usize) -> Option<(f32, f32)>

Center point of tab tab_idx’s close-button hit region, in the same bar-relative space as Self::tab_center. None when the tab is scrolled out of view (see Self::tab_center) or when it drew no close button this frame — is_closable: false on the tab, or show_tab_close: false on the bar.

Trait Implementations

impl Clone for TabBarLayout

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 TabBarLayout

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

Formats the value using the given formatter.

impl PartialEq for TabBarLayout

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for TabBarLayout