Enum TabSizing 

pub enum TabSizing {
    Shared,
    Independent,
    Fill,
}

How wide each tab is: shared across all unpinned tabs, chosen per-tab from content, or stretched to fill the bar.

Shared and Independent size the layout axis (width in horizontal bars, height in vertical bars); Fill sizes the tab’s width in both orientations — see each variant. See the module docs of crate::tab_widget for how this is applied per orientation. In wrap (multi-line horizontal) mode Independent is forced regardless of this setting — equal-width tabs in a wrapping row look like a tile grid and lose the bookmark-bar / pill-strip aesthetic.

Variants

Shared

All non-pinned tabs share the same extent on the layout axis. The available region is divided equally across the unpinned count, then clamped to [min_tab_extent, max_tab_extent]. Below the min, content overflows into scroll. Above the max, slack is left as empty space at the trailing edge.

In a vertical bar the layout axis is the pill height, so this yields uniform pills whose width fits the widest label (clamped to [min_tab_width, max_tab_width]).

Independent

Each tab sizes to its content (icon + label + slots), clamped to [min_tab_extent, max_tab_extent]. Truncation via ellipsis when content hits max.

Fill

Tabs stretch to the full width the bar is offered — no slack left over, no fit-to-content shrinking. The nav-rail / segmented-control look (VS Code’s settings sidebar, a full-bleed tab strip).

• Horizontal: the viewport width is divided equally across the unpinned tabs and max_tab_width is not applied, so the strip is filled edge to edge instead of leaving trailing slack. min_tab_width still holds — below it the headers overflow into scroll rather than squeezing to nothing.
• Vertical: every pill takes the bar’s full proposed width (the widest-label clamp is bypassed), so the tabs span the sidebar. Pill height is unchanged (the intrinsic editor_tab_height, or the tab_bar_height override).

With no width proposed at all (an unbounded measure — a Center, an HStack asking for the natural size), there is nothing to fill: a vertical bar falls back to the Shared fit-to-widest-label width. Give the bar a bounded width (a FixedSize, an Expand in a sized parent) for Fill to have any effect.

Trait Implementations

impl Clone for TabSizing

fn clone(&self) -> TabSizing

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for TabSizing

impl Debug for TabSizing

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

Formats the value using the given formatter.

impl Eq for TabSizing

impl PartialEq for TabSizing

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for TabSizing