Struct Spacer

pub struct Spacer {
    pub weight: u32,
    pub fixed_height: Option<Length>,
    pub fixed_width: Option<Length>,
}

A flexible, invisible spacer that expands to fill available space.

The optional weight controls how much of the remaining space this spacer claims relative to other spacers in the same layout. A spacer with weight = 2 takes twice as much space as one with weight = 1.

Place a Spacer between two widgets inside a Column or Row to push them apart:

column()
    .push( text( "Top" ) )
    .push( spacer() )    // pushes "Bottom" to the bottom
    .push( text( "Bottom" ) )
.into()

Use .weight(n) to replace several consecutive spacers:

// These two are equivalent:
let _: Column<Msg> = column().push( spacer().weight( 3 ) );
let _: Column<Msg> = column().push( spacer() ).push( spacer() ).push( spacer() );

Use .height(px) to create a fixed-size vertical spacer:

column()
    .push( text( "Header" ) )
    .push( spacer().height( 20.0 ) )  // Exactly 20 px gap
    .push( text( "Content" ) )
.into()

.height(...) and .width(...) also accept any crate::Length, so the gap can scale with the surface instead of being frozen at a px constant:

column()
    .push( text( "Header" ) )
    // 6 % of the surface's smaller side, never below 16 px or above 64 px.
    .push( spacer().height( Length::vmin( 6.0 ).clamp( 16.0, 64.0 ) ) )
    .push( text( "Content" ) )
.into()

Fields

weight: u32

Relative weight of this spacer (default 1).

fixed_height: Option<Length>

Fixed height (overrides flexible behavior in a column). Accepts any Length — pass an f32/i32/u32 for the px case (kept for backward compatibility with existing call sites), or Length::vmin( … ) etc. for viewport-relative gaps.

fixed_width: Option<Length>

Fixed width (overrides flexible behavior in a row). Same length-type semantics as Self::fixed_height.

Implementations

impl Spacer

pub fn weight(self, w: u32) -> Self

Set the relative weight of this spacer (default 1).

pub fn height(self, h: impl Into<Length>) -> Self

Set a fixed height for this spacer. Accepts any Length: a bare 24.0_f32 is treated as Length::px( 24.0 ) for source-level backwards compatibility; a Length::vmin( 6.0 ) makes the gap scale with the surface’s smaller dimension.

pub fn width(self, w: impl Into<Length>) -> Self

Set a fixed width for this spacer. Mirrors Self::height for the horizontal axis.

pub fn preferred_size(&self, canvas: &Canvas) -> (f32, f32)

Returns ( fixed_width, fixed_height ) resolved against the current canvas viewport, falling back to 0.0 on axes that were not pinned. The parent layout distributes leftover along its main axis among the still-flexible spacers and Flex wrappers, weighted by weight.

pub fn resolved_height(&self, canvas: &Canvas) -> Option<f32>

Resolved fixed height in logical pixels, or None when the spacer is flex. Cheaper than Self::preferred_size when the layout only needs the main-axis size for one orientation.

pub fn resolved_width(&self, canvas: &Canvas) -> Option<f32>

pub fn draw(&self)

No-op — spacers are invisible.

Trait Implementations

impl<Msg: Clone + 'static> From<Spacer> for Element<Msg>

fn from(s: Spacer) -> Self

Converts to this type from the input type.