Struct Row 

pub struct Row<F: Fn(&mut RowContent<'_, '_, '_>)> {
    pub gap: f32,
    pub expand: bool,
    pub collapse: bool,
    pub content: F,
}

A container that arranges child elements horizontally with flexible sizing.

Elements can be sized as self-sized, fixed width, or expanding to fill available space. The expand option makes all children the same height by passing the maximum height and break count as preferred_height and preferred_height_break_count, enabling features like bottom alignment and background fills.

The preferred_height_break_count represents the number of page breaks, with preferred_height being the height on the final page. For example, if preferred_height_break_count = 2 and preferred_height = 15.0, it means "break twice, then use 15mm on the final page".

Flex System

• Flex::SelfSized: Element uses its natural width
• Flex::Fixed(width): Element uses the specified width
• Flex::Expand(weight): Element gets a portion of remaining space based on weight

Remaining space is calculated as: total_width - sum(self_sized_widths) - sum(fixed_widths) Then distributed proportionally: element_width = remaining_space * (weight / total_weights)

Performance Note

When expand: false, only self-sized elements are measured in the first pass. When expand: true, all elements must be measured before drawing to determine the maximum height, which requires an additional measurement pass.

Fields

gap: f32

Horizontal spacing between elements in millimeters

expand: bool

Whether to expand all children to the same height by passing preferred_height

collapse: bool

Whether to collapse when all children have None height/width

content: F

Closure that gets called for adding the content.

The closure is basically an internal iterator that produces elements by calling RowContent::add.

This closure will be called at least twice because the non-expanded elements need to be measured first. Depending on the surrounding context it could be called more than that (though in real world layouts this effect should be minimal as not all containers need a measure pass before drawing). Because of this it’s beneficial to keep expensive computations and allocations outside of this closure.

Implementations

impl<F: Fn(&mut RowContent<'_, '_, '_>)> Row<F>

pub fn new(content: F) -> Self

pub fn with_gap(self, gap: f32) -> Self

pub fn with_expand(self, expand: bool) -> Self

pub fn with_collapse(self, collapse: bool) -> Self

pub fn expand(self) -> Self

Trait Implementations

impl<F: Fn(&mut RowContent<'_, '_, '_>)> Element for Row<F>

fn first_location_usage( &self, ctx: FirstLocationUsageCtx<'_>, ) -> FirstLocationUsage

fn measure(&self, ctx: MeasureCtx<'_>) -> ElementSize

fn draw(&self, ctx: DrawCtx<'_, '_>) -> ElementSize

fn with_padding_top(self, padding: f32) -> Padding<Self>

where Self: Sized,

fn with_vertical_padding(self, padding: f32) -> Padding<Self>

where Self: Sized,

fn debug(self, color: u8) -> Debug<Self>

where Self: Sized,