Enum zng::layout::WidgetLength

pub enum WidgetLength {
    Default,
    Leftover(Factor),
    Exact,
}

Represents the width or height property value set on a widget.

Properties like size, width and height set the WIDGET_SIZE metadata in the widget state. Panels can use this info to implement Length::Leftover support.

Variants

Default

Evaluates to PxConstraints2d::fill_size when measured, can serve as a request for size-to-fit.

The Grid! widget uses this to fit the column and row widgets to their cells, as they don’t logically own the cells, this fit needs to be computed by the parent panel.

Leftover(Factor)

The Length::Leftover value. Evaluates to the LayoutMetrics::leftover value when measured, if a leftover value is not provided evaluates like a Length::Factor.

The leftover length needs to be computed by the parent panel, as it depends on the length of the sibling widgets, not just the panel constraints. Panels that support this, compute the value for each widget and measure/layout each using LAYOUT.with_leftover to inject the computed value.

Exact

Any of the other Length kinds. All contextual metrics needed to compute these values is already available in the LayoutMetrics, panels that support Length::Leftover can layout this widget first to compute the leftover length.

Trait Implementations

impl Clone for WidgetLength

fn clone(&self) -> WidgetLength

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for WidgetLength

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

Formats the value using the given formatter.

impl Default for WidgetLength

fn default() -> WidgetLength

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for WidgetLength

fn deserialize<__D>( __deserializer: __D, ) -> Result<WidgetLength, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<&Length> for WidgetLength

fn from(value: &Length) -> WidgetLength

Converts to this type from the input type.

impl PartialEq for WidgetLength

fn eq(&self, other: &WidgetLength) -> 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 Serialize for WidgetLength

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for WidgetLength

impl StructuralPartialEq for WidgetLength