Struct SliverLogicalParentData 

pub struct SliverLogicalParentData {
    pub layout_offset: Option<f64>,
}

Parent data structure used by parents of slivers that position their children using layout offsets.

This data structure is optimized for fast layout. It is best used by parents that expect to have many children whose relative positions don’t change even when the scroll offset does.

Fields

layout_offset: Option<f64>

The position of the child relative to the zero scroll offset.

The number of pixels from the zero scroll offset of the parent sliver (the line at which its SliverConstraints::scroll_offset is zero) to the side of the child closest to that offset. It can be None when it cannot be determined. The value will be set after layout.

In a typical list, this does not change as the parent is scrolled.

Implementations

impl SliverLogicalParentData

pub const fn new() -> SliverLogicalParentData

Creates parent data with no layout offset.

Trait Implementations

impl Clone for SliverLogicalParentData

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for SliverLogicalParentData

impl Debug for SliverLogicalParentData

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

Formats the value using the given formatter.

impl Default for SliverLogicalParentData

fn default() -> Self

Returns the “default value” for a type.

impl Display for SliverLogicalParentData

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

Formats the value using the given formatter.

impl ParentData for SliverLogicalParentData

fn provide(&self, id: TypeId) -> Option<&dyn Any>

The half of this parent data whose type is id, if it embeds one.

fn provide_mut(&mut self, id: TypeId) -> Option<&mut dyn Any>

See provide; mirrors it exactly.

fn detach(&mut self)

Called when the render object is removed from the tree.