Struct SliverPhysicalParentData 

pub struct SliverPhysicalParentData {
    pub paint_offset: Offset,
    pub cross_axis_flex: Option<i32>,
}

Parent data structure used by parents of slivers that position their children using absolute coordinates.

For example, used by crate::RenderViewport.

This data structure is optimized for fast painting, at the cost of requiring additional work during layout when the children change their offsets. It is best used by parents that expect to have few children, especially if those children will themselves be very tall relative to the parent.

Fields

paint_offset: Offset

The position of the child relative to the parent.

This is the distance from the top left visible corner of the parent to the top left visible corner of the sliver.

cross_axis_flex: Option<i32>

The cross axis flex factor to use for this sliver child.

If used outside of a SliverCrossAxisGroup widget, this value has no meaning.

If None or zero, the child is inflexible and determines its own size in the cross axis. If non-zero, the amount of space the child can occupy in the cross axis is determined by dividing the free space (after placing the inflexible children) according to the flex factors of the flexible children.

Implementations

impl SliverPhysicalParentData

pub const fn new() -> SliverPhysicalParentData

Creates parent data with a zero paint offset.

pub fn apply_paint_transform(&self, transform: &mut Matrix4)

Apply the paint_offset to the given transform.

Used to implement RenderObject::apply_paint_transform by slivers that use SliverPhysicalParentData.

Trait Implementations

impl Clone for SliverPhysicalParentData

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 SliverPhysicalParentData

impl Debug for SliverPhysicalParentData

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

Formats the value using the given formatter.

impl Default for SliverPhysicalParentData

fn default() -> SliverPhysicalParentData

Returns the “default value” for a type.

impl Display for SliverPhysicalParentData

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

Formats the value using the given formatter.

impl ParentData for SliverPhysicalParentData

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.