Struct re_ui::list_item::scope::LayoutInfo

pub struct LayoutInfo {
    pub(crate) left_x: f32,
    pub(crate) left_column_width: Option<f32>,
    pub(crate) reserve_action_button_space: bool,
    scope_id: Id,
    pub(crate) property_content_max_width: Option<f32>,
}

Layout information prepared by list_item_scope to be used by super::ListItemContent.

This structure has two purposes:

• Provide read-only layout information to be used when rendering the list item.
• Provide an API to register needs (such as left column width). These needs are then accumulated and used to set up the next frame’s layout information.

super::ListItemContent implementations have access to this structure via super::ContentContext.

Fields

left_x: f32

Left-most X coordinate for the scope.

This is the reference point for tracking column width. This is set by list_item_scope based on ui.max_rect().

left_column_width: Option<f32>

Column width to be read this frame.

The column width has left_x as reference, so it includes:

• All the indentation on the left side of the list item.
• Any extra indentation added by the list item itself.
• The list item’s collapsing triangle, if any.

The effective left column width for a given super::ListItemContent implementation can be calculated as left_column_width - (context.rect.left() - left_x).

This value is set to None during the first frame, when list_item_scope isn’t able to determine a suitable value. In that case, implementations should devise a suitable default value.

reserve_action_button_space: bool

If true, right-aligned space should be reserved for the action button, even if not used.

scope_id: Id

Scope id, used to retrieve the corresponding LayoutStatistics.

property_content_max_width: Option<f32>

PropertyContent only — last frame’s max content width, to be used in desired_width()

This value is measured from left_x.

Implementations

impl LayoutInfo

pub fn register_desired_left_column_width( &self, ctx: &Context, desired_width: f32 )

Register the desired width of the left column.

All super::ListItemContent implementation that attempt to align on the two-column system should call this function once in their super::ListItemContent::ui method.

pub fn reserve_action_button_space(&self, ctx: &Context, reserve: bool)

Indicate whether right-aligned space should be reserved for the action button.

pub(crate) fn register_max_item_width(&self, ctx: &Context, width: f32)

Register the maximum width of the item.

Should only be set by super::ListItem.

pub(super) fn register_property_content_max_width( &self, ctx: &Context, width: f32 )

PropertyContent only — register max content width in the current scope

Trait Implementations

impl Clone for LayoutInfo

fn clone(&self) -> LayoutInfo

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for LayoutInfo

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

Formats the value using the given formatter.

impl Default for LayoutInfo

fn default() -> Self

Returns the “default value” for a type.