Struct TopAppBarScrollBehavior 

pub struct TopAppBarScrollBehavior {
    pub collapsed_offset: Signal<f32>,
    pub height: f32,
    pub collapsed_height: f32,
    pub mode: TopAppBarScrollMode,
    /* private fields */
}

Drives scroll-based collapsing/expanding of a TopAppBar.

Create one, pass its nested_scroll_connection to a lazy list’s [set_nested_scroll_parent] method, and either set the resulting collapsed_offset on the TopAppBar via TopAppBarConfig::scroll_offset, or attach it via TopAppBarConfig::scroll_behavior so the bar wires offset + color itself.

Fields

collapsed_offset: Signal<f32>

height: f32

collapsed_height: f32

mode: TopAppBarScrollMode

Implementations

impl TopAppBarScrollBehavior

pub fn new( height: f32, collapsed_height: f32, mode: TopAppBarScrollMode, ) -> Self

pub fn nested_scroll_connection(&self) -> NestedScrollConnection

Returns a NestedScrollConnection that collapses the bar on downward scroll and expands on upward scroll. ExitUntilCollapsed only expands once the nested content is back at the top.

pub fn offset(&self) -> f32

Returns the current collapsed offset (0 = fully expanded, negative = collapsed).

pub fn collapsed_fraction(&self) -> f32

Collapse progress in 0.0..=1.0 (0 = expanded, 1 = fully collapsed). Drives the container color lerp so the scrolled color tracks the offset.

Trait Implementations

impl Clone for TopAppBarScrollBehavior

fn clone(&self) -> TopAppBarScrollBehavior

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TopAppBarScrollBehavior

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

Formats the value using the given formatter.