Struct ScrollBounce 

pub struct ScrollBounce { /* private fields */ }

Adds vertical touch overscroll to an existing scroll viewport.

The child owns layout, content, and ordinary scrolling; handle must be the child’s scroll handle. Only unused vertical deltas stretch the viewport. The stable id owns gesture and spring state. Change it when replacing the document. Put fixed chrome (scrollbars, toolbars) outside this wrapper.

Enabled by default where the platform’s own scroll views bounce: iOS, Android and macOS. Reduced motion disables displacement. Keyboard and focus remain owned by the child. No colors, padding, or dimensions are imposed.

Nested scroll areas follow the platform: the innermost one under the pointer takes the whole gesture, at its ends too, and bounces there rather than handing the rest to the area around it. A disabled ScrollBounce still scrolls its child and keeps the gesture from the areas around it; it only stops at the ends instead of stretching.

Implementations

impl ScrollBounce

pub fn new<H: ScrollbarHandle + Clone>( id: impl Into<ElementId>, handle: &H, child: impl IntoElement, ) -> Self

pub const fn enabled_by_default() -> bool

Whether scroll areas bounce on this platform unless told otherwise: on iOS, Android and macOS, whose own scroll views do.

pub fn enabled(self, enabled: bool) -> Self

Turn the bounce on or off. Defaults to Self::enabled_by_default.

pub fn scroll_wheel(self, enabled: bool) -> Self

Own vertical scrolling using the shared input overscroll engine. Precise pixel input can bounce; ordinary line-wheel input only scrolls and cancels any existing displacement. Keep fixed chrome outside it.

On by default. Turned off, the child scrolls itself and only its unused deltas stretch the edge; that needs input that emits Ended at finger release, before momentum, as touch does.

pub fn motion(self, motion: ScrollBounceMotion) -> Self

Set how far a drag stretches past an edge and how the edge returns.

pub fn on_scroll( self, handler: impl Fn(&mut Window, &mut App) + 'static, ) -> Self

Observe a logical scroll performed when a reverse drag leaves the stretched region. Runs after the handle update, with no internal state borrowed. Ordinary child scrolling continues to use the child’s own notifications.

Trait Implementations

impl Element for ScrollBounce

type RequestLayoutState = ()

The type of state returned from Element::request_layout. A mutable reference to this state is subsequently provided to Element::prepaint and Element::paint.

type PrepaintState = ScrollBouncePrepaintState

The type of state returned from Element::prepaint. A mutable reference to this state is subsequently provided to Element::paint.

fn id(&self) -> Option<ElementId>

If this element has a unique identifier, return it here. This is used to track elements across frames, and will cause a GlobalElementId to be passed to the request_layout, prepaint, and paint methods.

fn source_location(&self) -> Option<&'static Location<'static>>

Source location where this element was constructed, used to disambiguate elements in the inspector and navigate to their source code.

fn request_layout( &mut self, _: Option<&GlobalElementId>, _: Option<&InspectorElementId>, window: &mut Window, cx: &mut App, ) -> (LayoutId, ())

Before an element can be painted, we need to know where it’s going to be and how big it is. Use this method to request a layout from Taffy and initialize the element’s state.

fn prepaint( &mut self, id: Option<&GlobalElementId>, _: Option<&InspectorElementId>, bounds: Bounds<Pixels>, _: &mut (), window: &mut Window, cx: &mut App, ) -> Self::PrepaintState

After laying out an element, we need to commit its bounds to the current frame for hitbox purposes. The state argument is the same state that was returned from Element::request_layout().

fn paint( &mut self, _: Option<&GlobalElementId>, _: Option<&InspectorElementId>, bounds: Bounds<Pixels>, _: &mut (), prepaint: &mut Self::PrepaintState, window: &mut Window, cx: &mut App, )

Once layout has been completed, this method will be called to paint the element to the screen. The state argument is the same state that was returned from Element::request_layout().

fn a11y_role(&self) -> Option<Role>

Returns the accessible role for this element, if any. Elements that return None are not included in the accessibility tree.

fn write_a11y_info(&self, _node: &mut Node)

Write accessibility properties to the given node. Called only when a11y_role() returns Some.

fn a11y_synthetic_children( &mut self, _prepaint: &mut Self::PrepaintState, _builder: &mut A11ySubtreeBuilder<'_>, )

Add synthetic child nodes to an Element that has an .id() and a .role().

fn into_any(self) -> AnyElement

Convert this element into a dynamically-typed AnyElement.

impl IntoElement for ScrollBounce

type Element = ScrollBounce

The specific type of element into which the implementing type is converted. Useful for converting other types into elements automatically, like Strings

fn into_element(self) -> Self

Convert self into a type that implements Element.

fn into_any_element(self) -> AnyElement

Convert self into a dynamically-typed AnyElement.