RefreshIndicator

RefreshIndicator adds a pull-to-refresh interaction around scrollable content.

It is stateless. The app stores the current refresh status and pulled distance, reducers update those values from drag events, and on_refresh starts the actual refresh work. This keeps refresh behavior testable and consistent with the rest of Fission's state model.

Basic shape

use fission::prelude::*;

let content = RefreshIndicator::new(product_list)
    .id(WidgetNodeId::explicit("catalog.refresh"))
    .status(view.state.refresh_status)
    .pulled_extent(view.state.pulled_extent)
    .trigger_distance(80.0)
    .displacement(64.0)
    .on_pull_start(with_reducer!(ctx, PullStarted, on_pull_started))
    .on_pull_update(with_reducer!(ctx, PullUpdated, on_pull_updated))
    .on_pull_cancel(with_reducer!(ctx, PullCanceled, on_pull_canceled))
    .on_refresh(with_reducer!(ctx, RefreshProducts, on_refresh_products))
    .build(ctx, view);

on_pull_update receives pointer drag data through the reducer context. Store the accumulated pulled distance in state. When the user releases after crossing trigger_distance, on_refresh fires.

Field table

Field	Type	Meaning	Notes / default behavior
id	WidgetNodeId	Stable identity for the refresh indicator and its progress animation.	Set this explicitly when a screen has more than one refresh region.
child	Box<Node>	Content being refreshed.	Usually a scrollable list or grid.
status	RefreshIndicatorStatus	Current visual and interaction state.	Defaults to Inactive.
pulled_extent	f32	Current pull distance in logical points.	Stored in app state.
trigger_distance	f32	Pull distance needed to trigger refresh.	Defaults to 80.0.
displacement	f32	How far the child content is visually displaced.	Defaults to 40.0.
edge_offset	f32	Extra top offset before the indicator appears.	Defaults to 0.0.
color	Option<Color>	Progress arc color override.	Defaults to theme primary.
background_color	Option<Color>	Indicator container background override.	Defaults to theme surface.
track_color	Option<Color>	Progress track color override.	Defaults to theme border.
stroke_width	f32	Progress stroke width.	Defaults to 4.0.
indicator_size	f32	Inner progress indicator size.	Defaults to 36.0.
on_pull_start	Option<ActionEnvelope>	Action dispatched when dragging starts.	Usually sets status to Drag.
on_pull_update	Option<ActionEnvelope>	Action dispatched for drag movement.	Usually updates pulled_extent and arms the refresh.
on_pull_cancel	Option<ActionEnvelope>	Action dispatched when release does not refresh.	Usually resets status and pull distance.
on_refresh	Option<ActionEnvelope>	Action dispatched when the pull is released while armed.	Usually starts a job/resource refresh.

Status values

Status	Meaning
Inactive	No pull is active and the indicator is hidden.
Drag	The user is pulling but has not crossed the trigger distance.
Armed	The pull distance is enough to refresh if released.
Refreshing	Refresh work is running. The indicator uses indeterminate progress.
Done	Refresh has completed and the indicator can settle.