Struct VirtualList

pub struct VirtualList {
    pub max_scroll: DynamicReader<Point<UPx>>,
    pub scroll: Dynamic<Point<UPx>>,
    /* private fields */
}

A virtuallized list view

This widget allows scrolling a list of rows by lazily loading only the rows that are currently being displayed to the screen.

Fields

max_scroll: DynamicReader<Point<UPx>>

Maximum scroll value - max_scroll.y + control_size.height should be the height of the content.

scroll: Dynamic<Point<UPx>>

Current scroll value. Changes to this dynamic will scroll the list programmatically.

Implementations

impl VirtualList

pub fn new<MakeRow, Row>( item_count: impl IntoValue<usize>, make_row: MakeRow, ) -> Self

where MakeRow: FnMut(usize) -> Row + Send + 'static, Row: MakeWidget,

Creates a new VirtualList that displays item_count rows, loading each row as needed by invoking make_row.

make_row will be called each time a new row becomes visible. As rows are no longer visible, they will be freed, ensuring a minimum number of widgets is kept in memory at any given time.

Each row will be sized to match the first visible row. To ensure all rows have a consistent size, use the Resize widget.

pub const fn content_watcher(&self) -> &Watcher

Returns a Watcher that when notified will force this list to reload its contents, including the currently visible rows.

pub const fn max_scroll(&self) -> &DynamicReader<Point<UPx>>

Returns a reader for the maximum scroll value.

This represents the maximum amount that the scroll can be moved by.

pub fn content_size(&self) -> DynamicReader<Size<UPx>>

Returns a reader for the size of the scrollable area.

pub fn control_size(&self) -> DynamicReader<Size<UPx>>

Returns a reader for the size of this Scroll widget.

pub fn visible_range(&self) -> DynamicReader<Range<usize>>

Returns a reader for number of visible items. 0 indexed.

Trait Implementations

impl Debug for VirtualList

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

Formats the value using the given formatter.

impl Widget for VirtualList

fn hit_test( &mut self, _location: Point<Px>, _context: &mut EventContext<'_>, ) -> bool

Returns true if this widget should respond to mouse input at location.

fn hover( &mut self, _location: Point<Px>, context: &mut EventContext<'_>, ) -> Option<CursorIcon>

The widget is currently has a cursor hovering it at location.

fn unhover(&mut self, context: &mut EventContext<'_>)

The widget is no longer being hovered.

fn mounted(&mut self, context: &mut EventContext<'_>)

The widget has been mounted into a parent widget.

fn redraw(&mut self, context: &mut GraphicsContext<'_, '_, '_, '_>)

Redraw the contents of this widget.

fn layout( &mut self, available_space: Size<ConstraintLimit>, context: &mut LayoutContext<'_, '_, '_, '_>, ) -> Size<UPx>

Layout this widget and returns the ideal size based on its contents and the available_space.

fn mouse_wheel( &mut self, _device_id: DeviceId, delta: MouseScrollDelta, _phase: TouchPhase, context: &mut EventContext<'_>, ) -> EventHandling

A mouse wheel event has been sent to this widget. Returns whether the event has been handled or not.

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

Writes a summary of this widget into fmt.

fn full_control_redraw(&self) -> bool

Returns true if this widget handles all built-in style components that apply.

fn unmounted(&mut self, context: &mut EventContext<'_>)

The widget has been removed from its parent widget.

fn accept_focus(&mut self, context: &mut EventContext<'_>) -> bool

This widget has been targeted to be focused. If this function returns true, the widget will be focused. If false, Cushy will continue searching for another focus target.

fn focus(&mut self, context: &mut EventContext<'_>)

The widget has received focus for user input.

fn advance_focus( &mut self, direction: VisualOrder, context: &mut EventContext<'_>, ) -> EventHandling

The widget should switch to the next focusable area within this widget, honoring direction in a consistent manner. Returning HANDLED will cause the search for the next focus widget stop.

fn allow_blur(&mut self, context: &mut EventContext<'_>) -> bool

The widget is about to lose focus. Returning true allows the focus to switch away from this widget.

fn blur(&mut self, context: &mut EventContext<'_>)

The widget is no longer focused for user input.

fn activate(&mut self, context: &mut EventContext<'_>)

The widget has become the active widget.

fn deactivate(&mut self, context: &mut EventContext<'_>)

The widget is no longer active.

fn mouse_down( &mut self, location: Point<Px>, device_id: DeviceId, button: MouseButton, context: &mut EventContext<'_>, ) -> EventHandling

A mouse button event has occurred at location. Returns whether the event has been handled or not.

fn mouse_drag( &mut self, location: Point<Px>, device_id: DeviceId, button: MouseButton, context: &mut EventContext<'_>, )

A mouse button is being held down as the cursor is moved across the widget.

fn mouse_up( &mut self, location: Option<Point<Px>>, device_id: DeviceId, button: MouseButton, context: &mut EventContext<'_>, )

A mouse button is no longer being pressed.

fn keyboard_input( &mut self, device_id: DeviceId, input: KeyEvent, is_synthetic: bool, context: &mut EventContext<'_>, ) -> EventHandling

A keyboard event has been sent to this widget. Returns whether the event has been handled or not.

fn ime(&mut self, ime: Ime, context: &mut EventContext<'_>) -> EventHandling

An input manager event has been sent to this widget. Returns whether the event has been handled or not.

fn root_behavior( &mut self, context: &mut EventContext<'_>, ) -> Option<(RootBehavior, WidgetInstance)>

Returns a reference to a single child widget if this widget is a widget that primarily wraps a single other widget to customize its behavior.