Struct OverlayScrollbar 

pub struct OverlayScrollbar { /* private fields */ }

A vertical overlay scroll bar. The host keeps its own offset and gives the bar the area it scrolls (Self::track) and its ScrollMetrics each time; the bar keeps the drag, the hover and the idle fade, and the theme’s sizes and motion policy as last given (Self::set_theme).

Implementations

impl OverlayScrollbar

pub fn vertical() -> OverlayScrollbar

A vertical bar along the trailing edge, at the default theme’s sizes.

pub fn set_theme(&mut self, theme: &Theme)

Take the sizes and the motion policy of theme.

pub fn lane(&self, area: Rect) -> Rect

The lane along the trailing edge of area the bar lies in, over the content: the pointer there holds the bar shown.

pub fn track(&self, area: Rect) -> Rect

The thumb’s track over area, where a Scrollable’s would be.

pub fn wake(&self)

Show the bar now, as a scroll does.

pub fn note_offset(&self, offset: f64)

Note the offset the content is shown at; a change since the last one shows the bar, whatever moved it (the wheel, a key, the bar).

pub fn update_pointer( &mut self, area: Rect, metrics: ScrollMetrics, cursor: Point, ) -> bool

Follow the pointer at cursor over area: the thumb under it brightens and the bar stays shown while it is in the lane. Returns whether anything the bar paints changed.

pub fn pointer_left(&mut self) -> bool

The pointer left: the bar fades as at rest. Returns whether anything the bar paints changed.

pub fn press( &mut self, area: Rect, metrics: ScrollMetrics, cursor: Point, ) -> PressOutcome

A press at cursor on the bar over area; see Scrollbar::press. A bar that has faded out takes none.

pub fn drag_to( &self, area: Rect, metrics: ScrollMetrics, cursor: Point, ) -> Option<f64>

The offset a drag in progress asks for; see Scrollbar::drag_to.

pub fn release(&mut self) -> bool

End a drag; returns whether one was in progress.

pub fn is_dragging(&self) -> bool

Whether the thumb is being dragged.

pub fn opacity(&self) -> f32

The bar’s opacity at this frame.

pub fn paint( &self, scene: &mut Scene, transform: Affine, area: Rect, metrics: ScrollMetrics, theme: &Theme, )

Paint the thumb over area for metrics, faded as the bar is now. Paints nothing while the content fits or the bar has faded out.

pub fn needs_animation_frame(&self) -> bool

Whether the fade needs frames now, for the host’s needs_animation_frame.

pub fn next_wake_deadline(&self) -> Option<Instant>

When the fade starts, for the host’s next_wake_deadline.

Trait Implementations

impl Debug for OverlayScrollbar

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

Formats the value using the given formatter.

impl Default for OverlayScrollbar

fn default() -> OverlayScrollbar

Returns the “default value” for a type.