Struct ShownFrames 

pub struct ShownFrames<S> { /* private fields */ }

The frame being drawn and the frame on screen, as noted.

Implementations

impl<S> ShownFrames<S>

pub fn note(&self, shown: S)

From the scroller’s draw: what this frame shows.

pub fn present(&mut self)

From the scroller’s mark_drawn: the frame just drawn is on screen. Not drawn this frame, what the screen shows where the scroller lies is not known to be its content, and its next frame repaints.

pub fn frames(&self) -> Option<(Ref<'_, S>, &S)>

The frame being drawn and the frame on screen, when both are noted.

pub fn drawing(&self) -> Option<Ref<'_, S>>

The frame being drawn, when noted.

pub fn drawing_mut(&self) -> Option<RefMut<'_, S>>

The frame being drawn, to add what its draw learns late (the thumbs its bars painted).

pub fn presented(&self) -> Option<&S>

The frame on screen, when noted.

pub fn forget(&mut self)

Forget both frames: an outer cache owns the draw now, and the next frame the scroller draws repaints.

impl<S> ShownFrames<S>

where S: Shown + PartialEq,

pub fn compare<T>(&self, owner: &T, regions: &mut Vec<Rect>) -> Since

where T: ?Sized,

From the scroller’s collect_damage: how this frame differs from the one on screen, offering a scroll to a host that copies on behalf of owner (the widget in the tree the scroller draws in). What stays put over the content and changed (or that a copy moves) is added to regions.

impl ShownFrames<Showing<Around, Painted>>

pub fn damage_within<T>(&self, owner: &T, bounds: Rect, regions: &mut Vec<Rect>)

where T: ?Sized,

Self::damage, and on a frame that repaints, the whole box the scroller paints now, bounds, and where it painted before.

impl<L, P> ShownFrames<Showing<L, P>>

where L: PartialEq, P: PartialEq,

pub fn damage<T>(&self, owner: &T, regions: &mut Vec<Rect>) -> Since

where T: ?Sized,

From the scroller’s collect_damage: Self::compare, then the pieces that changed, came or went where the screen showed them before; the viewport when the frame repaints. Returns how the frame compared.

Trait Implementations

impl<S> Debug for ShownFrames<S>

where S: Debug,

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

Formats the value using the given formatter.

impl<S> Default for ShownFrames<S>

fn default() -> ShownFrames<S>

Returns the “default value” for a type.