Struct ScrollTo 

pub struct ScrollTo { /* private fields */ }

A scroll view’s motion toward what it was asked to show.

Implementations

impl ScrollTo

pub const SPEC: MotionSpec

The glide: fast both ways; a key’s jump still glides (spatial context, fast at most); reduced motion lands.

pub const FADE: MotionSpec

The fade-in after a long jump: fast, also under reduced motion and for a key’s jump.

pub const GLIDE_VIEWPORTS: f64 = 3.0

The longest jump, in viewports along either axis, that glides; a longer one fades in at the target.

pub fn new() -> ScrollTo

pub fn go( &mut self, drawn: Vec2, target: Vec2, viewport: Vec2, motion: EffectiveMotion, now: Instant, ) -> ScrollJump

Move the content from drawn, the offset it is drawn at now, to target, in a view viewport large. The input the person just made decides how (super::recent_input): a click, a finger or a key glides a short jump and fades in a long one; with no recent input (a sync, a restored view, a script) or for an agent’s action, it lands. A jump while gliding retargets from where the content is drawn and how fast it moves there.

pub fn go_from( &mut self, drawn: Vec2, target: Vec2, viewport: Vec2, motion: EffectiveMotion, source: MotionSource, now: Instant, ) -> ScrollJump

Self::go for a jump source caused.

pub fn settle( &mut self, drawn: Vec2, target: Vec2, velocity: Vec2, motion: EffectiveMotion, source: MotionSource, now: Instant, ) -> ScrollJump

Settle on target, the way a scroll view whose content offers detents comes to rest on one (super::Snap): a gesture’s release hands its velocity to the settle, so a fling coasts on into the detent without turning back; anything else takes the paged-strip settle (base). Reduced motion lands on it.

pub fn land(&mut self, target: Vec2)

Show target on the next frame: keyboard focus moving to a control off screen while tabbing.

pub fn take_over(&mut self, now: Instant) -> Option<Vec2>

The hand takes over (a wheel, a finger, a bar drag): the motion stops where the content is drawn. Returns that offset when a glide was under way.

pub fn offset(&self, now: Instant) -> Option<Vec2>

Where the content is drawn at now while it glides; None when the scroller’s own offset is where it is.

pub fn offset_in_device_pixels( &self, now: Instant, device_per_unit: f64, ) -> Option<Vec2>

Self::offset in whole pixels of a display with device_per_unit device pixels per logical pixel; the target itself where it rests.

pub fn target(&self) -> Option<Vec2>

Where the motion is going, while it glides.

pub fn opacity(&self, now: Instant) -> f32

The content’s opacity at now: below 1 while it fades in after a long jump.

pub fn is_gliding(&self, now: Instant) -> bool

Whether the content still glides at now; once it arrives, the scroller’s offset is the target and the motion asks for nothing.

pub fn is_moving(&self, now: Instant) -> bool

Whether anything still moves at now: the glide or the fade-in.

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

When everything has arrived; None at rest.

pub fn arrived(&mut self, now: Instant) -> Option<Vec2>

Once the glide has arrived, forget it: the scroller’s own offset is the target from then on. Returns the target it arrived at.

Trait Implementations

impl Clone for ScrollTo

fn clone(&self) -> ScrollTo

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ScrollTo

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

Formats the value using the given formatter.

impl Default for ScrollTo

fn default() -> ScrollTo

Returns the “default value” for a type.

impl Copy for ScrollTo