Struct FixedViewportOffset 

pub struct FixedViewportOffset { /* private fields */ }

A ViewportOffset whose pixels value does not change unless the viewport issues a correction.

Flutter’s private _FixedViewportOffset, reached through the ViewportOffset.fixed and ViewportOffset.zero factories.

Implementations

impl FixedViewportOffset

pub fn new(app: &mut App, value: f64) -> Handle<FixedViewportOffset>

Creates a viewport offset with the given pixels value.

Dart’s ViewportOffset.fixed.

pub fn zero(app: &mut App) -> Handle<FixedViewportOffset>

Creates a viewport offset with a pixels value of 0.0.

Dart’s ViewportOffset.zero.

Trait Implementations

impl ChangeNotifier for FixedViewportOffset

fn change_notifier_data(&self) -> &ChangeNotifierData

fn change_notifier_data_mut(&mut self) -> &mut ChangeNotifierData

fn will_add_listener(self: Handle<Self>, app: &mut App)

Runs before the listener is stored. Dart overrides of addListener that work before super.addListener go here.

fn did_remove_listener(self: Handle<Self>, app: &mut App)

Runs after the listener is removed. Dart overrides of removeListener that work after super.removeListener go here.

impl Debug for FixedViewportOffset

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

Formats the value using the given formatter.

impl Default for FixedViewportOffset

fn default() -> Self

Returns the “default value” for a type.

impl ViewportOffset for FixedViewportOffset

fn pixels(self: Handle<Self>, app: &App) -> f64

The number of pixels to offset the children in the opposite of the axis direction.

fn has_pixels(self: Handle<Self>, _app: &App) -> bool

Whether the pixels property is available.

fn apply_viewport_dimension( self: Handle<Self>, _app: &mut App, _viewport_dimension: f64, ) -> bool

Called when the viewport’s extents are established.

fn apply_content_dimensions( self: Handle<Self>, _app: &mut App, _min_scroll_extent: f64, _max_scroll_extent: f64, ) -> bool

Called when the viewport’s content extents are established.

fn correct_by(self: Handle<Self>, app: &mut App, correction: f64)

Apply a layout-time correction to the scroll offset.

fn jump_to(self: Handle<Self>, _app: &mut App, _pixels: f64)

Jumps pixels from its current value to the given value, without animation, and without checking if the new value is in range.

fn animate_to( self: Handle<Self>, _app: &mut App, _to: f64, _duration: Duration, _curve: Rc<dyn Curve>, ) -> CompleterFuture<()>

Animates pixels from its current value to the given value.

fn user_scroll_direction(self: Handle<Self>, _app: &App) -> ScrollDirection

The direction in which the user is trying to change pixels, relative to the viewport’s axis_direction.

fn allow_implicit_scrolling(self: Handle<Self>, _app: &App) -> bool

Whether a viewport is allowed to change pixels implicitly to respond to a call to crate::RenderObject::show_on_screen.

fn move_to( self: Handle<Self>, app: &mut App, to: f64, duration: Option<Duration>, curve: Option<Rc<dyn Curve>>, clamp: Option<bool>, ) -> CompleterFuture<()>

Calls jump_to if duration is None or zero, otherwise animate_to is called.

fn debug_fill_description( self: Handle<Self>, app: &App, description: &mut Vec<String>, )

Add additional information to the given description for use by Dart’s toString.

fn as_viewport_offset(self: Handle<Self>) -> AnyViewportOffset

The type-erased ViewportOffset handle. Free: the vtable is a const, and the id is copied.