Struct OpacityLayer 

pub struct OpacityLayer { /* private fields */ }

A composited layer that makes its children partially transparent.

When debugging, setting debug_disable_opacity_layers to true will cause this layer to be skipped (directly replaced by its children). This can be helpful to track down the cause of performance problems.

Try to avoid an OpacityLayer with no children. Remove that layer if possible to save some tree walks.

Implementations

impl OpacityLayer

pub fn new(app: &mut App) -> Handle<OpacityLayer>

Creates an opacity layer.

The alpha property must be non-null before the compositing phase of the pipeline.

pub fn alpha(self: Handle<Self>, app: &App) -> Option<i32>

The amount to multiply into the alpha channel.

The opacity is expressed as an integer from 0 to 255, where 0 is fully transparent and 255 is fully opaque.

The scene must be explicitly recomposited after this property is changed (as described at Layer).

pub fn set_alpha(self: Handle<Self>, app: &mut App, value: i32)

See alpha.

Trait Implementations

impl ContainerLayer for OpacityLayer

const AS_OFFSET: Option<fn() -> &'static OffsetLayerVTable>

The offset table when this type extends OffsetLayer; container_layer_accessors!(offset) sets it. Dart’s layer is OffsetLayer.

fn container_layer_data(self: Handle<Self>, app: &App) -> &ContainerLayerData

Mixin field access.

fn container_layer_data_mut( self: Handle<Self>, app: &mut App, ) -> &mut ContainerLayerData

See container_layer_data.

fn apply_transform( self: Handle<Self>, app: &App, child: Option<AnyLayer>, transform: &mut Matrix4, )

Applies the transform that would be applied when compositing the given child to the given matrix.

fn as_container_layer(self: Handle<Self>) -> AnyContainerLayer

Dart’s implicit upcast of a concrete layer to ContainerLayer.

fn fire_composition_callbacks( self: Handle<Self>, app: &mut App, include_children: bool, )

ContainerLayer._fireCompositionCallbacks.

fn supports_rasterization(self: Handle<Self>, app: &App) -> bool

ContainerLayer.supportsRasterization.

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

ContainerLayer.dispose.

fn find_annotations( self: Handle<Self>, app: &App, result: &mut AnnotationSearch, local_position: Offset, only_first: bool, ) -> bool

ContainerLayer.findAnnotations.

fn attach(self: Handle<Self>, app: &mut App, owner: HandleId)

ContainerLayer.attach.

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

ContainerLayer.detach.

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

ContainerLayer.redepthChildren.

fn add_to_scene(self: Handle<Self>, app: &mut App, builder: &mut SceneBuilder)

ContainerLayer.addToScene.

impl Layer for OpacityLayer

const AS_CONTAINER: Option<fn() -> &'static ContainerLayerVTable>

The container table when this type extends ContainerLayer; layer_accessors!(container) sets it. Dart’s layer is ContainerLayer.

fn layer_data(self: Handle<Self>, app: &App) -> &LayerData

Dart’s base-class fields, held under the field layer ([layer_accessors!]).

fn layer_data_mut(self: Handle<Self>, app: &mut App) -> &mut LayerData

See layer_data.

fn supports_rasterization(self: Handle<Self>, app: &App) -> bool

Whether or not this layer, or any child layers, can be rasterized with Scene.toImage.

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

Clears any retained resources that this layer holds.

fn attach(self: Handle<Self>, app: &mut App, owner: HandleId)

Mark this layer as attached to the given owner.

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

Mark this layer as detached from its owner.

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

Adjust the depth of this node’s children, if any.

fn find_annotations( self: Handle<Self>, app: &App, result: &mut AnnotationSearch, local_position: Offset, only_first: bool, ) -> bool

Search this layer and its subtree for annotations of the searched type at the location described by local_position.

fn add_to_scene(self: Handle<Self>, app: &mut App, builder: &mut SceneBuilder)

Override this method to upload this layer to the engine.

fn fire_composition_callbacks( self: Handle<Self>, app: &mut App, include_children: bool, )

Dart’s _fireCompositionCallbacks; ContainerLayer recurses into its children.

fn describe_clip_bounds(self: Handle<Self>, app: &App) -> Option<Rect>

Describes the clip that would be applied to contents of this layer, if any.

fn always_needs_add_to_scene(self: Handle<Self>, app: &App) -> bool

Subclasses may override this to true to disable retained rendering.

impl OffsetLayerMixin for OpacityLayer

fn offset_layer_data(self: Handle<Self>, app: &App) -> &OffsetLayerData

Mixin field access.

fn offset_layer_data_mut( self: Handle<Self>, app: &mut App, ) -> &mut OffsetLayerData

See offset_layer_data.

fn as_offset_layer(self: Handle<Self>) -> AnyOffsetLayer

Dart’s implicit upcast of a concrete layer to OffsetLayer.

fn offset(self: Handle<Self>, app: &App) -> Offset

Offset from parent in the parent’s coordinate system.

fn set_offset(self: Handle<Self>, app: &mut App, value: Offset)

See offset.

fn find_annotations( self: Handle<Self>, app: &App, result: &mut AnnotationSearch, local_position: Offset, only_first: bool, ) -> bool

OffsetLayer.findAnnotations.

fn apply_transform( self: Handle<Self>, app: &App, child: Option<AnyLayer>, transform: &mut Matrix4, )

OffsetLayer.applyTransform.

fn add_to_scene(self: Handle<Self>, app: &mut App, builder: &mut SceneBuilder)

OffsetLayer.addToScene.