ContainerLayer class

A composited layer that has a list of children.

A ContainerLayer instance merely takes a list of children and inserts them into the composited rendering in order. There are subclasses of ContainerLayer which apply more elaborate effects in the process.





alwaysNeedsAddToScene bool
Subclasses may override this to true to disable retained rendering.
no setterinherited
attached bool
Whether the layer tree containing this layer is attached to an owner.
no setterinherited
debugCreator Object?
The object responsible for creating this layer.
getter/setter pairinherited
debugDisposed bool
If asserts are enabled, returns whether dispose has been called since the last time any retained resources were created.
no setterinherited
debugHandleCount int
Returns the number of objects holding a LayerHandle to this layer.
no setterinherited
debugSubtreeNeedsAddToScene bool?
Whether this or any descendant layer in the subtree needs addToScene.
no setterinherited
depth int
The depth of this layer in the layer tree.
no setterinherited
engineLayer EngineLayer?
Stores the engine layer created for this layer in order to reuse engine resources across frames for better app performance.
getter/setter pairinherited
firstChild Layer?
The first composited layer in this layer's child list.
no setter
hasChildren bool
Returns whether this layer has at least one child layer.
no setter
hashCode int
The hash code for this object.
no setterinherited
lastChild Layer?
The last composited layer in this layer's child list.
no setter
nextSibling Layer?
This layer's next sibling in the parent layer's child list.
no setterinherited
owner Object?
The owner for this layer (null if unattached).
no setterinherited
parent ContainerLayer?
This layer's parent in the layer tree.
no setterinherited
previousSibling Layer?
This layer's previous sibling in the parent layer's child list.
no setterinherited
runtimeType Type
A representation of the runtime type of the object.
no setterinherited
subtreeHasCompositionCallbacks bool
Whether the subtree rooted at this layer has any composition callback observers.
no setterinherited


addChildrenToScene(SceneBuilder builder) → void
Uploads all of this layer's children to the engine.
addCompositionCallback(CompositionCallback callback) VoidCallback
Adds a callback for when the layer tree that this layer is part of gets composited, or when it is detached and will not be rendered again.
addToScene(SceneBuilder builder) → void
Override this method to upload this layer to the engine.
append(Layer child) → void
Adds the given layer to the end of this layer's child list.
applyTransform(Layer? child, Matrix4 transform) → void
Applies the transform that would be applied when compositing the given child to the given matrix.
attach(covariant Object owner) → void
Mark this layer as attached to the given owner.
buildScene(SceneBuilder builder) Scene
Consider this layer as the root and build a scene (a tree of layers) in the engine.
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
debugMarkClean() → void
Mark that this layer is in sync with engine.
depthFirstIterateChildren() List<Layer>
Returns the descendants of this layer in depth first order.
describeClipBounds() Rect?
Describes the clip that would be applied to contents of this layer, if any.
detach() → void
Mark this layer as detached from its owner.
dispose() → void
Clears any retained resources that this layer holds.
find<S extends Object>(Offset localPosition) → S?
Search this layer and its subtree for the first annotation of type S under the point described by localPosition.
findAllAnnotations<S extends Object>(Offset localPosition) AnnotationResult<S>
Search this layer and its subtree for all annotations of type S under the point described by localPosition.
findAnnotations<S extends Object>(AnnotationResult<S> result, Offset localPosition, {required bool onlyFirst}) bool
Search this layer and its subtree for annotations of type S at the location described by localPosition.
markNeedsAddToScene() → void
Mark that this layer has changed and addToScene needs to be called.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
redepthChild(Layer child) → void
Adjust the depth of the given child to be greater than this node's own depth.
redepthChildren() → void
Adjust the depth of this node's children, if any.
remove() → void
Removes this layer from its parent layer's child list.
removeAllChildren() → void
Removes all of this layer's children from its child list.
supportsRasterization() bool
Whether or not this layer, or any child layers, can be rasterized with Scene.toImage or Scene.toImageSync.
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
toString({DiagnosticLevel minLevel =}) String
A string representation of this object.
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants.
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a one-line detailed description of the object.
toStringShort() String
A brief description of this object, usually just the runtimeType and the hashCode.
updateSubtreeNeedsAddToScene() → void
Traverses the layer subtree starting from this layer and determines whether it needs addToScene.


operator ==(Object other) bool
The equality operator.