TextureLayer class

A composited layer that maps a backend texture to a rectangle.

Backend textures are images that can be applied (mapped) to an area of the Flutter view. They are created, managed, and updated using a platform-specific texture registry. This is typically done by a plugin that integrates with host platform video player, camera, or OpenGL APIs, or similar image sources.

A texture layer refers to its backend texture using an integer ID. Texture IDs are obtained from the texture registry and are scoped to the Flutter view. Texture IDs may be reused after deregistration, at the discretion of the registry. The use of texture IDs currently unknown to the registry will silently result in a blank rectangle.

Once inserted into the layer tree, texture layers are repainted autonomously as dictated by the backend (e.g. on arrival of a video frame). Such repainting generally does not involve executing Dart code.

Texture layers are always leaves in the layer tree.

See also:

Inheritance

Constructors

TextureLayer({@required Rect rect, @required int textureId, bool freeze: false })
Creates a texture layer bounded by rect and with backend texture identified by textureId, if freeze is true new texture frames will not be populated to the texture.

Properties

freeze → bool
When true the texture that will not be updated with new frames. [...]
final
rect → Rect
Bounding rectangle of this layer.
final
textureId → int
The identity of the backend texture.
final
alwaysNeedsAddToScene → bool
Subclasses may override this to true to disable retained rendering.
@protected, read-only, inherited
attached → bool
Whether this node is in a tree whose root is attached to something. [...]
read-only, inherited
debugCreator ↔ dynamic
The object responsible for creating this layer. [...]
read / write, inherited
debugSubtreeNeedsAddToScene → bool
Whether any layer in the subtree needs addToScene. [...]
@visibleForTesting, read-only, inherited
depth → int
The depth of this node in the tree. [...]
read-only, inherited
hashCode → int
The hash code for this object. [...]
read-only, inherited
nextSibling → Layer
This layer's next sibling in the parent layer's child list.
read-only, inherited
owner → Object
The owner for this node (null if unattached). [...]
read-only, inherited
parent → ContainerLayer
This layer's parent in the layer tree. [...]
read-only, inherited
previousSibling → Layer
This layer's previous sibling in the parent layer's child list.
read-only, inherited
runtimeType → Type
A representation of the runtime type of the object.
read-only, inherited

Methods

addToScene(SceneBuilder builder, [ Offset layerOffset = Offset.zero ]) → EngineLayer
Override this method to upload this layer to the engine. [...]
override
find<S>(Offset regionOffset) → S
Returns the value of S that corresponds to the point described by regionOffset. [...]
override
adoptChild(covariant AbstractNode child) → void
Mark the given node as being a child of this node. [...]
inherited
attach(covariant Object owner) → void
Mark this node as attached to the given owner. [...]
@mustCallSuper, inherited
debugDescribeChildren() → List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children. [...]
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node. [...]
inherited
debugMarkClean() → void
Mark that this layer is in sync with engine. [...]
@visibleForTesting, inherited
detach() → void
Mark this node as detached. [...]
@mustCallSuper, inherited
dropChild(covariant AbstractNode child) → void
Disconnect the given node from this node. [...]
inherited
markNeedsAddToScene() → void
Mark that this layer has changed and addToScene needs to be called.
@protected, inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
inherited
redepthChild(AbstractNode child) → void
Adjust the depth of the given child to be greater than this node's own depth. [...]
@protected, inherited
redepthChildren() → void
Adjust the depth of this node's children, if any. [...]
inherited
remove() → void
Removes this layer from its parent layer's child list. [...]
@mustCallSuper, inherited
replaceWith(Layer newLayer) → void
Replaces this layer with the given layer in the parent layer's child list.
inherited
toDiagnosticsNode({String name, DiagnosticsTreeStyle style }) → DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by toStringDeep. [...]
inherited
toString({DiagnosticLevel minLevel: DiagnosticLevel.debug }) → String
Returns a string representation of this object.
inherited
toStringDeep({String prefixLineOne: '', String prefixOtherLines, DiagnosticLevel minLevel: DiagnosticLevel.debug }) → String
Returns a string representation of this node and its descendants. [...]
inherited
toStringShallow({String joiner: ', ', DiagnosticLevel minLevel: DiagnosticLevel.debug }) → String
Returns a one-line detailed description of the object. [...]
inherited
toStringShort() → String
A brief description of this object, usually just the runtimeType and the hashCode. [...]
inherited
updateSubtreeNeedsAddToScene() → void
Traverse the layer tree and compute if any subtree needs addToScene. [...]
@protected, inherited

Operators

operator ==(dynamic other) → bool
The equality operator. [...]
inherited