PdfTileRasterBackend class abstract
Creates a scene-scoped renderer for deep-zoom tiles or tile slabs.
PdfTileStore remains responsible for LoD selection, batching, caching, and composition. A backend only turns a retained-scene region into an image. Keeping the session at scene lifetime lets accelerated backends tessellate commands and upload buffers or textures once, then reuse those resources for every region the store requests.
Returning null from createSession, or throwing while creating or using a session, makes the page view fall back to PdfCanvasTileRasterBackend for that scene. Implementations should therefore reject unsupported command mixes conservatively instead of approximating painter order, groups, clipping, or blending.
- Implementers
Constructors
- PdfTileRasterBackend()
-
const
Properties
- debugLabel → String
-
A short diagnostics label, such as
canvasorflutter_gpu.no setter - hashCode → int
-
The hash code for this object.
no setterinherited
- lastSessionRejection → String?
-
Why the most recent createSession call returned null, when known.
no setter
- prefersDirectDecodedImageUploads → bool
-
Whether worker-decoded RGBA should stay attached to a retained scene
until this backend has created its scene resources.
no setter
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
Methods
-
createSession(
PdfRetainedScene scene) → PdfTileRasterSession? - Creates a lightweight owner for resources retained across tile renders.
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited