canvas_core_runtime library
Classes
- CanvasAppearance
- Appearance shared by text and icon sources.
- CanvasAssetRef
- CanvasBlobUrlAssetRef
- Browser blob URL reference.
- CanvasDataUriAssetRef
- Inline data URI reference.
- CanvasFieldKey
- Stable identity for a runtime-editable canvas field.
- CanvasFieldKeyConverter
- Serializes CanvasFieldKey as its stable string value.
- CanvasFields
- Built-in field keys for properties that exist in the base canvas_core runtime scene model.
- CanvasFileAssetRef
- Local file reference.
- CanvasFill
- Single source-of-truth fill for runtime. No backward-compat: only accepts the new {type: ...} JSON shape.
- CanvasFillConverter
- CanvasFillGradient
- CanvasFillNone
- CanvasFillSolid
- CanvasIconData
- CanvasImageAsset
- Backing source and optional natural dimensions for a document image.
- CanvasImageAssetResolver
- Resolves logical canvas image source references for the current host.
- CanvasRawAssetRef
- Bare/raw source reference with no recognized syntax.
- CanvasRenderPipeline
- Reusable runtime render pipeline.
- CanvasSceneDocument
- CanvasSceneValidationIssue
- One deterministic validation diagnostic for a CanvasSceneDocument.
- CanvasSchemeAssetRef
- Opaque custom-scheme reference, such as:
- CanvasSourceUnderlay
- Ordered paint that derives independently from the original source silhouette and is painted before the authored foreground.
- CanvasUrlAssetRef
- Network URL reference.
- CanvasViewportPlanner
- CanvasViewportTransform
- CircleSource
- ComputedScene
- Computed document/render geometry in document units; these maps are not serialized.
- ContentBoundsPolicy
- Generic runtime policy for content-bounds calculations.
- ContentBoundsSpec
- Runtime-owned spec for custom content-bounds computation.
- CoreServices
- DrawImageOp
- DrawItem
- DrawPathUnderlaysOp
- Ordered source-derived underlays for one resolved path-icon silhouette.
- DrawTextOp
- EllipseSource
- FillPathGradientOp
- FillPathOp
- FillRectGradientOp
- FillRectOp
- GroupBehaviorRef
- Generic runtime-owned behavior envelope for optional group semantics.
- IconResolver
- Sync resolver: the core pipeline (layout + paint op build) is synchronous. Any async download/fetch happens outside core (app/editor layer), then you provide a resolver that can answer synchronously.
- ImageData
- ImageIntrinsics
- Synchronous intrinsic-image lookup used by core scene computation.
- LinearGradientSpec
- Linear gradient parameters in core space.
- LinearGradientSpecConverter
- ---- LinearGradientSpec ----
- Node
- Runtime scene-graph node (hierarchical TRS).
- NodeGeometry
- NullableSize2DConverter
- NullableVec2Converter
- PaintOp
- PathCmd
- PathData
- PathIR
- Canonical compiled representation used everywhere internally.
- PathSource
- PathSourceConverter
- ---- PathSource ---- Use Object? as raw type to avoid brittle generic casts on web.
- PathStyle
- PillSource
- PolylineSource
- Rect2D
- RectSource
- RegularPolygonSource
- RenderSnapshot
- Runtime render snapshot.
- ResolvedIcon
- ResolvedIconPath
- Vector-backed icon (future-proof). Contract for now: the returned PathData should be normalized to your icon origin convention (ideally centered around (0,0) like Text baseline-center behavior).
- ResolvedIconText
- Font-backed icon (glyph in a font family).
- ResolvedLinearGradient
- RestoreOp
- RoundRectSource
- SaveOp
- SceneTreeOps
- SetTransformOp
- Size2D
- 2D size (width/height).
- Size2DConverter
- ---- Size2D ----
- StarSource
- StrokePathOp
- SvgPathSource
- TextData
- TextMeasurer
- Synchronous text measurement used by core scene computation.
- Transform2D
- UnderlineSource
- Vec2
- 2D point/vector.
- Vec2Converter
- ---- Vec2 ----
- Vec2ListNullableConverter
- ---- Vec2 list (nullable items) ----
Enums
- CanvasFit
- CanvasSceneValidationCode
- Stable machine-readable categories returned by scene validation.
- FillRule
- ImageFit
- OriginKind
- PathVerb
- StrokeCap
- StrokeJoin
Extensions
- CanvasImageAssetPatterns on CanvasImageAsset
- Adds pattern-matching-related methods to CanvasImageAsset.
- CanvasSceneDocumentPatterns on CanvasSceneDocument
- Adds pattern-matching-related methods to CanvasSceneDocument.
- NodeEditingX on Node
- Common immutable edits that preserve node identity and tree structure.
- NodeFields on Node
- Rect2DX on Rect2D
Constants
- currentCanvasSceneFormatVersion → const int
- Current persisted Canvas scene format; independent of package version.
- shadowBlurExtentInSigmas → const double
- Practical Gaussian-tail estimate, not a hard pixel-enclosure guarantee. Raster padding remains a separate export policy.
Functions
-
aabbOfTransformedRect(
Rect2D r, Matrix4 m) → Rect2D -
buildPaintOpsFromScene(
CanvasSceneDocument doc, ComputedScene computed) → List< PaintOp> -
collectAllNodeIds(
{CanvasSceneDocument? doc, Node? root}) → Set< ElementId> - Collect all node IDs from a document or a subtree root.
-
collectSceneFontFamilies(
CanvasSceneDocument scene, {Iterable< String> fallbackFontFamilies = const <String>[], IconResolver? icons}) → Set<String> - Collects logical font-family dependencies referenced by a scene.
-
computePaddedContentBounds(
{required CanvasSceneDocument scene, required ComputedScene computed, ContentBoundsPolicy policy = const ContentBoundsPolicy(), double paddingPx = 0}) → Rect2D? -
computeScene(
CanvasSceneDocument doc, CoreServices services) → ComputedScene -
computeViewport(
{required double artboardW, required double artboardH, required double targetW, required double targetH, Rect2D? bounds, double bleed = 0, CanvasFit fit = CanvasFit.contain, double? minUniformScale, double? maxUniformScale}) → CanvasViewportTransform - Fits either the artboard (bounds=null) or a world-space bounds rect into a target, with optional "bleed" (outer margin).
-
decodeCanvasScene(
Map< String, Object?> json) → CanvasSceneDocument - Decodes current, versioned persisted scene JSON.
-
encodeCanvasScene(
CanvasSceneDocument scene) → Map< String, Object?> - Encodes a runtime scene as current, versioned persisted JSON.
-
estimateAppearancePaintBounds(
{required Rect2D? sourceBounds, required bool foregroundPresent, required Iterable< CanvasSourceUnderlay> underlays}) → Rect2D? - Estimates visible paint for a text/icon appearance.
-
estimateSourceUnderlayPaintBounds(
Rect2D sourceBounds, CanvasSourceUnderlay underlay) → Rect2D? - Returns the paint estimate produced by one underlay from the ORIGINAL source bounds.
-
findById(
CanvasSceneDocument doc, ElementId id) → Node? - Find a node anywhere in the tree.
-
findParentOf(
CanvasSceneDocument doc, ElementId id) → ParentRef? -
Find parent + child-index of node
id. If the node is a root child, returns (parent: null, index: i). -
nodesInFrontToBackOrder(
List< Node> children) → List<Node> - Layer panels typically show frontmost first.
-
nodesInPaintOrder(
List< Node> children) → List<Node> - Sibling order is paint order:
-
parseCanvasAssetRef(
String input) → CanvasAssetRef -
replaceById(
CanvasSceneDocument doc, ElementId id, Node updated) → CanvasSceneDocument -
Replace node
idwithupdatedanywhere in the tree. -
resolveLinearGradient(
LinearGradientSpec spec, Size2D size, {double opacity = 1.0}) → ResolvedLinearGradient - Resolve editor semantics into renderer-agnostic data:
-
rewritePostOrder(
Node n, Node fn(Node), {bool skip(Node)?, bool prune(Node)?}) → Node - Post-order tree rewrite:
-
rewriteSceneDocument(
CanvasSceneDocument doc, Node rewriteRoot(Node)) → CanvasSceneDocument - Rewrite every root subtree in a scene document and preserve identity when no root changed.
-
shadowContributesToPaint(
ShadowEffect shadow) → bool - Invalid numeric/color values are skipped defensively by bounds/rendering. The document validator still reports invalid authored data, including for disabled effects.
-
sourceUnderlayContributesToPaint(
CanvasSourceUnderlay underlay) → bool -
upgradeCanvasScene(
Map< String, Object?> json, {bool legacyUnversioned = false, bool? resolveLegacyIconWasGlyph(String iconRef)?}) → Map<String, Object?> - Brings persisted scene JSON to the current Canvas scene format.
-
validateCanvasSceneDocument(
CanvasSceneDocument document) → List< CanvasSceneValidationIssue> - Validate generic runtime-scene integrity without interpreting component semantics.
-
visitSceneNodes(
CanvasSceneDocument doc, {bool includeHidden = false, required void visit(Node node)}) → void - Pure traversal: iterate all nodes (optionally skipping hidden subtrees).
Typedefs
- CanvasAssetId = String
- Document-local identifier for an entry in a scene's asset registry.
- Color32 = int
-
32-bit ARGB color. Same layout as Flutter's
Colorunder the hood: 0xAARRGGBB (e.g., 0xFF112233). - ContentBoundsElementSelector = ElementId? Function(CanvasSceneDocument scene)
-
ContentBoundsFallbackSelector
= Iterable<
ElementId> Function(CanvasSceneDocument scene) - ElementId = String
- FontWeightNum = int
- Numeric font weight (100, 200, …, 900). Common values: 400 (normal), 700 (bold).
- ImagePlacement = ({Rect2D dst, Rect2D src})
- ScenePreparer = CanvasSceneDocument Function(CanvasSceneDocument scene, CoreServices services)
- Pure, synchronous transformation from one runtime scene to another.