Documentation / @ripl/core / Context

Abstract Class: Context<TElement, TMeta>

Defined in: packages/core/src/context/context.ts:95

Abstract rendering context providing a unified API for Canvas and SVG, with state management and coordinate scaling.

Extends

• EventBus<ContextEventMap>

Type Parameters

Type Parameter	Default type
TElement extends Element	Element
TMeta extends Record<string, unknown>	Record<string, unknown>

Implements

• BaseState

Constructors

Constructor

new Context<TElement, TMeta>(type, element, options?): Context<TElement, TMeta>

Defined in: packages/core/src/context/context.ts:350

Parameters

Parameter	Type
type	string
element	TElement
options?	ContextOptions<TMeta>

Returns

Context<TElement, TMeta>

Overrides

EventBus.constructor

Properties

Property	Modifier	Type	Default value	Inherited from	Defined in
buffer	public	boolean	false	-	packages/core/src/context/context.ts:101
currentState	protected	BaseState	undefined	-	packages/core/src/context/context.ts:111
element	readonly	TElement	undefined	-	packages/core/src/context/context.ts:98
height	public	number	undefined	-	packages/core/src/context/context.ts:103
meta	readonly	TMeta	undefined	-	packages/core/src/context/context.ts:99
parent?	public	EventBus<ContextEventMap>	undefined	EventBus.parent	packages/core/src/core/event-bus.ts:79
renderDepth	protected	number	0	-	packages/core/src/context/context.ts:112
renderedElements	public	RenderElement[]	undefined	-	packages/core/src/context/context.ts:108
renderElement?	public	RenderElement	undefined	-	packages/core/src/context/context.ts:107
scaleDPR	public	Scale<number, number>	undefined	-	packages/core/src/context/context.ts:106
scaleX	public	Scale<number, number>	undefined	-	packages/core/src/context/context.ts:104
scaleY	public	Scale<number, number>	undefined	-	packages/core/src/context/context.ts:105
states	protected	BaseState[]	undefined	-	packages/core/src/context/context.ts:110
type	readonly	string	undefined	-	packages/core/src/context/context.ts:97
width	public	number	undefined	-	packages/core/src/context/context.ts:102
defaultKey	readonly	typeof defaultKey	undefined	EventBus.defaultKey	packages/core/src/core/disposer.ts:10

Accessors

currentRenderElement

Get Signature

get currentRenderElement(): RenderElement | undefined

Defined in: packages/core/src/context/context.ts:114

Returns

RenderElement | undefined

Set Signature

set currentRenderElement(element): void

Defined in: packages/core/src/context/context.ts:118

Parameters

Parameter	Type
element	RenderElement | undefined

Returns

void

---

direction

Get Signature

get direction(): Direction

Defined in: packages/core/src/context/context.ts:142

Returns

Direction

Set Signature

set direction(value): void

Defined in: packages/core/src/context/context.ts:146

Parameters

Parameter	Type
value	Direction

Returns

void

Implementation of

BaseState.direction

---

fill

Get Signature

get fill(): string

Defined in: packages/core/src/context/context.ts:126

Returns

string

Set Signature

set fill(value): void

Defined in: packages/core/src/context/context.ts:130

Parameters

Parameter	Type
value	string

Returns

void

Implementation of

BaseState.fill

---

filter

Get Signature

get filter(): string

Defined in: packages/core/src/context/context.ts:134

Returns

string

Set Signature

set filter(value): void

Defined in: packages/core/src/context/context.ts:138

Parameters

Parameter	Type
value	string

Returns

void

Implementation of

BaseState.filter

---

font

Get Signature

get font(): string

Defined in: packages/core/src/context/context.ts:150

Returns

string

Set Signature

set font(value): void

Defined in: packages/core/src/context/context.ts:154

Parameters

Parameter	Type
value	string

Returns

void

Implementation of

BaseState.font

---

fontKerning

Get Signature

get fontKerning(): FontKerning

Defined in: packages/core/src/context/context.ts:158

Returns

FontKerning

Set Signature

set fontKerning(value): void

Defined in: packages/core/src/context/context.ts:162

Parameters

Parameter	Type
value	FontKerning

Returns

void

Implementation of

BaseState.fontKerning

---

globalCompositeOperation

Get Signature

get globalCompositeOperation(): unknown

Defined in: packages/core/src/context/context.ts:174

Returns

unknown

Set Signature

set globalCompositeOperation(value): void

Defined in: packages/core/src/context/context.ts:178

Parameters

Parameter	Type
value	unknown

Returns

void

Implementation of

BaseState.globalCompositeOperation

---

lineCap

Get Signature

get lineCap(): LineCap

Defined in: packages/core/src/context/context.ts:182

Returns

LineCap

Set Signature

set lineCap(value): void

Defined in: packages/core/src/context/context.ts:186

Parameters

Parameter	Type
value	LineCap

Returns

void

Implementation of

BaseState.lineCap

---

lineDash

Get Signature

get lineDash(): number[]

Defined in: packages/core/src/context/context.ts:190

Returns

number[]

Set Signature

set lineDash(value): void

Defined in: packages/core/src/context/context.ts:194

Parameters

Parameter	Type
value	number[]

Returns

void

Implementation of

BaseState.lineDash

---

lineDashOffset

Get Signature

get lineDashOffset(): number

Defined in: packages/core/src/context/context.ts:198

Returns

number

Set Signature

set lineDashOffset(value): void

Defined in: packages/core/src/context/context.ts:202

Parameters

Parameter	Type
value	number

Returns

void

Implementation of

BaseState.lineDashOffset

---

lineJoin

Get Signature

get lineJoin(): LineJoin

Defined in: packages/core/src/context/context.ts:206

Returns

LineJoin

Set Signature

set lineJoin(value): void

Defined in: packages/core/src/context/context.ts:210

Parameters

Parameter	Type
value	LineJoin

Returns

void

Implementation of

BaseState.lineJoin

---

lineWidth

Get Signature

get lineWidth(): number

Defined in: packages/core/src/context/context.ts:214

Returns

number

Set Signature

set lineWidth(value): void

Defined in: packages/core/src/context/context.ts:218

Parameters

Parameter	Type
value	number

Returns

void

Implementation of

BaseState.lineWidth

---

miterLimit

Get Signature

get miterLimit(): number

Defined in: packages/core/src/context/context.ts:222

Returns

number

Set Signature

set miterLimit(value): void

Defined in: packages/core/src/context/context.ts:226

Parameters

Parameter	Type
value	number

Returns

void

Implementation of

BaseState.miterLimit

---

opacity

Get Signature

get opacity(): number

Defined in: packages/core/src/context/context.ts:166

Returns

number

Set Signature

set opacity(value): void

Defined in: packages/core/src/context/context.ts:170

Parameters

Parameter	Type
value	number

Returns

void

Implementation of

BaseState.opacity

---

rotation

Get Signature

get rotation(): Rotation

Defined in: packages/core/src/context/context.ts:326

Returns

Rotation

Set Signature

set rotation(value): void

Defined in: packages/core/src/context/context.ts:330

Parameters

Parameter	Type
value	Rotation

Returns

void

Implementation of

BaseState.rotation

---

shadowBlur

Get Signature

get shadowBlur(): number

Defined in: packages/core/src/context/context.ts:230

Returns

number

Set Signature

set shadowBlur(value): void

Defined in: packages/core/src/context/context.ts:234

Parameters

Parameter	Type
value	number

Returns

void

Implementation of

BaseState.shadowBlur

---

shadowColor

Get Signature

get shadowColor(): string

Defined in: packages/core/src/context/context.ts:238

Returns

string

Set Signature

set shadowColor(value): void

Defined in: packages/core/src/context/context.ts:242

Parameters

Parameter	Type
value	string

Returns

void

Implementation of

BaseState.shadowColor

---

shadowOffsetX

Get Signature

get shadowOffsetX(): number

Defined in: packages/core/src/context/context.ts:246

Returns

number

Set Signature

set shadowOffsetX(value): void

Defined in: packages/core/src/context/context.ts:250

Parameters

Parameter	Type
value	number

Returns

void

Implementation of

BaseState.shadowOffsetX

---

shadowOffsetY

Get Signature

get shadowOffsetY(): number

Defined in: packages/core/src/context/context.ts:254

Returns

number

Set Signature

set shadowOffsetY(value): void

Defined in: packages/core/src/context/context.ts:258

Parameters

Parameter	Type
value	number

Returns

void

Implementation of

BaseState.shadowOffsetY

---

stroke

Get Signature

get stroke(): string

Defined in: packages/core/src/context/context.ts:262

Returns

string

Set Signature

set stroke(value): void

Defined in: packages/core/src/context/context.ts:266

Parameters

Parameter	Type
value	string

Returns

void

Implementation of

BaseState.stroke

---

textAlign

Get Signature

get textAlign(): TextAlignment

Defined in: packages/core/src/context/context.ts:270

Returns

TextAlignment

Set Signature

set textAlign(value): void

Defined in: packages/core/src/context/context.ts:274

Parameters

Parameter	Type
value	TextAlignment

Returns

void

Implementation of

BaseState.textAlign

---

textBaseline

Get Signature

get textBaseline(): TextBaseline

Defined in: packages/core/src/context/context.ts:278

Returns

TextBaseline

Set Signature

set textBaseline(value): void

Defined in: packages/core/src/context/context.ts:282

Parameters

Parameter	Type
value	TextBaseline

Returns

void

Implementation of

BaseState.textBaseline

---

transformOriginX

Get Signature

get transformOriginX(): TransformOrigin

Defined in: packages/core/src/context/context.ts:334

Returns

TransformOrigin

Set Signature

set transformOriginX(value): void

Defined in: packages/core/src/context/context.ts:338

Parameters

Parameter	Type
value	TransformOrigin

Returns

void

Implementation of

BaseState.transformOriginX

---

transformOriginY

Get Signature

get transformOriginY(): TransformOrigin

Defined in: packages/core/src/context/context.ts:342

Returns

TransformOrigin

Set Signature

set transformOriginY(value): void

Defined in: packages/core/src/context/context.ts:346

Parameters

Parameter	Type
value	TransformOrigin

Returns

void

Implementation of

BaseState.transformOriginY

---

transformScaleX

Get Signature

get transformScaleX(): number

Defined in: packages/core/src/context/context.ts:310

Returns

number

Set Signature

set transformScaleX(value): void

Defined in: packages/core/src/context/context.ts:314

Parameters

Parameter	Type
value	number

Returns

void

Implementation of

BaseState.transformScaleX

---

transformScaleY

Get Signature

get transformScaleY(): number

Defined in: packages/core/src/context/context.ts:318

Returns

number

Set Signature

set transformScaleY(value): void

Defined in: packages/core/src/context/context.ts:322

Parameters

Parameter	Type
value	number

Returns

void

Implementation of

BaseState.transformScaleY

---

translateX

Get Signature

get translateX(): number

Defined in: packages/core/src/context/context.ts:294

Returns

number

Set Signature

set translateX(value): void

Defined in: packages/core/src/context/context.ts:298

Parameters

Parameter	Type
value	number

Returns

void

Implementation of

BaseState.translateX

---

translateY

Get Signature

get translateY(): number

Defined in: packages/core/src/context/context.ts:302

Returns

number

Set Signature

set translateY(value): void

Defined in: packages/core/src/context/context.ts:306

Parameters

Parameter	Type
value	number

Returns

void

Implementation of

BaseState.translateY

---

zIndex

Get Signature

get zIndex(): number

Defined in: packages/core/src/context/context.ts:286

Returns

number

Set Signature

set zIndex(value): void

Defined in: packages/core/src/context/context.ts:290

Parameters

Parameter	Type
value	number

Returns

void

Implementation of

BaseState.zIndex

Methods

applyClip()

applyClip(path, fillRule?): void

Defined in: packages/core/src/context/context.ts:499

Clips subsequent drawing operations to the given path.

Parameters

Parameter	Type
path	ContextPath
fillRule?	FillRule

Returns

void

---

applyFill()

applyFill(path, fillRule?): void

Defined in: packages/core/src/context/context.ts:504

Fills the given path or text element using the current fill style.

Parameters

Parameter	Type
path	ContextElement
fillRule?	FillRule

Returns

void

---

applyStroke()

applyStroke(path): void

Defined in: packages/core/src/context/context.ts:509

Strokes the given path or text element using the current stroke style.

Parameters

Parameter	Type
path	ContextElement

Returns

void

---

batch()

batch<TResult>(body): TResult

Defined in: packages/core/src/context/context.ts:440

Clears the rendering surface and brackets the callback in markRenderStart/markRenderEnd, returning the callback's result.

Type Parameters

Type Parameter	Default type
TResult	void

Parameters

Parameter	Type
body	() => TResult

Returns

TResult

---

clear()

clear(): void

Defined in: packages/core/src/context/context.ts:407

Clears the entire rendering surface.

Returns

void

---

createPath()

createPath(id?): ContextPath

Defined in: packages/core/src/context/context.ts:484

Creates a new path element, optionally reusing an id for SVG diffing efficiency.

Parameters

Parameter	Type
id?	string

Returns

ContextPath

---

createText()

createText(options): ContextText

Defined in: packages/core/src/context/context.ts:489

Creates a new text element from the given options.

Parameters

Parameter	Type
options	TextOptions

Returns

ContextText

---

destroy()

destroy(): void

Defined in: packages/core/src/context/context.ts:542

Destroys the context and disposes all resources.

Returns

void

Overrides

EventBus.destroy

---

dispose()

protected dispose(key?): void

Defined in: packages/core/src/core/disposer.ts:24

Disposes all resources under the given key, or all resources if no key is provided.

Parameters

Parameter	Type
key?	PropertyKey

Returns

void

Inherited from

EventBus.dispose

---

drawImage()

drawImage(image, x, y, width?, height?): void

Defined in: packages/core/src/context/context.ts:494

Draws an image onto the rendering surface at the given position and optional size.

Parameters

Parameter	Type
image	CanvasImageSource
x	number
y	number
width?	number
height?	number

Returns

void

---

emit()

Call Signature

emit<TEvent>(event): TEvent

Defined in: packages/core/src/core/event-bus.ts:127

Emits an event, invoking all matching handlers and bubbling to the parent if applicable.

Type Parameters

Type Parameter	Default type
TEvent extends Event<undefined>	Event<undefined>

Parameters

Parameter	Type
event	TEvent

Returns

TEvent

Inherited from

EventBus.emit

Call Signature

emit<TEvent>(type, data): Event<ContextEventMap[TEvent]>

Defined in: packages/core/src/core/event-bus.ts:128

Emits an event, invoking all matching handlers and bubbling to the parent if applicable.

Type Parameters

Type Parameter
TEvent extends keyof ContextEventMap

Parameters

Parameter	Type
type	TEvent
data	ContextEventMap[TEvent]

Returns

Event<ContextEventMap[TEvent]>

Inherited from

EventBus.emit

---

getDefaultState()

protected getDefaultState(): BaseState

Defined in: packages/core/src/context/context.ts:380

Returns

BaseState

---

has()

has(type): boolean

Defined in: packages/core/src/core/event-bus.ts:84

Returns whether there are any listeners registered for the given event type.

Parameters

Parameter	Type
type	keyof ContextEventMap

Returns

boolean

Inherited from

EventBus.has

---

hitTest()

protected hitTest(events, x, y): RenderElement[]

Defined in: packages/core/src/context/context.ts:533

Tests which rendered elements intersect the given point for the given event types.

Parameters

Parameter	Type
events	string[]
x	number
y	number

Returns

RenderElement[]

---

invalidateTrackedElements()

invalidateTrackedElements(event?): void

Defined in: packages/core/src/context/context.ts:417

Clears the cached list of tracked elements for interaction, forcing a rebuild on the next hit test.

Parameters

Parameter	Type
event?	string

Returns

void

---

isPointInPath()

isPointInPath(path, x, y, fillRule?): boolean

Defined in: packages/core/src/context/context.ts:514

Tests whether a point is inside the filled region of a path.

Parameters

Parameter	Type
path	ContextPath
x	number
y	number
fillRule?	FillRule

Returns

boolean

---

isPointInStroke()

isPointInStroke(path, x, y): boolean

Defined in: packages/core/src/context/context.ts:519

Tests whether a point is on the stroked outline of a path.

Parameters

Parameter	Type
path	ContextPath
x	number
y	number

Returns

boolean

---

layer()

layer<TResult>(body): TResult

Defined in: packages/core/src/context/context.ts:396

Executes a callback within a save/restore pair, returning the callback's result.

Type Parameters

Type Parameter	Default type
TResult	void

Parameters

Parameter	Type
body	() => TResult

Returns

TResult

---

markRenderEnd()

markRenderEnd(): void

Defined in: packages/core/src/context/context.ts:435

Signals the end of a render pass.

Returns

void

---

markRenderStart()

markRenderStart(): void

Defined in: packages/core/src/context/context.ts:426

Signals the start of a render pass; resets the rendered-elements list at depth 0.

Returns

void

---

measureText()

measureText(text, font?): TextMetrics

Defined in: packages/core/src/context/context.ts:479

Measures text dimensions using the context's current font or an optional override.

Parameters

Parameter	Type
text	string
font?	string

Returns

TextMetrics

---

off()

off<TEvent>(type, handler): void

Defined in: packages/core/src/core/event-bus.ts:102

Removes a previously registered handler for the given event type.

Type Parameters

Type Parameter
TEvent extends keyof ContextEventMap

Parameters

Parameter	Type
type	TEvent
handler	EventHandler<ContextEventMap[TEvent]>

Returns

void

Inherited from

EventBus.off

---

on()

on<TEvent>(type, handler, options?): Disposable

Defined in: packages/core/src/core/event-bus.ts:89

Subscribes a handler to the given event type and returns a disposable for cleanup.

Type Parameters

Type Parameter
TEvent extends keyof ContextEventMap

Parameters

Parameter	Type
type	TEvent
handler	EventHandler<ContextEventMap[TEvent]>
options?	EventSubscriptionOptions

Returns

Disposable

Inherited from

EventBus.on

---

once()

once<TEvent>(type, handler, options?): Disposable

Defined in: packages/core/src/core/event-bus.ts:117

Subscribes a handler that is automatically removed after it fires once.

Type Parameters

Type Parameter
TEvent extends keyof ContextEventMap

Parameters

Parameter	Type
type	TEvent
handler	EventHandler<ContextEventMap[TEvent]>
options?	EventSubscriptionOptions

Returns

Disposable

Inherited from

EventBus.once

---

rescale()

protected rescale(width, height): void

Defined in: packages/core/src/context/context.ts:370

Parameters

Parameter	Type
width	number
height	number

Returns

void

---

reset()

reset(): void

Defined in: packages/core/src/context/context.ts:412

Resets the context to its initial state.

Returns

void

---

restore()

restore(): void

Defined in: packages/core/src/context/context.ts:391

Restores the most recently saved state from the stack.

Returns

void

---

retain()

protected retain(value, key?): void

Defined in: packages/core/src/core/disposer.ts:13

Registers a disposable resource under an optional key for later cleanup.

Parameters

Parameter	Type	Default value
value	Disposable	undefined
key	PropertyKey	Disposer.defaultKey

Returns

void

Inherited from

EventBus.retain

---

rotate()

rotate(angle): void

Defined in: packages/core/src/context/context.ts:454

Applies a rotation transformation.

Parameters

Parameter	Type
angle	number

Returns

void

---

save()

save(): void

Defined in: packages/core/src/context/context.ts:385

Pushes the current state onto the stack and resets to defaults.

Returns

void

---

scale()

scale(x, y): void

Defined in: packages/core/src/context/context.ts:459

Applies a scale transformation.

Parameters

Parameter	Type
x	number
y	number

Returns

void

---

setTransform()

setTransform(a, b, c, d, e, f): void

Defined in: packages/core/src/context/context.ts:469

Parameters

Parameter	Type
a	number
b	number
c	number
d	number
e	number
f	number

Returns

void

---

sortByZIndex()

protected sortByZIndex(elements): RenderElement[]

Defined in: packages/core/src/context/context.ts:528

Sorts render elements by z-index (highest first) for hit testing priority.

Parameters

Parameter	Type
elements	RenderElement[]

Returns

RenderElement[]

---

transform()

transform(a, b, c, d, e, f): void

Defined in: packages/core/src/context/context.ts:474

Parameters

Parameter	Type
a	number
b	number
c	number
d	number
e	number
f	number

Returns

void

---

translate()

translate(x, y): void

Defined in: packages/core/src/context/context.ts:464

Applies a translation transformation.

Parameters

Parameter	Type
x	number
y	number

Returns

void