I

IObjectRenderer<TRenderTag>

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Central interface used by the CanvasComponent to render elements from the scene graph.
Inheritance Hierarchy

Remarks

Implementations will be queried using the tag for the corresponding implementations of the various aspects of the render tag.

This interface can conveniently be implemented by subclassing ObjectRendererBase<TRenderTag, TVisual>.

Type Parameters

TRenderTag

See Also

Developer's Guide

API

ObjectRendererBase, RenderTree

Members

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Methods

getBoundsProvider

(renderTag: TRenderTag): IBoundsProvider
abstract
Returns an implementation of IBoundsProvider that can determine the visible bounds of the rendering of the render tag.
This method may always return the same instance. By contract, clients will not cache instances returned, but will always call this method before the methods on the instance will be called. This contract enables the use of the flyweight design pattern. Implementations of this class can always return the same instance and reconfigure this instance upon each call to this method.
abstract

Parameters

renderTag: TRenderTag
the render tag to query the bounds for

Return Value

IBoundsProvider
An implementation of IBoundsProvider to determine the bounds of the visualization.

getHitTestable

(renderTag: TRenderTag): IHitTestable
abstract
Returns an implementation of IHitTestable that can determine whether the rendering of the render tag has been hit at a given coordinate.
This method may always return the same instance. By contract, clients will not cache instances returned, but will always call this method before the methods on the instance will be called. This contract enables the use of the flyweight design pattern. Implementations of this class can always return the same instance and reconfigure this instance upon each call to this method.
abstract

Parameters

renderTag: TRenderTag
the render tag to do the hit testing for

Return Value

IHitTestable
An implementation of IHitTestable to determine visibility.

getVisibilityTestable

(renderTag: TRenderTag): IVisibilityTestable
abstract
Returns an implementation of IVisibilityTestable that can determine if the rendering of the render tag would be visible in a given context.
This method may always return the same instance. By contract clients will not cache instances returned but will always call this method before the methods on the instance will be called. This contract enables the use of the flyweight design pattern. Implementations of this class can always return the same instance and reconfigure this instance upon each call to this method.
abstract

Parameters

renderTag: TRenderTag
the render tag to query visibility for

Return Value

IVisibilityTestable
An implementation of IVisibilityTestable to determine visibility.

Implemented in

HandlesRenderer.getVisibilityTestable, GraphOverviewRenderer.getVisibilityTestable, GridRenderer.getVisibilityTestable, ObjectRendererBase.getVisibilityTestable, PortCandidateRenderer.getVisibilityTestable, EdgeStyleIndicatorRenderer.getVisibilityTestable, LabelStyleIndicatorRenderer.getVisibilityTestable, NodeStyleIndicatorRenderer.getVisibilityTestable, PortStyleIndicatorRenderer.getVisibilityTestable, EdgeStyleIndicatorRenderer.getVisibilityTestable, LabelStyleIndicatorRenderer.getVisibilityTestable, NodeStyleIndicatorRenderer.getVisibilityTestable, PortStyleIndicatorRenderer.getVisibilityTestable, EdgeStyleIndicatorRenderer.getVisibilityTestable, LabelStyleIndicatorRenderer.getVisibilityTestable, NodeStyleIndicatorRenderer.getVisibilityTestable, PortStyleIndicatorRenderer.getVisibilityTestable

getVisualCreator

(renderTag: TRenderTag): IVisualCreator
abstract
Returns an implementation of IVisualCreator that will create the Visual tree for the render tag.
This method may always return the same instance. By contract, clients will not cache instances returned, but will always call this method before the methods on the instance will be called. This contract enables the use of the flyweight design pattern. Implementations of this class can always return the same instance and reconfigure this instance upon each call to this method.
abstract

Parameters

renderTag: TRenderTag
the render tag to create a Visual for

Return Value

IVisualCreator
An implementation of IVisualCreator to create or update the visualization.

See Also

Developer's Guide

Constants

LOOKUP

: IObjectRenderer<ILookup>
static
A renderer that treats tag as an instance of ILookup to obtain suitable interface implementations.

This renderer tries to cast the tag to ILookup and obtain the appropriate interface implementations for its methods from it.

If the tag does not implement ILookup nothing will be displayed.

static

Examples

Adding a visualization. The renderer queries the tag's lookup for an IVisualCreator instance.
// the node provides an IVisualCreator via its lookup
const renderTreeElement = graphComponent.renderTree.createElement(
  graphComponent.renderTree.backgroundGroup,
  node,
)

VISUAL

: IObjectRenderer<Visual>
static
A renderer that treats tag as Visual to use directly.
If the tag is not a Visual nothing will be displayed.
static

Examples

Adding a visualization. The renderer installs the provided image to the canvas.
const image = window.document.createElementNS(
  'http://www.w3.org/2000/svg',
  'image',
)
image.setAttributeNS(
  'http://www.w3.org/1999/xlink',
  'href',
  'resources/background.png',
)
image.x.baseVal.value = 1
image.y.baseVal.value = 1
image.width.baseVal.value = 100
image.height.baseVal.value = 100
const visual = new SvgVisual(image)
graphComponent.renderTree.createElement(
  graphComponent.renderTree.rootGroup,
  visual,
)

VISUAL_CREATOR

: IObjectRenderer<IVisualCreator>
static
A renderer that treats tag as an instance of IVisualCreator.

This renderer tries to cast the tag to IVisualCreator and use this instance to handle the visual representation of the IRenderTreeElement.

If the tag does not implement IVisualCreator nothing will be displayed.

static

Examples

Adding a visualization. The tag is an IVisualCreator instance.
const renderTreeElement = graphComponent.renderTree.createElement(
  graphComponent.renderTree.backgroundGroup,
  new RectangleVisualCreator(rectangle),
)

VOID_OBJECT_RENDERER

: IObjectRenderer<unknown>
static
An immutable and shareable instance of the IObjectRenderer<T> class that renders nothing.