com.yworks.yfiles.view

Interface IRenderContext

All Superinterfaces:

ICanvasContext, ILookup

public interface IRenderContext
extends ICanvasContext

An interface that describes the current context for rendering routines.

See Also:

IVisualCreator

Field Summary

Fields inherited from interface com.yworks.yfiles.view.ICanvasContext

DEFAULT

Fields inherited from interface com.yworks.yfiles.graph.ILookup

EMPTY

Method Summary

Modifier and Type	Method and Description
default void	childVisualRemoved(Node visual) Notifies the context that the visual has been removed from the visual tree.
RectD	getClip() The clipping rectangle in world coordinates.
Transform	getViewTransform() A transform that can be added to the transform list of a visual to be displayed in the original coordinate system (the view coordinate system).
default void	registerForChildrenIfNecessary(Node visual, IDisposeVisualCallback callback) Registers a visual if children have registered themselves for disposal.
default void	setDisposeCallback(Node visual, IDisposeVisualCallback callback) Registers a callback which will be called when the visual will be removed from the visual tree.
PointD	toViewCoordinates(PointD worldPoint) Converts the given set of world coordinates to a coordinate pair that can be used to render within the ViewTransform.

Methods inherited from interface com.yworks.yfiles.view.ICanvasContext

create, create, create, getCanvasControl, getHitTestRadius, getZoom

Methods inherited from interface com.yworks.yfiles.graph.ILookup

createDictionaryLookup, createDynamic, createSingle, createSingle, createWrapped, lookup, lookup, lookup, safeLookup

Method Detail

childVisualRemoved

default void childVisualRemoved(Node visual)

Notifies the context that the visual has been removed from the visual tree.

This has to be done in a IVisualCreator's IVisualCreator.updateVisual(IRenderContext, Node) method if a IVisualCreator's IVisualCreator.createVisual(IRenderContext) is called or a previously added visual will be removed or replaced. Calling this method will call a previously registered IDisposeVisualCallback that the visual has been removed and needs to free its resources.

If the visual has not been registered previously this method will do nothing.

Parameters:

visual - The visual which has been removed.

See Also:

setDisposeCallback(Node, IDisposeVisualCallback), IVisualCreator, IVisualCreator.updateVisual(IRenderContext, Node), IDisposeVisualCallback

getClip

RectD getClip()

The clipping rectangle in world coordinates.

Rendering outside of this clip may be skipped altogether.

Returns:

The Clip.

getViewTransform

Transform getViewTransform()

A transform that can be added to the transform list of a visual to be displayed in the original coordinate system (the view coordinate system).

In contrast to the world coordinate system where the logical coordinates of the elements that are managed by a CanvasControl (for example, graph elements like node and edges), the view coordinate system is used to display visualizations that are independent to scale (zoom) or translation transformations (like handles or selection indicators).

Returns:

The transform to display elements in the view coordinate system.

registerForChildrenIfNecessary

default void registerForChildrenIfNecessary(Node visual,
                                            IDisposeVisualCallback callback)

Registers a visual if children have registered themselves for disposal.

This is necessary for visual creators which delegate to another visual creator to create one or more child visuals, like style decorators.

Implementors have to add a call to this method at the end of their IVisualCreator.createVisual(IRenderContext) and IVisualCreator.updateVisual(IRenderContext, Node) methods.

The registered callback has to call childVisualRemoved(Node) on all child visuals of the visual.

Parameters:

visual - The visual to be registered. This is the visual which is returned by the IVisualCreator.createVisual(IRenderContext) or IVisualCreator.updateVisual(IRenderContext, Node) method which calls this method.

callback - A IDisposeVisualCallback which calls childVisualRemoved(Node) on all child visuals of the registered visual.

setDisposeCallback

default void setDisposeCallback(Node visual,
                                IDisposeVisualCallback callback)

Registers a callback which will be called when the visual will be removed from the visual tree.

This applies to a IVisualCreator's IVisualCreator.createVisual(IRenderContext) method if the created visual allocates resources which should be freed after the visual is no longer used. In this case the visual has to be registered together with a IDisposeVisualCallback which can free the allocated resources. The callback will be called by the framework when the visual is removed from the visual tree.

The callback can also be used to support caching for temporarily removed visuals. See IDisposeVisualCallback.

Parameters:

visual - The visual which needs to be disposed after removal.

callback - A callback which will dispose the visual.

See Also:

IVisualCreator, IVisualCreator.createVisual(IRenderContext), IDisposeVisualCallback

toViewCoordinates

PointD toViewCoordinates(PointD worldPoint)

Converts the given set of world coordinates to a coordinate pair that can be used to render within the ViewTransform.

Parameters:

worldPoint - The coordinates in the world coordinate system.

Returns:

The coordinates in the view coordinate system.

See Also:

getViewTransform()