com.yworks.yfiles.graph.styles

Class AbstractNodeStyle

java.lang.Object

com.yworks.yfiles.graph.styles.AbstractNodeStyle

All Implemented Interfaces:

INodeStyle, ICloneable, Cloneable

public abstract class AbstractNodeStyle
extends Object
implements INodeStyle, Cloneable

An abstract base class that makes it possible to easily implement a custom INodeStyle.

The only method that needs to be implemented by subclasses is createVisual(IRenderContext, INode), however to improve rendering performance it is highly recommended to implement at least updateVisual(IRenderContext, Node, INode), too.

This implementation differs from the straightforward INodeStyle implementation in that there is no visible separation between the style and its INodeStyleRenderer. Instead the renderer used by the base class is fixed and delegates all calls back to the style instance.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractNodeStyle() Initializes a new instance of the AbstractNodeStyle class.

Method Summary

Modifier and Type	Method and Description
AbstractNodeStyle	clone() Creates a new object that is a copy of the current instance.
protected abstract Node	createVisual(IRenderContext context, INode node) Callback that creates the visual.
protected RectD	getBounds(ICanvasContext context, INode node) Gets the bounds of the visual for the node in the given context.
protected PointD	getIntersection(INode node, PointD inner, PointD outer) Gets the intersection of a line with the visual representation of the node.
protected GeneralPath	getOutline(INode node) Gets the outline of the visual style.
INodeStyleRenderer	getRenderer() Gets the renderer implementation for this instance.
protected boolean	isHit(IInputModeContext context, PointD location, INode node) Determines whether the visual representation of the node has been hit at the given location.
protected boolean	isInBox(IInputModeContext context, RectD rectangle, INode node) Determines whether the visualization for the specified node is included in the marquee selection.
protected boolean	isInside(INode node, PointD location) Determines whether the provided point is geometrically inside the visual bounds of the node.
protected boolean	isVisible(ICanvasContext context, RectD rectangle, INode node) Determines whether the visualization for the specified node is visible in the context.
protected Object	lookup(INode node, Class type) Performs the ILookup.lookup(Class) operation for the INodeStyleRenderer.getContext(INode, INodeStyle) that has been queried from the Renderer.
protected Node	updateVisual(IRenderContext context, Node oldVisual, INode node) Callback that updates the visual previously created by createVisual(IRenderContext, INode).

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractNodeStyle

protected AbstractNodeStyle()

Initializes a new instance of the AbstractNodeStyle class.

Method Detail

clone

public AbstractNodeStyle clone()

Creates a new object that is a copy of the current instance.

Immutable subclasses should consider returning this.

Specified by:

clone in interface ICloneable

Overrides:

clone in class Object

Returns:

A new object that is a copy of this instance using Object.clone().

See Also:

Object.clone()

createVisual

protected abstract Node createVisual(IRenderContext context,
                                     INode node)

Callback that creates the visual.

This method is called in response to a IVisualCreator.createVisual(IRenderContext) call to the instance that has been queried from the Renderer.

Parameters:

context - The render context.

node - The node to which this style instance is assigned.

Returns:

The visual as required by the IVisualCreator.createVisual(IRenderContext) interface.

See Also:

updateVisual(IRenderContext, Node, INode)

getBounds

protected RectD getBounds(ICanvasContext context,
                          INode node)

Gets the bounds of the visual for the node in the given context.

This method is called in response to a IBoundsProvider.getBounds(ICanvasContext) call to the instance that has been queried from the Renderer. This implementation simply yields the Layout.

Parameters:

context - The canvas context.

node - The node to which this style instance is assigned.

Returns:

The visual bounds of the visual representation.

getIntersection

protected PointD getIntersection(INode node,
                                 PointD inner,
                                 PointD outer)

Gets the intersection of a line with the visual representation of the node.

This method is called in response to a IShapeGeometry.getIntersection(PointD, PointD) call to the instance that has been queried from the Renderer. This implementation simply uses the outline to determine the intersection or the Layout if the outline is null. If it is feasible to determine the intersection point for the current shape, this method should be implemented in addition to getOutline(INode) to improve performance.

Parameters:

node - The node to which this style instance is assigned.

inner - The coordinates of a point lying inside the shape.

outer - The coordinates of a point lying outside the shape.

Returns:

The intersection point if one has been found or null, otherwise.

See Also:

isInside(INode, PointD)

getOutline

protected GeneralPath getOutline(INode node)

Gets the outline of the visual style.

This implementation yields null to indicate that the Layout depicts the outline. Implementing this method influences the behavior of isInside(INode, PointD) and getIntersection(INode, PointD, PointD) since the default implementations delegate to it.

Parameters:

node - The node to which this style instance is assigned.

Returns:

The outline of the visual representation or null.

getRenderer

public final INodeStyleRenderer getRenderer()

Gets the renderer implementation for this instance.

The private implementation will delegate all API calls back to this instance.

Specified by:

getRenderer in interface INodeStyle

Returns:

The Renderer.

isHit

protected boolean isHit(IInputModeContext context,
                        PointD location,
                        INode node)

Determines whether the visual representation of the node has been hit at the given location.

This method is called in response to a IHitTestable.isHit(IInputModeContext, PointD) call to the instance that has been queried from the Renderer. This implementation uses the outline to determine whether the node has been hit.

Parameters:

context - The canvas context.

location - The point to test.

node - The node to which this style instance is assigned.

Returns:

true if the specified node representation is hit; false otherwise.

isInBox

protected boolean isInBox(IInputModeContext context,
                          RectD rectangle,
                          INode node)

Determines whether the visualization for the specified node is included in the marquee selection.

This method is called in response to a IMarqueeTestable.isInBox(IInputModeContext, RectD) call to the instance that has been queried from the Renderer. This implementation simply tests whether the bounds intersect the marquee box.

Parameters:

context - The input mode context.

rectangle - The marquee selection box.

node - The node to which this style instance is assigned.

Returns:

true if the specified node is visible is selected by the marquee rectangle; false otherwise.

isInside

protected boolean isInside(INode node,
                           PointD location)

Determines whether the provided point is geometrically inside the visual bounds of the node.

This method is called in response to a IShapeGeometry.isInside(PointD) call to the instance that has been queried from the Renderer. This implementation simply uses the outline to determine whether the point is contained or the Layout if the outline is null. If it is feasible to determine whether a given point lies inside the shape, this method should be implemented in addition to getOutline(INode) to improve performance.

Parameters:

node - The node to which this style instance is assigned.

location - The point to test.

Returns:

Whether the point is considered to lie inside the shape.

isVisible

protected boolean isVisible(ICanvasContext context,
                            RectD rectangle,
                            INode node)

Determines whether the visualization for the specified node is visible in the context.

This method is called in response to a IVisibilityTestable.isVisible(ICanvasContext, RectD) call to the instance that has been queried from the Renderer. This implementation simply tests whether the bounds intersect the clip.

Parameters:

context - The canvas context.

rectangle - The clipping rectangle.

node - The node to which this style instance is assigned.

Returns:

true if the specified node is visible in the clipping rectangle; false otherwise.

lookup

protected Object lookup(INode node,
                        Class type)

Performs the ILookup.lookup(Class) operation for the INodeStyleRenderer.getContext(INode, INodeStyle) that has been queried from the Renderer.

This implementation yields null for everything but:

• IHitTestable
• IVisualCreator
• IBoundsProvider
• IVisibilityTestable
• IMarqueeTestable
• ILookup
• IShapeGeometry

For these interfaces an implementation will be returned that delegates to the methods in this instance.

Parameters:

node - The node to use for the context lookup.

type - The type to query.

Returns:

An implementation of the type or null.

updateVisual

protected Node updateVisual(IRenderContext context,
                            Node oldVisual,
                            INode node)

Callback that updates the visual previously created by createVisual(IRenderContext, INode).

This method is called in response to a IVisualCreator.updateVisual(IRenderContext, Node) call to the instance that has been queried from the Renderer. This implementation simply delegates to createVisual(IRenderContext, INode) so subclasses should override to improve rendering performance.

Parameters:

context - The render context.

oldVisual - The visual that has been created in the call to createVisual(IRenderContext, INode).

node - The node to which this style instance is assigned.

Returns:

The visual as required by the IVisualCreator.createVisual(IRenderContext) interface.

See Also:

createVisual(IRenderContext, INode)