com.yworks.yfiles.layout

Class PortCalculator

java.lang.Object

com.yworks.yfiles.layout.AbstractLayoutStage

com.yworks.yfiles.layout.PortCalculator

All Implemented Interfaces:

ILayoutAlgorithm, ILayoutStage

public class PortCalculator
extends AbstractLayoutStage
implements ILayoutStage

PortCalculator adjusts the final port assignments after a layout has been calculated.

This can be useful if the port assignment calculated by the layout algorithm is insufficient. This stage uses IDataProvider instances registered with the graph using the keys defined in the IIntersectionCalculator interface to calculate the new port offsets.

For each edge in the graph, IIntersectionCalculators are retrieved from these IDataProviders. If such an IIntersectionCalculator is assigned, it will provide the intersection point of the edge and the node. Then this point is added to the IEdgeLayout.

For this layout stage to work properly, use CompositeLayoutStage.prependStage(ILayoutStage) or MultiStageLayout.prependStage(ILayoutStage) to add this layout stage and register appropriate IDataProviders with the graph using the keys defined in IIntersectionCalculator.

Note that this class will not change the coordinates of a port if it is associated with a strong port constraint.

See Also:

IIntersectionCalculator, IntersectionCalculatorKeys.SOURCE_INTERSECTION_CALCULATOR_DPKEY, IntersectionCalculatorKeys.TARGET_INTERSECTION_CALCULATOR_DPKEY, PortConstraint

Field Summary

Fields

Modifier and Type	Field and Description
protected double	Eps EPSILON used by equalsEps(double, double, double, double).

Constructor Summary

Constructors

Constructor and Description
PortCalculator() Creates a new PortCalculator instance with an optional core layout algorithm.

Method Summary

Modifier and Type	Method and Description
void	applyLayout(LayoutGraph graph) Adjusts the ports after invoking the core layout algorithm.
protected void	calculatePorts(LayoutGraph graph) Performs the actual port calculation on the specified graph instance.
protected boolean	equalsEps(double x1, double y1, double x2, double y2) Determines whether two points are equal.

Methods inherited from class com.yworks.yfiles.layout.AbstractLayoutStage

applyLayoutCore, getCoreLayout, setCoreLayout

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.yworks.yfiles.layout.ILayoutStage

getCoreLayout, setCoreLayout

Field Detail

Eps

protected double Eps

EPSILON used by equalsEps(double, double, double, double).

By default this is 0.2d.

Constructor Detail

PortCalculator

public PortCalculator()

Creates a new PortCalculator instance with an optional core layout algorithm.

Method Detail

applyLayout

public void applyLayout(LayoutGraph graph)

Adjusts the ports after invoking the core layout algorithm.

Specified by:

applyLayout in interface ILayoutAlgorithm

Specified by:

applyLayout in class AbstractLayoutStage

Parameters:

graph - the input graph

calculatePorts

protected void calculatePorts(LayoutGraph graph)

Performs the actual port calculation on the specified graph instance.

Parameters:

graph - the input graph

equalsEps

protected boolean equalsEps(double x1,
                            double y1,
                            double x2,
                            double y2)

Determines whether two points are equal.

This implementation uses Eps to add some tolerance to the comparison. It is called by calculatePorts(LayoutGraph) and may be overridden to change the accuracy/tolerance of the comparison.

Parameters:

x1 - the x-coordinate of the first point

y1 - the y-coordinate of the first point

x2 - the x-coordinate of the second point

y2 - the y-coordinate of the second point

Returns:

true if both points are considered equal, false otherwise

See Also:

calculatePorts(LayoutGraph), Eps