y.layout
Class PortCalculator

java.lang.Object
  y.layout.AbstractLayoutStage
      y.layout.PortCalculator

All Implemented Interfaces:

Layouter, LayoutStage

public class PortCalculator
extends AbstractLayoutStage
implements LayoutStage

This class implements a LayoutStage that can be used to adjust 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 DataProvider instances bound to the graph using the keys defined in the IntersectionCalculator interface to calculate the new port offsets. For each edge in the LayoutGraph instance the DataProviders are queried for an implementation of the IntersectionCalculator interface. If the result is non-null, that implementation will be queried and if the result of the query is non-null, the returned point will be applied to the edge layout.

For this layout stage to work use CompositeLayoutStage.prependStage(y.layout.LayoutStage) or CanonicMultiStageLayouter.prependStage(y.layout.LayoutStage) to add this layout stage and register appropriate DataProvider implementations to the graph using the keys defined in IntersectionCalculator.

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

See Also:

IntersectionCalculator, IntersectionCalculator.SOURCE_INTERSECTION_CALCULATOR_DPKEY, IntersectionCalculator.TARGET_INTERSECTION_CALCULATOR_DPKEY, PortConstraint

Field Summary

protected double

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

Fields inherited from interface y.layout.Layouter

EDGE_ID_DPKEY, NODE_ID_DPKEY, SELECTED_EDGES, SELECTED_NODES

Constructor Summary

PortCalculator()
Creates a new PortCalculator without a core layouter.

PortCalculator(Layouter core)
Creates a new PortCalculator using the given layouter as the core of this layout stage.

Method Summary

protected void	calculatePorts(LayoutGraph graph) Performs the actual port calculation on the specified graph instance.
boolean	canLayout(LayoutGraph graph) Returns true iff the given graph can be laid out by this algorithm.
void	doLayout(LayoutGraph graph) Main layout routine that assigns new layout information to the given graph.
protected boolean	equalsEps(double x1, double y1, double x2, double y2) Callback method that determines whether two points are equal.

Methods inherited from class y.layout.AbstractLayoutStage

canLayoutCore, doLayoutCore, getCoreLayouter, setCoreLayouter

Methods inherited from class java.lang.Object

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

Methods inherited from interface y.layout.LayoutStage

getCoreLayouter, setCoreLayouter

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 without a core layouter.

PortCalculator

public PortCalculator(Layouter core)

Creates a new PortCalculator using the given layouter as the core of this layout stage.

Method Detail

canLayout

public boolean canLayout(LayoutGraph graph)

Description copied from interface: Layouter

Returns true iff the given graph can be laid out by this algorithm. Calling doLayout with the given graph as its argument will only success if this method returns true.

Specified by:

canLayout in interface Layouter

doLayout

public void doLayout(LayoutGraph graph)

Description copied from interface: Layouter

Main layout routine that assigns new layout information to the given graph.

Specified by:

doLayout in interface Layouter

calculatePorts

protected void calculatePorts(LayoutGraph graph)

Performs the actual port calculation on the specified graph instance.

equalsEps

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

Callback method that determines whether two points are equal.