PortConstraint (yFiles-for-JavaFX-Complete-3.0 API)

java.lang.Object
- com.yworks.yfiles.layout.PortConstraint

```
public class PortConstraint
extends Object
```
A PortConstraint represents a constraint for the source or target port of an edge path.
It determines the location at which an edge path can be connected to its source and/or target node. There exist two different types of PortConstraints:
- Weak PortConstraints determine the side of the node to which an edge can be connected.
- Strong PortConstraints determine the exact coordinates of the point to which an edge path can be connected. These coordinates are determined at the time the edge is processed by a layout or routing algorithm and are always interpreted relative to a node's center.
Sample output of weak port constraints. For both edges, source port constraints are associated with side PortSide.EAST while target port constraints are associated with side PortSide.WEST. Red rectangles indicate that edges can be connected to any point of these sides. Black rectangles represent the selected ports. Sample output of strong port constraints. For both edges, source port constraints are associated with side PortSide.EAST while target port constraints are associated with side PortSide.WEST. Black rectangles indicate the exact points on the corresponding sides of the nodes to which edges can be connected.

Information about PortConstraints is held by IDataProviders that are registered with the graph using keys PortConstraintKeys.SOURCE_PORT_CONSTRAINT_DPKEY (to specify PortConstraints for an edge on its source node) and PortConstraintKeys.TARGET_PORT_CONSTRAINT_DPKEY (to specify PortConstraints for an edge on its target node).

Not all layout and routing algorithms are able to handle PortConstraints. Major layout algorithms that obey them are HierarchicLayout, TreeLayout, EdgeRouter, ChannelEdgeRouter and BusRouter.
PortPlacementStage can be appended to any layout algorithm that cannot handle port constraints in order to assign edges to the ports specified by PortConstraints or PortCandidates after calling the core layout algorithm.

In case that both PortConstraints and PortCandidates (on edges and/or nodes) are defined for a graph, the layout or the routing algorithm will try to match both of them in order to find an appropriate port. The matching process depends on the actual algorithm.

See Also:

PortConstraintKeys

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static PortConstraint`	`create(PortSide side)` Creates a new `PortConstraint` that constrains the edge to connect to the given side of a node and that can be either strong or weak.
`static PortConstraint`	`create(PortSide side, boolean strong)` Creates a new `PortConstraint` that constrains the edge to connect to the given side of a node and that can be either strong or weak.
`boolean`	`equals(Object other)` Returns whether or not this `PortConstraint` is equal to another `PortConstraint` based on whether they are both strong constraints or not and the side attribute.
`PortSide`	`getSide()` Gets the side of the node to which an edge should connect.
`static PortConstraint`	`getSPC(LayoutGraph graph, Edge e)` Returns the source `PortConstraint` associated with the given edge.
`static PortConstraint`	`getTPC(LayoutGraph graph, Edge e)` Returns the target `PortConstraint` associated with the given edge.
`int`	`hashCode()` Returns a hash code value for this `PortConstraint` instance based on whether it is a strong constraint or not and the side attribute.
`static boolean`	`hasPC(LayoutGraph graph, Edge e)` Checks whether or not there exist source or target `PortConstraint`s associated with the given edge.
`static boolean`	`hasSPC(LayoutGraph graph, Edge e)` Checks whether or not there exist source `PortConstraint`s associated with the given edge.
`static boolean`	`hasTPC(LayoutGraph graph, Edge e)` Checks whether or not there exist target `PortConstraint`s associated with the given edge.
`boolean`	`isAtAnySide()` Gets whether or not this `PortConstraint` instance is associated with side `PortSide.ANY`.
`boolean`	`isAtEast()` Gets whether or not this `PortConstraint` instance is associated with side `PortSide.EAST`.
`boolean`	`isAtNorth()` Gets whether or not this `PortConstraint` instance is associated with side `PortSide.NORTH`.
`boolean`	`isAtSouth()` Gets whether or not this `PortConstraint` instance is associated with side `PortSide.SOUTH`.
`boolean`	`isAtWest()` Gets whether or not this `PortConstraint` instance is associated with side `PortSide.WEST`.
`boolean`	`isStrong()` Gets whether or not this `PortConstraint` instance represents a strong constraint.
`String`	`toString()` Returns a `String` representation of this `PortConstraint` instance.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Method Detail
  - create
```
public static final PortConstraint create(PortSide side)
```
    Creates a new PortConstraint that constrains the edge to connect to the given side of a node and that can be either strong or weak.
    If the PortConstraint is strong, the layout or routing algorithm should use the port coordinates of this constraint.
    
    Throws:
    
    IllegalArgumentException - if an unknown side is given
    
    Parameters:
    
    side - one of the default side specifiers
    
    Returns:
    
    a new PortConstraint instance
  - create
```
public static final PortConstraint create(PortSide side,
                                          boolean strong)
```
    Creates a new PortConstraint that constrains the edge to connect to the given side of a node and that can be either strong or weak.
    If the PortConstraint is strong, the layout or routing algorithm should use the port coordinates of this constraint.
    
    Throws:
    
    IllegalArgumentException - if an unknown side is given
    
    Parameters:
    
    side - one of the default side specifiers
    
    strong - true if this PortConstraint is strong, false otherwise
    
    Returns:
    
    a new PortConstraint instance
  - equals
```
public boolean equals(Object other)
```
    Returns whether or not this PortConstraint is equal to another PortConstraint based on whether they are both strong constraints or not and the side attribute.
    
    Overrides:
    
    equals in class Object
    
    Parameters:
    
    other - the reference PortConstraint object with which to compare
    
    Returns:
    
    true if this PortConstraint is equal to the given PortConstraint argument, false otherwise
  - getSide
```
public PortSide getSide()
```
    Gets the side of the node to which an edge should connect.
    
    Returns:
    
    one of the default side specifiers
  - getSPC
```
public static final PortConstraint getSPC(LayoutGraph graph,
                                          Edge e)
```
    Returns the source PortConstraint associated with the given edge.
    To retrieve the IDataProvider that holds information about source PortConstraints, key PortConstraintKeys.SOURCE_PORT_CONSTRAINT_DPKEY is used.
    
    Parameters:
    
    graph - the input graph
    
    e - the edge
    
    Returns:
    
    the source PortConstraint of the given edge or null if there is none
  - getTPC
```
public static final PortConstraint getTPC(LayoutGraph graph,
                                          Edge e)
```
    Returns the target PortConstraint associated with the given edge.
    To retrieve the IDataProvider that holds information about target PortConstraints, key PortConstraintKeys.TARGET_PORT_CONSTRAINT_DPKEY is used.
    
    Parameters:
    
    graph - the input graph
    
    e - the edge
    
    Returns:
    
    the target PortConstraint of the given edge or null if there is none
  - hashCode
```
public int hashCode()
```
    Returns a hash code value for this PortConstraint instance based on whether it is a strong constraint or not and the side attribute.
    
    Overrides:
    
    hashCode in class Object
    
    Returns:
    
    a hash code value
  - hasPC
```
public static final boolean hasPC(LayoutGraph graph,
                                  Edge e)
```
    Checks whether or not there exist source or target PortConstraints associated with the given edge.
    To retrieve the IDataProviders that hold information about source or target PortConstraints, keys PortConstraintKeys.SOURCE_PORT_CONSTRAINT_DPKEY and PortConstraintKeys.TARGET_PORT_CONSTRAINT_DPKEY are used.
    
    A weak PortConstraint that allows any side is not considered to be a real constraint and ignored during this check.
    
    Parameters:
    
    graph - the input graph
    
    e - the edge
    
    Returns:
    
    true if the edge has source or target PortConstraints, false otherwise
  - hasSPC
```
public static final boolean hasSPC(LayoutGraph graph,
                                   Edge e)
```
    Checks whether or not there exist source PortConstraints associated with the given edge.
    To retrieve the IDataProvider that holds information about source PortConstraints, key PortConstraintKeys.SOURCE_PORT_CONSTRAINT_DPKEY is used.
    
    A weak PortConstraint that allows any side is not considered to be a real constraint and ignored during this check.
    
    Parameters:
    
    graph - the input graph
    
    e - the edge
    
    Returns:
    
    true if the edge has source PortConstraints, false otherwise
  - hasTPC
```
public static final boolean hasTPC(LayoutGraph graph,
                                   Edge e)
```
    Checks whether or not there exist target PortConstraints associated with the given edge.
    To retrieve the IDataProvider that holds information about target PortConstraints, key PortConstraintKeys.TARGET_PORT_CONSTRAINT_DPKEY is used.
    
    A weak PortConstraint that allows any side is not considered to be a real constraint and ignored during this check.
    
    Parameters:
    
    graph - the input graph
    
    e - the edge
    
    Returns:
    
    true if the edge has target PortConstraints, false otherwise
  - isAtAnySide
```
public boolean isAtAnySide()
```
    Gets whether or not this PortConstraint instance is associated with side PortSide.ANY.
    
    Returns:
    
    true if the associated side is PortSide.ANY, false otherwise
  - isAtEast
```
public boolean isAtEast()
```
    Gets whether or not this PortConstraint instance is associated with side PortSide.EAST.
    
    Returns:
    
    true if the associated side is PortSide.EAST, false otherwise
  - isAtNorth
```
public boolean isAtNorth()
```
    Gets whether or not this PortConstraint instance is associated with side PortSide.NORTH.
    
    Returns:
    
    true if the associated side is PortSide.NORTH, false otherwise
  - isAtSouth
```
public boolean isAtSouth()
```
    Gets whether or not this PortConstraint instance is associated with side PortSide.SOUTH.
    
    Returns:
    
    true if the associated side is PortSide.SOUTH, false otherwise
  - isAtWest
```
public boolean isAtWest()
```
    Gets whether or not this PortConstraint instance is associated with side PortSide.WEST.
    
    Returns:
    
    true if the associated side is PortSide.WEST, false otherwise
  - isStrong
```
public boolean isStrong()
```
    Gets whether or not this PortConstraint instance represents a strong constraint.
    A strong PortConstraint determines the exact coordinates where the edge path's end should be located.
    
    Returns:
    
    true if this PortConstraint is strong, false if it is a weak one
  - toString
```
public String toString()
```
    Returns a String representation of this PortConstraint instance.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    
    a String representation of the PortConstraint

Class PortConstraint

Method Summary

Methods inherited from class java.lang.Object

Method Detail

create

create

equals

getSide

getSPC

getTPC

hashCode

hasPC

hasSPC

hasTPC

isAtAnySide

isAtEast

isAtNorth

isAtSouth

isAtWest

isStrong

toString