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

java.lang.Object
- com.yworks.yfiles.layout.AbstractLayoutStage
- - com.yworks.yfiles.layout.SelfLoopRouter

All Implemented Interfaces:

ILayoutAlgorithm, ILayoutStage
```
public class SelfLoopRouter
extends AbstractLayoutStage
```
A SelfLoopRouter routes the self-loops (reflexive edges) of a graph.

Layout Style
The nodes and normal edges are arranged by the core layout algorithm. This layout algorithm only handles the paths of self-loops.

Self-loops are routed either orthogonal or with rounded corners. The layout algorithm places the self-loops in the least crowded quadrant around a node.

Small graph with self-loops

Concept
Self-loops are handled in four steps:
1. Remove all self-loops of the input graph
2. Invoke the core layout algorithm on the now self-loops free graph
3. Reinsert all formerly removed self-loops
4. Route the self-loops of the input graph
Features

SelfLoopRouter can either be used as a ILayoutStage wrapping a layout algorithm which cannot handle self-loops. Then it will hide the self-loops from this core layout algorithm and take over the routing of them.
If no core layout algorithm is specified, SelfLoopRouter can work alone. It will route only the self-loops and keep the remaining graph unchanged.

When all self-loops already have a suitable layout, this layout algorithm can keep the self-loop paths. It will just hide the self-loops before invoking the core layout algorithm, such that they are not altered by it.
To only exclude some self-loops from routing, a IDataProvider registered with KEEP_SELF_LOOP_LAYOUT_DPKEY can be used for marking those self-loops.
See Also:

MultiStageLayout

Field Summary

Fields
Modifier and Type	Field and Description
`static EdgeDpKey<Boolean>`	`KEEP_SELF_LOOP_LAYOUT_DPKEY` A `DataProvider` key for determining which self-loops should keep their current path If no `IDataProvider` is registered with this key, all self-loops will be routed.

Constructor Summary

Constructors
Constructor and Description
`SelfLoopRouter()` Creates a new `SelfLoopRouter` with an optional `core layout algorithm`.
`SelfLoopRouter(ILayoutAlgorithm coreLayouter)` Creates a new `SelfLoopRouter` with an optional `core layout algorithm`.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`applyLayout(LayoutGraph graph)` Delegates the arrangement of nodes and edges to the `core layout algorithm` and routes the self-loops.
`int`	`getCornerApproximationPointsCount()` Gets the number of points that are used for rounding the corners of the self-loops.
`SelfLoopStyle`	`getLayoutStyle()` Gets the layout style of the self-loops.
`double`	`getLineDistance()` Gets the distance between two self-loops incident to the same node.
`boolean`	`isKeepingAllSelfLoopRoutesEnabled()` Gets whether or not this algorithm should keep all self-loop routes.
`boolean`	`isSmartSelfLoopPlacementEnabled()` Gets whether or not the algorithm chooses the side of the self-loop depending on the incident edges.
`protected void`	`layoutSelfLoops(LayoutGraph graph)` Calculates the routes of the self-loops in the given graph.
`void`	`setCornerApproximationPointsCount(int value)` Sets the number of points that are used for rounding the corners of the self-loops.
`void`	`setKeepingAllSelfLoopRoutesEnabled(boolean value)` Sets whether or not this algorithm should keep all self-loop routes.
`void`	`setLayoutStyle(SelfLoopStyle value)` Sets the layout style of the self-loops.
`void`	`setLineDistance(double value)` Sets the distance between two self-loops incident to the same node.
`void`	`setSmartSelfLoopPlacementEnabled(boolean value)` Sets whether or not the algorithm chooses the side of the self-loop depending on the incident edges.

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

- Field Detail
  - KEEP_SELF_LOOP_LAYOUT_DPKEY
```
public static final EdgeDpKey<Boolean> KEEP_SELF_LOOP_LAYOUT_DPKEY
```
    A DataProvider key for determining which self-loops should keep their current path
    If no IDataProvider is registered with this key, all self-loops will be routed.
    
    See Also:
    
    setKeepingAllSelfLoopRoutesEnabled(boolean)
- Constructor Detail
  - SelfLoopRouter
```
public SelfLoopRouter()
```
    Creates a new SelfLoopRouter with an optional core layout algorithm.
  - SelfLoopRouter
```
public SelfLoopRouter(ILayoutAlgorithm coreLayouter)
```
    Creates a new SelfLoopRouter with an optional core layout algorithm.
    
    Parameters:
    
    coreLayouter - The core layout algorithm.
- Method Detail
  - applyLayout
```
public void applyLayout(LayoutGraph graph)
```
    Delegates the arrangement of nodes and edges to the core layout algorithm and routes the self-loops.
    
    Specified by:
    
    applyLayout in interface ILayoutAlgorithm
    
    Specified by:
    
    applyLayout in class AbstractLayoutStage
    
    Parameters:
    
    graph - the input graph
  - getCornerApproximationPointsCount
```
public int getCornerApproximationPointsCount()
```
    Gets the number of points that are used for rounding the corners of the self-loops.
    For rounded corners, the number of points should be at least 2. All smaller values will produce one bend and, therefore, an orthogonal path.
    
    The number of points for a corner must be at least 1.
    
    Throws:
    
    IllegalArgumentException - if the specified point count is less than 1
    
    This option is only considered when style SelfLoopStyle.ROUNDED is used.
    
    Default Value:
    The default value is 2.
    
    Returns:
    
    the number of bends that are inserted to round the corners of self-loops
    
    See Also:
    
    setLayoutStyle(SelfLoopStyle), SelfLoopStyle.ROUNDED, setCornerApproximationPointsCount(int)
  - getLayoutStyle
```
public SelfLoopStyle getLayoutStyle()
```
    Gets the layout style of the self-loops.
    
    Throws:
    
    IllegalArgumentException - if the specified style is unknown
    
    Default Value:
    The default value is SelfLoopStyle.ROUNDED
    
    Returns:
    
    the layout style for self-loops
    
    See Also:
    
    setLayoutStyle(SelfLoopStyle)
  - getLineDistance
```
public double getLineDistance()
```
    Gets the distance between two self-loops incident to the same node.
    The distance needs to be a non-negative value.
    
    Throws:
    
    IllegalArgumentException - if the specified distance is negative
    
    This value is only considered for layout style SelfLoopStyle.ROUNDED.
    
    Default Value:
    The default value is 5.
    
    Returns:
    
    the distance between the self-loops
    
    See Also:
    
    SelfLoopStyle.ROUNDED, setLineDistance(double)
  - isKeepingAllSelfLoopRoutesEnabled
```
public boolean isKeepingAllSelfLoopRoutesEnabled()
```
    Gets whether or not this algorithm should keep all self-loop routes.
    When enabled, no self-loop will be routed, instead the existing self-loop layout will be moved with its node.
    
    Enabling this option will override the information in the IDataProvider registered with KEEP_SELF_LOOP_LAYOUT_DPKEY. Self-loops that were not marked will still not be routed.
    
    Default Value:
    The default value is false. Self-loops get a new route.
    
    Returns:
    
    true if all self-loops should keep their routes, false otherwise
    
    See Also:
    
    setKeepingAllSelfLoopRoutesEnabled(boolean)
  - isSmartSelfLoopPlacementEnabled
```
public boolean isSmartSelfLoopPlacementEnabled()
```
    Gets whether or not the algorithm chooses the side of the self-loop depending on the incident edges.
    If this option is enabled, self-loops are placed on one of the four corners of the corresponding node. For the choice of the corner, the algorithm considers all incident edges. Otherwise, self-loops are always placed at the upper left corner of the corresponding node.
    
    Default Value:
    The default value is true. The corner of the nodes where self-loops are placed is chosen considering incident edges.
    
    Returns:
    
    true if self-loops are placed smartly, false otherwise
    
    See Also:
    
    setSmartSelfLoopPlacementEnabled(boolean)
  - layoutSelfLoops
```
protected void layoutSelfLoops(LayoutGraph graph)
```
    Calculates the routes of the self-loops in the given graph.
    This method will only change the routes of self-loops that are not marked to be kept.
    
    This method is called by applyLayout(LayoutGraph) after the core layout algorithm has arranged the graph and all self-loops have been reinserted into the graph. It may be overridden to introduce custom self-loop styles.
    
    Parameters:
    
    graph - the input graph
  - setCornerApproximationPointsCount
```
public void setCornerApproximationPointsCount(int value)
```
    Sets the number of points that are used for rounding the corners of the self-loops.
    For rounded corners, the number of points should be at least 2. All smaller values will produce one bend and, therefore, an orthogonal path.
    
    The number of points for a corner must be at least 1.
    
    Throws:
    
    IllegalArgumentException - if the specified point count is less than 1
    
    This option is only considered when style SelfLoopStyle.ROUNDED is used.
    
    Default Value:
    The default value is 2.
    
    Parameters:
    
    value - the number of bends that are inserted to round the corners of self-loops
    
    See Also:
    
    setLayoutStyle(SelfLoopStyle), SelfLoopStyle.ROUNDED, getCornerApproximationPointsCount()
  - setKeepingAllSelfLoopRoutesEnabled
```
public void setKeepingAllSelfLoopRoutesEnabled(boolean value)
```
    Sets whether or not this algorithm should keep all self-loop routes.
    When enabled, no self-loop will be routed, instead the existing self-loop layout will be moved with its node.
    
    Enabling this option will override the information in the IDataProvider registered with KEEP_SELF_LOOP_LAYOUT_DPKEY. Self-loops that were not marked will still not be routed.
    
    Default Value:
    The default value is false. Self-loops get a new route.
    
    Parameters:
    
    value - true if all self-loops should keep their routes, false otherwise
    
    See Also:
    
    isKeepingAllSelfLoopRoutesEnabled()
  - setLayoutStyle
```
public void setLayoutStyle(SelfLoopStyle value)
```
    Sets the layout style of the self-loops.
    
    Throws:
    
    IllegalArgumentException - if the specified style is unknown
    
    Default Value:
    The default value is SelfLoopStyle.ROUNDED
    
    Parameters:
    
    value - the layout style for self-loops
    
    See Also:
    
    getLayoutStyle()
  - setLineDistance
```
public void setLineDistance(double value)
```
    Sets the distance between two self-loops incident to the same node.
    The distance needs to be a non-negative value.
    
    Throws:
    
    IllegalArgumentException - if the specified distance is negative
    
    This value is only considered for layout style SelfLoopStyle.ROUNDED.
    
    Default Value:
    The default value is 5.
    
    Parameters:
    
    value - the distance between the self-loops
    
    See Also:
    
    SelfLoopStyle.ROUNDED, getLineDistance()
  - setSmartSelfLoopPlacementEnabled
```
public void setSmartSelfLoopPlacementEnabled(boolean value)
```
    Sets whether or not the algorithm chooses the side of the self-loop depending on the incident edges.
    If this option is enabled, self-loops are placed on one of the four corners of the corresponding node. For the choice of the corner, the algorithm considers all incident edges. Otherwise, self-loops are always placed at the upper left corner of the corresponding node.
    
    Default Value:
    The default value is true. The corner of the nodes where self-loops are placed is chosen considering incident edges.
    
    Parameters:
    
    value - true if self-loops are placed smartly, false otherwise
    
    See Also:
    
    isSmartSelfLoopPlacementEnabled()

Class SelfLoopRouter

Layout Style

Concept

Features

Field Summary

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

Field Detail

KEEP_SELF_LOOP_LAYOUT_DPKEY

Constructor Detail

SelfLoopRouter

SelfLoopRouter

Method Detail

applyLayout

getCornerApproximationPointsCount

getLayoutStyle

getLineDistance

isKeepingAllSelfLoopRoutesEnabled

isSmartSelfLoopPlacementEnabled

layoutSelfLoops

setCornerApproximationPointsCount

setKeepingAllSelfLoopRoutesEnabled

setLayoutStyle

setLineDistance

setSmartSelfLoopPlacementEnabled