ilog.views.sdm.renderer.graphlayout

Class IlvLinkLayoutRenderer

java.lang.Object

ilog.views.sdm.renderer.IlvSDMRenderer

ilog.views.sdm.renderer.IlvFilterSDMRenderer

ilog.views.sdm.renderer.graphlayout.IlvGraphLayoutRenderer

ilog.views.sdm.renderer.graphlayout.IlvLinkLayoutRenderer

public class IlvLinkLayoutRenderer
extends IlvGraphLayoutRenderer

The class IlvLinkLayoutRenderer is a subclass of IlvGraphLayoutRenderer that is specialized for link layout. It applies a layout algorithm that routes the links of the graph, leaving the node positions unchanged.

The layout algorithm used can be either a normal link layout with NodeSideFilter enabled, or a hierarchical layout configured to only route the links. Normal link layouts are IlvLinkLayout, IlvShortLinkLayout, and IlvLongLinkLayout. By default, an IlvLinkLayout is used. A hierarchical layout can only be used if a graph layout renderer is installed that uses an instance of IlvHierarchicalLayout for graph layout. (The graph layout renderer can be either enabled or disabled, see IlvGraphLayoutRenderer#setEnabled(boolean).) In this case, this instance is reused but for the purpose of the link layout renderer configured to only route the links. To use the hierarchical layout, you must call setHierarchical(true).

The renderer defines two rendering properties on nodes and links (in addition to any node and link properties defined by the layout algorithm itself; see IlvGraphLayoutRenderer for explanations):

• NodeSideForOrigin, which requests the layout algorithm to attach the link to the specified side of the origin node.
• NodeSideForDestination, which requests the layout algorithm to attach the link to the specified side of the destination node.

The values for these properties can be Top, Bottom, Left, Right, Horizontal, Vertical, or Any (default). For example, a specification for a link in the style sheet such as NodeSideForDestination: Horizontal; means the link should arrive at the left side or the right side of the node. If the property is defined on a node, it holds for any link that connects to this node. If the property is defined on a link, it holds for any node to which the link is connected. If the property is defined on both a link and the node to which the link is connected, the property defined on the link is taken into account.

Note: these properties are only effective for normal link layout algorithms. If an IlvHierarchicalLayout layout is used, you must use the specific properties of this algorithm that control the way links are connected. Examples of this are:

• ilog.views.graphlayout.hierarchical.IlvHierarchicalLayout#setFromPortSide
• ilog.views.graphlayout.hierarchical.IlvHierarchicalLayout#setToPortSide

Warning: Using the NodeSideFilter constraints reduces the degree of freedom of the layout to choose the link shapes. Using this filter may create additional link bends and crossings.

CSS example:

LinkLayout {
addingLinkConnectors : "false";
alias : "<value>";
connectingLinksToShape : "false";
constraintsURL : "url(spec)";
enabled : "false";
ensureAppropriateLinks : "false";
ensureModelOrdering : "false";
graphLayout : "@#shortLinkLayout";
graphLayoutExceptionPassedOn : "false";
hierarchical : "false";
linkConnectorMode : "CENTER";
partialLayout : "false";
performingLayoutOnZoom : "false";
rotationAngle : "3.0";
rotationTransformer : "0.3, 0.5, 0.5, 0.3, 0.5, 0.5";
savingNodePositions : "false";
useOldLinkRoutesInHierarchical : "false";
usePerObjectParameters : "false";
}

Subobject#shortLinkLayout {
class : "ilog.views.graphlayout.link.shortlink.IlvShortLinkLayout";
}

Property Summary

Properties

Modifier and Type	Property and Description
boolean	addingLinkConnectors Deprecated. Since JViews 6.0, use IlvGraphLayoutRenderer.ensureAppropriateLinks.
java.lang.String	alias Sets the alias of this renderer.
boolean	connectingLinksToShape Specifies whether the graph layout algorithm should connect the links to the shape of the nodes or to the global bounding box of the nodes.
java.net.URL	constraintsURL Sets the URL that specifies the layout constraints.
boolean	enabled Enables or disables the graph layout algorithm.
boolean	ensureAppropriateLinks Sets whether the renderer automatically makes sure that appropriate links and link connectors are used when needed.
boolean	ensureModelOrdering Specifies that the graphic nodes and links should be ordered during graph layout in the same order as the corresponding SDM model objects.
IlvGraphLayout	graphLayout Sets the graph layout algorithm that this renderer will apply to the grapher.
boolean	graphLayoutExceptionPassedOn Sets whether the graph layout exception is passed on.
boolean	hierarchical Configures this link layout renderer to use the same hierarchical layout algorithm as the one used to position the nodes of the graph.
int	linkConnectorMode Sets the link connector mode.
boolean	partialLayout Enables or disables the partial layout mode of the layout.
boolean	performingLayoutOnZoom Specifies whether the layout algorithm should be applied every time the transformer of the reference view changes, or only when the data is initially rendered.
double	rotationAngle Sets the rotation angle of the graph model.
ilog.views.IlvTransformer	rotationTransformer Sets the rotation transformer of the graph model.
boolean	savingNodePositions Specifies whether the positions of the nodes, as computed by the graph layout algorithm, will be saved to the data model, or if the data model will be left unchanged.
boolean	useOldLinkRoutesInHierarchical Sets whether this link layout renderer, when using the hierarchical layout, keeps the old link routes before starting the hierarchical layout.
boolean	usePerObjectParameters Enables or disables per-object layout parameters.

Method Summary

Methods inherited from class java.lang.Object

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

Property Detail

addingLinkConnectors

public boolean addingLinkConnectors

Deprecated. Since JViews 6.0, use IlvGraphLayoutRenderer.ensureAppropriateLinks.

Sets whether a link connector is added to the nodes to compute the link connection points.

CSS example: addingLinkConnectors : "false";

alias

public java.lang.String alias

Sets the alias of this renderer. The alias is the symbolic name used to designate the renderer in the SDM style sheet, for example SubGraph or GraphLayout.

CSS example: alias : "<value>";

connectingLinksToShape

public boolean connectingLinksToShape

Specifies whether the graph layout algorithm should connect the links to the shape of the nodes or to the global bounding box of the nodes.

Some nodes (for example, the IlvGeneralNode) have a basic shape and a label that may be outside the shape. If this method is called with a true parameter, the links will be connected to the shape, and the label will not be considered part of the node. If the method is called with a false parameter, the links will be connected to the global bounding rectangle of the node, that is, the union of the shape's bounding rectangle and the label's bounding rectangle.

The bounding rectangle of the shape is the rectangle returned by the ilog.views.sdm.renderer.IlvSDMRenderer#getLinkConnectionRectangle. The global bounding rectangle of the node is the rectangle returned by the IlvGraphic.boundingBox(ilog.views.IlvTransformer).

CSS example: connectingLinksToShape : "false";

constraintsURL

public java.net.URL constraintsURL

Sets the URL that specifies the layout constraints. Currently, only the hierarchical layout supports layout constraints.

CSS example: constraintsURL : "url(spec)";

enabled

public boolean enabled

Enables or disables the graph layout algorithm.

CSS example: enabled : "false";

ensureAppropriateLinks

public boolean ensureAppropriateLinks

Sets whether the renderer automatically makes sure that appropriate links and link connectors are used when needed. Some layout algorithms require specific types of links and link connectors. Typically, subclasses of ilog.views.graphic.IlvPolylineLinkImage and subclasses of IlvFreeLinkConnector are suitable for all layout algorithms.

If layout cannot be performed because an inappropriate link or link connector is detected, then the following happens:

• If graph layout exceptions are passed on, a corresponding graph layout exception of type IlvInappropriateLinkException is thrown.
• Otherwise, if ensuring appropriate links is enabled, the inappropriate links are replaced by instances of ilog.views.graphic.IlvPolylineLinkImage, and the inappropriate link connectors are replaced by instances of IlvSDMFreeLinkConnector. Then layout is performed.
• Otherwise, layout is performed on the inappropriate links and connectors and the result is undefined. Typically, the layout result is faulty in this case, for example, the link shape is not as specified in the graph layout parameters.

CSS example: ensureAppropriateLinks : "false";

ensureModelOrdering

public boolean ensureModelOrdering

Specifies that the graphic nodes and links should be ordered during graph layout in the same order as the corresponding SDM model objects. Some layouts produce different results if the order of the nodes change. If this option is enabled, those layouts will only produce different results if the order of objects in the SDM model changes, but not if the order of the graphic objects change. This is in particular useful if the layer of graphic objects change due to selections or other events. The result of layout appears more stable if this option is enabled.

The option is enabled by default. Only when the option is disabled, it is possible to specify a node or link comparator.

CSS example: ensureModelOrdering : "false";

graphLayout

public IlvGraphLayout graphLayout

Sets the graph layout algorithm that this renderer will apply to the grapher.

CSS example:

graphLayout : "@#shortLinkLayout";

Subobject#shortLinkLayout {
class : "ilog.views.graphlayout.link.shortlink.IlvShortLinkLayout";
}

Allowed values:
Circular		new ilog.views.graphlayout.circular.IlvCircularLayout()
Grid		new ilog.views.graphlayout.grid.IlvGridLayout()
Hierarchical		new ilog.views.graphlayout.hierarchical.IlvHierarchicalLayout()
Random		new ilog.views.graphlayout.random.IlvRandomLayout()
SpringEmbedder		new ilog.views.graphlayout.springembedder.IlvSpringEmbedderLayout()
TopologicalMesh		new ilog.views.graphlayout.topologicalmesh.IlvTopologicalMeshLayout()
Tree		new ilog.views.graphlayout.tree.IlvTreeLayout()
UniformLengthEdges		new ilog.views.graphlayout.uniformlengthedges.IlvUniformLengthEdgesLayout()

graphLayoutExceptionPassedOn

public boolean graphLayoutExceptionPassedOn

Sets whether the graph layout exception is passed on. If enabled, all exceptions of type IlvGraphLayoutException are passed to the outside as runtime exceptions. If disabled, the exceptions are caught and handled internally. This option is disabled by default. It is useful only for debugging purpose to pass on the graph layout exception. Independently of whether the exception is passed on or not, the exception is logged at the logger "ilog.views.sdm.renderer.graphlayout".

CSS example: graphLayoutExceptionPassedOn : "false";

hierarchical

public boolean hierarchical

Configures this link layout renderer to use the same hierarchical layout algorithm as the one used to position the nodes of the graph.

Beginning with JViews 5.5, the IlvHierarchicalLayout algorithm is able to only route the links of the graph, leaving the positions of the node unchanged. This method lets you use this feature easily. For example, here are the rules to put in the style sheet to use the same hierarchical layout algorithm for positioning the nodes and routing the links:

    SDM {
      GraphLayout : "Hierarchical";
      LinkLayout : "true";
    }
    
    GraphLayout {
      flowDirection : "Bottom";
      globalLinkStyle : "ORTHOGONAL_STYLE";
    }
    LinkLayout {
      hierarchical : "true";
    }
  

Notes:

1. When the hierarchical mode is used, intergraph links (that is, links between nodes contained in different subgraphs) are still routed using a normal link layout (usually IlvLinkLayout).
2. The properties of the hierarchical layout (for example, globalLinkStyle in the example shown) must still be set in the GraphLayout rule of the style sheet, even though the hierarchical graph layout object is also used by the LinkLayout renderer.

CSS example: hierarchical : "false";

See Also:

IlvHierarchicalLayout, IlvGraphLayoutRenderer

linkConnectorMode

public int linkConnectorMode

Sets the link connector mode. Possible modes are:

• IlvStyleSheetRenderer#CENTER - Link connector mode: Use IlvSDMLinkConnector for all nodes. The links will be connected to the node center.
• IlvStyleSheetRenderer#FREE - Link connector mode: Use IlvSDMFreeLinkConnector for all nodes. The links will be connected to the node border.
• IlvStyleSheetRenderer#CLIP - Use IlvSDMClippingLinkConnector for all nodes. The links will point to the node but end on the outline of the shape of the node. How the outline of a node is calculated depends on the implementation of IlvGraphic#getIntersectionWithOutline.

This method calls simply IlvStyleSheetRenderer#setLinkConnectorMode.

CSS example: linkConnectorMode : "CENTER";

Allowed values:
CENTER		Link connector mode: Use IlvSDMLinkConnector for all nodes. The links will be connected to the center of the rectangle returned by #getLinkConnectionRectangle.
FREE		Link connector mode: Use IlvSDMFreeLinkConnector for all nodes. The links will be connected to the border of the rectangle returned by #getLinkConnectionRectangle.
CLIP		Link connector mode: Use IlvSDMClippingLinkConnector for all nodes. The links will point to the the rectangle returned by #getLinkConnectionRectangle but end on the outline of the shape of the node. How the outline of a node is calculated depends on the implementation of IlvGraphic#getIntersectionWithOutline.

partialLayout

public boolean partialLayout

Enables or disables the partial layout mode of the layout. If this property is true, and objects are selected, all the nodes except the selected nodes are marked as fixed, so that the layout is applied only on the selected nodes.

CSS example: partialLayout : "false";

performingLayoutOnZoom

public boolean performingLayoutOnZoom

Specifies whether the layout algorithm should be applied every time the transformer of the reference view changes, or only when the data is initially rendered.

CSS example: performingLayoutOnZoom : "false";

rotationAngle

public double rotationAngle

Sets the rotation angle of the graph model. This is useful to perform a rotated layout, for instance a hierarchical layout with flow direction diagonal. The rotation angle must be between -360 and 360 degree. If the rotation angle is not 0, the renderer uses a IlvRotatedGraphModel that rotates all coordinates by the specific angle. The bounding box of nodes remains upright despite of the rotation.

Specifying a rotation angle is only suitable for flat graphs. It is not suitable for nested graphs with intergraph links, since those are routed incorrectly when a rotation is specified. When using a rotation angle, it is recommended to the the link connector mode to IlvStyleSheetRenderer#CLIP, otherwise the links do not end at the nodes.

Rotation works well with most layout styles on flat graphs. It does not work well with Bus Layout and Long Link Layout since those layouts are not fully rotatable.

Setting the rotation angle modifies the rotation transformer.

CSS example: rotationAngle : "3.0";

rotationTransformer

public ilog.views.IlvTransformer rotationTransformer

Sets the rotation transformer of the graph model. This is useful to perform a rotated layout, for instance a hierarchical layout with flow direction diagonal. If the rotation transformer is not null, the renderer uses a IlvRotatedGraphModel that transform all coordinates. The bounding box of nodes remains upright despite of the rotation.

Specifying a rotation transformer is only suitable for flat graphs. It is not suitable for nested graphs with intergraph links, since those are routed incorrectly when a rotation transformer is specified. When using a rotation transformer, it is recommended to the the link connector mode to IlvStyleSheetRenderer#CLIP, otherwise the links do not end at the nodes.

Rotation works well with most layout styles on flat graphs. It does not work well with Bus Layout and Long Link Layout since those layouts are not fully rotatable.

CSS example: rotationTransformer : "0.3, 0.5, 0.5, 0.3, 0.5, 0.5";

savingNodePositions

public boolean savingNodePositions

Specifies whether the positions of the nodes, as computed by the graph layout algorithm, will be saved to the data model, or if the data model will be left unchanged.

CSS example: savingNodePositions : "false";

useOldLinkRoutesInHierarchical

public boolean useOldLinkRoutesInHierarchical

Sets whether this link layout renderer, when using the hierarchical layout, keeps the old link routes before starting the hierarchical layout. The result of the new link routing depends on the layout parameters of the hierarchical layout. When performing a link routing in hierarchical mode, the hierarchical layout is set to incremental mode, which means it takes the old coordinates of nodes and links into account in some way. In particular when the layout parameter IlvHierarchicalLayout#setLongLinkCrossingReductionDuringIncremental is disabled, the hierarchical layout tries to respect the old link routes for long links. In this case, it is useful to enable the use of old link routes in hierarchical layout.

This mode has no effect when the hierarchical mode is disabled.

CSS example: useOldLinkRoutesInHierarchical : "false";

See Also:

hierarchical

usePerObjectParameters

public boolean usePerObjectParameters

Enables or disables per-object layout parameters.

This method can be used to disable or re-enable the mechanism that sets per-node or per-link parameters, as explained in the class description.

By default, per-object parameters are enabled. You can disable them if you are sure that your style sheet does not use any per-object layout parameters. Disabling per-object parameters speeds up the SDM rendering process.

CSS example: usePerObjectParameters : "false";