Class OrthogonalGroupLayouter knows a number of data provider keys which are used to retrieve supplemental layout data for a graph's elements. The data is bound to the graph by means of a data provider, which is registered using a given look-up key. Table 5.45, “Data provider look-up keys” lists all look-up keys for OrthogonalGroupLayouter.

Binding supplemental layout data to a graph is described in the section called “Providing Supplemental Layout Data”.

Table 5.45. Data provider look-up keys

Key	Element Type	Value Type	Description
GROUP_DPKEY	node	Boolean	For each node a boolean value indicating whether it is a group node or not.
NODE_ID_DPKEY	node	Object	For each node an Object that serves as a unique ID.
PARENT_NODE_ID_DPKEY	node	Object	For each node an Object indicating the group node it belongs to. The Object matches the unique ID of a group node that is in the same graph.
GROUP_NODE_INSETS_DPKEY	node	Insets	For each group node a YInsets object that encodes the group node's insets.
MINIMUM_NODE_SIZE_DPKEY	node	YDimension	For each group node a YDimension object that specifies the group node's minimum size constraint.
EDGE_LABEL_LAYOUT_KEY	edge	Vector.<Object>	For each edge a Vector of LabelLayoutData objects that encode size and preferred placement for all labels of the edge.
EDGE_LAYOUT_DESCRIPTOR_DPKEY	edge	EdgeLayoutDescriptor	For each edge an EdgeLayoutDescriptor object that configures edge-related options.
NODE_HALO_DPKEY	node	NodeHalo	A NodeHalo object that specifies the halo sizes at each side of a node.
ABORT_HANDLER_DPKEY	graph	AbortHandler	An AbortHandler instance that will be queried by the layout algorithm to determine whether layout calculation shall be terminated.

Setup of a grouped graph's hierarchy of nodes (using GROUP_DPKEY, NODE_ID_DPKEY, and PARENT_NODE_ID_DPKEY) is done transparently by the IGraph-related adapter mechanisms. See also the section called “Setup for Layout” and Chapter 3, Using yFiles FLEX Client Layout Extension Functionality.

Unlike the more general orthogonal layout algorithm this specialized layout algorithm provides only a few options.

grid:int

layoutQuality:Number

The additional size requirements of group nodes (e.g., special insets or space for custom labels) can be specified by the use of a data provider that provides YInsets objects for each group node. The data provider must be registered with the input graph using the key GROUP_NODE_INSETS_DPKEY.

When calculating a layout for a grouped graph, OrthogonalGroupLayouter also supports minimum size constraints for group nodes. A minimum size constraint can be conveniently used in order for the group node to accommodate for the size of its label. If a data provider is registered with the graph using the look-up key MINIMUM_NODE_SIZE_DPKEY, any minimum size constraints for group nodes held by this data provider are respected by default.

Class EdgeLayoutDescriptor can be used to specify further edge-related layout options. An instance of this class is held by OrthogonalGroupLayouter to store and retrieve default values for edges.

OrthogonalGroupLayouter provides access to the default EdgeLayoutDescriptor instance through:

edgeLayoutDescriptor:EdgeLayoutDescriptor

In addition to the instance held directly by OrthogonalGroupLayouter, layout descriptors can also be associated with single edges in order to specify individual settings for them. Setting individual descriptors for edges is done through a data provider that is bound to the graph. See Related Classes.

In addition to these options, OrthogonalGroupLayouter by default also supports node halos as soon as they are declared using the data provider key NODE_HALO_DPKEY.

Besides the generic labeling support as described in the section called “Generic Labeling”, which is available with all yFiles layout algorithms, OrthogonalGroupLayouter additionally supports integrated labeling. Furthermore, it can also be set up to take node labels into account during layout.

integratedEdgeLabeling:Boolean

considerNodeLabels:Boolean

Class EdgeLayoutDescriptor can be used to configure edge-related layout options. The following options can be set for edges:

minimumFirstSegmentLength:Number
minimumLastSegmentLength:Number

An EdgeLayoutDescriptor instance can be specified individually for single edges by means of a data provider that is bound to the graph. The data provider is expected to be registered with the graph using key EDGE_LAYOUT_DESCRIPTOR_DPKEY. In the absence of an individual descriptor for an edge, the default EdgeLayoutDescriptor instance that is registered with OrthogonalGroupLayouter will be used.

The following table lists the data provider look-up keys that are recognized by OrthogonalGroupLayouter in conjunction with individual layout settings for edges.

Table 5.46. Data provider look-up keys

Key	Element Type	Value Type	Description
EDGE_LAYOUT_DESCRIPTOR_DPKEY	edge	EdgeLayoutDescriptor	For each edge an EdgeLayoutDescriptor object that configures edge-related options.

Table 5.47, “Layout Stages” lists layout stages that can be used to enhance the layout process of class OrthogonalGroupLayouter.

Table 5.47. Layout Stages

Classname	Description
PolylineLayoutStage	With class OrthogonalGroupLayouter as the core layouter, this stage adds octilinear edge routing to the diagram that results from the orthogonal layout calculation.

Tutorial demo application SimpleLayoutDemo.mxml shows the configuration of class OrthogonalGroupLayouter.