Overview of generic features
The ibm_ilog.graphlayout.hierarchical.HierarchicalLayout class supports the following
generic features defined in the ibm_ilog.graphlayout.GraphLayout class (see Base class parameters and features):
The following paragraphs describe the particular way
in which these parameters are used by this subclass.
Allowed time (HL)
The layout algorithm stops if the allowed time setting
has elapsed. (For a description of this layout parameter in the
ibm_ilog.graphlayout.GraphLayout
class,
see Allowed time.) If the layout
stops early because the allowed time has elapsed, the nodes and links
are not moved from their positions before the layout call and the
result code in the layout report is ibm_ilog.graphlayout.GraphLayoutReport.STOPPED_AND_INVALID
. Layout of connected components (HL)
The layout algorithm can use the generic mechanism to
lay out connected components. (For more information about this mechanism,
see Layout of connected components.) When using
this mechanism, each component is laid out in its own individual level
structure. Nodes of the first level of one component can be placed
at a different position than nodes of the first level of another component.
The generic mechanism to lay out connected components
is, however, disabled by default. In this case, the layout algorithm
can still handle disconnected graphs. It merges all components into
a global level structure.
Link connection box (HL)
The layout algorithm can use a link connection box provider
interface. For details, see Using a link connection box interface (HL).
Percentage of completion calculation (HL)
The layout algorithm calculates the estimated percentage
of completion. This value can be obtained from the layout report during
the run of the layout. (For a detailed description of this features,
see Percentage of completion calculation and Graph layout event listeners.)
Preserve fixed links (HL)
The layout algorithm does not reshape the links that
are specified as fixed. In fact, fixed links are ignored. (For more
information about link parameters in the
ibm_ilog.graphlayout.GraphLayout
class,
see Preserve fixed links and Link style (TL).) Preserve fixed nodes (HL)
The layout algorithm does not move the nodes that are
specified as fixed. (For more information about node parameters in
the
ibm_ilog.graphlayout.GraphLayout
class,
see Preserve fixed nodes.) Moreover,
the layout algorithm ignores fixed nodes and also does not route the
links that are incident to the fixed nodes. It can result in unwanted
overlapping nodes and link crossings. However, this feature is useful
for individual, disconnected components that can be laid out independently.
Stop immediately (HL)
The layout algorithm stops after cleanup if the method stopImmediately is called. (For a description
of this method in the
ibm_ilog.graphlayout.GraphLayout
class,
see Stop immediately.) If the layout
stops early because the allowed time has elapsed, the nodes and links
are not moved from their positions before the layout call and the
result code in the layout report is ibm_ilog.graphlayout.GraphLayoutReport.STOPPED_AND_INVALID
.