ilog.views.hypergraph.crossing

Interface IlvCrossingOwner

public interface IlvCrossingOwner

A owner of a crossing. Since a crossing means that two line segments intersect, each crossing is contained in two crossing owners. The crossing is active for the crossing owner that corresponds to the line segment that displays a jog, and passive for the other crossing owner. A crossing owner can cache crossings so that they don't need to be recalculated all the time. Hence, the rules are the following:

• If the active crossing owner does not cache the crossing, the crossing is only added to the active crossing owner, not to the passive crossing owner, independently of whether the passive crossing owner caches.
• If the active crossing owner caches the crossing, the crossing is added to both crossing owners.
• If the segment related to the passive crossing owner changes, the passive crossing owner must recalculate the crossings. In this case, it must also remove the passive crossing from its active crossing owner.
• If the passive crossing owner does not cache the crossing, it must mark the cache of the active crossing owner invalid before removing the crossing from the active crossing owner. This tells the active crossing owner that it must recalculate the crossings itself, because the passive crossing owner may not recalculate the crossings for the active crossing owner.
• The cache of a crossing owner remains invalid until the crossing owner decides to recalculate all its crossings.

You can call the utility IlvCrossingCalculation.removeCrossings(java.util.Iterator) which takes care of removing crossings from active and passive owners and marks the caches automatically invalid when needed.

Since:

JViews 8.1

Method Summary

Modifier and Type	Method and Description
void	addCrossing(IlvCrossing crossing, boolean active) Adds a crossing.
IlvCrossingAwareObject	getObject() Returns the corresponding crossing aware object.
boolean	isCachingCrossings() Returns whether the crossing owner is caching the crossings.
void	markCrossingCacheInvalid() Marks the cache of the crossing owner as invalid.
void	removeCrossing(IlvCrossing crossing) Removes a crossing.

Method Detail

getObject

IlvCrossingAwareObject getObject()

Returns the corresponding crossing aware object.

addCrossing

void addCrossing(IlvCrossing crossing,
                 boolean active)

Adds a crossing. If active is true, the crossing is active for this crossing owner, i.e. it is drawn as a jog.

removeCrossing

void removeCrossing(IlvCrossing crossing)

Removes a crossing.

isCachingCrossings

boolean isCachingCrossings()

Returns whether the crossing owner is caching the crossings.

markCrossingCacheInvalid

void markCrossingCacheInvalid()

Marks the cache of the crossing owner as invalid.