com.vividsolutions.jts.planargraph.GraphComponent Maven / Gradle / Ivy
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/*
* The JTS Topology Suite is a collection of Java classes that
* implement the fundamental operations required to validate a given
* geo-spatial data set to a known topological specification.
*
* Copyright (C) 2001 Vivid Solutions
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* For more information, contact:
*
* Vivid Solutions
* Suite #1A
* 2328 Government Street
* Victoria BC V8T 5G5
* Canada
*
* (250)385-6040
* www.vividsolutions.com
*/
package com.vividsolutions.jts.planargraph;
import java.util.Iterator;
/**
* The base class for all graph component classes.
* Maintains flags of use in generic graph algorithms.
* Provides two flags:
*
* - marked - typically this is used to indicate a state that persists
* for the course of the graph's lifetime. For instance, it can be
* used to indicate that a component has been logically deleted from the graph.
*
- visited - this is used to indicate that a component has been processed
* or visited by an single graph algorithm. For instance, a breadth-first traversal of the
* graph might use this to indicate that a node has already been traversed.
* The visited flag may be set and cleared many times during the lifetime of a graph.
*
*
* Graph components support storing user context data. This will typically be
* used by client algorithms which use planar graphs.
*
* @version 1.7
*/
public abstract class GraphComponent
{
/**
* Sets the Visited state for all {@link GraphComponent}s in an {@link Iterator}
*
* @param i the Iterator to scan
* @param visited the state to set the visited flag to
*/
public static void setVisited(Iterator i, boolean visited)
{
while (i.hasNext()) {
GraphComponent comp = (GraphComponent) i.next();
comp.setVisited(visited);
}
}
/**
* Sets the Marked state for all {@link GraphComponent}s in an {@link Iterator}
*
* @param i the Iterator to scan
* @param marked the state to set the Marked flag to
*/
public static void setMarked(Iterator i, boolean marked)
{
while (i.hasNext()) {
GraphComponent comp = (GraphComponent) i.next();
comp.setMarked(marked);
}
}
/**
* Finds the first {@link GraphComponent} in a {@link Iterator} set
* which has the specified visited state.
*
* @param i an Iterator of GraphComponents
* @param visitedState the visited state to test
* @return the first component found, or null if none found
*/
public static GraphComponent getComponentWithVisitedState(Iterator i, boolean visitedState)
{
while (i.hasNext()) {
GraphComponent comp = (GraphComponent) i.next();
if (comp.isVisited() == visitedState)
return comp;
}
return null;
}
protected boolean isMarked = false;
protected boolean isVisited = false;
private Object data;
public GraphComponent() {
}
/**
* Tests if a component has been visited during the course of a graph algorithm
* @return true if the component has been visited
*/
public boolean isVisited() { return isVisited; }
/**
* Sets the visited flag for this component.
* @param isVisited the desired value of the visited flag
*/
public void setVisited(boolean isVisited) { this.isVisited = isVisited; }
/**
* Tests if a component has been marked at some point during the processing
* involving this graph.
* @return true if the component has been marked
*/
public boolean isMarked() { return isMarked; }
/**
* Sets the marked flag for this component.
* @param isMarked the desired value of the marked flag
*/
public void setMarked(boolean isMarked) { this.isMarked = isMarked; }
/**
* Sets the user-defined data for this component.
*
* @param data an Object containing user-defined data
*/
public void setContext(Object data) { this.data = data; }
/**
* Gets the user-defined data for this component.
*
* @return the user-defined data
*/
public Object getContext() { return data; }
/**
* Sets the user-defined data for this component.
*
* @param data an Object containing user-defined data
*/
public void setData(Object data) { this.data = data; }
/**
* Gets the user-defined data for this component.
*
* @return the user-defined data
*/
public Object getData() { return data; }
/**
* Tests whether this component has been removed from its containing graph
*
* @return true if this component is removed
*/
public abstract boolean isRemoved();
}