org.graphstream.graph.Element Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of gs-core Show documentation
Show all versions of gs-core Show documentation
The GraphStream library. With GraphStream you deal with
graphs. Static and Dynamic. You create them from scratch, from a file
or any source. You display and render them. This is the core package
that contains the minimal needed to read and write a graph.
/*
* Copyright 2006 - 2015
* Stefan Balev
* Julien Baudry
* Antoine Dutot
* Yoann Pigné
* Guilhelm Savin
*
* This file is part of GraphStream .
*
* GraphStream is a library whose purpose is to handle static or dynamic
* graph, create them from scratch, file or any source and display them.
*
* This program is free software distributed under the terms of two licenses, the
* CeCILL-C license that fits European law, and the GNU Lesser General Public
* License. You can use, modify and/ or redistribute the software under the terms
* of the CeCILL-C license as circulated by CEA, CNRS and INRIA at the following
* URL or under the terms of the GNU LGPL as published by
* the Free Software Foundation, either version 3 of the License, or (at your
* option) any later version.
*
* This program 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 program. If not, see
* An interface that defines common method to manipulate identifiers, attributes
* and indices of the elements (graph, nodes and edges) of a graph.
*
* *
*
* Attributes can be any object and are identified by arbitrary strings. Some
* attributes are stored as numbers or strings and are in this case named
* number, label or vector. There are utility methods to handle these attributes
* ({@link #getNumber(String)}, {@link #getLabel(String)}) or
* {@link #getVector(String)}, however they are also accessible through the more
* general method {@link #getAttribute(String)}.
*
*
* Important
*
* Implementing classes should indicate the complexity of their implementation
* for each method.
*
*
* @since July 12 2007
*
*/
public interface Element {
/**
* Unique identifier of this element.
*
* @return The identifier value.
*/
String getId();
/**
* The current index of this element
*
* @return The index value
*/
int getIndex();
/**
* Get the attribute object bound to the given key. The returned value may
* be null to indicate the attribute does not exists or is not supported.
*
* @param key
* Name of the attribute to search.
* @return The object bound to the given key or null if no object match this
* attribute name.
*/
// Object getAttribute( String key );
T getAttribute(String key);
/**
* Like {@link #getAttribute(String)}, but returns the first existing
* attribute in a list of keys, instead of only one key. The key list order
* matters.
*
* @param keys
* Several strings naming attributes.
* @return The first attribute that exists.
*/
// Object getFirstAttributeOf( String... keys );
T getFirstAttributeOf(String... keys);
/**
* Get the attribute object bound to the given key if it is an instance of
* the given class. Some The returned value maybe null to indicate the
* attribute does not exists or is not an instance of the given class.
*
* @param key
* The attribute name to search.
* @param clazz
* The expected attribute class.
* @return The object bound to the given key or null if no object match this
* attribute.
*/
// Object getAttribute( String key, Class clazz );
T getAttribute(String key, Class clazz);
/**
* Like {@link #getAttribute(String, Class)}, but returns the first existing
* attribute in a list of keys, instead of only one key. The key list order
* matters.
*
* @param clazz
* The class the attribute must be instance of.
* @param keys
* Several string naming attributes.
* @return The first attribute that exists.
*/
// Object getFirstAttributeOf( Class clazz, String... keys );
T getFirstAttributeOf(Class clazz, String... keys);
/**
* Get the label string bound to the given key key. Labels are special
* attributes whose value is a character sequence. If an attribute with the
* same name exists but is not a character sequence, null is returned.
*
* @param key
* The label to search.
* @return The label string value or null if not found.
*/
CharSequence getLabel(String key);
/**
* Get the number bound to key. Numbers are special attributes whose value
* is an instance of Number. If an attribute with the same name exists but
* is not a Number, NaN is returned.
*
* @param key
* The name of the number to search.
* @return The number value or NaN if not found.
*/
double getNumber(String key);
/**
* Get the vector of number bound to key. Vectors of numbers are special
* attributes whose value is a sequence of numbers. If an attribute with the
* same name exists but is not a vector of number, null is returned.
*
* @param key
* The name of the number to search.
* @return The vector of numbers or null if not found.
*/
ArrayList getVector(String key);
/**
* Get the array of objects bound to key. Arrays of objects are special
* attributes whose value is a sequence of objects. If an attribute with the
* same name exists but is not an array, null is returned.
*
* @param key
* The name of the array to search.
* @return The array of objects or null if not found.
*/
Object[] getArray(String key);
/**
* Get the hash bound to key. Hashes are special attributes whose value is a
* set of pairs (name,object). Instances of object implementing the
* {@link CompoundAttribute} interface are considered like hashes since they
* can be transformed to a hash. If an attribute with the same name exists
* but is not a hash, null is returned. We cannot enforce the type of the
* key. It is considered a string and you should use "Object.toString()" to
* get it.
*
* @param key
* The name of the hash to search.
* @return The hash or null if not found.
*/
HashMap getHash(String key);
/**
* Does this element store a value for the given attribute key?
*
* @param key
* The name of the attribute to search.
* @return True if a value is present for this attribute.
*/
boolean hasAttribute(String key);
/**
* Does this element store a value for the given attribute key and this
* value is an instance of the given class?
*
* @param key
* The name of the attribute to search.
* @param clazz
* The expected class of the attribute value.
* @return True if a value is present for this attribute.
*/
boolean hasAttribute(String key, Class clazz);
/**
* Does this element store a label value for the given key? A label is an
* attribute whose value is a string.
*
* @param key
* The name of the label.
* @return True if a value is present for this attribute and implements
* CharSequence.
*/
boolean hasLabel(String key);
/**
* Does this element store a number for the given key? A number is an
* attribute whose value is an instance of Number.
*
* @param key
* The name of the number.
* @return True if a value is present for this attribute and can contain a
* double (inherits from Number).
*/
boolean hasNumber(String key);
/**
* Does this element store a vector value for the given key? A vector is an
* attribute whose value is a sequence of numbers.
*
* @param key
* The name of the vector.
* @return True if a value is present for this attribute and can contain a
* sequence of numbers.
*/
boolean hasVector(String key);
/**
* Does this element store an array value for the given key? A vector is an
* attribute whose value is an array of objects.
*
* @param key
* The name of the array.
* @return True if a value is present for this attribute and can contain an
* array object.
*/
boolean hasArray(String key);
/**
* Does this element store a hash value for the given key? A hash is a set
* of pairs (key,value) or objects that implement the
* {@link org.graphstream.graph.CompoundAttribute} class.
*
* @param key
* The name of the hash.
* @return True if a value is present for this attribute and can contain a
* hash.
*/
boolean hasHash(String key);
/**
* Iterator on all attributes keys.
*
* @return An iterator on the key set of attributes.
*/
Iterator getAttributeKeyIterator();
/**
* An iterable view on the set of attribute keys usable within a for-each
* loop.
*
* @return an iterable view on attribute keys.
*/
Iterable getEachAttributeKey();
/**
* An unmodifiable view on the set of attribute keys.
*
* @return an unmodifiable collection containing the attribute keys.
*/
Collection getAttributeKeySet();
/**
* Remove all registered attributes. This includes numbers, labels and
* vectors.
*/
void clearAttributes();
/**
* Add or replace the value of an attribute. Existing attributes are
* overwritten silently. All classes inheriting from Number can be
* considered as numbers. All classes inheriting from CharSequence can be
* considered as labels. You can pass zero, one or more arguments for the
* attribute values. If no value is given, a boolean with value "true" is
* added. If there is more than one value, an array is stored. If there is
* only one value, the value is stored (but not in an array).
*
* @param attribute
* The attribute name.
* @param values
* The attribute value or set of values.
*/
void addAttribute(String attribute, Object... values);
/**
* Like {@link #addAttribute(String, Object...)} but for consistency.
*
* @param attribute
* The attribute name.
* @param values
* The attribute value or array of values.
* @see #addAttribute(String, Object...)
*/
void changeAttribute(String attribute, Object... values);
/**
* Like {@link #addAttribute(String, Object...)} but for consistency.
*
* @param attribute
* The attribute name.
* @param values
* The attribute value or array of values.
* @see #addAttribute(String, Object...)
*/
void setAttribute(String attribute, Object... values);
/**
* Add or replace each attribute found in attributes. Existing attributes
* are overwritten silently. All classes inheriting from Number can be
* considered as numbers. All classes inheriting from CharSequence can be
* considered as labels.
*
* @param attributes
* A set of (key,value) pairs.
*/
void addAttributes(Map attributes);
/**
* Remove an attribute. Non-existent attributes errors are ignored silently.
*
* @param attribute
* Name of the attribute to remove.
*/
void removeAttribute(String attribute);
/**
* Number of attributes stored in this element.
*
* @return the number of attributes.
*/
int getAttributeCount();
}