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package javax.accessibility;

import java.util.Vector;


Class AccessibleRelationSet determines a component's relation set. The relation set of a component is a set of AccessibleRelation objects that describe the component's relationships with other components. 
Author:Lynn Monsanto
See Also:
Since:1.3
/**
 * Class {@code AccessibleRelationSet} determines a component's relation set.
 * The relation set of a component is a set of {@code AccessibleRelation}
 * objects that describe the component's relationships with other components.
 *
 * @author Lynn Monsanto
 * @see AccessibleRelation
 * @since 1.3
 */
public class AccessibleRelationSet {

    
Each entry in the Vector represents an AccessibleRelation. 
See Also:
/**
     * Each entry in the {@code Vector} represents an
     * {@code AccessibleRelation}.
     *
     * @see #add
     * @see #addAll
     * @see #remove
     * @see #contains
     * @see #get
     * @see #size
     * @see #toArray
     * @see #clear
     */
    protected Vector<AccessibleRelation> relations = null;

    
Creates a new empty relation set.

/**
     * Creates a new empty relation set.
     */
    public AccessibleRelationSet() {
        relations = null;
    }

    
Creates a new relation with the initial set of relations contained in the
array of relations passed in. Duplicate entries are ignored.

Params:
  • relations – an array of AccessibleRelation describing the relation set
/**
     * Creates a new relation with the initial set of relations contained in the
     * array of relations passed in. Duplicate entries are ignored.
     *
     * @param  relations an array of {@code AccessibleRelation} describing the
     *         relation set
     */
    public AccessibleRelationSet(AccessibleRelation[] relations) {
        if (relations.length != 0) {
            this.relations = new Vector<>(relations.length);
            for (int i = 0; i < relations.length; i++) {
                add(relations[i]);
            }
        }
    }

    
Adds a new relation to the current relation set. If the relation is
already in the relation set, the target(s) of the specified relation is
merged with the target(s) of the existing relation. Otherwise, the new
relation is added to the relation set.

Params:
  • relation – the relation to add to the relation set
Returns:true if relation is added to the relation set; false if the relation set is unchanged
/**
     * Adds a new relation to the current relation set. If the relation is
     * already in the relation set, the target(s) of the specified relation is
     * merged with the target(s) of the existing relation. Otherwise, the new
     * relation is added to the relation set.
     *
     * @param  relation the relation to add to the relation set
     * @return {@code true} if relation is added to the relation set;
     *         {@code false} if the relation set is unchanged
     */
    public boolean add(AccessibleRelation relation) {
        if (relations == null) {
            relations = new Vector<>();
        }

        // Merge the relation targets if the key exists
        AccessibleRelation existingRelation = get(relation.getKey());
        if (existingRelation == null) {
            relations.addElement(relation);
            return true;
        } else {
            Object [] existingTarget = existingRelation.getTarget();
            Object [] newTarget = relation.getTarget();
            int mergedLength = existingTarget.length + newTarget.length;
            Object [] mergedTarget = new Object[mergedLength];
            for (int i = 0; i < existingTarget.length; i++) {
                mergedTarget[i] = existingTarget[i];
            }
            for (int i = existingTarget.length, j = 0;
                 i < mergedLength;
                 i++, j++) {
                mergedTarget[i] = newTarget[j];
            }
            existingRelation.setTarget(mergedTarget);
        }
        return true;
    }

    
Adds all of the relations to the existing relation set. Duplicate entries
are ignored.

Params:
  • relations – AccessibleRelation array describing the relation set
/**
     * Adds all of the relations to the existing relation set. Duplicate entries
     * are ignored.
     *
     * @param  relations {@code AccessibleRelation} array describing the
     *         relation set
     */
    public void addAll(AccessibleRelation[] relations) {
        if (relations.length != 0) {
            if (this.relations == null) {
                this.relations = new Vector<>(relations.length);
            }
            for (int i = 0; i < relations.length; i++) {
                add(relations[i]);
            }
        }
    }

    
Removes a relation from the current relation set. If the relation is not in the set, the relation set will be unchanged and the return value will be false. If the relation is in the relation set, it will be removed from the set and the return value will be true. 
Params:
  • relation – the relation to remove from the relation set
Returns:true if the relation is in the relation set; false if the relation set is unchanged
/**
     * Removes a relation from the current relation set. If the relation is not
     * in the set, the relation set will be unchanged and the return value will
     * be {@code false}. If the relation is in the relation set, it will be
     * removed from the set and the return value will be {@code true}.
     *
     * @param  relation the relation to remove from the relation set
     * @return {@code true} if the relation is in the relation set;
     *         {@code false} if the relation set is unchanged
     */
    public boolean remove(AccessibleRelation relation) {
        if (relations == null) {
            return false;
        } else {
            return relations.removeElement(relation);
        }
    }

    
Removes all the relations from the current relation set.

/**
     * Removes all the relations from the current relation set.
     */
    public void clear() {
        if (relations != null) {
            relations.removeAllElements();
        }
    }

    
Returns the number of relations in the relation set.

Returns:the number of relations in the relation set
/**
     * Returns the number of relations in the relation set.
     *
     * @return the number of relations in the relation set
     */
    public int size() {
        if (relations == null) {
            return 0;
        } else {
            return relations.size();
        }
    }

    
Returns whether the relation set contains a relation that matches the
specified key.

Params:
  • key – the AccessibleRelation key
Returns:true if the relation is in the relation set; otherwise false
/**
     * Returns whether the relation set contains a relation that matches the
     * specified key.
     *
     * @param  key the {@code AccessibleRelation} key
     * @return {@code true} if the relation is in the relation set; otherwise
     *         {@code false}
     */
    public boolean contains(String key) {
        return get(key) != null;
    }

    
Returns the relation that matches the specified key.

Params:
  • key – the AccessibleRelation key
Returns:the relation, if one exists, that matches the specified key. Otherwise, null is returned.
/**
     * Returns the relation that matches the specified key.
     *
     * @param  key the {@code AccessibleRelation} key
     * @return the relation, if one exists, that matches the specified key.
     *         Otherwise, {@code null} is returned.
     */
    public AccessibleRelation get(String key) {
        if (relations == null) {
            return null;
        } else {
            int len = relations.size();
            for (int i = 0; i < len; i++) {
                AccessibleRelation relation = relations.elementAt(i);
                if (relation != null && relation.getKey().equals(key)) {
                    return relation;
                }
            }
            return null;
        }
    }

    
Returns the current relation set as an array of AccessibleRelation. 
Returns:AccessibleRelation array contacting the current relation
/**
     * Returns the current relation set as an array of
     * {@code AccessibleRelation}.
     *
     * @return {@code AccessibleRelation} array contacting the current relation
     */
    public AccessibleRelation[] toArray() {
        if (relations == null) {
            return new AccessibleRelation[0];
        } else {
            AccessibleRelation[] relationArray
                = new AccessibleRelation[relations.size()];
            for (int i = 0; i < relationArray.length; i++) {
                relationArray[i] = relations.elementAt(i);
            }
            return relationArray;
        }
    }

    
Creates a localized string representing all the relations in the set
using the default locale.

See Also:
Returns:comma separated localized string
/**
     * Creates a localized string representing all the relations in the set
     * using the default locale.
     *
     * @return comma separated localized string
     * @see AccessibleBundle#toDisplayString
     */
    public String toString() {
        String ret = "";
        if ((relations != null) && (relations.size() > 0)) {
            ret = (relations.elementAt(0)).toDisplayString();
            for (int i = 1; i < relations.size(); i++) {
                ret = ret + ","
                        + (relations.elementAt(i)).toDisplayString();
            }
        }
        return ret;
    }
}