Copyright (c) 2000, 2015 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.core.runtime;

Qualified names are two-part names: qualifier and local name.
The qualifier must be in URI form (see RFC2396).  
Note however that the qualifier may be null if
the default name space is being used.  The empty string is not 
a valid local name.

This class can be used without OSGi running.

This class is not intended to be subclassed by clients.

/**
 * Qualified names are two-part names: qualifier and local name.
 * The qualifier must be in URI form (see RFC2396).  
 * Note however that the qualifier may be <code>null</code> if
 * the default name space is being used.  The empty string is not 
 * a valid local name.
 * <p>
 * This class can be used without OSGi running.
 * </p><p>
 * This class is not intended to be subclassed by clients.
 * </p>
 */
public final class QualifiedName {

	
Qualifier part (potentially null). /** Qualifier part (potentially <code>null</code>). */
	/*package*/
	String qualifier = null;

	
Local name part. /** Local name part. */
	/*package*/
	String localName = null;

	
Creates and returns a new qualified name with the given qualifier
and local name.  The local name must not be the empty string.
The qualifier may be null.

Clients may instantiate.

Params:
qualifier – the qualifier string, or null
localName – the local name string/**
	 * Creates and returns a new qualified name with the given qualifier
	 * and local name.  The local name must not be the empty string.
	 * The qualifier may be <code>null</code>.
	 * <p>
	 * Clients may instantiate.
	 * </p>
	 * @param qualifier the qualifier string, or <code>null</code>
	 * @param localName the local name string
	 */
	public QualifiedName(String qualifier, String localName) {
		Assert.isLegal(localName != null && localName.length() != 0);
		this.qualifier = qualifier;
		this.localName = localName;
	}

	
Returns whether this qualified name is equivalent to the given object.

Qualified names are equal if and only if they have the same
qualified parts and local parts.
Qualified names are not equal to objects other than qualified names.

Params:
obj – the object to compare to
Returns:
true if these are equivalent qualified
   names, and false otherwise/**
	 * Returns whether this qualified name is equivalent to the given object.
	 * <p>
	 * Qualified names are equal if and only if they have the same
	 * qualified parts and local parts.
	 * Qualified names are not equal to objects other than qualified names.
	 * </p>
	 *
	 * @param obj the object to compare to
	 * @return <code>true</code> if these are equivalent qualified
	 *    names, and <code>false</code> otherwise
	 */
	@Override
	public boolean equals(Object obj) {
		if (obj == this) {
			return true;
		}
		if (!(obj instanceof QualifiedName)) {
			return false;
		}
		QualifiedName qName = (QualifiedName) obj;
		/* There may or may not be a qualifier */
		if (qualifier == null && qName.getQualifier() != null) {
			return false;
		}
		if (qualifier != null && !qualifier.equals(qName.getQualifier())) {
			return false;
		}
		return localName.equals(qName.getLocalName());
	}

	
Returns the local part of this name.
Returns:
the local name string/**
	 * Returns the local part of this name.
	 *
	 * @return the local name string
	 */
	public String getLocalName() {
		return localName;
	}

	
Returns the qualifier part for this qualified name, or null
if none.
Returns:
the qualifier string, or null/**
	 * Returns the qualifier part for this qualified name, or <code>null</code>
	 * if none.
	 *
	 * @return the qualifier string, or <code>null</code>
	 */
	public String getQualifier() {
		return qualifier;
	}

	/* (Intentionally omitted from javadoc)
	 * Implements the method <code>Object.hashCode</code>.
	 * 
	 * Returns the hash code for this qualified name.
	 */
	@Override
	public int hashCode() {
		return (qualifier == null ? 0 : qualifier.hashCode()) + localName.hashCode();
	}

	
Converts this qualified name into a string, suitable for 
debug purposes only.
/**
	 * Converts this qualified name into a string, suitable for 
	 * debug purposes only.
	 */
	@Override
	public String toString() {
		return (getQualifier() == null ? "" : getQualifier() + ':') + getLocalName(); //$NON-NLS-1$
	}
}