IconResourceFileNameMap.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.framework.resources;

/**
 * Interface used by DefaultIconRepository to map icon keys
 * to their associated resource files.
 */
public interface IconResourceFileNameMap {

    /**
     * Return whether there is a resource file name associated with the
     * specified key.  This is to avoid throwing tons of MissingIconExceptions.
     * Call this before calling #getResourceFileName(String)
     */
    boolean  hasResourceFileName(String key);

    /**
     * Return the name of the resource file containing the icon
     * associated with the specified key. Throw a MissingIconException
     * if there is not resource file name associated with the specified key.
     */
    String getResourceFileName(String key);


    // ********** null implementation **********

    /**
     * This instance will throw an exception for any key.
     */
    IconResourceFileNameMap NULL_INSTANCE =
        new IconResourceFileNameMap() {
            public boolean hasResourceFileName(String key) {
                return false;
            }
            public String getResourceFileName(String key) {
                throw new MissingIconException("Missing icon file resource name: " + key, key);
            }
            public String toString() {
                return "NullIconResourceFileNameMap";
            }
        };

}