/*

 * Copyright (c) 2002, 2008, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package javax.swing.plaf.basic;

import java.lang.reflect.*;

import javax.swing.*;

import javax.swing.plaf.*;

/**

 * An ActionMap that populates its contents as necessary. The

 * contents are populated by invoking the <code>loadActionMap</code>

 * method on the passed in Object.

 *

 * @author Scott Violet

 */

class LazyActionMap extends ActionMapUIResource {

    /**

     * Object to invoke <code>loadActionMap</code> on. This may be

     * a Class object.

     */

    private transient Object _loader;

    /**

     * Installs an ActionMap that will be populated by invoking the

     * <code>loadActionMap</code> method on the specified Class

     * when necessary.

     * <p>

     * This should be used if the ActionMap can be shared.

     *

     * @param c JComponent to install the ActionMap on.

     * @param loaderClass Class object that gets loadActionMap invoked

     *                    on.

     * @param defaultsKey Key to use to defaults table to check for

     *        existing map and what resulting Map will be registered on.

     */

    static void installLazyActionMap(JComponent c, Class loaderClass,

                                     String defaultsKey) {

        ActionMap map = (ActionMap)UIManager.get(defaultsKey);

        if (map == null) {

            map = new LazyActionMap(loaderClass);

            UIManager.getLookAndFeelDefaults().put(defaultsKey, map);

        }

        SwingUtilities.replaceUIActionMap(c, map);

    }

    /**

     * Returns an ActionMap that will be populated by invoking the

     * <code>loadActionMap</code> method on the specified Class

     * when necessary.

     * <p>

     * This should be used if the ActionMap can be shared.

     *

     * @param c JComponent to install the ActionMap on.

     * @param loaderClass Class object that gets loadActionMap invoked

     *                    on.

     * @param defaultsKey Key to use to defaults table to check for

     *        existing map and what resulting Map will be registered on.

     */

    static ActionMap getActionMap(Class loaderClass,

                                  String defaultsKey) {

        ActionMap map = (ActionMap)UIManager.get(defaultsKey);

        if (map == null) {

            map = new LazyActionMap(loaderClass);

            UIManager.getLookAndFeelDefaults().put(defaultsKey, map);

        }

        return map;

    }

    private LazyActionMap(Class loader) {

        _loader = loader;

    }

    public void put(Action action) {

        put(action.getValue(Action.NAME), action);

    }

    public void put(Object key, Action action) {

        loadIfNecessary();

        super.put(key, action);

    }

    public Action get(Object key) {

        loadIfNecessary();

        return super.get(key);

    }

    public void remove(Object key) {

        loadIfNecessary();

        super.remove(key);

    }

    public void clear() {

        loadIfNecessary();

        super.clear();

    }

    public Object[] keys() {

        loadIfNecessary();

        return super.keys();

    }

    public int size() {

        loadIfNecessary();

        return super.size();

    }

    public Object[] allKeys() {

        loadIfNecessary();

        return super.allKeys();

    }

    public void setParent(ActionMap map) {

        loadIfNecessary();

        super.setParent(map);

    }

    private void loadIfNecessary() {

        if (_loader != null) {

            Object loader = _loader;

            _loader = null;

            Class<?> klass = (Class<?>)loader;

            try {

                Method method = klass.getDeclaredMethod("loadActionMap",

                                      new Class[] { LazyActionMap.class });

                method.invoke(klass, new Object[] { this });

            } catch (NoSuchMethodException nsme) {

                assert false : "LazyActionMap unable to load actions " +

                        klass;

            } catch (IllegalAccessException iae) {

                assert false : "LazyActionMap unable to load actions " +

                        iae;

            } catch (InvocationTargetException ite) {

                assert false : "LazyActionMap unable to load actions " +

                        ite;

            } catch (IllegalArgumentException iae) {

                assert false : "LazyActionMap unable to load actions " +

                        iae;

            }

        }

    }

}