/*

 * Copyright 1996-2009 Sun Microsystems, Inc.  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.  Sun designates this

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

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package java.beans;

import com.sun.beans.finder.PropertyEditorFinder;

import sun.awt.AppContext;

/**

 * The PropertyEditorManager can be used to locate a property editor for

 * any given type name.  This property editor must support the

 * java.beans.PropertyEditor interface for editing a given object.

 * <P>

 * The PropertyEditorManager uses three techniques for locating an editor

 * for a given type.  First, it provides a registerEditor method to allow

 * an editor to be specifically registered for a given type.  Second it

 * tries to locate a suitable class by adding "Editor" to the full

 * qualified classname of the given type (e.g. "foo.bah.FozEditor").

 * Finally it takes the simple classname (without the package name) adds

 * "Editor" to it and looks in a search-path of packages for a matching

 * class.

 * <P>

 * So for an input class foo.bah.Fred, the PropertyEditorManager would

 * first look in its tables to see if an editor had been registered for

 * foo.bah.Fred and if so use that.  Then it will look for a

 * foo.bah.FredEditor class.  Then it will look for (say)

 * standardEditorsPackage.FredEditor class.

 * <p>

 * Default PropertyEditors will be provided for the Java primitive types

 * "boolean", "byte", "short", "int", "long", "float", and "double"; and

 * for the classes java.lang.String. java.awt.Color, and java.awt.Font.

 */

public class PropertyEditorManager {

    private static final Object FINDER_KEY = new Object();

    /**

     * Registers an editor class to edit values of the given target class.

     * If the editor class is {@code null},

     * then any existing definition will be removed.

     * Thus this method can be used to cancel the registration.

     * The registration is canceled automatically

     * if either the target or editor class is unloaded.

     * <p>

     * If there is a security manager, its {@code checkPropertiesAccess}

     * method is called. This could result in a {@linkplain SecurityException}.

     *

     * @param targetType   the class object of the type to be edited

     * @param editorClass  the class object of the editor class

     * @throws SecurityException  if a security manager exists and

     *                            its {@code checkPropertiesAccess} method

     *                            doesn't allow setting of system properties

     *

     * @see SecurityManager#checkPropertiesAccess

     */

    public static void registerEditor(Class<?> targetType, Class<?> editorClass) {

        SecurityManager sm = System.getSecurityManager();

        if (sm != null) {

            sm.checkPropertiesAccess();

        }

        PropertyEditorFinder finder = getFinder();

        synchronized (finder) {

            finder.register(targetType, editorClass);

        }

    }

    /**

     * Locate a value editor for a given target type.

     *

     * @param targetType  The Class object for the type to be edited

     * @return An editor object for the given target class.

     * The result is null if no suitable editor can be found.

     */

    public static PropertyEditor findEditor(Class<?> targetType) {

        PropertyEditorFinder finder = getFinder();

        synchronized (finder) {

            return finder.find(targetType);

        }

    }

    /**

     * Gets the package names that will be searched for property editors.

     *

     * @return  The array of package names that will be searched in

     *          order to find property editors.

     * <p>     The default value for this array is implementation-dependent,

     *         e.g. Sun implementation initially sets to  {"sun.beans.editors"}.

     */

    public static String[] getEditorSearchPath() {

        PropertyEditorFinder finder = getFinder();

        synchronized (finder) {

            return finder.getPackages();

        }

    }

    /**

     * Change the list of package names that will be used for

     *          finding property editors.

     *

     * <p>First, if there is a security manager, its <code>checkPropertiesAccess</code>

     * method is called. This could result in a SecurityException.

     *

     * @param path  Array of package names.

     * @exception  SecurityException  if a security manager exists and its

     *             <code>checkPropertiesAccess</code> method doesn't allow setting

     *              of system properties.

     * @see SecurityManager#checkPropertiesAccess

     */

    public static void setEditorSearchPath(String[] path) {

        SecurityManager sm = System.getSecurityManager();

        if (sm != null) {

            sm.checkPropertiesAccess();

        }

        PropertyEditorFinder finder = getFinder();

        synchronized (finder) {

            finder.setPackages(path);

        }

    }

    private static PropertyEditorFinder getFinder() {

        AppContext context = AppContext.getAppContext();

        Object object = context.get(FINDER_KEY);

        if (object instanceof PropertyEditorFinder) {

            return (PropertyEditorFinder) object;

        }

        PropertyEditorFinder finder = new PropertyEditorFinder();

        context.put(FINDER_KEY, finder);

        return finder;

    }

}