/*

 * The contents of this file are subject to the terms of the Common Development

 * and Distribution License (the License). You may not use this file except in

 * compliance with the License.

 *

 * You can obtain a copy of the License at http://www.netbeans.org/cddl.html

 * or http://www.netbeans.org/cddl.txt.

 *

 * When distributing Covered Code, include this CDDL Header Notice in each file

 * and include the License file at http://www.netbeans.org/cddl.txt.

 * If applicable, add the following below the CDDL Header, with the fields

 * enclosed by brackets [] replaced by your own identifying information:

 * "Portions Copyrighted [year] [name of copyright owner]"

 *

 * The Original Software is NetBeans. The Initial Developer of the Original

 * Software is Sun Microsystems, Inc. Portions Copyright 1997-2007 Sun

 * Microsystems, Inc. All Rights Reserved.

 */

package org.netbeans.api.queries;

import java.nio.charset.Charset;

import java.util.prefs.Preferences;

import org.netbeans.spi.queries.FileEncodingQueryImplementation;

import org.openide.filesystems.FileObject;

import org.openide.util.Lookup;

import org.openide.util.NbPreferences;

/**

 * The query is used for finding encoding of files.

 * The query should be used when reading or writing files to use the

 * correct encoding.

 * @since org.netbeans.modules.queries/1 1.9

 * @see FileEncodingQueryImplementation

 * @author Tomas Zezula

 */

public class FileEncodingQuery {

    private static final String DEFAULT_ENCODING = "default-encoding";    //NOI18N

    private static final String UTF_8 = "UTF-8";                          //NOI18N    

    private FileEncodingQuery() {

    }

    /**

     * Returns encoding of given file.

     * @param file to find an encoding for

     * @return encoding which should be used for given file, never returns null.

     */

    public static Charset getEncoding (FileObject file) {

        assert file != null;

        Charset encoding;

        for (FileEncodingQueryImplementation impl : Lookup.getDefault().lookupAll(FileEncodingQueryImplementation.class)) {

            encoding = impl.getEncoding(file);

            if (encoding != null) {

                return encoding;

            }

        }

        String _encoding = System.getProperty("file.encoding");     //NOI18N

        assert _encoding != null;        

        encoding = Charset.forName(_encoding);

        assert encoding != null;

        return encoding;        

    }   

    /**

     * Returns the encoding which should be used for newly created projects.

     * The typical user of this method is a code generating new projects.

     * The returned value is a last used encoding set for project.

     * @return the default encoding 

     * 

     */

    public static Charset getDefaultEncoding () {

        Preferences prefs = NbPreferences.forModule(FileEncodingQuery.class);

        String defaultEncoding = prefs.get (DEFAULT_ENCODING,UTF_8);

        return Charset.forName(defaultEncoding);

    }

    /**

     * Sets the encoding which should be used for newly created projects.

     * The typical user of this method is a project customizer, when the

     * user sets a new encoding the customizer code should update the defaul

     * encoding by this method.

     * @param encoding the new default encoding

     * 

     */

    public static void setDefaultEncoding (final Charset encoding) {

        assert encoding != null;

        Preferences prefs = NbPreferences.forModule(FileEncodingQuery.class);

        prefs.put(DEFAULT_ENCODING, encoding.name());

    }

}

/*

 * The contents of this file are subject to the terms of the Common Development

 * and Distribution License (the License). You may not use this file except in

 * compliance with the License.

 *

 * You can obtain a copy of the License at http://www.netbeans.org/cddl.html

 * or http://www.netbeans.org/cddl.txt.

 *

 * When distributing Covered Code, include this CDDL Header Notice in each file

 * and include the License file at http://www.netbeans.org/cddl.txt.

 * If applicable, add the following below the CDDL Header, with the fields

 * enclosed by brackets [] replaced by your own identifying information:

 * "Portions Copyrighted [year] [name of copyright owner]"

 *

 * The Original Software is NetBeans. The Initial Developer of the Original

 * Software is Sun Microsystems, Inc. Portions Copyright 1997-2007 Sun

 * Microsystems, Inc. All Rights Reserved.

 */

package org.netbeans.spi.queries;

import java.nio.charset.Charset;

import org.openide.filesystems.FileObject;

/**

 * Information about encoding of a file.

 * <p>

 * A default implementations are registered by the

 * <code>org.netbeans.modules.projectapi</code> module which firstly looks up the

 * implementation of this interface in the <code>DataObject</code> lookup. When

 * available it delegates to it. When the implementation isn't available in the

 * <code>DataObject</code> lookup or it returns null it tries to find a

 * project corresponding to the file and checks whether that project has an

 * implementation of this interface in its lookup. If so, it delegates to 

 * that implementation. Therefore it is not generally necessary

 * for a project type provider nor data loader to register its own global implementation of

 * this query. 

 * </p> 

 * @see org.netbeans.api.queries.FileEncodingQuery

 * @since org.netbeans.modules.queries/1 1.9

 * @author Tomas Zezula

 */

public interface FileEncodingQueryImplementation {

    /**

     * Returns encoding of a given file.

     * @param file to find an encoding for

     * @return encoding which should be used for given file

     * or null when nothing is known about the file encoding.

     */

    public Charset getEncoding (FileObject file);

}