/*******************************************************************************
 * 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.ui.internal.keys;

import java.util.Comparator;
import java.util.ResourceBundle;

import org.eclipse.ui.internal.util.Util;
import org.eclipse.ui.keys.Key;
import org.eclipse.ui.keys.KeySequence;
import org.eclipse.ui.keys.KeyStroke;
import org.eclipse.ui.keys.ModifierKey;

/**
 * A key formatter providing the Emacs-style accelerators using single letters
 * to represent the modifier keys.
 *
 * @since 3.0
 */
public class EmacsKeyFormatter extends AbstractKeyFormatter {

	/**
	 * A comparator that guarantees that modifier keys will be sorted the same
	 * across different platforms.
	 */
	private static final Comparator EMACS_MODIFIER_KEY_COMPARATOR = new AlphabeticModifierKeyComparator();

	/**
	 * The resource bundle used by <code>format()</code> to translate formal string
	 * representations by locale.
	 */
	private static final ResourceBundle RESOURCE_BUNDLE = ResourceBundle.getBundle(EmacsKeyFormatter.class.getName());

	/**
	 * Formats an individual key into a human readable format. This converts the key
	 * into a format similar to Xemacs.
	 *
	 * @param key The key to format; must not be <code>null</code>.
	 * @return The key formatted as a string; should not be <code>null</code>.
	 */
	@Override
	public String format(Key key) {
		if (key instanceof ModifierKey) {
			String formattedName = Util.translateString(RESOURCE_BUNDLE, key.toString(), null, false, false);
			if (formattedName != null) {
				return formattedName;
			}
		}

		return super.format(key).toLowerCase();
	}

	@Override
	protected String getKeyDelimiter() {
		return Util.translateString(RESOURCE_BUNDLE, KEY_DELIMITER_KEY, KeyStroke.KEY_DELIMITER, false, false);
	}

	@Override
	protected String getKeyStrokeDelimiter() {
		return Util.translateString(RESOURCE_BUNDLE, KEY_STROKE_DELIMITER_KEY, KeySequence.KEY_STROKE_DELIMITER, false,
				false);
	}

	@Override
	protected Comparator getModifierKeyComparator() {
		return EMACS_MODIFIER_KEY_COMPARATOR;
	}

}
