CodeFormatter.java

/*******************************************************************************
 * Copyright (c) 2000, 2004 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.rubypeople.rdt.core.formatter;

import org.eclipse.text.edits.TextEdit;

/**
 * Specification for a generic source code formatter.
 * 
 * @since 0.8.0
 */
public abstract class CodeFormatter {

    /**
     * Unknown kind
     */
    public static final int K_UNKNOWN = 0x00;

    /**
     * Kind used to format an expression
     */
    public static final int K_EXPRESSION = 0x01;
    
    /**
     * Kind used to format a set of statements
     */
    public static final int K_STATEMENTS = 0x02;
    
    /**
     * Kind used to format a set of class body declarations
     */
    public static final int K_CLASS_BODY_DECLARATIONS = 0x04;
    
    /**
     * Kind used to format a ruby script
     */
    public static final int K_RUBY_SCRIPT = 0x08;

    /**
     * Kind used to format a single-line comment
     * @since 0.8.0
     */
    public static final int K_SINGLE_LINE_COMMENT = 0x10;
    /**
     * Kind used to format a multi-line comment
     * @since 0.8.0
     */
    public static final int K_MULTI_LINE_COMMENT = 0x20;
    /**
     * Kind used to format a Javadoc comment
     * @since 0.8.0
     */
    public static final int K_RUBY_DOC = 0x40;

    /** 
     * Format <code>source</code>,
     * and returns a text edit that correspond to the difference between the given string and the formatted string.
     * It returns null if the given string cannot be formatted.
     * 
     * If the offset position is matching a whitespace, the result can include whitespaces. It would be up to the
     * caller to get rid of preceeding whitespaces.
     * 
     * @param kind Use to specify the kind of the code snippet to format. It can be any of these:
     *        K_EXPRESSION, K_STATEMENTS, K_CLASS_BODY_DECLARATIONS, K_RUBY_SCRIPT, K_UNKNOWN,
     *        K_SINGLE_LINE_COMMENT, K_MULTI_LINE_COMMENT, K_RUBY_DOC
     * @param source the source to format
     * @param offset the given offset to start recording the edits (inclusive).
     * @param length the given length to stop recording the edits (exclusive).
     * @param indentationLevel the initial indentation level, used 
     *      to shift left/right the entire source fragment. An initial indentation
     *      level of zero or below has no effect.
     * @param lineSeparator the line separator to use in formatted source,
     *     if set to <code>null</code>, then the platform default one will be used.
     * @return the text edit
     * @throws IllegalArgumentException if offset is lower than 0, length is lower than 0 or
     * length is greater than source length.
     */
    public abstract TextEdit format(int kind, String source, int offset, int length, int indentationLevel, String lineSeparator);
}