Java Array Normalize normalizeRecorderColumn(int column, int tabSize, int[] tabIndices)

Description

Normalizes the given column index computed by KeY's recorder component into a normal column index in that each tab ( '\t' ) character has a fixed tab size of one which means that a tab is treated as a normal character.

License

Open Source License

Parameter

Parameter	Description
column	The column computed by KeY's recorder component.
tabSize	The tab size to use.
tabIndices	The indices of tab ( '\t' ) characters in the current line. They can be computed for instance via IOUtil#computeLineInformation(File) .

Return

The normalized column index in that each tab ( '\t' ) character has a fixed tab size of one which means that a tab is treated as a normal character.

Declaration

public static int normalizeRecorderColumn(int column, int tabSize, int[] tabIndices)

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright (c) 2014 Karlsruhe Institute of Technology, Germany
 *                    Technical University Darmstadt, Germany
 *                    Chalmers University of Technology, Sweden
 * 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://from   www. j ava  2s .c o  m
 *    Technical University Darmstadt - initial API and implementation and/or initial documentation
 *******************************************************************************/

public class Main {
    /**
     * The used tab size in KeY's recorder component.
     */
    public static final int RECORDER_TAB_SIZE = 8;

    /**
     * <p>
     * Normalizes the given column index computed by KeY's recorder component into
     * a normal column index in that each tab ({@code '\t'}) character has a fixed tab size 
     * of one which means that a tab is treated as a normal character.
     * </p>
     * <p>
     * KeY's recorder component has a default tab size of {@link #RECORDER_TAB_SIZE}.
     * But instead of using this fixed tab size the recorder component uses the following
     * simplified code to compute the column index:
     * <pre><code>
     * int column = 0;
     * for (char sign : signs) {
     *    switch (sign) {
     *        case '\t' : column += (tabSize - (column % tabSize));
     *                    break;
     *        default : column ++;
     *     }
     * }
     * </code></pre>
     * The class of recorder which does the mentioned computation is {@link JavaCharStream}.
     * </p>
     * @param column The column computed by KeY's recorder component.
     * @param tabIndices The indices of tab ({@code '\t'}) characters in the current line. They can be computed for instance via {@link IOUtil#computeLineInformation(File)}. 
     * @return The normalized column index in that each tab ({@code '\t'}) character has a fixed tab size of one which means that a tab is treated as a normal character.
     */
    public static int normalizeRecorderColumn(int column, int[] tabIndices) {
        return normalizeRecorderColumn(column, RECORDER_TAB_SIZE, tabIndices);
    }

    /**
     * <p>
     * Normalizes the given column index computed by KeY's recorder component into
     * a normal column index in that each tab ({@code '\t'}) character has a fixed tab size 
     * of one which means that a tab is treated as a normal character.
     * </p>
     * <p>
     * KeY's recorder component has a default tab size of {@link #RECORDER_TAB_SIZE}.
     * But instead of using this fixed tab size the recorder component uses the following
     * simplified code to compute the column index:
     * <pre><code>
     * int column = 0;
     * for (char sign : signs) {
     *    switch (sign) {
     *        case '\t' : column += (tabSize - (column % tabSize));
     *                    break;
     *        default : column ++;
     *     }
     * }
     * </code></pre>
     * The class of recorder which does the mentioned computation is {@link JavaCharStream}.
     * </p>
     * @param column The column computed by KeY's recorder component.
     * @param tabSize The tab size to use.
     * @param tabIndices The indices of tab ({@code '\t'}) characters in the current line. They can be computed for instance via {@link IOUtil#computeLineInformation(File)}. 
     * @return The normalized column index in that each tab ({@code '\t'}) character has a fixed tab size of one which means that a tab is treated as a normal character.
     */
    public static int normalizeRecorderColumn(int column, int tabSize, int[] tabIndices) {
        if (column >= 0 && tabSize >= 2 && tabIndices != null) {
            int result = 0;
            int i = 0;
            int lastTab = -1;
            int tabOverhead = 0;
            while (i < tabIndices.length) {
                if (lastTab >= 0) {
                    result += tabIndices[i] - lastTab;
                } else {
                    result = tabIndices[i];
                }
                if (result < column) {
                    tabOverhead += (tabSize - (result % tabSize) - 1);
                    result += (tabSize - (result % tabSize) - 1);
                }
                lastTab = tabIndices[i];
                i++;
            }
            return column - tabOverhead;
        } else {
            return column;
        }
    }
}