////////////////////////////////////////////////////////////////////////////////
   // checkstyle: Checks Java source code for adherence to a set of rules.
   // Copyright (C) 2001-2019 the original author or authors.
   //
   // This library is free software; you can redistribute it and/or
   // modify it under the terms of the GNU Lesser General Public
   // License as published by the Free Software Foundation; either
   // version 2.1 of the License, or (at your option) any later version.
   //
  // This library 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
  // Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public
  // License along with this library; if not, write to the Free Software
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  ////////////////////////////////////////////////////////////////////////////////
  
  package com.puppycrawl.tools.checkstyle.checks.sizes;
  
  import java.util.regex.Pattern;
  
  import com.puppycrawl.tools.checkstyle.StatelessCheck;
  import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
  import com.puppycrawl.tools.checkstyle.api.DetailAST;
  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
  
  /**
   * Checks for long lines.
   *
   * <p>
   * Rationale: Long lines are hard to read in printouts or if developers
   * have limited screen space for the source code, e.g. if the IDE displays
   * additional information like project tree, class hierarchy, etc.
   * </p>
   *
   * <p>
   * Package statements and import statements (lines matching pattern
   * {@code ^(package|import) .*}), and are not verified by this check.
   * </p>
   * <p>
   * The default maximum allowable line length is 80 characters. To change the
   * maximum, set property max.
   * </p>
   * <p>
   * To ignore lines in the check, set property ignorePattern to a regular
   * expression for the lines to ignore.
   * </p>
   * <p>
   * An example of how to configure the check is:
   * </p>
   * <pre>
   * &lt;module name="LineLength"/&gt;
   * </pre>
   * <p> An example of how to configure the check to accept lines up to 120
   * characters long is:
   *</p>
   * <pre>
   * &lt;module name="LineLength"&gt;
   *    &lt;property name="max" value="120"/&gt;
   * &lt;/module&gt;
   * </pre>
   * <p> An example of how to configure the check to ignore lines that begin with
   * &quot; * &quot;, followed by just one word, such as within a Javadoc comment,
   * is:
   * </p>
   * <pre>
   * &lt;module name="LineLength"&gt;
   *    &lt;property name="ignorePattern" value="^ *\* *[^ ]+$"/&gt;
   * &lt;/module&gt;
   * </pre>
   *
   */
  @StatelessCheck
  public class LineLengthCheck extends AbstractCheck {
  
      /**
       * A key is pointing to the warning message text in "messages.properties"
       * file.
       */
      public static final String MSG_KEY = "maxLineLen";
  
      /** Default maximum number of columns in a line. */
      private static final int DEFAULT_MAX_COLUMNS = 80;
  
      /** Patterns matching package, import, and import static statements. */
      private static final Pattern IGNORE_PATTERN = Pattern.compile("^(package|import) .*");
  
      /** The maximum number of columns in a line. */
      private int max = DEFAULT_MAX_COLUMNS;
  
      /** The regexp when long lines are ignored. */
      private Pattern ignorePattern = Pattern.compile("^$");
  
      @Override
      public int[] getDefaultTokens() {
          return getRequiredTokens();
      }
 
     @Override
     public int[] getAcceptableTokens() {
         return getRequiredTokens();
     }
 
     @Override
     public int[] getRequiredTokens() {
         return CommonUtil.EMPTY_INT_ARRAY;
     }
 
     @Override
     public void beginTree(DetailAST rootAST) {
         final String[] lines = getLines();
         for (int i = 0; i < lines.length; i++) {
             final String line = lines[i];
             final int realLength = CommonUtil.lengthExpandedTabs(
                 line, line.length(), getTabWidth());
 
             if (realLength > max && !IGNORE_PATTERN.matcher(line).find()
                 && !ignorePattern.matcher(line).find()) {
                 log(i + 1, MSG_KEY, max, realLength);
             }
         }
     }
 
     /**
      * Sets the maximum length of a line.
      * @param length the maximum length of a line
      */
     public void setMax(int length) {
         max = length;
     }
 
     /**
      * Set the ignore pattern.
      * @param pattern a pattern.
      */
     public final void setIgnorePattern(Pattern pattern) {
         ignorePattern = pattern;
     }
 
 }