initial implementation of CommentManager, calling report methods from the grammar will be next

src/checkstyle/com/puppycrawl/tools/checkstyle/CommentManager.java

@@ -0,0 +1,172 @@
+////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code for adherence to a set of rules.
+// Copyright (C) 2001-2002  Oliver Burn
+//
+// 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;
+
+import java.util.Iterator;
+import java.util.SortedMap;
+import java.util.TreeMap;
+
+/**
+ * Checks can query the CommentManager if they want to analyse comments.
+ * <p>
+ * The AST tree does not contain comments as they can occur at arbitrary places.
+ * Adding them to the AST tree would make it very hard to write checks, as you would
+ * always have to beware of comment nodes.
+ * </p>
+ * <p>
+ * Instead, during Java parsing comments are registered with the CommentManager, and
+ * Checks that need to analyse comments can use the CommentManager to access that data.
+ * </p>
+ * <p>
+ * Sample Checks that use the CommentManager are the to-do check and the javadoc check.
+ * </p>
+ * @author Lars Kühne
+ */
+public class CommentManager
+{
+    private String[] mLines;
+
+    /** maps end line numbers of javadoc comments to the comment contents. */
+    private final SortedMap mJavaDoc = new TreeMap();
+
+    /** maps end line numbers of C comments to the comment contents. */
+        private final SortedMap mCComments = new TreeMap();
+
+    /** maps line numbers of CPP comments to the comment contents. */
+    private final SortedMap mCppComments = new TreeMap();
+
+    private static class CommentIterator implements Iterator
+    {
+        public boolean hasNext()
+        {
+            // TODO: implement this for real
+            return false;
+        }
+
+        public Object next()
+        {
+            // TODO: implement this for real
+            return null;
+        }
+
+        public void remove()
+        {
+            throw new UnsupportedOperationException();
+        }
+    }
+
+    /**
+     * creates a new CommentManager instance.
+     * This should be called for every file that is checked.
+     * @param aLines all lines in a file.
+     */
+    CommentManager(String[] aLines)
+    {
+        mLines = aLines;
+    }
+
+    /**
+     * Report the location of a CPP-style comment.
+     * @param aStartLineNo the starting line number
+     * @param aStartColNo the starting column number
+     **/
+    void reportCPPComment(int aStartLineNo, int aStartColNo)
+    {
+        final String cmt = mLines[aStartLineNo - 1].substring(aStartColNo);
+        Integer line = new Integer(aStartLineNo);
+        mCppComments.put(line, cmt);
+    }
+
+    /**
+     * Report the location of a C-style comment.
+     * @param aStartLineNo the starting line number
+     * @param aStartColNo the starting column number
+     * @param aEndLineNo the ending line number
+     * @param aEndColNo the ending column number
+     **/
+    void reportCComment(int aStartLineNo, int aStartColNo,
+                        int aEndLineNo, int aEndColNo)
+    {
+        final String[] cc = extractCComment(aStartLineNo, aStartColNo,
+                                            aEndLineNo, aEndColNo);
+
+        Integer endline = new Integer(aEndLineNo - 1);
+
+        if (mLines[aStartLineNo - 1].indexOf("/**", aStartColNo) != -1) {
+            mJavaDoc.put(endline, cc);
+        }
+        else {
+            mCComments.put(endline, cc);
+        }
+    }
+
+    /**
+     * Returns the specified C comment as a String array.
+     * @return C comment as a array
+     * @param aStartLineNo the starting line number
+     * @param aStartColNo the starting column number
+     * @param aEndLineNo the ending line number
+     * @param aEndColNo the ending column number
+     **/
+    private String[] extractCComment(int aStartLineNo, int aStartColNo,
+                                     int aEndLineNo, int aEndColNo)
+    {
+        String[] retVal;
+        if (aStartLineNo == aEndLineNo) {
+            retVal = new String[1];
+            retVal[0] = mLines[aStartLineNo - 1].substring(aStartColNo,
+                                                           aEndColNo + 1);
+        }
+        else {
+            retVal = new String[aEndLineNo - aStartLineNo + 1];
+            retVal[0] = mLines[aStartLineNo - 1].substring(aStartColNo);
+            for (int i = aStartLineNo; i < aEndLineNo; i++) {
+                retVal[i - aStartLineNo + 1] = mLines[i];
+            }
+            retVal[retVal.length - 1] =
+                mLines[aEndLineNo - 1].substring(0, aEndColNo + 1);
+        }
+        return retVal;
+    }
+
+    // PUBLIC API
+
+    /**
+     * An iterator over all comments.
+     * @return an iterator that contains entries of type String (CPP style comments)
+     *  or String[] (C style comments)
+     */
+    public Iterator iterator()
+    {
+      return new CommentIterator();
+    }
+
+    /**
+     * Returns the Javadoc comment before the specified line. null is none.
+     * @return the Javadoc comment, or <code>null</code> if none
+     * @param aLineNo the line number to check before
+     **/
+    public String[] getJavadocBefore(int aLineNo)
+    {
+        Object key = mJavaDoc.headMap(new Integer(aLineNo)).lastKey();
+        return (String[]) mJavaDoc.get(key);
+    }
+
+}