| /* |
| * Copyright 2003-2007 the original author or authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.codehaus.groovy.antlr; |
| |
| import java.util.List; |
| import java.util.ArrayList; |
| |
| /** |
| * A simple buffer that provides line/col access to chunks of source code |
| * held within itself. |
| * |
| * @author <a href="mailto:groovy@ross-rayner.com">Jeremy Rayner</a> |
| * @version $Revision$ |
| */ |
| public class SourceBuffer { |
| private final List lines; |
| private StringBuffer current; |
| |
| public SourceBuffer() { |
| lines = new ArrayList(); |
| //lines.add(new StringBuffer()); // dummy row for position [0] in the List |
| |
| current = new StringBuffer(); |
| lines.add(current); |
| } |
| |
| /** |
| * Obtains a snippet of the source code within the bounds specified |
| * @param start (inclusive line/ inclusive column) |
| * @param end (inclusive line / exclusive column) |
| * @return specified snippet of source code as a String, or null if no source available |
| */ |
| public String getSnippet(LineColumn start, LineColumn end) { |
| // preconditions |
| if (start == null || end == null) { return null; } // no text to return |
| if (start.equals(end)) { return null; } // no text to return |
| if (lines.size() == 1 && current.length() == 0) { return null; } // buffer hasn't been filled yet |
| |
| // working variables |
| int startLine = start.getLine(); |
| int startColumn = start.getColumn(); |
| int endLine = end.getLine(); |
| int endColumn = end.getColumn(); |
| |
| // reset any out of bounds requests |
| if (startLine < 1) { startLine = 1;} |
| if (endLine < 1) { endLine = 1;} |
| if (startColumn < 1) { startColumn = 1;} |
| if (endColumn < 1) { endColumn = 1;} |
| if (startLine > lines.size()) { startLine = lines.size(); } |
| if (endLine > lines.size()) { endLine = lines.size(); } |
| |
| // obtain the snippet from the buffer within specified bounds |
| StringBuffer snippet = new StringBuffer(); |
| for (int i = startLine - 1; i < endLine;i++) { |
| String line = ((StringBuffer)lines.get(i)).toString(); |
| if (startLine == endLine) { |
| // reset any out of bounds requests (again) |
| if (startColumn > line.length()) { startColumn = line.length();} |
| if (startColumn < 1) { startColumn = 1;} |
| if (endColumn > line.length()) { endColumn = line.length() + 1;} |
| if (endColumn < 1) { endColumn = 1;} |
| |
| line = line.substring(startColumn - 1, endColumn - 1); |
| } else { |
| if (i == startLine - 1) { |
| if (startColumn - 1 < line.length()) { |
| line = line.substring(startColumn - 1); |
| } |
| } |
| if (i == endLine - 1) { |
| if (endColumn - 1 < line.length()) { |
| line = line.substring(0,endColumn - 1); |
| } |
| } |
| } |
| snippet.append(line); |
| } |
| return snippet.toString(); |
| } |
| |
| /** |
| * Writes the specified character into the buffer |
| * @param c |
| */ |
| public void write(int c) { |
| if (c != -1) { |
| current.append((char)c); |
| } |
| if (c == '\n') { |
| current = new StringBuffer(); |
| lines.add(current); |
| } |
| } |
| } |