org.codehaus.groovy.antlr.SourceBuffer Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.ArrayList;
import java.util.List;
/**
* A simple buffer that provides line/col access to chunks of source code
* held within itself.
*
* @author Jeremy Rayner
*/
public class SourceBuffer {
private final List lines;
private StringBuilder current;
public SourceBuffer() {
lines = new ArrayList();
//lines.add(new StringBuilder()); // dummy row for position [0] in the List
current = new StringBuilder();
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
StringBuilder snippet = new StringBuilder();
for (int i = startLine - 1; i < endLine;i++) {
String line = ((StringBuilder)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;}
if (endColumn < startColumn) { endColumn = startColumn;}
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 StringBuilder();
lines.add(current);
}
}
}