/*
* This file is part of muCommander, http://www.mucommander.com
* Copyright (C) 2002-2016 Maxence Bernard
*
* muCommander is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* muCommander 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.mucommander.shell;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import javax.xml.parsers.SAXParserFactory;
import java.io.InputStream;
/**
* Parses XML shell history files and populates the {@link com.mucommander.shell.ShellHistoryManager}.
* @author Nicolas Rinaudo
*/
class ShellHistoryReader extends DefaultHandler implements ShellHistoryConstants {
// - Reader statuses -----------------------------------------------------
// -----------------------------------------------------------------------
/** Parsing hasn't started. */
private static final int STATUS_UNKNOWN = 0;
/** Currently parsing the root tag. */
private static final int STATUS_ROOT = 1;
/** Currently parsing a command tag. */
private static final int STATUS_COMMAND = 2;
// - Instance fields -----------------------------------------------------
// -----------------------------------------------------------------------
/** Reader's current status. */
private int status;
/** Buffer for the current command. */
private StringBuilder command;
/** muCommander version that was used to write the shell history file */
private String version;
// - Initialisation ------------------------------------------------------
// -----------------------------------------------------------------------
/**
* Creates a new shell history reader.
*/
private ShellHistoryReader() {
command = new StringBuilder();
status = STATUS_UNKNOWN;
}
/**
* Returns the muCommander version that was used to write the shell history file, <code>null</code> if it is unknown.
* <p>
* Note: the version attribute was introduced in muCommander 0.8.4.
* </p>
*
* @return the muCommander version that was used to write the shell history file, <code>null</code> if it is unknown.
*/
public String getVersion() {
return version;
}
// - XML interaction -----------------------------------------------------
// -----------------------------------------------------------------------
/**
* Reads shell history from the specified input stream.
* @param in where to read the history from.
*/
public static void read(InputStream in) throws Exception {SAXParserFactory.newInstance().newSAXParser().parse(in, new ShellHistoryReader());}
/**
* Notifies the reader that CDATA has been encountered.
*/
@Override
public void characters(char[] ch, int start, int length) {
if(status == STATUS_COMMAND)
command.append(ch, start, length);
}
/**
* Notifies the reader that a new XML element is starting.
*/
@Override
public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
// Root element declaration.
if(qName.equals(ROOT_ELEMENT) && (status == STATUS_UNKNOWN)) {
status = STATUS_ROOT;
version = attributes.getValue(ATTRIBUTE_VERSION);
}
// Command element declaration.
else if(qName.equals(COMMAND_ELEMENT) && status == STATUS_ROOT)
status = STATUS_COMMAND;
}
/**
* Notifies the reader that the current element declaration is over.
*/
@Override
public void endElement(String uri, String localName, String qName) throws SAXException {
// Root element finished.
if(qName.equals(ROOT_ELEMENT) && (status == STATUS_ROOT))
status = STATUS_UNKNOWN;
// Command element finished.
else if(qName.equals(COMMAND_ELEMENT) && (status == STATUS_COMMAND)) {
status = STATUS_ROOT;
// Adds the current command to shell history.
ShellHistoryManager.add(command.toString().trim());
command.setLength(0);
}
}
}