// Date: 4/25/02
// Author: Paul Robertson, Copyright (c) DOLL, Inc.
// File: XMLStream.java
// Description: XML Basic stream I/O support

// Stream for reading and writing XML

package mit16_410_13;

import java.util.Vector;
import java.io.InputStream;
import java.io.PrintStream;
import java.io.EOFException;
import java.io.IOException;
import java.io.FileInputStream;

public class XMLStream
{
InputStream readfrom;
PrintStream writeto;
int ch; // one character lookahead

public XMLStream (InputStream istrm)
{
readfrom=istrm;
try {
ch=istrm.read();
}
catch (IOException e) {
System.out.println("Can't read from XML input stream.");
System.exit(1);
}
writeto=null;
}

public XMLStream (PrintStream ostrm)
{
writeto=ostrm;
readfrom=null;
}

public XMLStream (InputStream istrm, PrintStream ostrm)
{
readfrom=istrm;
try {
ch=istrm.read();
}
catch (IOException e) {
System.out.println("Can't read from XML input stream.");
System.exit(1);
}
writeto=ostrm;
}

public InputStream getInputStream ()
{
return readfrom;
}

public PrintStream getPrintStream ()
{
return writeto;
}

void readnextcharacter () throws IOException, EOFException
{
ch=readfrom.read();
if (ch==-1) throw new EOFException();
}

XMLAttribute readNextAttribute () throws IOException
{
String attributestr=new String();
String valuestr=new String();
boolean eofreached=false;
while (ch==' ') readnextcharacter(); // skip over whitespace
try {
while ((ch!=' ')&&(ch!='=')) {
attributestr=attributestr+(char)ch;
readnextcharacter();
}
}
catch (EOFException e) { eofreached=true; }
if (!eofreached) {
while (ch==' ') readnextcharacter(); // skip over whitespace
if (ch=='=') readnextcharacter();
while (ch==' ') readnextcharacter(); // skip over whitespace
if (ch=='\"') readnextcharacter();
try {
while (ch!='\"') {
valuestr=valuestr+(char)ch;
readnextcharacter();
}
}
catch (EOFException e) { eofreached=true; }
readnextcharacter();
return new XMLAttribute(attributestr, valuestr);
}
return null;
}

public XMLTag readNextTag () throws IOException
{
String tagname=new String();
XMLTag result;
// Skip over any leading non tag characters
try {
while (ch!='<') readnextcharacter();
int pos=0;
readnextcharacter();
while ((ch!=' ')&&(ch!='>')) {
pos++;
tagname=tagname+(char)ch;
readnextcharacter();
}
result=new XMLTag(tagname);
while (ch==' ') readnextcharacter(); // skip over whitespace
while (ch!='>') {
XMLAttribute anattribute=readNextAttribute();
result.addAttribute(anattribute);
}
if (ch=='>') readnextcharacter();
if (ch=='\r') readnextcharacter();
if (ch=='\n') readnextcharacter();
}
catch (EOFException e) { return null; }
return result;
}

public String readText () throws IOException
{
String flattext=new String();
int pos=0;
try {
while (ch!='<') {
pos++;
flattext=flattext+(char)ch;
readnextcharacter();
}
}
catch (EOFException e) {
}
if (pos==0) return null;
return flattext;
}
}


// Fin