echopointng.stylesheet.CssObjectDeclarationParser Maven / Gradle / Ivy
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Echo2 bundled with Echo2_Extras, Echo2_FileTransfer and echopointing and various improvements/bugfixes
package echopointng.stylesheet;
/*
* This file is part of the Echo Point Project. This project is a collection
* of Components that have extended the Echo Web Application Framework.
*
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*/
import java.io.StreamTokenizer;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;
/**
* CssObjectDeclarationParser takes CSS object declarations
* and parse them into their value parts. A CSS object declaration
* is defined as
*
* cssobjectdecl ::= <identifier> '(' <cssobjectvaleq> ')'
*
* cssobjectvaleq ::= <cssobjectval> { "," cssobjectval }
*
* cssobjectval ::= <cssobjectdecl> ||
* <anystring>
*
*
* An CSS object declaration can contain child declarations as in
*
* fillimage(image('imageurl',12px,12px),repeat);
*
* This parser only returns the top level values of the outer
* CSS object declarations. You will need to "reparse" child
* declarations as required. So in the above example the parser
* will return the strings :
*
* "fillimage" "image('imageurl',12px,12px)" "repeat"
*
* The object type name will always be in the first array element. In
* the above example "fillimage" is the object type name.
*
*/
public class CssObjectDeclarationParser {
/**
* This will parse an CSS object declaration into its top level
* string components. Any child CSS object declarations will be left
* in place as a string value, ready for further parsing.
*
* If it cannot be parsed, then an empty String[] will be returned. A
* valid CSS object declaration will always have at least one token
* which is the object type name.
*
* @param objDecl - the CSS object declaration string to be parsed.
* @return an array of the values that make up the CSS object declaration
* or an empty String[] if its cant be parsed.
*/
public static String[] parse(String objDecl) {
return tokenize(objDecl);
}
/**
* Returns true if the objDecl string is in fact in the correct
* for an CSS object declaration.
*
* @param objDecl - the string to test
* @return true if its a CSS object declaration
*/
public static boolean isCssObjectDeclaration(String objDecl) {
return tokenize(objDecl).length > 0;
}
private static boolean isIdentifier(String s) {
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (i == 0) {
if (! Character.isJavaIdentifierStart(c))
return false;
} else {
if (! Character.isJavaIdentifierPart(c))
return false;
}
}
return true;
}
private static String[] tokenize(String str) {
return doTokenize(str,"(),",0,32,33,0xFF,true, false);
}
private static final String STATE_START = "STATE_START";
private static final String STATE_END = "STATE_END";
private static final String STATE_OBJNAME = "STATE_OBJNAME";
private static final String STATE_OB = "STATE_OB";
private static final String STATE_VAL = "STATE_VAL";
private static final String STATE_INNEROBJ = "STATE_INNEROBJ";
private static String[] doTokenize(String str, String delims, int loWhiteSpace, int hiWhiteSpace, int loWordChar, int hiWordChar, boolean useQuotes, boolean noCommonWhiteSpace) {
try {
List tokenList = new ArrayList();
StringReader sr = new StringReader(str);
StreamTokenizer st = new StreamTokenizer(sr);
st.resetSyntax();
st.whitespaceChars(loWhiteSpace, hiWhiteSpace);
st.wordChars(loWordChar, hiWordChar);
for (int i = 0; i < delims.length(); i++) {
st.ordinaryChar(delims.charAt(i));
}
if (useQuotes) {
st.quoteChar('\'');
st.quoteChar('"');
}
if (noCommonWhiteSpace) {
st.wordChars(' ',' ');
st.wordChars('\t','\t');
st.wordChars('\n','\n');
st.wordChars('\r','\r');
}
int tt = st.nextToken();
int braceCount = 0;
String state = STATE_START;
String prevState = STATE_START;
String currentVal = "";
String token = "";
while (tt != java.io.StreamTokenizer.TT_EOF) {
token = null;
boolean isWordToken = true;
switch (tt) {
case java.io.StreamTokenizer.TT_WORD :
// A word was found; the value is in sval
token = st.sval;
break;
case '"' :
// A double-quoted string was found; sval contains the contents
if (state == STATE_INNEROBJ) {
// we dont want quoting when in an inner object
token = "\"" + st.sval + "\"" ;
} else {
token = st.sval;
}
break;
case '\'' :
// A single-quoted string was found; sval contains the contents
if (state == STATE_INNEROBJ) {
// we dont want quoting when in an inner object
token = "'" + st.sval + "'" ;
} else {
token = st.sval;
}
break;
case java.io.StreamTokenizer.TT_EOF :
// End of file has been reached
break;
default :
// A regular character was found; the value is the token itself
token = new String(new char[] {(char)tt});
isWordToken = false;
break;
}
// ======
// WHAT STATE ARE WE IN
// ======
// STATE_OBJNAME
if (state == STATE_START) {
if (! isWordToken )
throw new RuntimeException("Expecting obj decl name");
if (! isIdentifier(token))
throw new RuntimeException("obj name must be a java identifier");
tokenList.add(token);
currentVal = "";
prevState = state;
state = STATE_OBJNAME;
// STATE_OBJNAME
} else if (state == STATE_OBJNAME) {
if (! token.equals("("))
throw new RuntimeException("Expecting ( after obj decl name");
prevState = state;
state = STATE_OB;
// STATE_OB
} else if (state == STATE_OB) {
if (token.equals(")")) {
if (prevState != STATE_OBJNAME)
tokenList.add(currentVal);
prevState = state;
state = STATE_END;
continue;
} else if (token.equals(",")) {
// empty value
tokenList.add("");
currentVal = "";
prevState = state;
state = STATE_OB;
} else {
if (! isWordToken)
throw new RuntimeException("Expecting a obj value here");
currentVal = token;
prevState = state;
state = STATE_VAL;
}
// STATE_VAL
} else if (state == STATE_VAL) {
if (token.equals("(")) {
// start of an inner object
currentVal += token;
braceCount++;
prevState = state;
state = STATE_INNEROBJ;
} else if (token.equals(",")) {
tokenList.add(currentVal);
currentVal = "";
prevState = state;
state = STATE_OB;
} else if (token.equals(")")) {
// the logical end of stream
tokenList.add(currentVal);
prevState = state;
state = STATE_END;
} else {
throw new RuntimeException("Unexpected input" + token);
}
// STATE_INNEROBJ
} else if (state == STATE_INNEROBJ) {
// spin around till we hit ')'
if (token.equals(")")) {
braceCount--;
currentVal += token;
if (braceCount == 0) {
// end of an inner object
prevState = state;
state = STATE_VAL;
}
} else {
// ooh another embedded bracket obj
if (token.equals("(")) {
braceCount++;
}
currentVal += token;
}
// STATE_END
} else if (state == STATE_END) {
break;
}
tt = st.nextToken();
}
if (state != STATE_END)
return new String[0];
else
return (String[]) tokenList.toArray(new String[tokenList.size()]);
} catch (Exception e) {
return new String[0];
}
}
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