javax.swing.text.html
Class CSSParser

java.lang.Object
  javax.swing.text.html.CSSParser

class CSSParser

extends Object

A CSS parser. This works by way of a delegate that implements the CSSParserCallback interface. The delegate is notified of the following events:

• Import statement: handleImport
• Selectors handleSelector. This is invoked for each string. For example if the Reader contained p, bar , a {}, the delegate would be notified 4 times, for 'p,' 'bar' ',' and 'a'.
• When a rule starts, startRule
• Properties in the rule via the handleProperty. This is invoked one per property/value key, eg font size: foo;, would cause the delegate to be notified once with a value of 'font size'.
• Values in the rule via the handleValue, this is notified for the total value.
• When a rule ends, endRule

This will parse much more than CSS 1, and loosely implements the recommendation for Forward-compatible parsing in section 7.1 of the CSS spec found at: http://www.w3.org/TR/REC-CSS1. If an error results in parsing, a RuntimeException will be thrown.

This will preserve case. If the callback wishes to treat certain poritions case insensitively (such as selectors), it should use toLowerCase, or something similar.

Author:

Scott Violet

Nested Class Summary

(package private) static interface

CSSParser.CSSParserCallback

Field Summary

private static int	BRACE_CLOSE
private static int	BRACE_OPEN
private static int	BRACKET_CLOSE
private static int	BRACKET_OPEN
private CSSParser.CSSParserCallback	callback Notified of state.
private static char[]	charMapping
private boolean	didPushChar Set to true if one character has been read ahead.
private boolean	encounteredRuleSet Set to true when the first non @ rule is encountered.
private static int	END
private static int	IDENTIFIER
private static int	PAREN_CLOSE
private static int	PAREN_OPEN
private int	pushedChar The read ahead character.
private Reader	reader Holds the incoming CSS rules.
private boolean	readWS Set to true if any whitespace is read.
private int	stackCount Number of valid blocks.
private char[]	tokenBuffer nextToken() inserts the string here.
private int	tokenBufferLength Current number of chars in tokenBufferLength.
private StringBuffer	unitBuffer Temporary place to hold identifiers.
private int[]	unitStack Used to indicate blocks.

Constructor Summary

(package private)

CSSParser()

Method Summary

private void	append(char character)
private void	endBlock(int endToken) Called when an end block is encountered )]}
private boolean	getIdentifier(char stopChar) Gets an identifier, returning true if the length of the string is greater than 0, stopping when stopChar, whitespace, or one of {}()[] is hit.
private boolean	getNextStatement() Gets the next statement, returning false if the end is reached.
private boolean	inBlock()
private int	nextToken(char idChar) Fetches the next token.
(package private) void	parse(Reader reader, CSSParser.CSSParserCallback callback, boolean inRule)
private void	parseAtRule() Parses an @ rule, stopping at a matching brace pair, or ;.
private int	parseDeclaration() Parses a single declaration, which is an identifier a : and another identifier.
private void	parseDeclarationBlock() Parses a declaration block.
private int	parseIdentifiers(char extraChar, boolean wantsBlocks) Parses identifiers until extraChar is encountered, returning the ending token, which will be IDENTIFIER if extraChar is found.
private void	parseRuleSet() Parses the next rule set, which is a selector followed by a declaration block.
private boolean	parseSelectors() Parses a set of selectors, returning false if the end of the stream is reached.
private void	parseTillClosed(int openToken) Parses till a matching block close is encountered.
private void	pushChar(int tempChar) Supports one character look ahead, this will throw if called twice in a row.
private int	readChar() Reads a character from the stream.
private void	readComment() Parses a comment block.
private void	readTill(char stopChar) Reads till a stopChar is encountered, escaping characters as necessary.
private int	readWS() Skips any white space, returning the character after the white space.
private void	startBlock(int startToken) Called when a block start is encountered ({[.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

IDENTIFIER

private static final int IDENTIFIER

See Also:

Constant Field Values

BRACKET_OPEN

private static final int BRACKET_OPEN

See Also:

Constant Field Values

BRACKET_CLOSE

private static final int BRACKET_CLOSE

See Also:

Constant Field Values

BRACE_OPEN

private static final int BRACE_OPEN

See Also:

Constant Field Values

BRACE_CLOSE

private static final int BRACE_CLOSE

See Also:

Constant Field Values

PAREN_OPEN

private static final int PAREN_OPEN

See Also:

Constant Field Values

PAREN_CLOSE

private static final int PAREN_CLOSE

See Also:

Constant Field Values

END

private static final int END

See Also:

Constant Field Values

charMapping

private static final char[] charMapping

didPushChar

private boolean didPushChar

Set to true if one character has been read ahead.

pushedChar

private int pushedChar

The read ahead character.

unitBuffer

private StringBuffer unitBuffer

Temporary place to hold identifiers.

unitStack

private int[] unitStack

Used to indicate blocks.

stackCount

private int stackCount

Number of valid blocks.

reader

private Reader reader

Holds the incoming CSS rules.

encounteredRuleSet

private boolean encounteredRuleSet

Set to true when the first non @ rule is encountered.

callback

private CSSParser.CSSParserCallback callback

Notified of state.

tokenBuffer

private char[] tokenBuffer

nextToken() inserts the string here.

tokenBufferLength

private int tokenBufferLength

Current number of chars in tokenBufferLength.

readWS

private boolean readWS

Set to true if any whitespace is read.

Constructor Detail

CSSParser

CSSParser()

Method Detail

parse

void parse(Reader reader,
           CSSParser.CSSParserCallback callback,
           boolean inRule)
     throws IOException

Throws:

IOException

getNextStatement

private boolean getNextStatement()
                          throws IOException

Gets the next statement, returning false if the end is reached. A statement is either an @rule, or a ruleset.

Throws:

IOException

parseAtRule

private void parseAtRule()
                  throws IOException

Parses an @ rule, stopping at a matching brace pair, or ;.

Throws:

IOException

parseRuleSet

private void parseRuleSet()
                   throws IOException

Parses the next rule set, which is a selector followed by a declaration block.

Throws:

IOException

parseSelectors

private boolean parseSelectors()
                        throws IOException

Parses a set of selectors, returning false if the end of the stream is reached.

Throws:

IOException

parseDeclarationBlock

private void parseDeclarationBlock()
                            throws IOException

Parses a declaration block. Which a number of declarations followed by a })].

Throws:

IOException

parseDeclaration

private int parseDeclaration()
                      throws IOException

Parses a single declaration, which is an identifier a : and another identifier. This returns the last token seen.

Throws:

IOException

parseIdentifiers

private int parseIdentifiers(char extraChar,
                             boolean wantsBlocks)
                      throws IOException

Parses identifiers until extraChar is encountered, returning the ending token, which will be IDENTIFIER if extraChar is found.

Throws:

IOException

parseTillClosed

private void parseTillClosed(int openToken)
                      throws IOException

Parses till a matching block close is encountered. This is only appropriate to be called at the top level (no nesting).

Throws:

IOException

nextToken

private int nextToken(char idChar)
               throws IOException

Fetches the next token.

Throws:

IOException

getIdentifier

private boolean getIdentifier(char stopChar)
                       throws IOException

Gets an identifier, returning true if the length of the string is greater than 0, stopping when stopChar, whitespace, or one of {}()[] is hit.

Throws:

IOException

readTill

private void readTill(char stopChar)
               throws IOException

Reads till a stopChar is encountered, escaping characters as necessary.

Throws:

IOException

append

private void append(char character)

readComment

private void readComment()
                  throws IOException

Parses a comment block.

Throws:

IOException

startBlock

private void startBlock(int startToken)

Called when a block start is encountered ({[.

endBlock

private void endBlock(int endToken)

Called when an end block is encountered )]}

inBlock

private boolean inBlock()

Returns:

true if currently in a block.

readWS

private int readWS()
            throws IOException

Skips any white space, returning the character after the white space.

Throws:

IOException

readChar

private int readChar()
              throws IOException

Reads a character from the stream.

Throws:

IOException

pushChar

private void pushChar(int tempChar)

Supports one character look ahead, this will throw if called twice in a row.