import org.eclipse.jface.text.IDocument;
/**
- * Reads from a document either forwards or backwards. May be configured to
- * skip comments and strings.
+ * Reads from a document either forwards or backwards. May be configured to skip
+ * comments and strings.
*/
public class PHPCodeReader extends SingleCharReader {
-
+
/** The EOF character */
- public static final int EOF= -1;
-
- private boolean fSkipComments= false;
- private boolean fSkipStrings= false;
- private boolean fForward= false;
+ public static final int EOF = -1;
+ private boolean fSkipComments = false;
+ private boolean fSkipStrings = false;
+ private boolean fForward = false;
private IDocument fDocument;
- private int fOffset;
-
- private int fEnd= -1;
- private int fCachedLineNumber= -1;
- private int fCachedLineOffset= -1;
-
+ private int fOffset; // The current text position within the editor's text
+ private int fEnd = -1;
+ private int fCachedLineNumber = -1; // Holds the last line we checked for single line comments
+
public PHPCodeReader() {
}
-
+
/**
- * Returns the offset of the last read character. Should only be called after read has been called.
+ * Returns the offset of the last read character. Should only be called
+ * after read has been called.
*/
public int getOffset() {
- return fForward ? fOffset -1 : fOffset;
+ return fForward ? fOffset - 1 : fOffset;
}
-
- public void configureForwardReader(IDocument document, int offset, int length, boolean skipComments, boolean skipStrings) throws IOException {
- fDocument= document;
- fOffset= offset;
- fSkipComments= skipComments;
- fSkipStrings= skipStrings;
-
- fForward= true;
- fEnd= Math.min(fDocument.getLength(), fOffset + length);
+
+ public void configureForwardReader(IDocument document, int offset,
+ int length, boolean skipComments, boolean skipStrings)
+ throws IOException {
+ fDocument = document;
+ fOffset = offset;
+ fSkipComments = skipComments;
+ fSkipStrings = skipStrings;
+
+ fForward = true;
+ fEnd = Math.min(fDocument.getLength(), fOffset + length);
}
-
- public void configureBackwardReader(IDocument document, int offset, boolean skipComments, boolean skipStrings) throws IOException {
- fDocument= document;
- fOffset= offset;
- fSkipComments= skipComments;
- fSkipStrings= skipStrings;
-
- fForward= false;
+
+ public void configureBackwardReader(IDocument document, int offset,
+ boolean skipComments, boolean skipStrings) throws IOException {
+ fDocument = document;
+ fOffset = offset;
+ fSkipComments = skipComments;
+ fSkipStrings = skipStrings;
+
+ fForward = false;
try {
- fCachedLineNumber= fDocument.getLineOfOffset(fOffset);
+ fCachedLineNumber = fDocument.getLineOfOffset(fOffset);
} catch (BadLocationException x) {
throw new IOException(x.getMessage());
}
}
-
+
/*
* @see Reader#close()
*/
public void close() throws IOException {
- fDocument= null;
+ fDocument = null;
}
-
+
/*
* @see SingleCharReader#read()
*/
throw new IOException(x.getMessage());
}
}
-
- private void gotoCommentEnd() throws BadLocationException {
- while (fOffset < fEnd) {
- char current= fDocument.getChar(fOffset++);
+
+ private int gotoCommentEnd (int nTextPos) throws BadLocationException {
+ while (nTextPos < fEnd) {
+ char current = fDocument.getChar (nTextPos++);
+
if (current == '*') {
- if (fOffset < fEnd && fDocument.getChar(fOffset) == '/') {
- ++ fOffset;
- return;
+ if ((nTextPos < fEnd) &&
+ (fDocument.getChar (nTextPos) == '/')) {
+ ++nTextPos;
+
+ return nTextPos;
}
}
}
+
+ return nTextPos;
}
-
- private void gotoStringEnd(char delimiter) throws BadLocationException {
- while (fOffset < fEnd) {
- char current= fDocument.getChar(fOffset++);
- if (current == '\\') {
- // ignore escaped characters
- ++ fOffset;
- } else if (current == delimiter) {
- return;
+
+ /**
+ *
+ * @param delimiter
+ * @throws BadLocationException
+ */
+ private int gotoStringEnd (int nTextPos, char delimiter) throws BadLocationException {
+ while (nTextPos < fEnd) { // If long as we are not at the end of text
+ char current = fDocument.getChar (nTextPos++);
+
+ if (current == '\\') { // ignore escaped characters
+ ++nTextPos;
+ }
+ else if (current == delimiter) {
+ return nTextPos;
}
}
+
+ return nTextPos; // End position
}
-
- private void gotoLineEnd() throws BadLocationException {
- int line= fDocument.getLineOfOffset(fOffset);
- fOffset= fDocument.getLineOffset(line + 1);
+
+ /**
+ *
+ * @param nTextPos The current text position
+ *
+ * @return The position of the start of next line
+ *
+ * @throws BadLocationException
+ */
+ private int gotoLineEnd (int nTextPos) throws BadLocationException {
+ int line = fDocument.getLineOfOffset (nTextPos); // Get the line number of the current text position
+
+ return fDocument.getLineOffset (line + 1);
}
-
- private int readForwards() throws BadLocationException {
+
+ private int readForwards () throws BadLocationException {
while (fOffset < fEnd) {
- char current= fDocument.getChar(fOffset++);
-
+ char current = fDocument.getChar(fOffset++);
+
switch (current) {
- case '#':
-
- if (fSkipComments && fOffset < fEnd) {
- gotoLineEnd();
- continue;
- }
-
- return current;
-
- case '/':
-
- if (fSkipComments && fOffset < fEnd) {
- char next= fDocument.getChar(fOffset);
- if (next == '*') {
- // a comment starts, advance to the comment end
- ++ fOffset;
- gotoCommentEnd();
- continue;
- } else if (next == '/') {
- // '//'-comment starts, advance to the line end
- gotoLineEnd();
- continue;
- }
- }
-
- return current;
-
- case '"':
- case '\'':
+ case '"':
+ case '\'':
+ if (fSkipStrings) {
+ fOffset = gotoStringEnd (fOffset, current);
+ continue;
+ }
+ return current;
- if (fSkipStrings) {
- gotoStringEnd(current);
- continue;
- }
-
- return current;
+ case '#':
+ if (fSkipComments && fOffset < fEnd) {
+ fOffset = gotoLineEnd (fOffset);
+ continue;
+ }
+ return current;
+
+ case '/':
+ if (fSkipComments && fOffset < fEnd) {
+ char next = fDocument.getChar(fOffset);
+
+ if (next == '*') { // A comment starts, advance to the comment end
+ ++fOffset;
+ fOffset = gotoCommentEnd (fOffset);
+ continue;
+ } else if (next == '/') { // '//'-comment starts, advance to the line end
+ fOffset = gotoLineEnd (fOffset);
+ continue;
+ }
+ }
+ return current;
}
-
+
return current;
}
-
+
return EOF;
}
+
+ /**
+ * Check whether the current line contains a single line comment.
+ * If it contains a single line comment (// or #), than set fOffset (the global character index)
+ * to the character just before the single line comment.
+ *
+ * @throws BadLocationException
+ */
- private void handleSingleLineComment() throws BadLocationException {
- int line= fDocument.getLineOfOffset(fOffset);
- if (line < fCachedLineNumber) {
- fCachedLineNumber= line;
- fCachedLineOffset= fDocument.getLineOffset(line);
- int offset= fOffset;
- while (fCachedLineOffset < offset) {
- char current= fDocument.getChar(offset--);
- if (current == '/' && fCachedLineOffset <= offset && fDocument.getChar(offset) == '/') {
- fOffset= offset;
- return;
+ private void handleSingleLineComment () throws BadLocationException {
+ char current;
+ int line = fDocument.getLineOfOffset (fOffset); // Get the line number which belongs to the current text position fOffset
+
+ if (line < fCachedLineNumber) { // If we didn't parse this line already
+ fCachedLineNumber = line; // Remember this line for the next time (so we don't search again!)
+ int nOffset = fDocument.getLineOffset (line); // Get the start position of current line
+
+ while (nOffset < fOffset) { // As long as the text position is within the current line
+ current = fDocument.getChar (nOffset); // Get the character from the current text position
+
+ switch (current) {
+ case '/':
+ if (fDocument.getChar (nOffset + 1) == '/') { // If the following character is '/'
+ fOffset = nOffset - 1;
+
+ return;
+ }
+ break;
+
+ case '#':
+ fOffset = nOffset - 1;
+ return;
+
+ case '"': // It's a string start quote
+ case '\'':
+ nOffset++; // Set to next character
+
+ while (nOffset < fOffset) { // As long as we are within the same line
+ char cChar = fDocument.getChar (nOffset++);
+
+ if (cChar == '\\') { // Ignore escaped characters
+ ++nOffset;
+ }
+ else if (cChar == current) { // If end of string found
+ break;
+ }
+ }
+ break;
}
- if (current == '#' && fCachedLineOffset <= offset) {
- fOffset= offset;
- return;
- }
+
+ nOffset++; // Go for the next character
}
}
}
+
+ /**
+ * We search the for the block comment start sequence "/*"
+ *
+ * The returned value points to the '/'
+ *
+ * @throws BadLocationException
+ *
+ * @return The new text position
+ */
- private void gotoCommentStart() throws BadLocationException {
- while (0 < fOffset) {
- char current= fDocument.getChar(fOffset--);
- if (current == '*' && 0 <= fOffset && fDocument.getChar(fOffset) == '/')
- return;
+ private int gotoCommentStart (int nTextPos) throws BadLocationException {
+ while (0 < nTextPos) { // As long as we are not at the start of the editor text
+ char current = fDocument.getChar (nTextPos--); // Get the character from the current text position
+
+ if ((current == '*') && // If current character is a '*'
+ (0 <= nTextPos) && // and if we are not yet at the start of the editor text
+ (fDocument.getChar (nTextPos) == '/')) { // and the previous character is a '/',
+ return nTextPos; // We found the block comment start "/*"
+ }
}
+
+ return nTextPos;
}
-
- private void gotoStringStart(char delimiter) throws BadLocationException {
- while (0 < fOffset) {
- char current= fDocument.getChar(fOffset);
- if (current == delimiter) {
- if ( !(0 <= fOffset && fDocument.getChar(fOffset -1) == '\\'))
- return;
+
+ /**
+ * The string closing quote has been found, when reading the editor text backwards.
+ * So we have to search for the start of the string
+ *
+ * The returned value points to '"' or '''
+ *
+ * @param delimiter The string double quote '"' or single ''' quote we search for
+ *
+ * @throws BadLocationException
+ */
+ private int gotoStringStart (int nTextPos, char delimiter) throws BadLocationException {
+ while (0 < nTextPos) { // As long as we are not at the start of the editor text
+ char current = fDocument.getChar (nTextPos); // Get the character from the current text position
+
+ if (current == delimiter) { // If we found the same character ('"' or ''') again, we have found the string start
+ if (!(0 <= nTextPos &&
+ fDocument.getChar (nTextPos - 1) == '\\')) // If the character before the string quote is not an '/'
+ return nTextPos; // we found the string start
}
- -- fOffset;
+
+ --nTextPos; // Go one character back
}
- }
+ return nTextPos;
+ }
+
+ /**
+ * Read the editor text backwards
+ *
+ */
+
private int readBackwards() throws BadLocationException {
-
- while (0 < fOffset) {
- -- fOffset;
-
- handleSingleLineComment();
-
- char current= fDocument.getChar(fOffset);
- switch (current) {
- case '/':
-
- if (fSkipComments && fOffset > 1) {
- char next= fDocument.getChar(fOffset - 1);
- if (next == '*') {
- // a comment ends, advance to the comment start
- fOffset -= 2;
- gotoCommentStart();
- continue;
- }
- }
-
- return current;
-
- case '"':
- case '\'':
-
- if (fSkipStrings) {
- -- fOffset;
- gotoStringStart(current);
- continue;
- }
-
- return current;
+ char current; // The character on position fOffset
+
+ while (0 < fOffset) { // As long as we are not at the beginning of the editor text
+ --fOffset; // Step back one character
+
+ handleSingleLineComment (); // Search for a single line comment within the current line
+ // If there is a single line comment, fOffset is set to position just before the single line comment
+
+ current = fDocument.getChar (fOffset); // Read the current character
+ switch (current) { // Process the current character
+ case '/': // Is it a single line comment?
+ if (fSkipComments && // When comments should be skipped when parsing
+ fOffset > 1) { // and if there is indeed an additional character before that '/'
+ char prev = fDocument.getChar (fOffset - 1); // Look at the character in front of the '/'
+
+ if (prev == '*') { // If '*' than a block comment ends here, advance to the comment start
+ fOffset -= 2; // Set character pointer to character before "*/"
+ fOffset = gotoCommentStart (fOffset); // and search for the starting "/*" of the block comment
+ continue;
+ }
+ }
+ return current; // No block comment end, so return the current character
+
+ case '"': // Is it a string double quote closing '"'?
+ case '\'': // or a string single quote closing '''?
+ if (fSkipStrings) { // If we should skip strings when parsing
+ --fOffset; // Set pointer one before the string closing quote
+ fOffset = gotoStringStart (fOffset, current);// and search the start of string ('"' or ''')
+ continue;
+ }
+ return current; // No string skip, so return the current character
}
-
- return current;
+
+ return current; // No string and no comment
}
-
- return EOF;
+
+ return EOF; // When the start of the text has been found
}
}
-