--- /dev/null
+package net.sourceforge.phpdt.internal.ui.text;
+
+/*
+ * (c) Copyright IBM Corp. 2000, 2001.
+ * All Rights Reserved.
+ */
+
+import java.io.IOException;
+
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.IDocument;
+
+import net.sourceforge.phpdt.internal.corext.phpdoc.SingleCharReader;
+
+/**
+ * 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;
+
+ private IDocument fDocument;
+ private int fOffset;
+
+ private int fEnd= -1;
+ private int fCachedLineNumber= -1;
+ private int fCachedLineOffset= -1;
+
+
+ public PHPCodeReader() {
+ }
+
+ /**
+ * 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;
+ }
+
+ 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;
+ try {
+ fCachedLineNumber= fDocument.getLineOfOffset(fOffset);
+ } catch (BadLocationException x) {
+ throw new IOException(x.getMessage());
+ }
+ }
+
+ /*
+ * @see Reader#close()
+ */
+ public void close() throws IOException {
+ fDocument= null;
+ }
+
+ /*
+ * @see SingleCharReader#read()
+ */
+ public int read() throws IOException {
+ try {
+ return fForward ? readForwards() : readBackwards();
+ } catch (BadLocationException x) {
+ throw new IOException(x.getMessage());
+ }
+ }
+
+ private void gotoCommentEnd() throws BadLocationException {
+ while (fOffset < fEnd) {
+ char current= fDocument.getChar(fOffset++);
+ if (current == '*') {
+ if (fOffset < fEnd && fDocument.getChar(fOffset) == '/') {
+ ++ fOffset;
+ return;
+ }
+ }
+ }
+ }
+
+ 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;
+ }
+ }
+ }
+
+ private void gotoLineEnd() throws BadLocationException {
+ int line= fDocument.getLineOfOffset(fOffset);
+ fOffset= fDocument.getLineOffset(line + 1);
+ }
+
+ private int readForwards() throws BadLocationException {
+ while (fOffset < fEnd) {
+ char current= fDocument.getChar(fOffset++);
+
+ switch (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 '\'':
+
+ if (fSkipStrings) {
+ gotoStringEnd(current);
+ continue;
+ }
+
+ return current;
+ }
+
+ return current;
+ }
+
+ return EOF;
+ }
+
+ 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 gotoCommentStart() throws BadLocationException {
+ while (0 < fOffset) {
+ char current= fDocument.getChar(fOffset--);
+ if (current == '*' && 0 <= fOffset && fDocument.getChar(fOffset) == '/')
+ return;
+ }
+ }
+
+ 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;
+ }
+ -- fOffset;
+ }
+ }
+
+ 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;
+ }
+
+ return current;
+ }
+
+ return EOF;
+ }
+}
+