refactory: added UI removed from core plugin.
[phpeclipse.git] / net.sourceforge.phpeclipse.ui / src / net / sourceforge / phpdt / internal / ui / text / PHPCodeReader.java
diff --git a/net.sourceforge.phpeclipse.ui/src/net/sourceforge/phpdt/internal/ui/text/PHPCodeReader.java b/net.sourceforge.phpeclipse.ui/src/net/sourceforge/phpdt/internal/ui/text/PHPCodeReader.java
new file mode 100644 (file)
index 0000000..fffffda
--- /dev/null
@@ -0,0 +1,256 @@
+package net.sourceforge.phpdt.internal.ui.text;
+
+/*
+ * (c) Copyright IBM Corp. 2000, 2001.
+ * All Rights Reserved.
+ */
+
+import java.io.IOException;
+
+import net.sourceforge.phpdt.internal.corext.phpdoc.SingleCharReader;
+
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.IDocument;
+
+/**
+ * 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 '"':
+                       case '\'':
+
+                               if (fSkipStrings) {
+                                       gotoStringEnd(current);
+                                       continue;
+                               }
+
+                               return 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;
+
+                       }
+
+                       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;
+                               }
+
+                               if (current == '#' && fCachedLineOffset <= 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;
+       }
+}