refactory: added UI removed from core plugin.

[phpeclipse.git] / net.sourceforge.phpeclipse.ui / src / net / sourceforge / phpdt / internal / ui / text / BufferedDocumentScanner.java

diff --git a/net.sourceforge.phpeclipse.ui/src/net/sourceforge/phpdt/internal/ui/text/BufferedDocumentScanner.java b/net.sourceforge.phpeclipse.ui/src/net/sourceforge/phpdt/internal/ui/text/BufferedDocumentScanner.java
new file mode 100644 (file)
index 0000000..cd6833f
--- /dev/null
+++ b/net.sourceforge.phpeclipse.ui/src/net/sourceforge/phpdt/internal/ui/text/BufferedDocumentScanner.java
@@ -0,0 +1,173 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2004 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package net.sourceforge.phpdt.internal.ui.text;
+
+import org.eclipse.jface.text.Assert;
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.rules.ICharacterScanner;
+
+/**
+ * A buffered document scanner. The buffer always contains a section of a fixed
+ * size of the document to be scanned.
+ */
+
+public final class BufferedDocumentScanner implements ICharacterScanner {
+
+       /** The document being scanned. */
+       private IDocument fDocument;
+
+       /** The offset of the document range to scan. */
+       private int fRangeOffset;
+
+       /** The length of the document range to scan. */
+       private int fRangeLength;
+
+       /** The delimiters of the document. */
+       private char[][] fDelimiters;
+
+       /** The buffer. */
+       private final char[] fBuffer;
+
+       /** The offset of the buffer within the document. */
+       private int fBufferOffset;
+
+       /** The valid length of the buffer for access. */
+       private int fBufferLength;
+
+       /** The offset of the scanner within the buffer. */
+       private int fOffset;
+
+       /**
+        * Creates a new buffered document scanner. The buffer size is set to the
+        * given number of characters.
+        * 
+        * @param size
+        *            the buffer size
+        */
+       public BufferedDocumentScanner(int size) {
+               Assert.isTrue(size >= 1);
+               fBuffer = new char[size];
+       }
+
+       /**
+        * Fills the buffer with the contens of the document starting at the given
+        * offset.
+        * 
+        * @param offset
+        *            the document offset at which the buffer starts
+        */
+       private final void updateBuffer(int offset) {
+
+               fBufferOffset = offset;
+
+               if (fBufferOffset + fBuffer.length > fRangeOffset + fRangeLength)
+                       fBufferLength = fRangeLength - (fBufferOffset - fRangeOffset);
+               else
+                       fBufferLength = fBuffer.length;
+
+               try {
+                       final String content = fDocument.get(fBufferOffset, fBufferLength);
+                       if (content != null) {
+                               content.getChars(0, fBufferLength, fBuffer, 0);
+                       }
+               } catch (BadLocationException e) {
+               }
+       }
+
+       /**
+        * Configures the scanner by providing access to the document range over
+        * which to scan.
+        * 
+        * @param document
+        *            the document to scan
+        * @param offset
+        *            the offset of the document range to scan
+        * @param length
+        *            the length of the document range to scan
+        */
+       public final void setRange(IDocument document, int offset, int length) {
+
+               fDocument = document;
+               fRangeOffset = offset;
+               fRangeLength = length;
+
+               String[] delimiters = document.getLegalLineDelimiters();
+               fDelimiters = new char[delimiters.length][];
+               for (int i = 0; i < delimiters.length; i++)
+                       fDelimiters[i] = delimiters[i].toCharArray();
+
+               updateBuffer(offset);
+               fOffset = 0;
+       }
+
+       /*
+        * @see ICharacterScanner#read()
+        */
+       public final int read() {
+
+               if (fOffset == fBufferLength) {
+                       if (fBufferOffset + fBufferLength == fDocument.getLength())
+                               return EOF;
+                       else {
+                               updateBuffer(fBufferOffset + fBufferLength);
+                               fOffset = 0;
+                       }
+               }
+               try {
+                       return fBuffer[fOffset++];
+               } catch (ArrayIndexOutOfBoundsException e) {
+                       System.out.println("Offset:" + fOffset);
+                       System.out.println("Buffer:" + fBuffer.toString());
+                       throw e;
+               }
+       }
+
+       /*
+        * @see ICharacterScanner#unread
+        */
+       public final void unread() {
+
+               if (fOffset == 0) {
+                       if (fBufferOffset == fRangeOffset) {
+                               // error: BOF
+                       } else {
+                               updateBuffer(fBufferOffset - fBuffer.length);
+                               fOffset = fBuffer.length - 1;
+                       }
+               } else {
+                       --fOffset;
+               }
+       }
+
+       /*
+        * @see ICharacterScanner#getColumn()
+        */
+       public final int getColumn() {
+
+               try {
+                       final int offset = fBufferOffset + fOffset;
+                       final int line = fDocument.getLineOfOffset(offset);
+                       final int start = fDocument.getLineOffset(line);
+                       return offset - start;
+               } catch (BadLocationException e) {
+               }
+
+               return -1;
+       }
+
+       /*
+        * @see ICharacterScanner#getLegalLineDelimiters()
+        */
+       public final char[][] getLegalLineDelimiters() {
+               return fDelimiters;
+       }
+}