1 files changed, 173 insertions, 0 deletions
diff --git a/org.eclipse.mylyn.commons.core/src/org/eclipse/mylyn/internal/commons/core/SubstitutionTextReader.java b/org.eclipse.mylyn.commons.core/src/org/eclipse/mylyn/internal/commons/core/SubstitutionTextReader.java
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+++ b/org.eclipse.mylyn.commons.core/src/org/eclipse/mylyn/internal/commons/core/SubstitutionTextReader.java
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+/*******************************************************************************
+ * Copyright (c) 2000, 2007 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.mylyn.internal.commons.core;
+
+import java.io.IOException;
+import java.io.Reader;
+
+/**
+ * Reads the text contents from a reader and computes for each character a potential substitution. The substitution may
+ * eat more characters than only the one passed into the computation routine.
+ * <p>
+ * Moved into this package from <code>org.eclipse.jface.internal.text.revisions</code>.
+ * </p>
+ * <p>
+ * Based on {@link org.eclipse.mylyn.internal.commons.core.jface.internal.text.html.SubstitutionTextReader}.
+ * </p>
+ */
+public abstract class SubstitutionTextReader extends SingleCharReader {
+
+	protected static final String LINE_DELIM = System.getProperty("line.separator", "\n"); //$NON-NLS-1$ //$NON-NLS-2$
+
+	private final Reader fReader;
+
+	protected boolean fWasWhiteSpace;
+
+	private int fCharAfterWhiteSpace;
+
+	/**
+	 * Tells whether white space characters are skipped.
+	 */
+	private boolean fSkipWhiteSpace = true;
+
+	private boolean fReadFromBuffer;
+
+	private final StringBuffer fBuffer;
+
+	private int fIndex;
+
+	protected SubstitutionTextReader(Reader reader) {
+		fReader = reader;
+		fBuffer = new StringBuffer();
+		fIndex = 0;
+		fReadFromBuffer = false;
+		fCharAfterWhiteSpace = -1;
+		fWasWhiteSpace = true;
+	}
+
+	/**
+	 * Computes the substitution for the given character and if necessary subsequent characters. Implementation should
+	 * use <code>nextChar</code> to read subsequent characters.
+	 * 
+	 * @param c
+	 *            the character to be substituted
+	 * @return the substitution for <code>c</code>
+	 * @throws IOException
+	 *             in case computing the substitution fails
+	 */
+	protected abstract String computeSubstitution(int c) throws IOException;
+
+	/**
+	 * Returns the internal reader.
+	 * 
+	 * @return the internal reader
+	 */
+	protected Reader getReader() {
+		return fReader;
+	}
+
+	/**
+	 * Returns the next character.
+	 * 
+	 * @return the next character
+	 * @throws IOException
+	 *             in case reading the character fails
+	 */
+	protected int nextChar() throws IOException {
+		fReadFromBuffer = (fBuffer.length() > 0);
+		if (fReadFromBuffer) {
+			char ch = fBuffer.charAt(fIndex++);
+			if (fIndex >= fBuffer.length()) {
+				fBuffer.setLength(0);
+				fIndex = 0;
+			}
+			return ch;
+		}
+
+		int ch = fCharAfterWhiteSpace;
+		if (ch == -1) {
+			ch = fReader.read();
+		}
+		if (fSkipWhiteSpace && Character.isWhitespace((char) ch)) {
+			do {
+				ch = fReader.read();
+			} while (Character.isWhitespace((char) ch));
+			if (ch != -1) {
+				fCharAfterWhiteSpace = ch;
+				return ' ';
+			}
+		} else {
+			fCharAfterWhiteSpace = -1;
+		}
+		return ch;
+	}
+
+	/**
+	 * @see Reader#read()
+	 */
+	@Override
+	public int read() throws IOException {
+		int c;
+		do {
+
+			c = nextChar();
+			while (!fReadFromBuffer) {
+				String s = computeSubstitution(c);
+				if (s == null) {
+					break;
+				}
+				if (s.length() > 0) {
+					fBuffer.insert(0, s);
+				}
+				c = nextChar();
+			}
+
+		} while (fSkipWhiteSpace && fWasWhiteSpace && (c == ' '));
+		fWasWhiteSpace = (c == ' ' || c == '\r' || c == '\n');
+		return c;
+	}
+
+	/**
+	 * @see Reader#ready()
+	 */
+	@Override
+	public boolean ready() throws IOException {
+		return fReader.ready();
+	}
+
+	/**
+	 * @see Reader#close()
+	 */
+	@Override
+	public void close() throws IOException {
+		fReader.close();
+	}
+
+	/**
+	 * @see Reader#reset()
+	 */
+	@Override
+	public void reset() throws IOException {
+		fReader.reset();
+		fWasWhiteSpace = true;
+		fCharAfterWhiteSpace = -1;
+		fBuffer.setLength(0);
+		fIndex = 0;
+	}
+
+	protected final void setSkipWhitespace(boolean state) {
+		fSkipWhiteSpace = state;
+	}
+
+	protected final boolean isSkippingWhitespace() {
+		return fSkipWhiteSpace;
+	}
+}