1 files changed, 155 insertions, 0 deletions
diff --git a/archive/org.eclipse.qvt.declarative.editor.imp.runtime/src/org/eclipse/imp/ui/textPresentation/SubstitutionTextReader.java b/archive/org.eclipse.qvt.declarative.editor.imp.runtime/src/org/eclipse/imp/ui/textPresentation/SubstitutionTextReader.java
new file mode 100644
index 000000000..d66a5d7cb
--- /dev/null
+++ b/archive/org.eclipse.qvt.declarative.editor.imp.runtime/src/org/eclipse/imp/ui/textPresentation/SubstitutionTextReader.java
@@ -0,0 +1,155 @@
+/*******************************************************************************
+* Copyright (c) 2007 IBM Corporation.
+* 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:
+*    Robert Fuhrer (rfuhrer@watson.ibm.com) - initial API and implementation
+
+*******************************************************************************/
+
+
+package org.eclipse.imp.ui.textPresentation;
+
+
+import java.io.IOException;
+import java.io.Reader;
+
+//import org.eclipse.jdt.internal.corext.javadoc.SingleCharReader;
+
+
+/**
+ * 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.
+ */
+public abstract class SubstitutionTextReader extends SingleCharReader {
+
+	protected static final String LINE_DELIM= System.getProperty("line.separator", "\n"); //$NON-NLS-1$ //$NON-NLS-2$
+
+	private Reader fReader;
+	protected boolean fWasWhiteSpace;
+	private int fCharAfterWhiteSpace;
+
+	/**
+	 * Tells whether white space characters are skipped.
+	 */
+	private boolean fSkipWhiteSpace= true;
+
+	private boolean fReadFromBuffer;
+	private StringBuffer fBuffer;
+	private int fIndex;
+
+
+	protected SubstitutionTextReader(Reader reader) {
+		fReader= reader;
+		fBuffer= new StringBuffer();
+		fIndex= 0;
+		fReadFromBuffer= false;
+		fCharAfterWhiteSpace= -1;
+		fWasWhiteSpace= true;
+	}
+
+	/**
+	 * Implement to compute the substitution for the given character and
+	 * if necessary subsequent characters. Use <code>nextChar</code>
+	 * to read subsequent characters.
+	 */
+	protected abstract String computeSubstitution(int c) throws IOException;
+
+	/**
+	 * Returns the internal reader.
+	 */
+	protected Reader getReader() {
+		return fReader;
+	}
+
+	/**
+	 * Returns the next character.
+	 */
+	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;
+		} else {
+			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()
+	 */
+	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()
+	 */
+    public boolean ready() throws IOException {
+		return fReader.ready();
+	}
+
+	/**
+	 * @see Reader#close()
+	 */
+	public void close() throws IOException {
+		fReader.close();
+	}
+
+	/**
+	 * @see Reader#reset()
+	 */
+	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;
+	}
+}