--- /dev/null
+/**********************************************************************
+ Copyright (c) 2000, 2002 IBM Corp. 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 implementation
+ **********************************************************************/
+
+package net.sourceforge.phpdt.internal.ui.text;
+
+import java.io.IOException;
+import java.io.Reader;
+
+import net.sourceforge.phpdt.internal.corext.phpdoc.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;
+
+ private 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;
+ }
+}
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