1 files changed, 120 insertions, 0 deletions
diff --git a/src/org/jivesoftware/smack/util/ObservableWriter.java b/src/org/jivesoftware/smack/util/ObservableWriter.java
new file mode 100644
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+++ b/src/org/jivesoftware/smack/util/ObservableWriter.java
@@ -0,0 +1,120 @@
+/**
+ * $RCSfile$
+ * $Revision$
+ * $Date$
+ *
+ * Copyright 2003-2007 Jive Software.
+ *
+ * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jivesoftware.smack.util;
+
+import java.io.*;
+import java.util.*;
+
+/**
+ * An ObservableWriter is a wrapper on a Writer that notifies to its listeners when
+ * writing to character streams.
+ * 
+ * @author Gaston Dombiak
+ */
+public class ObservableWriter extends Writer {
+
+    Writer wrappedWriter = null;
+    List<WriterListener> listeners = new ArrayList<WriterListener>();
+
+    public ObservableWriter(Writer wrappedWriter) {
+        this.wrappedWriter = wrappedWriter;
+    }
+
+    public void write(char cbuf[], int off, int len) throws IOException {
+        wrappedWriter.write(cbuf, off, len);
+        String str = new String(cbuf, off, len);
+        notifyListeners(str);
+    }
+
+    public void flush() throws IOException {
+        wrappedWriter.flush();
+    }
+
+    public void close() throws IOException {
+        wrappedWriter.close();
+    }
+
+    public void write(int c) throws IOException {
+        wrappedWriter.write(c);
+    }
+
+    public void write(char cbuf[]) throws IOException {
+        wrappedWriter.write(cbuf);
+        String str = new String(cbuf);
+        notifyListeners(str);
+    }
+
+    public void write(String str) throws IOException {
+        wrappedWriter.write(str);
+        notifyListeners(str);
+    }
+
+    public void write(String str, int off, int len) throws IOException {
+        wrappedWriter.write(str, off, len);
+        str = str.substring(off, off + len);
+        notifyListeners(str);
+    }
+
+    /**
+     * Notify that a new string has been written.
+     * 
+     * @param str the written String to notify 
+     */
+    private void notifyListeners(String str) {
+        WriterListener[] writerListeners = null;
+        synchronized (listeners) {
+            writerListeners = new WriterListener[listeners.size()];
+            listeners.toArray(writerListeners);
+        }
+        for (int i = 0; i < writerListeners.length; i++) {
+            writerListeners[i].write(str);
+        }
+    }
+
+    /**
+     * Adds a writer listener to this writer that will be notified when
+     * new strings are sent.
+     *
+     * @param writerListener a writer listener.
+     */
+    public void addWriterListener(WriterListener writerListener) {
+        if (writerListener == null) {
+            return;
+        }
+        synchronized (listeners) {
+            if (!listeners.contains(writerListener)) {
+                listeners.add(writerListener);
+            }
+        }
+    }
+
+    /**
+     * Removes a writer listener from this writer.
+     *
+     * @param writerListener a writer listener.
+     */
+    public void removeWriterListener(WriterListener writerListener) {
+        synchronized (listeners) {
+            listeners.remove(writerListener);
+        }
+    }
+
+}