Scrollback class for scrollback history

src/org/yaaic/model/Scrollback.java

@@ -0,0 +1,96 @@
+/*
+Yaaic - Yet Another Android IRC Client
+
+Copyright 2009-2010 Sebastian Kaspari
+
+This file is part of Yaaic.
+
+Yaaic is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Yaaic is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with Yaaic.  If not, see <http://www.gnu.org/licenses/>.
+*/
+package org.yaaic.model;
+
+import java.util.LinkedList;
+
+/**
+ * Class for handling the scrollback history
+ * 
+ * @author Sebastian Kaspari <sebastian@yaaic.org>
+ */
+public class Scrollback
+{
+	public static final int MAX_HISTORY = 10;
+	
+	private LinkedList<String> messages;
+	private int pointer;
+	
+	/**
+	 * Create a new scrollback object
+	 */
+	public Scrollback()
+	{
+		messages = new LinkedList<String>();
+	}
+	
+	/**
+	 * Add a message to the history
+	 */
+	public void addMessage(String message)
+	{
+		messages.addLast(message);
+		
+		if (messages.size() > MAX_HISTORY) {
+			messages.removeFirst();
+		}
+		
+		pointer = messages.size();
+	}
+	
+	/**
+	 * Go back in history
+	 * 
+	 * @return
+	 */
+	public String goBack()
+	{
+		if (pointer > 0) {
+			pointer--;
+		}
+		
+		if (messages.size() >= 0) {
+			return messages.get(pointer);
+		}
+	
+		return null;
+	}
+	
+	/**
+	 * Go forward in history
+	 * 
+	 * @return
+	 */
+	public String goForward()
+	{
+		if (pointer < messages.size() - 1) {
+			pointer++;
+		} else {
+			return "";
+		}
+		
+		if (messages.size() > 0) {
+			return messages.get(pointer);
+		}
+		
+		return null;
+	}
+}