/*
* This file is part of the Echo Web Application Framework (hereinafter "Echo").
* Copyright (C) 2002-2009 NextApp, Inc.
*
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*/
package echo2example.chatclient;
import java.text.DateFormat;
import nextapp.echo2.app.Column;
import nextapp.echo2.app.ContentPane;
import nextapp.echo2.app.Extent;
import nextapp.echo2.app.Label;
import nextapp.echo2.app.Row;
/**
* A <code>ContentPane</code> which displays the messages which have been posted
* in the chat.
*/
public class MessagePane extends ContentPane {
/**
* <code>DateFormat</code> object to render post times.
*/
private static final DateFormat dateFormat = DateFormat.getTimeInstance(DateFormat.SHORT);
/**
* Maximum number of messages to display simultaneously.
*/
private static final int MAX_MESSAGE_COUNT = 100;
/**
* Extent specifying the 'scroll-to-bottom' position (-1px).
*/
private static final Extent BOTTOM = new Extent(-1, Extent.PX);
private Column listColumn;
private String userName;
/**
* Creates a new <code>MessagePane</code>.
*/
public MessagePane() {
super();
listColumn = new Column();
listColumn.setStyleName("MessagePane.ListColumn");
add(listColumn);
userName = ChatApp.getApp().getUserName();
}
/**
* Updates the state of the <code>MessagePane</code> based on new messages
* by querying the <code>ChatApp</code> for new messages.
*/
public void update() {
ChatApp app = ChatApp.getApp();
ChatSession.Message[] messages = app.getNewMessages();
Label label;
for (int i = 0; i < messages.length; ++i) {
boolean announcement = messages[i].getUserName() == null;
Row row = new Row();
row.setStyleName(announcement ? "MessagePane.MessageRow.Announcement" : "MessagePane.MessageRow");
label = new Label(dateFormat.format(messages[i].getDate()));
label.setStyleName("MessagePane.DateLabel");
row.add(label);
if (announcement) {
label = new Label(messages[i].getContent());
label.setStyleName("MessagePane.SystemMessageLabel");
row.add(label);
} else {
label = new Label(messages[i].getUserName());
label.setStyleName(userName.equals(messages[i].getUserName())
? "MessagePane.UserNameLabel.Yourself" : "MessagePane.UserNameLabel.Other");
row.add(label);
label = new Label(messages[i].getContent());
row.add(label);
}
listColumn.add(row);
}
// Remove leading messages greater than MAX_MESSAGE_COUNT.
int componentCount = listColumn.getComponentCount();
for (int i = MAX_MESSAGE_COUNT; i < componentCount; ++i) {
listColumn.remove(0);
}
setVerticalScroll(BOTTOM);
}
}