package org.jgroups.demos;
import org.jgroups.*;
import org.jgroups.jmx.JmxConfigurator;
import org.jgroups.util.Util;
import javax.management.MBeanServer;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.util.List;
import java.io.*;
/**
* Shared whiteboard, each new instance joins the same group. Each instance chooses a random color,
* mouse moves are broadcast to all group members, which then apply them to their canvas<p>
* @author Bela Ban, Oct 17 2001
*/
public class Draw extends ReceiverAdapter implements ActionListener, ChannelListener {
String groupname="draw-cluster";
private Channel channel=null;
private int member_size=1;
private JFrame mainFrame=null;
private JPanel sub_panel=null;
private DrawPanel panel=null;
private JButton clear_button, leave_button;
private final Random random=new Random(System.currentTimeMillis());
private final Font default_font=new Font("Helvetica",Font.PLAIN,12);
private final Color draw_color=selectColor();
private static final Color background_color=Color.white;
boolean no_channel=false;
boolean jmx;
private boolean use_state=false;
private long state_timeout=5000;
private boolean use_unicasts=false;
private final List<Address> members=new ArrayList<Address>();
public Draw(String props, boolean no_channel, boolean jmx, boolean use_state, long state_timeout,
boolean use_unicasts, String name) throws Exception {
this.no_channel=no_channel;
this.jmx=jmx;
this.use_state=use_state;
this.state_timeout=state_timeout;
this.use_unicasts=use_unicasts;
if(no_channel)
return;
channel=new JChannel(props);
if(name != null)
channel.setName(name);
channel.setReceiver(this);
channel.addChannelListener(this);
}
public Draw(Channel channel) throws Exception {
this.channel=channel;
channel.setReceiver(this);
channel.addChannelListener(this);
}
public Draw(Channel channel, boolean use_state, long state_timeout) throws Exception {
this.channel=channel;
channel.setReceiver(this);
channel.addChannelListener(this);
this.use_state=use_state;
this.state_timeout=state_timeout;
}
public String getGroupName() {
return groupname;
}
public void setGroupName(String groupname) {
if(groupname != null)
this.groupname=groupname;
}
public static void main(String[] args) {
Draw draw=null;
String props=null;
boolean no_channel=false;
boolean jmx=true;
boolean use_state=false;
String group_name=null;
long state_timeout=5000;
boolean use_unicasts=false;
String name=null;
for(int i=0; i < args.length; i++) {
if("-help".equals(args[i])) {
help();
return;
}
if("-props".equals(args[i])) {
props=args[++i];
continue;
}
if("-no_channel".equals(args[i])) {
no_channel=true;
continue;
}
if("-jmx".equals(args[i])) {
jmx=Boolean.parseBoolean(args[++i]);
continue;
}
if("-groupname".equals(args[i])) {
group_name=args[++i];
continue;
}
if("-state".equals(args[i])) {
use_state=true;
continue;
}
if("-timeout".equals(args[i])) {
state_timeout=Long.parseLong(args[++i]);
continue;
}
if("-bind_addr".equals(args[i])) {
System.setProperty("jgroups.bind_addr", args[++i]);
continue;
}
if("-use_unicasts".equals(args[i])) {
use_unicasts=true;
continue;
}
if("-name".equals(args[i])) {
name=args[++i];
continue;
}
help();
return;
}
try {
draw=new Draw(props, no_channel, jmx, use_state, state_timeout, use_unicasts, name);
if(group_name != null)
draw.setGroupName(group_name);
draw.go();
}
catch(Throwable e) {
e.printStackTrace(System.err);
System.exit(0);
}
}
static void help() {
System.out.println("\nDraw [-help] [-no_channel] [-props <protocol stack definition>]" +
" [-groupname <name>] [-state] [-timeout <state timeout>] [-use_unicasts] " +
"[-bind_addr <addr>] [-jmx <true | false>] [-name <logical name>]");
System.out.println("-no_channel: doesn't use JGroups at all, any drawing will be relected on the " +
"whiteboard directly");
System.out.println("-props: argument can be an old-style protocol stack specification, or it can be " +
"a URL. In the latter case, the protocol specification will be read from the URL\n");
}
private Color selectColor() {
int red=Math.abs(random.nextInt()) % 255;
int green=Math.abs(random.nextInt()) % 255;
int blue=Math.abs(random.nextInt()) % 255;
return new Color(red, green, blue);
}
private void sendToAll(byte[] buf) throws Exception {
for(Address mbr: members) {
Message msg=new Message(mbr, null, buf);
channel.send(msg);
}
}
public void go() throws Exception {
if(!no_channel && !use_state) {
channel.connect(groupname);
}
mainFrame=new JFrame();
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
panel=new DrawPanel(use_state);
panel.setBackground(background_color);
sub_panel=new JPanel();
mainFrame.getContentPane().add("Center", panel);
clear_button=new JButton("Clear");
clear_button.setFont(default_font);
clear_button.addActionListener(this);
leave_button=new JButton("Leave");
leave_button.setFont(default_font);
leave_button.addActionListener(this);
sub_panel.add("South", clear_button);
sub_panel.add("South", leave_button);
mainFrame.getContentPane().add("South", sub_panel);
mainFrame.setBackground(background_color);
clear_button.setForeground(Color.blue);
leave_button.setForeground(Color.blue);
mainFrame.pack();
mainFrame.setLocation(15, 25);
mainFrame.setBounds(new Rectangle(250, 250));
if(!no_channel && use_state) {
channel.connect(groupname, null, state_timeout);
}
mainFrame.setVisible(true);
setTitle();
}
void setTitle(String title) {
String tmp="";
if(no_channel) {
mainFrame.setTitle(" Draw Demo ");
return;
}
if(title != null) {
mainFrame.setTitle(title);
}
else {
if(channel.getAddress() != null)
tmp+=channel.getAddress();
tmp+=" (" + member_size + ")";
mainFrame.setTitle(tmp);
}
}
void setTitle() {
setTitle(null);
}
public void receive(Message msg) {
byte[] buf=msg.getRawBuffer();
if(buf == null) {
System.err.println("[" + channel.getAddress() + "] received null buffer from " + msg.getSrc() +
", headers: " + msg.printHeaders());
return;
}
try {
DrawCommand comm=(DrawCommand)Util.streamableFromByteBuffer(DrawCommand.class, buf, msg.getOffset(), msg.getLength());
switch(comm.mode) {
case DrawCommand.DRAW:
if(panel != null)
panel.drawPoint(comm);
break;
case DrawCommand.CLEAR:
clearPanel();
break;
default:
System.err.println("***** received invalid draw command " + comm.mode);
break;
}
}
catch(Exception e) {
e.printStackTrace();
}
}
public void viewAccepted(View v) {
member_size=v.size();
if(mainFrame != null)
setTitle();
members.clear();
members.addAll(v.getMembers());
if(v instanceof MergeView) {
System.out.println("** MergeView=" + v);
// This is an example of a simple merge function, which fetches the state from the coordinator
// on a merge and overwrites all of its own state
if(use_state && !members.isEmpty()) {
Address coord=members.get(0);
Address local_addr=channel.getAddress();
if(local_addr != null && !local_addr.equals(coord)) {
try {
System.out.println("fetching state from " + coord);
channel.getState(coord, 5000);
}
catch(Exception e) {
e.printStackTrace();
}
}
}
}
else
System.out.println("** View=" + v);
}
public void getState(OutputStream ostream) throws Exception {
panel.writeState(ostream);
}
public void setState(InputStream istream) throws Exception {
panel.readState(istream);
}
/* --------------- Callbacks --------------- */
public void clearPanel() {
if(panel != null)
panel.clear();
}
public void sendClearPanelMsg() {
DrawCommand comm=new DrawCommand(DrawCommand.CLEAR);
try {
byte[] buf=Util.streamableToByteBuffer(comm);
if(use_unicasts)
sendToAll(buf);
else
channel.send(new Message(null, null, buf));
}
catch(Exception ex) {
System.err.println(ex);
}
}
public void actionPerformed(ActionEvent e) {
String command=e.getActionCommand();
if("Clear".equals(command)) {
if(no_channel) {
clearPanel();
return;
}
sendClearPanelMsg();
}
else if("Leave".equals(command)) {
stop();
}
else
System.out.println("Unknown action");
}
public void stop() {
if(!no_channel) {
try {
channel.close();
}
catch(Exception ex) {
System.err.println(ex);
}
}
mainFrame.setVisible(false);
mainFrame.dispose();
}
/* ------------------------------ ChannelListener interface -------------------------- */
public void channelConnected(Channel channel) {
if(jmx) {
Util.registerChannel((JChannel)channel, "jgroups");
}
}
public void channelDisconnected(Channel channel) {
if(jmx) {
MBeanServer server=Util.getMBeanServer();
if(server != null) {
try {
JmxConfigurator.unregisterChannel((JChannel)channel,server, groupname);
}
catch(Exception e) {
e.printStackTrace();
}
}
}
}
public void channelClosed(Channel channel) {
}
/* --------------------------- End of ChannelListener interface ---------------------- */
private class DrawPanel extends JPanel implements MouseMotionListener {
final Dimension preferred_size=new Dimension(235, 170);
Image img=null; // for drawing pixels
Dimension d, imgsize=null;
Graphics gr=null;
final Map<Point,Color> state;
public DrawPanel(boolean use_state) {
if(use_state)
state=new LinkedHashMap<Point,Color>();
else
state=null;
createOffscreenImage(false);
addMouseMotionListener(this);
addComponentListener(new ComponentAdapter() {
public void componentResized(ComponentEvent e) {
if(getWidth() <= 0 || getHeight() <= 0) return;
createOffscreenImage(false);
}
});
}
public void writeState(OutputStream outstream) throws IOException {
if(state == null)
return;
synchronized(state) {
DataOutputStream dos=new DataOutputStream(new BufferedOutputStream(outstream, 4096));
// DataOutputStream dos=new DataOutputStream(outstream);
dos.writeInt(state.size());
for(Map.Entry<Point,Color> entry: state.entrySet()) {
Point point=entry.getKey();
Color col=entry.getValue();
dos.writeInt(point.x);
dos.writeInt(point.y);
dos.writeInt(col.getRGB());
}
dos.flush();
}
}
public void readState(InputStream instream) throws IOException {
DataInputStream in=new DataInputStream(instream);
Map<Point,Color> new_state=new HashMap<Point,Color>();
int num=in.readInt();
for(int i=0; i < num; i++) {
Point point=new Point(in.readInt(), in.readInt());
Color col=new Color(in.readInt());
new_state.put(point, col);
}
synchronized(state) {
state.clear();
state.putAll(new_state);
System.out.println("read state: " + state.size() + " entries");
createOffscreenImage(true);
}
}
final void createOffscreenImage(boolean discard_image) {
d=getSize();
if(discard_image) {
img=null;
imgsize=null;
}
if(img == null || imgsize == null || imgsize.width != d.width || imgsize.height != d.height) {
img=createImage(d.width, d.height);
if(img != null) {
gr=img.getGraphics();
if(gr != null && state != null) {
drawState();
}
}
imgsize=d;
}
repaint();
}
/* ---------------------- MouseMotionListener interface------------------------- */
public void mouseMoved(MouseEvent e) {}
public void mouseDragged(MouseEvent e) {
int x=e.getX(), y=e.getY();
DrawCommand comm=new DrawCommand(DrawCommand.DRAW, x, y,
draw_color.getRed(), draw_color.getGreen(), draw_color.getBlue());
if(no_channel) {
drawPoint(comm);
return;
}
try {
byte[] buf=Util.streamableToByteBuffer(comm);
if(use_unicasts)
sendToAll(buf);
else
channel.send(new Message(null, null, buf));
}
catch(Exception ex) {
System.err.println(ex);
}
}
/* ------------------- End of MouseMotionListener interface --------------------- */
/**
* Adds pixel to queue and calls repaint() whenever we have MAX_ITEMS pixels in the queue
* or when MAX_TIME msecs have elapsed (whichever comes first). The advantage compared to just calling
* repaint() after adding a pixel to the queue is that repaint() can most often draw multiple points
* at the same time.
*/
public void drawPoint(DrawCommand c) {
if(c == null || gr == null) return;
Color col=new Color(c.r, c.g, c.b);
gr.setColor(col);
gr.fillOval(c.x, c.y, 10, 10);
repaint();
if(state != null) {
synchronized(state) {
state.put(new Point(c.x, c.y), col);
}
}
}
public void clear() {
if(gr == null) return;
gr.clearRect(0, 0, getSize().width, getSize().height);
repaint();
if(state != null) {
synchronized(state) {
state.clear();
}
}
}
/** Draw the entire panel from the state */
public void drawState() {
// clear();
Map.Entry entry;
Point pt;
Color col;
synchronized(state) {
for(Iterator it=state.entrySet().iterator(); it.hasNext();) {
entry=(Map.Entry)it.next();
pt=(Point)entry.getKey();
col=(Color)entry.getValue();
gr.setColor(col);
gr.fillOval(pt.x, pt.y, 10, 10);
}
}
repaint();
}
public Dimension getPreferredSize() {
return preferred_size;
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
if(img != null) {
g.drawImage(img, 0, 0, null);
}
}
}
}