org.jgroups.demos.StompDraw Maven / Gradle / Ivy
package org.jgroups.demos;
import org.jgroups.client.StompConnection;
import org.jgroups.util.Util;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import java.util.List;
/**
* Simple STOMP demo client. Use -h and -p to connect to *any* JGroups server (has to have STOMP in the config)
*
* @author Bela Ban, Oct 17 2001
*/
public class StompDraw implements StompConnection.Listener, ActionListener {
private int num_servers=1;
private int num_clients=0;
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;
private final List servers=new ArrayList<>();
private final Set clients=new HashSet<>();
protected StompConnection stomp_client;
protected static final String draw_dest="/topics/draw-demo";
protected static final String clients_dest="/topics/clients";
public StompDraw(String host, String port) throws Exception {
stomp_client=new StompConnection(host + ":" + port);
stomp_client.addListener(this);
}
public static void main(String[] args) {
StompDraw draw=null;
String host="localhost", port="8787";
for(int i=0; i < args.length; i++) {
if("-help".equals(args[i])) {
help();
return;
}
if("-h".equals(args[i])) {
host=args[++i];
continue;
}
if("-p".equals(args[i])) {
port=args[++i];
continue;
}
help();
return;
}
try {
draw=new StompDraw(host, port);
draw.go();
}
catch(Throwable e) {
System.err.println("fatal error: " + e.getLocalizedMessage() + ", cause: ");
Throwable t=e.getCause();
if(t != null)
t.printStackTrace(System.err);
System.exit(0);
}
}
static void help() {
System.out.println("\nDraw [-help] [-no_channel] [-h host] [-port port]");
}
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 {
if(buf != null)
stomp_client.send(draw_dest, buf, 0, buf.length);
}
public void go() throws Exception {
stomp_client.connect();
stomp_client.subscribe(draw_dest);
stomp_client.subscribe(clients_dest);
mainFrame=new JFrame();
mainFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
panel=new DrawPanel(false);
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));
mainFrame.setVisible(true);
setTitle();
String session_id=stomp_client.getSessionId();
if(session_id != null)
stomp_client.send(clients_dest, null, 0, 0, "client-joined", session_id);
Runtime.getRuntime().addShutdownHook(new Thread(StompDraw.this::stop));
}
void setTitle() {
if(mainFrame != null)
mainFrame.setTitle(num_servers + " server(s), " + num_clients + " client(s)");
}
int getNumberOfClients() {
synchronized(clients) {
return clients.size();
}
}
String getAllClients() {
StringBuilder sb=new StringBuilder();
boolean first=true;
for(String client: clients) {
if(first)
first=false;
else
sb.append(",");
sb.append(client);
}
return sb.toString();
}
public void onInfo(Map information) {
String view=information.get("view");
Collection list;
if(view != null) {
list=Util.parseCommaDelimitedStrings(view);
if(list != null) {
num_servers=list.size();
if(mainFrame != null)
setTitle();
servers.clear();
servers.addAll(list);
}
else {
String targets=information.get("endpoints");
if(targets != null) {
list=Util.parseCommaDelimitedStrings(targets);
if(list != null) {
num_servers=list.size();
if(mainFrame != null)
setTitle();
servers.clear();
servers.addAll(list);
}
}
}
}
}
public void onMessage(Map headers, byte[] buf, int offset, int length) {
if(buf == null)
return;
String destination=headers.get("destination");
if(Objects.equals(destination, clients_dest)) {
String new_client=headers.get("client-joined");
if(new_client != null) {
synchronized(clients) {
if(clients.add(new_client)) {
num_clients=clients.size();
setTitle();
}
}
stomp_client.send(clients_dest, null, 0, 0, "clients", getAllClients());
}
String left_client=headers.get("client-left");
if(left_client != null) {
synchronized(clients) {
if(clients.remove(left_client)) {
num_clients=clients.size();
setTitle();
}
}
}
String all_clients=headers.get("clients");
if(all_clients != null) {
List list=Util.parseCommaDelimitedStrings(all_clients);
if(list != null) {
synchronized(clients) {
if(clients.addAll(list)) {
num_clients=clients.size();
setTitle();
}
}
}
}
return;
}
try {
DrawCommand comm=Util.streamableFromByteBuffer(DrawCommand::new, buf, offset, length);
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();
}
}
/* --------------- Callbacks --------------- */
public void clearPanel() {
if(panel != null)
panel.clear();
}
public void sendClearPanelMsg() {
DrawCommand comm=new DrawCommand(DrawCommand.CLEAR);
try {
byte[] buf=Util.streamableToByteBuffer(comm);
sendToAll(buf);
}
catch(Exception ex) {
System.err.println(ex);
}
}
public void actionPerformed(ActionEvent e) {
String command=e.getActionCommand();
if("Clear".equals(command)) {
sendClearPanelMsg();
}
else if("Leave".equals(command)) {
stop();
mainFrame.setVisible(false);
mainFrame.dispose();
}
else
System.out.println("Unknown action");
}
public void stop() {
if(!stomp_client.isConnected())
return;
String session_id=stomp_client.getSessionId();
if(session_id != null) {
stomp_client.send(clients_dest, null, 0, 0, "client-left", session_id);
}
stomp_client.disconnect();
}
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 state;
public DrawPanel(boolean use_state) {
if(use_state)
state=new LinkedHashMap<>();
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(outstream);
dos.writeInt(state.size());
Point point;
Color col;
for (Map.Entry entry : state.entrySet()) {
point = entry.getKey();
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 new_state=new HashMap<>();
int num=in.readInt();
Point point;
Color col;
for(int i=0; i < num; i++) {
point=new Point(in.readInt(), in.readInt());
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.getRGB());
try {
byte[] buf=Util.streamableToByteBuffer(comm);
sendToAll(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.rgb);
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);
}
}
}
}