I have to develop a whiteboard application in which both the local user and the remote user should be able to draw simultaneously, is this possible? If possible then any logic?
I have already developed a code but in which i am not able to do this, when the remote user starts drawing the shape which i am drawing is being replaced by his shape and co-ordinates.
This problem is only when both draw simultaneously.
any idea guys?
Here is my code
class Paper extends JPanel implements MouseListener,MouseMotionListener,ActionListener
{
static BufferedImage image;
int bpressed;
Color color;
Point start;
Point end;
Point mp;
Button elipse=new Button("elipse");
Button rectangle=new Button("rect");
Button line=new Button("line");
Button empty=new Button("");
JButton save=new JButton("Save");
JButton erase=new JButton("Erase");
String selected;
int ex,ey;//eraser
DatagramSocket dataSocket;
JButton button = new JButton("test");
Client client;
Point p=new Point();
int w,h;
public Paper(DatagramSocket dataSocket)
{
this.dataSocket=dataSocket;
client=new Client(dataSocket);
System.out.println("paper");
setBackground(Color.white);
addMouseListener(this);
addMouseMotionListener(this);
color = Color.black;
setBorder(BorderFactory.createLineBorder(Color.black));
//save.setPreferredSize(new Dimension(100,20));
save.setMaximumSize(new Dimension(75,27));
erase.setMaximumSize(new Dimension(75,27));
}
public void paintComponent(Graphics g)
{
try
{
g.drawImage(image, 0, 0, this);
Graphics2D g2 = (Graphics2D)g;
g2.setPaint(Color.black);
if(selected==("elipse"))
g2.drawOval(start.x, start.y,(end.x-start.x),(end.y-start.y));
else if(selected==("rect"))
g2.drawRect(start.x, start.y, (end.x-start.x),(end.y-start.y));
else if(selected==("line"))
g2.drawLine(start.x,start.y,end.x,end.y);
}
catch(Exception e)
{}
}
//Function to draw the shape on image
public void draw()
{
Graphics2D g2 = image.createGraphics();
g2.setPaint(color);
if(selected=="line")
g2.drawLine(start.x, start.y, end.x, end.y);
if(selected=="elipse")
g2.drawOval(start.x, start.y, (end.x-start.x),(end.y-start.y));
if(selected=="rect")
g2.drawRect(start.x, start.y, (end.x-start.x),(end.y-start.y));
repaint();
g2.dispose();
start=null;
}
//To add the point to the board which is broadcasted by the server
public synchronized void addPoint(Point ps,String varname,String shape,String event)
{
try
{
if(end==null)
end = new Point();
if(start==null)
start = new Point();
if(shape.equals("elipse"))
selected="elipse";
else if(shape.equals("line"))
selected="line";
else if(shape.equals("rect"))
selected="rect";
else if(shape.equals("erase"))
{
selected="erase";
erase();
}
if(end!=null && start!=null)
{
if(varname.equals("end"))
end=ps;
if(varname.equals("mp"))
mp=ps;
if(varname.equals("start"))
start=ps;
if(event.equals("drag"))
repaint();
else if(event.equals("release"))
draw();
}
}
catch(Exception e)
{
e.printStackTrace();
}
}
//To set the size of the image
public void setWidth(int x,int y)
{
System.out.println("("+x+","+y+")");
w=x;
h=y;
image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = image.createGraphics();
g2.setPaint(Color.white);
g2.fillRect(0,0,w,h);
g2.dispose();
}
//Function which provides the erase functionality
public void erase()
{
Graphics2D pic=(Graphics2D) image.getGraphics();
pic.setPaint(Color.white);
pic.fillRect(start.x, start.y, 10, 10);
}
//Function to add buttons into the panel, calling this function returns a panel
public JPanel addButtons()
{
JPanel buttonpanel=new JPanel();
JPanel row1=new JPanel();
JPanel row2=new JPanel();
JPanel row3=new JPanel();
JPanel row4=new JPanel();
buttonpanel.setPreferredSize(new Dimension(80,80));
//buttonpanel.setMinimumSize(new Dimension(150,150));
row1.setLayout(new BoxLayout(row1,BoxLayout.X_AXIS));
row1.setPreferredSize(new Dimension(150,150));
row2.setLayout(new BoxLayout(row2,BoxLayout.X_AXIS));
row3.setLayout(new BoxLayout(row3,BoxLayout.X_AXIS));
row4.setLayout(new BoxLayout(row4,BoxLayout.X_AXIS));
buttonpanel.setLayout(new BoxLayout(buttonpanel,BoxLayout.Y_AXIS));
elipse.addActionListener(this);
rectangle.addActionListener(this);
line.addActionListener( this);
save.addActionListener( this);
erase.addActionListener( this);
buttonpanel.add(Box.createRigidArea(new Dimension(10,10)));
row1.add(elipse);
row1.add(Box.createRigidArea(new Dimension(5,0)));
row1.add(rectangle);
buttonpanel.add(row1);
buttonpanel.add(Box.createRigidArea(new Dimension(10,10)));
row2.add(line);
row2.add(Box.createRigidArea(new Dimension(5,0)));
row2.add(empty);
buttonpanel.add(row2);
buttonpanel.add(Box.createRigidArea(new Dimension(10,10)));
row3.add(save);
buttonpanel.add(row3);
buttonpanel.add(Box.createRigidArea(new Dimension(10,10)));
row4.add(erase);
buttonpanel.add(row4);
return buttonpanel;
}
//To save the image drawn
public void save()
{
try
{
ByteArrayOutputStream bos = new ByteArrayOutputStream();
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(bos);
JFileChooser fc = new JFileChooser();
fc.showSaveDialog(this);
encoder.encode(image);
byte[] jpgData = bos.toByteArray();
FileOutputStream fos = new FileOutputStream(fc.getSelectedFile()+".jpeg");
fos.write(jpgData);
fos.close();
//add replce confirmation here
}
catch (IOException e)
{
System.out.println(e);
}
}
public void mouseClicked(MouseEvent arg0) {
// TODO Auto-generated method stub
}
@Override
public void mouseEntered(MouseEvent arg0) {
}
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}
public void mousePressed(MouseEvent e)
{
if(selected=="line"||selected=="erase")
{
start=e.getPoint();
client.broadcast(start,"start", selected,"press");
}
else if(selected=="elipse"||selected=="rect")
{
mp = e.getPoint();
client.broadcast(mp,"mp", selected,"press");
}
}
public void mouseReleased(MouseEvent e)
{
if(start!=null)
{
if(selected=="line")
{
end=e.getPoint();
client.broadcast(end,"end", selected,"release");
}
else if(selected=="elipse"||selected=="rect")
{
end.x = Math.max(mp.x,e.getX());
end.y = Math.max(mp.y,e.getY());
client.broadcast(end,"end", selected,"release");
}
draw();
}
//start=null;
}
public void mouseDragged(MouseEvent e)
{
if(end==null)
end = new Point();
if(start==null)
start = new Point();
if(selected=="line")
{
end=e.getPoint();
client.broadcast(end,"end", selected,"drag");
}
else if(selected=="erase")
{
start=e.getPoint();
erase();
client.broadcast(start,"start", selected,"drag");
}
else if(selected=="elipse"||selected=="rect")
{
start.x = Math.min(mp.x,e.getX());
start.y = Math.min(mp.y,e.getY());
end.x = Math.max(mp.x,e.getX());
end.y = Math.max(mp.y,e.getY());
client.broadcast(start,"start", selected,"drag");
client.broadcast(end,"end", selected,"drag");
}
repaint();
}
@Override
public void mouseMoved(MouseEvent arg0) {
// TODO Auto-generated method stub
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==elipse)
selected="elipse";
if(e.getSource()==line)
selected="line";
if(e.getSource()==rectangle)
selected="rect";
if(e.getSource()==save)
save();
if(e.getSource()==erase)
{
selected="erase";
erase();
}
}
}
class Button extends JButton
{
String name;
public Button(String name)
{
this.name=name;
Dimension buttonSize = new Dimension(35,35);
setMaximumSize(buttonSize);
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
//g2.setStroke(new BasicStroke(1.2f));
if (name == "line") g.drawLine(5,5,30,30);
if (name == "elipse") g.drawOval(5,7,25,20);
if (name== "rect") g.drawRect(5,5,25,23);
}
}
