help newbie : frame resets

M

Madhur Ahuja

Hello

In following code attatched, whenever I press send button, the whole of
my frame resets. The JTextField are set to zero columns. The server field
can
be set to *localhost*.

Please Help, why this resetting happens.

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.net.*;
import java.io.*;

class mainapp implements ActionListener,KeyListener
{

JPanel mainpanel;

JTextField to,server,from;

JTextArea body,result;
JFrame mainframe;
GridBagLayout gbc;
GridBagConstraints constraints;
JButton send;
JLabel lfrom,lto,lserver,lbody,lresult,iphost;

public mainapp()
{

gbc=new GridBagLayout();
mainpanel=new JPanel(gbc);
constraints = new GridBagConstraints();

mainframe =new JFrame("Mail send");
mainpanel.addKeyListener(this);
mainframe.addKeyListener(this);
addwidgets();

mainframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// mainframe.setSize(new Dimension(120, 40));
mainframe.getContentPane().add(mainpanel);
mainpanel.setSize(400,400);

mainframe.pack();
mainframe.validate();
mainframe.setVisible(true);
}


void addwidgets()
{
from=new JTextField(10);
from.setColumns(10);
body=new JTextArea(10,30);
to=new JTextField(10);
to.setColumns(10);
server=new JTextField(10);
server.setColumns(10);
send=new JButton("Send");
result=new JTextArea(4,30);

lfrom=new JLabel("From:");
lbody=new JLabel("Body:");
lto=new JLabel("To:");
lserver=new JLabel("Server:");
lresult=new JLabel("Result:");
iphost=new JLabel("ffffffffff");

from.addActionListener(this);
to.addActionListener(this);
server.addActionListener(this);
send.addActionListener(this);


buildConstraints(constraints,0,0,1,1,80,10);
gbc.setConstraints(lfrom, constraints);
mainpanel.add(lfrom);

buildConstraints(constraints,1,0,1,1,20,10);
gbc.setConstraints(from, constraints);
mainpanel.add(from);

buildConstraints(constraints,0,3,1,1,0,10);
gbc.setConstraints(lbody, constraints);
mainpanel.add(lbody);


buildConstraints(constraints,1,3,1,1,0,10);
gbc.setConstraints(body, constraints);
mainpanel.add(body);


buildConstraints(constraints,0,1,1,1,0,10);
gbc.setConstraints(lto, constraints);
mainpanel.add(lto);


buildConstraints(constraints,1,1,1,1,0,10);
gbc.setConstraints(to, constraints);
mainpanel.add(to);


buildConstraints(constraints,0,2,1,1,0,10);
gbc.setConstraints(lserver, constraints);
mainpanel.add(lserver);


buildConstraints(constraints,1,2,1,1,0,10);
gbc.setConstraints(server, constraints);
mainpanel.add(server);

buildConstraints(constraints,2,2,1,1,0,10);
gbc.setConstraints(iphost, constraints);
mainpanel.add(iphost);


buildConstraints(constraints,1,4,1,1,0,0);
gbc.setConstraints(send, constraints);
mainpanel.add(send);


buildConstraints(constraints,0,5,1,1,0,10);
gbc.setConstraints(lresult, constraints);
mainpanel.add(lresult);

buildConstraints(constraints,1,5,1,1,0,10);
gbc.setConstraints(result, constraints);
mainpanel.add(result);

}

public void keyTyped(KeyEvent e)
{
System.out.println("dfd");
if(from.getText()=="" || to.getText()==""||server.getText()=="")
{
send.setEnabled(false);
System.out.println("dfd");
}
else
send.setEnabled(false);
}

public void keyPressed(KeyEvent e)
{
System.out.println("dfd");
}

public void keyReleased(KeyEvent e)
{
}

public static void main(String args[])
{
new mainapp();

}


public void actionPerformed(ActionEvent e)
{
if(e.getSource().getClass()==JTextField.class)
{
System.out.println("dfd");
JTextField obj=(JTextField)e.getSource();
if(obj.getText()=="")
{
send.setEnabled(false);
}
else
send.setEnabled(true);
}



if(e.getSource()==send)
{

new mailit();

}


}

void buildConstraints(GridBagConstraints gbc, int gx, int gy,
int gw, int gh, int wx, int wy) {
gbc.gridx = gx;
gbc.gridy = gy;
gbc.gridwidth = gw;
gbc.gridheight = gh;
gbc.weightx = wx;
gbc.weighty = wy;
}



class mailit extends Thread
{
Socket smtpsocket;
String host;
InetAddress add;
PrintWriter pw;
BufferedReader br;
public void run()
{

try
{
smtpsocket=new Socket();
System.out.println(add);
smtpsocket.connect(new InetSocketAddress(add,25));
br=new BufferedReader(new InputStreamReader(smtpsocket.getInputStream()));
pw=new PrintWriter(new OutputStreamWriter(smtpsocket.getOutputStream()));

pw.println("Helo mad");
pw.println("mail from :"+from.getText());
pw.println("rcpt to:"+to.getText());
pw.println("data");
pw.flush();
pw.println(body.getText());
pw.println(".");
pw.flush();

while(true)
{
String line=br.readLine();
if(line==null) break;
result.append(line+"\n");

System.out.println(line);

}

smtpsocket.close();

}

catch(Exception IOException)
{
IOException.printStackTrace();
JOptionPane.showMessageDialog(null,"Error during
connection","Mail",JOptionPane.ERROR_MESSAGE);
}



}

mailit()
{
try
{
add=InetAddress.getByName(server.getText());
iphost.setText(add.getHostAddress());
System.out.println(add.getHostAddress()) ;
this.start();
}
catch(Exception UnknownHostException)
{
JOptionPane.showMessageDialog(null,"Cannot resolve
hostname","Mail",JOptionPane.ERROR_MESSAGE);
}

}

}


}


--
Winners dont do different things, they do things differently.

Madhur Ahuja
India

Homepage : http://madhur.netfirms.com
Email : madhur<underscore>ahuja<at>yahoo<dot>com
 
Z

zoopy

Hello

In following code attatched, whenever I press send button, the whole of
my frame resets. The JTextField are set to zero columns. The server field
can
be set to *localhost*.

Please Help, why this resetting happens.
Click to expand...
If you enlarge the frame beyond certain size it doesn't happen anymore. It's likely caused by the
improper values for GridBagConstraints' weightx/weighty. GridBagLayout is quite complex and I've
always interpreted GBC weightx/y as values relative weights: a component with weightx==1 takes 1
amount of the width at hand (whatever that may be), weightx==2 takes 2 amounts, a component with
weightx==0 doesn't contribute for calculating the width of components with weightx>0, however it
does take the space it needs. [If I'm wrong, please correct me].

I've changed the weightx/y in the code below (and some other things, such as justifying some fields
horizontally).

Some other remarks:
- It's not necessary to do validate() right after pack()
- Use GridBagConstraints' fill field for justifying component horizontally/vertically/both
- GridBagLayout largely determines the size of a component (relative to others), therefore setting
number of columns and rows of a JTextField/JTextArea isn't always honoured.
- Don't use == (or !=) for comparing String *values*: use someString.equals(anotherString) instead;
to test if a string is empty you can use someString.length() == 0

-------------
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.net.*;
import java.io.*;

public class mainapp implements ActionListener, KeyListener
{

JPanel mainpanel;

JTextField to, server, from;

JTextArea body, result;
JFrame mainframe;
GridBagLayout gbc;
GridBagConstraints constraints;
JButton send;
JLabel lfrom, lto, lserver, lbody, lresult, iphost;

public mainapp()
{

gbc = new GridBagLayout();
mainpanel = new JPanel(gbc);
constraints = new GridBagConstraints();

mainframe = new JFrame("Mail send");
mainpanel.addKeyListener(this);
mainframe.addKeyListener(this);
addwidgets();

mainframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// mainframe.setSize(new Dimension(120, 40));
mainframe.getContentPane().add(mainpanel);
mainpanel.setPreferredSize(new Dimension(400, 400));

mainframe.pack();
//mainframe.validate();
mainframe.setVisible(true);
}

void addwidgets()
{
from = new JTextField(10);
from.setColumns(10);
body = new JTextArea(10, 30);
//body = new JTextArea();
to = new JTextField(10);
to.setColumns(10);
server = new JTextField(10);
server.setColumns(10);
send = new JButton("Send");
result = new JTextArea(4, 30);
//result = new JTextArea();

lfrom = new JLabel("From:");
lbody = new JLabel("Body:");
lto = new JLabel("To:");
lserver = new JLabel("Server:");
lresult = new JLabel("Result:");
iphost = new JLabel("ffffffffff");

from.addActionListener(this);
to.addActionListener(this);
server.addActionListener(this);
send.addActionListener(this);


buildConstraints(constraints, 0, 0, 1, 1, 0, 0);
gbc.setConstraints(lfrom, constraints);
mainpanel.add(lfrom);

buildConstraints(constraints, 1, 0, 1, 1, 1, 0);
constraints.fill = GridBagConstraints.HORIZONTAL;
gbc.setConstraints(from, constraints);
mainpanel.add(from);

buildConstraints(constraints, 0, 3, 1, 1, 0, 0);
gbc.setConstraints(lbody, constraints);
mainpanel.add(lbody);

buildConstraints(constraints, 1, 3, 1, 1, 1, 2);
constraints.fill = GridBagConstraints.BOTH;
gbc.setConstraints(body, constraints);
mainpanel.add(body);

buildConstraints(constraints, 0, 1, 1, 1, 0, 0);
gbc.setConstraints(lto, constraints);
mainpanel.add(lto);

buildConstraints(constraints, 1, 1, 1, 1, 1, 0);
constraints.fill = GridBagConstraints.HORIZONTAL;
gbc.setConstraints(to, constraints);
mainpanel.add(to);

buildConstraints(constraints, 0, 2, 1, 1, 0, 0);
gbc.setConstraints(lserver, constraints);
mainpanel.add(lserver);

buildConstraints(constraints, 1, 2, 1, 1, 1, 0);
constraints.fill = GridBagConstraints.HORIZONTAL;
gbc.setConstraints(server, constraints);
mainpanel.add(server);

buildConstraints(constraints, 2, 2, 1, 1, 0, 0);
gbc.setConstraints(iphost, constraints);
mainpanel.add(iphost);

buildConstraints(constraints, 1, 4, 1, 1, 0, 0);
constraints.fill = GridBagConstraints.NONE;
gbc.setConstraints(send, constraints);
mainpanel.add(send);

buildConstraints(constraints, 0, 5, 1, 1, 0, 0);
gbc.setConstraints(lresult, constraints);
mainpanel.add(lresult);

buildConstraints(constraints, 1, 5, 1, 1, 1, 1);
constraints.fill = GridBagConstraints.BOTH;
gbc.setConstraints(result, constraints);
mainpanel.add(result);

}

public void keyTyped(KeyEvent e)
{
System.out.println("dfd");
if ( from.getText().length() == 0
|| to.getText().length() == 0
|| server.getText().length() == 0)
{
send.setEnabled(false);
System.out.println("dfd");
}
else
send.setEnabled(true);
}

public void keyPressed(KeyEvent e)
{
System.out.println("dfd");
}

public void keyReleased(KeyEvent e)
{
}

public static void main(String args[])
{
new mainapp();

}

public void actionPerformed(ActionEvent e)
{
if (e.getSource().getClass() == JTextField.class)
{
System.out.println("dfd");
JTextField obj = (JTextField) e.getSource();
if (obj.getText().length()==0)
{
send.setEnabled(false);
}
else
send.setEnabled(true);
}

if (e.getSource() == send)
{

new mailit();

}

}

void buildConstraints(
GridBagConstraints gbc,
int gx,
int gy,
int gw,
int gh,
double wx,
double wy)
{
gbc.gridx = gx;
gbc.gridy = gy;
gbc.gridwidth = gw;
gbc.gridheight = gh;
gbc.weightx = wx;
gbc.weighty = wy;
}

class mailit extends Thread
{
Socket smtpsocket;
String host;
InetAddress add;
PrintWriter pw;
BufferedReader br;
public void run()
{

try
{
smtpsocket = new Socket();
System.out.println(add);
smtpsocket.connect(new InetSocketAddress(add, 25));
br =
new BufferedReader(
new InputStreamReader(smtpsocket.getInputStream()));
pw =
new PrintWriter(new OutputStreamWriter(smtpsocket.getOutputStream()));

pw.println("Helo mad");
pw.println("mail from :" + from.getText());
pw.println("rcpt to:" + to.getText());
pw.println("data");
pw.flush();
pw.println(body.getText());
pw.println(".");
pw.flush();

while (true)
{
String line = br.readLine();
if (line == null)
break;
result.append(line + "\n");

System.out.println(line);

}

smtpsocket.close();

}

catch (Exception IOException)
{
IOException.printStackTrace();
JOptionPane.showMessageDialog(
null,
"Error during connection",
"Mail",
JOptionPane.ERROR_MESSAGE);
}

}

mailit()
{
try
{
add = InetAddress.getByName(server.getText());
iphost.setText(add.getHostAddress());
System.out.println(add.getHostAddress());
this.start();
}
catch (Exception UnknownHostException)
{
JOptionPane.showMessageDialog(
null,
"Cannot resolve hostname",
"Mail",
JOptionPane.ERROR_MESSAGE);
}

}

}

}
 
M

Madhur Ahuja

zoopy said:
If you enlarge the frame beyond certain size it doesn't happen
anymore. It's likely caused by the improper values for
GridBagConstraints' weightx/weighty. GridBagLayout is quite complex
and I've always interpreted GBC weightx/y as values relative weights:
a component with weightx==1 takes 1 amount of the width at hand
(whatever that may be), weightx==2 takes 2 amounts, a component with
weightx==0 doesn't contribute for calculating the width of components
with weightx>0, however it does take the space it needs. [If I'm
wrong, please correct me].

I've changed the weightx/y in the code below (and some other things,
such as justifying some fields horizontally).

Some other remarks:
- It's not necessary to do validate() right after pack()
- Use GridBagConstraints' fill field for justifying component
horizontally/vertically/both
- GridBagLayout largely determines the size of a component (relative
to others), therefore setting number of columns and rows of a
JTextField/JTextArea isn't always honoured. - Don't use == (or !=)
for comparing String *values*: use someString.equals(anotherString)
instead; to test if a string is empty you can use someString.length()
== 0
Click to expand...

Thank you


--
Winners dont do different things, they do things differently.

Madhur Ahuja
India

Homepage : http://madhur.netfirms.com
Email : madhur<underscore>ahuja<at>yahoo<dot>com
 

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