Help with JButton
I want to link a button to a web page
making a button and adding ActionListener to it is ok from there how do i proceed.
Thanks.
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import javax.swing.*;
public class URL_Demo extends JFrame {
public URL_Demo() {
initComponents();
private void initComponents() {
setTitle("URL Connect");
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
toolbar = new JPanel();
tabbedpane = new JTabbedPane();
combobox = new JComboBox();
combobox.setModel(new javax.swing.DefaultComboBoxModel(new String[] {
"http://news.bbc.co.uk/sport1/hi/football/teams/a/arsenal/default.stm" ,
"http://www.amazon.com/",
"http://www.jackinworld.com/",
combobox.setPreferredSize(new java.awt.Dimension(500, 22));
combobox.setSelectedIndex(0);
combobox.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
displayPage();
toolbar.add(combobox);
getContentPane().add(toolbar, BorderLayout.NORTH);
getContentPane().add(tabbedpane);
setExtendedState(JFrame.MAXIMIZED_BOTH);
setVisible(true);
displayPage();
private void displayPage() {
urlString = combobox.getSelectedItem().toString();
setCursor(Cursor.WAIT_CURSOR);
URL url = null;
InputStream input = null;
try{
url = new URL( urlString );
}catch(MalformedURLException ex){
ex.printStackTrace();
StringBuffer strb = null;
try{
try{
input = url.openStream();
}catch(UnknownHostException ex){
if( input != null ){
int c = input.read();
strb = new StringBuffer();
while( c != -1 ){
char cc = (char)c;
strb.append(cc);
c = input.read();
}catch(IOException ex){
ex.printStackTrace();
scrollpane = new JScrollPane();
tabbedpane.add(scrollpane);
tabbedpane.setTitleAt(count++, urlString);
editorpane = new JEditorPane();
editorpane.setEditable(false);
editorpane.setContentType("text/html");
scrollpane.setViewportView(editorpane);
if( strb != null ){
editorpane.setText(strb.toString());
}else{
Toolkit.getDefaultToolkit().beep();
String htmlText =
"<html>"
+"<body BGCOLOR=\"#ffffe0\">"
+"<br>Connection failed: <br> " +urlString+
"<br><br>Make sure you are connected to the Internet"
+"</body>"
+"</html>";
editorpane.setText(htmlText);
setCursor(Cursor.DEFAULT_CURSOR);
public static void main(String args[]) {
new URL_Demo();
private String urlString;
private JEditorPane editorpane;
private JPanel toolbar;
private JTabbedPane tabbedpane;
private JComboBox combobox;
private JScrollPane scrollpane;
private int count;
}
Similar Messages
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Hi, I have a 2D array of JButton's in a gridLayout. This stores the buttons row/col and if it has an image:
for(int i = 0; i < 7; i++) {
for(int j = 0; j < 7; j++) {
button[i][j] = new JButton(peg); //Populates grid with ImageIcons
button[i][j].putClientProperty("column", i); //Stores all column properties
button[i][j].putClientProperty("row", j); //Stores all row properties
button[i][j].putClientProperty("ImageIcon" yes); //Sets each JButton to have an image
button[i][j].addActionListener(new MyActionListener()); //Add actionListener
add(button[i][j]); //Adds all buttons into gridLayout
When I click one of my buttons the action listener is implemented and I can get all of the information about this button using the e.getSource() method:
public class MyActionListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
if(isFirstClick){
JButton btn = (JButton) e.getSource(); //Get information on each button
My question is, when I click on one button, how can I get the information from the button directly to its left without clicking on that button?
I can get the button to the lefts row/col, but not the actually JButton's information like e.getSource()
Thanks very much, I hope this makes senseStore these buttons in an 2D array and use the clientProperty to fetch any other button relative from this button's position.
-
Need some quick help with jbutton
Hi,
My first post so please be gentle!
I currently have two buttons in my container. The first one when pressed calls another function that generates a set of coordinates (button = generate). I now have another button that wants to take those coordinates and draw them on-screen, but I'm having trouble doing this since I can't get the "generate" button function to pass the xycoords over to the "draw" button function. I'm more of a Fortran/Perl programmer and I'm a bit confused how to go about this. I tried making the variable (xycoords) a gloabl variable, but id rather not do this.
Any tips?
Cheers,
AdrianoSure, show us the code. Otherwise we have to try to read you mind.
Here is the scenario you are in:
Event Driven Method (ActionPerformed/ButtonClicked/etc): you do not have arguments that you can control, so if you want to use something from within that method you have to have visibility to it (global definition with respect to the routine) and in the Java world that usually boils down to class variables or some type of public data class.
Now, it you want the coordinates of the click event, that is contained in the MouseEvent... getX and getY, so you can use these as arguments to other methods from within your MouseListener. -
Help with if statement for a beginner.
Hello, Im new to the dev lark and wondered if someone could point me in the right direction.
I have the following (working!) app that lets users press a few buttons instead of typing console commands (please do not be too critical of it, its my first work prog).
//DBS File send and Receive app 1.0
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import java.applet.Applet;
public class Buttons extends JFrame
public Buttons()
super("DBS 2");
JTextArea myText = new JTextArea ("Welcome to the DBS application." +
"\n" +
"\n\n1. If you have received an email informing you that the DBS is ready to dowload please press the \"Receive DBS\" button." +
"\n" +
"\n1. Once this has been Received successfully please press the \"Prep File\" button." +
"\n\n2. Once the files have been moved to their appropriate locations, please do the \"Load\" into PAS." +
"\n\n3. Once the \"Load\" is complete, do the \"Extract\"." +
"\n\n4. When the \"Extract\" has taken place please press the \"File Shuffle\" button." +
"\n\n5. When the files have been shuffled, please press the \"Send DBS\" Button." +
"\n\nJob done." +
"\n", 20,50);
JPanel holdAll = new JPanel();
JPanel topPanel = new JPanel();
JPanel bottomPanel = new JPanel();
JPanel middle1 = new JPanel();
JPanel middle2 = new JPanel();
JPanel middle3 = new JPanel();
topPanel.setLayout(new FlowLayout());
middle1.setLayout(new FlowLayout());
middle2.setLayout(new FlowLayout());
middle3.setLayout(new FlowLayout());
bottomPanel.setLayout(new FlowLayout());
myText.setBackground(new java.awt.Color(0, 0, 0));
myText.setForeground(new java.awt.Color(255,255,255));
myText.setFont(new java.awt.Font("Times",0, 16));
myText.setLineWrap(true);
myText.setWrapStyleWord(true);
holdAll.setLayout(new BorderLayout());
topPanel.setBackground(new java.awt.Color(153, 101, 52));
bottomPanel.setForeground(new java.awt.Color(153, 0, 52));
holdAll.add(topPanel, BorderLayout.CENTER);
topPanel.add(myText, BorderLayout.NORTH);
setSize(700, 600);
setDefaultCloseOperation(EXIT_ON_CLOSE);
getContentPane().add(holdAll, BorderLayout.CENTER);
Container c = getContentPane();
c.setLayout(new FlowLayout());
final JButton receiveDBS = new JButton("Receive DBS"); //marked as final as it is called in an Inner Class later
final JButton filePrep = new JButton("Prep File");
final JButton fileShuffle = new JButton("File Shuffle");
final JButton sendDBS = new JButton("Send DBS");
JButton exitButton = new JButton("Exit");
// JLabel statusbar = new JLabel("Text here");
receiveDBS.setFont(new java.awt.Font("Arial", 0, 25));
filePrep.setFont(new java.awt.Font("Arial", 0, 25));
fileShuffle.setFont(new java.awt.Font("Arial", 0, 25));
sendDBS.setFont(new java.awt.Font("Arial", 0, 25));
exitButton.setBorderPainted ( false );
exitButton.setMargin( new Insets ( 10, 10, 10, 10 ));
exitButton.setToolTipText( "EXIT Button" );
exitButton.setFont(new java.awt.Font("Arial", 0, 20));
exitButton.setEnabled(true); //Set to (false) to disable
exitButton.setForeground(new java.awt.Color(0, 0, 0));
exitButton.setHorizontalTextPosition(SwingConstants.CENTER); //Don't know what this does
exitButton.setBounds(10, 30, 90, 50); //Don't know what this does
exitButton.setBackground(new java.awt.Color(153, 101, 52));
topPanel.add(receiveDBS);
middle1.add(filePrep);
middle2.add(exitButton);
middle3.add(fileShuffle);
bottomPanel.add(sendDBS);
receiveDBS.addActionListener(new ActionListener()
public void actionPerformed(ActionEvent ae)
if (ae.getSource() == receiveDBS);
try
Runtime.getRuntime().exec("cmd.exe /c start c:\\DBS\\ReceiveDBSfile.bat");
catch(Exception e)
System.out.println(e.toString());
e.printStackTrace();
filePrep.addActionListener(new ActionListener()
public void actionPerformed(ActionEvent ae)
if (ae.getSource() == filePrep);
try
Runtime.getRuntime().exec("cmd.exe /c start c:\\DBS\\filePrep.bat");
catch(Exception e)
System.out.println(e.toString());
e.printStackTrace();
exitButton.addActionListener(new ActionListener()
public void actionPerformed(ActionEvent ae)
System.exit(0);
fileShuffle.addActionListener(new ActionListener()
public void actionPerformed(ActionEvent ae)
if (ae.getSource() == fileShuffle);
try
Runtime.getRuntime().exec("cmd.exe /c start c:\\DBS\\fileShuffle.bat");
catch(Exception e)
System.out.println(e.toString());
e.printStackTrace();
sendDBS.addActionListener(new ActionListener()
public void actionPerformed(ActionEvent ae)
if (ae.getSource() == sendDBS);
try
Runtime.getRuntime().exec("cmd.exe /c start c:\\DBS\\sendDBSFile.bat");
catch(Exception e)
System.out.println(e.toString());
e.printStackTrace();
c.add(receiveDBS);
c.add(filePrep);
c.add(fileShuffle);
c.add(sendDBS);
c.add(exitButton);
// c.add(statusbar);
public static void main(String args[])
Buttons xyz = new Buttons();
xyz.setVisible(true);
}What I would like help with is the following
I would like output to either a JLabel or JTextArea to appear if a file appears on the network. Something along these lines
If file named nststrace*.* is in \\[network path] then output Download successful, please proceed.
btw I have done my best to search this forum for something similar and had no luck, but I am looking forward to Encephalopathics answer as he/she has consistently made me laugh with posted responses (in a good way).
Thanks in advance, Paul.Hospital_Apps_Monkey wrote:
we're starting to get aquainted, but I think "best friend" could take a while as it is still as hard going as I recall, but I will persevere.Heh, it's not so bad! For example, if I had no idea how to test whether a file exists, I would just scan the big list of classes on the left for names that sound like they might include File operations. Hey look, File! Then I'd look at all of File's methods for something that tests whether it exists or not. Hey, exists! Then if I still couldn't figure out how to use it, I'd do a google search on that particular method. -
Need help with JTextArea and Scrolling
import java.awt.*;
import java.awt.event.*;
import java.text.DecimalFormat;
import javax.swing.*;
public class MORT_RETRY extends JFrame implements ActionListener
private JPanel keypad;
private JPanel buttons;
private JTextField lcdLoanAmt;
private JTextField lcdInterestRate;
private JTextField lcdTerm;
private JTextField lcdMonthlyPmt;
private JTextArea displayArea;
private JButton CalculateBtn;
private JButton ClrBtn;
private JButton CloseBtn;
private JButton Amortize;
private JScrollPane scroll;
private DecimalFormat calcPattern = new DecimalFormat("$###,###.00");
private String[] rateTerm = {"", "7years @ 5.35%", "15years @ 5.5%", "30years @ 5.75%"};
private JComboBox rateTermList;
double interest[] = {5.35, 5.5, 5.75};
int term[] = {7, 15, 30};
double balance, interestAmt, monthlyInterest, monthlyPayment, monPmtInt, monPmtPrin;
int termInMonths, month, termLoop, monthLoop;
public MORT_RETRY()
Container pane = getContentPane();
lcdLoanAmt = new JTextField();
lcdMonthlyPmt = new JTextField();
displayArea = new JTextArea();//DEFINE COMBOBOX AND SCROLL
rateTermList = new JComboBox(rateTerm);
scroll = new JScrollPane(displayArea);
scroll.setSize(600,170);
scroll.setLocation(150,270);//DEFINE BUTTONS
CalculateBtn = new JButton("Calculate");
ClrBtn = new JButton("Clear Fields");
CloseBtn = new JButton("Close");
Amortize = new JButton("Amortize");//DEFINE PANEL(S)
keypad = new JPanel();
buttons = new JPanel();//DEFINE KEYPAD PANEL LAYOUT
keypad.setLayout(new GridLayout( 4, 2, 5, 5));//SET CONTROLS ON KEYPAD PANEL
keypad.add(new JLabel("Loan Amount$ : "));
keypad.add(lcdLoanAmt);
keypad.add(new JLabel("Term of loan and Interest Rate: "));
keypad.add(rateTermList);
keypad.add(new JLabel("Monthly Payment : "));
keypad.add(lcdMonthlyPmt);
lcdMonthlyPmt.setEditable(false);
keypad.add(new JLabel("Amortize Table:"));
keypad.add(displayArea);
displayArea.setEditable(false);//DEFINE BUTTONS PANEL LAYOUT
buttons.setLayout(new GridLayout( 1, 3, 5, 5));//SET CONTROLS ON BUTTONS PANEL
buttons.add(CalculateBtn);
buttons.add(Amortize);
buttons.add(ClrBtn);
buttons.add(CloseBtn);//ADD ACTION LISTENER
CalculateBtn.addActionListener(this);
ClrBtn.addActionListener(this);
CloseBtn.addActionListener(this);
Amortize.addActionListener(this);
rateTermList.addActionListener(this);//ADD PANELS
pane.add(keypad, BorderLayout.NORTH);
pane.add(buttons, BorderLayout.SOUTH);
pane.add(scroll, BorderLayout.CENTER);
addWindowListener( new WindowAdapter()
public void windowClosing(WindowEvent e)
System.exit(0);
public void actionPerformed(ActionEvent e)
String arg = lcdLoanAmt.getText();
int combined = Integer.parseInt(arg);
if (e.getSource() == CalculateBtn)
try
JOptionPane.showMessageDialog(null, "Got try here", "Error", JOptionPane.ERROR_MESSAGE);
catch(NumberFormatException ev)
JOptionPane.showMessageDialog(null, "Got here", "Error", JOptionPane.ERROR_MESSAGE);
if ((e.getSource() == CalculateBtn) && (arg != null))
try{
if ((e.getSource() == CalculateBtn) && (rateTermList.getSelectedIndex() == 1))
monthlyInterest = interest[0] / (12 * 100);
termInMonths = term[0] * 12;
monthlyPayment = combined * (monthlyInterest / (1 - (Math.pow (1 + monthlyInterest, -termInMonths))));
lcdMonthlyPmt.setText(calcPattern.format(monthlyPayment));
if ((e.getSource() == CalculateBtn) && (rateTermList.getSelectedIndex() == 2))
monthlyInterest = interest[1] / (12 * 100);
termInMonths = term[1] * 12;
monthlyPayment = combined * (monthlyInterest / (1 - (Math.pow (1 + monthlyInterest, -termInMonths))));
lcdMonthlyPmt.setText(calcPattern.format(monthlyPayment));
if ((e.getSource() == CalculateBtn) && (rateTermList.getSelectedIndex() == 3))
monthlyInterest = interest[2] / (12 * 100);
termInMonths = term[2] * 12;
monthlyPayment = combined * (monthlyInterest / (1 - (Math.pow (1 + monthlyInterest, -termInMonths))));
lcdMonthlyPmt.setText(calcPattern.format(monthlyPayment));
catch(NumberFormatException ev)
JOptionPane.showMessageDialog(null, "Invalid Entry!\nPlease Try Again", "Error", JOptionPane.ERROR_MESSAGE);
} //IF STATEMENTS FOR AMORTIZATION
if ((e.getSource() == Amortize) && (rateTermList.getSelectedIndex() == 1))
loopy(7, 5.35);
if ((e.getSource() == Amortize) && (rateTermList.getSelectedIndex() == 2))
loopy(15, 5.5);
if ((e.getSource() == Amortize) && (rateTermList.getSelectedIndex() == 3))
loopy(30, 5.75);
if (e.getSource() == ClrBtn)
rateTermList.setSelectedIndex(0);
lcdLoanAmt.setText(null);
lcdMonthlyPmt.setText(null);
displayArea.setText(null);
if (e.getSource() == CloseBtn)
System.exit(0);
private void loopy(int lTerm,double lInterest)
double total, monthly, monthlyrate, monthint, monthprin, balance, lastint, paid;
int amount, months, termloop, monthloop;
String lcd2 = lcdLoanAmt.getText();
amount = Integer.parseInt(lcd2);
termloop = 1;
paid = 0.00;
monthlyrate = lInterest / (12 * 100);
months = lTerm * 12;
monthly = amount *(monthlyrate/(1-Math.pow(1+monthlyrate,-months)));
total = months * monthly;
balance = amount;
while (termloop <= lTerm)
displayArea.setCaretPosition(0);
displayArea.append("\n");
displayArea.append("Year " + termloop + " of " + lTerm + ": payments\n");
displayArea.append("\n");
displayArea.append("Month\tMonthly\tPrinciple\tInterest\tBalance\n");
monthloop = 1;
while (monthloop <= 12)
monthint = balance * monthlyrate;
monthprin = monthly - monthint;
balance -= monthprin;
paid += monthly;
displayArea.setCaretPosition(0);
displayArea.append(monthloop + "\t" + calcPattern.format(monthly) + "\t" + calcPattern.format(monthprin) + "\t");
displayArea.append(calcPattern.format(monthint) + "\t" + calcPattern.format(balance) + "\n");
monthloop ++;
termloop ++;
public static void main(String args[])
MORT_RETRY f = new MORT_RETRY();
f.setTitle("MORTGAGE PAYMENT CALCULATOR");
f.setBounds(600, 600, 500, 500);
f.setLocationRelativeTo(null);
f.setVisible(true);
}need help with displaying the textarea correctly and the scroll bar please.
Message was edited by:
new2this2020What's the problem you're having ???
PS. -
Help with making JLabel visible for a few seconds only
Hello guys,
I need help with making a JLabel object visible for a few seconds only and disappear when a JButton has been clicked.
Here is piece of code where I add mouse listener to the JButton object in my case is (jrbFigure1) and
when is called sets icon and text to the JLabel jlbl object:
jrbFigure1.addMouseListener(new MouseAdapter() {
jrbFigure1.addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent e) {
jlbl.setIcon(cross);
jlbl.setText(wrong);
This piece of code is in a switch statement, the statement is in a method.
The JLabel jlbl object is added in a panel in the constructor of the class.
I really hope someone could help me on this issue.
I would like to thank you in advance for any help or advice given.Bobson wrote:
Sorry for posting my issue twice, I thought, I posted it in a wrong forum:)It's OK. We'll ask the mods to delete the other thread.
I want the label to appear for X seconds when then button is pressed and disappear after that.Then a Swing Timer is what you want to use.
I need to do this in a number of cases from a switch statement because I several buttons.Better to have several ActionListeners, one for each button or each type of button, rather than one ActionListener with a large switch statement, a so-called switch-board listener. They're messy to debug and upgrade.
I tried to use Swing Timer, but I cannot set it properly.Go through the Sun Swing tutorial on Swing Timers. It's all outlined for you there: [http://java.sun.com/docs/books/tutorial/uiswing/misc/timer.html] -
Need help with my graphic calculator!!!
Hello everybody!! I need help with my little program I made.... The problem is that I am unable to use to calculate but it is possible to compile the code!! What should I do?? Thanks in advance.
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class Aritmetik extends JFrame implements ActionListener{
private JLabel l1 = new JLabel("Tal1: ", JLabel.LEFT);
private JLabel l2 = new JLabel("Tal2: ", JLabel.LEFT);
private JLabel l3 = new JLabel("Resultat",JLabel.LEFT);
private JLabel l4 = new JLabel(" ", JLabel.RIGHT);
private JTextField t1 = new JTextField(" ",10);
private JTextField t2 = new JTextField(" ",10);
private JButton b1 = new JButton("+");
private JButton b2 = new JButton("-");
private JButton b3 = new JButton("*");
private JButton b4 = new JButton("/");
public Aritmetik(){
Container v = getContentPane();
v.setLayout(new GridLayout(5,2));
v.add(l1);
v.add(t1);
v.add(l2);
v.add(t2);
v.add(b1);
v.add(b2);
v.add(b3);
v.add(b4);
v.add(l3);
v.add(l4);
b1.addActionListener(this);
b2.addActionListener(this);
b3.addActionListener(this);
b4.addActionListener(this);
pack();
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
public void actionPerformed(ActionEvent e){
int tal1 = Integer.parseInt(t1.getText());
int tal2 = Integer.parseInt(t2.getText());
if(e.getSource() == b1){
if(t1.getText().equals("") || t2.getText().equals(""))
JOptionPane.showMessageDialog(null, "Mata in tal!");
else{
l3.setText("Resultat ");
l4.setText(" " + (tal1+tal2));
else if(e.getSource() == b2){
int sub = tal1-tal2;
l4.setText(" " + (sub));
else if(e.getSource() == b3){
int multi = tal1*tal2;
l4.setText(" " + (multi));
else if(e.getSource() == b4){
int div = tal1/tal2;
l4.setText(" " + (div));
public static void main(String[] arg){
Aritmetik A =new Aritmetik();Here is your problem:
public void actionPerformed(ActionEvent e){
int tal1 = Integer.parseInt(t1.getText().trim()); // add the trim()
int tal2 = Integer.parseInt(t2.getText().trim()); // add the trim()
if(e.getSource() == b1){
if(t1.getText().equals("") || t2.getText().equals(""))
JOptionPane.showMessageDialog(null, "Mata in tal!");
else{
l3.setText("Resultat ");
l4.setText(" " + (tal1+tal2));
}... Better ...
public void actionPerformed(ActionEvent e) throws NumberFormatException {
String tala = t1.getText().trim();
String talb = t2.getText().trim();
if ( tala == null || "".equals(tala) || talb == null || "".equals(talb) ) {
JOptionPane.showMessageDialog(null, "Mata in tal!");
return();
int tal1 = Integer.parseInt(tala);
int tal2 = Integer.parseInt(talb);
if(e.getSource() == b1){
l3.setText("Resultat ");
l4.setText(" " + (tal1+tal2));
else if(e.getSource() == b2){
int sub = tal1-tal2;
l4.setText(" " + (sub));
else if(e.getSource() == b3){
int multi = tal1*tal2;
l4.setText(" " + (multi));
else if(e.getSource() == b4){
int div = tal1/tal2;
l4.setText(" " + (div));
}Message was edited by:
abillconsl -
Need help with my addressbook program
hi,
i need help with my program here. this one should works as:
- saves user input into a txt file
- displays name of the saved person on the jlist whenever i run the program
- displays info about the person when clicked via textboxes given by reading the txt file where the user inputs are
- should scroll when the list exceeds the listbox
import java.awt.event.*;
import java.awt.*;
import javax.swing.*;
import javax.swing.JList;
import java.awt.event.ActionListener;
import java.io.*;
import javax.swing.event.*;
import java.io.FilterInputStream;
public class AddressList extends JPanel implements ActionListener
JTextField txt1 = new JTextField();
JTextField txt2 = new JTextField();
JTextField txt3 = new JTextField();
DefaultListModel mdl = new DefaultListModel();
JList list = new JList();
JScrollPane listScroller = new JScrollPane(list);
ListSelectionModel listSelectionModel;
File fob = new File("Address3.txt");
String name;
char[] chars;
public void ListDisplay()
try
RandomAccessFile rand = new RandomAccessFile(fob,"rw");
BufferedReader br = new BufferedReader(new FileReader("Address3.txt"));
if(fob.exists())
while((name = rand.readLine()) != null)
chars = name.toCharArray();
if(chars[0] == '*')
mdl.addElement(name);
list.setModel(mdl);
if(chars[0] == '#')
continue;
else
System.out.println("No such file..");
catch(IOException a)
System.out.println(a.getMessage());
public AddressList()
this.setLayout(null);
listSelectionModel = list.getSelectionModel();
listSelectionModel.addListSelectionListener(new ListInfo());
list.setBounds(10,40,330,270);
listScroller.setBounds(320,40,20,100);
add(list);
add(listScroller);
JLabel lbl4 = new JLabel("Name: ");
lbl4.setBounds(400,10,80,30);
add(lbl4);
JLabel lbl5 = new JLabel("Cellphone #: ");
lbl5.setBounds(400,50,80,30);
add(lbl5);
JLabel lbl6 = new JLabel("Address: ");
lbl6.setBounds(400,90,80,30);
add(lbl6);
JLabel lbl7 = new JLabel("List ");
lbl7.setBounds(10,10,100,30);
add(lbl7);
txt1.setBounds(480,10,200,30);
add(txt1);
txt2.setBounds(480,50,200,30);
add(txt2);
txt3.setBounds(480,90,200,30);
add(txt3);
JButton btn1 = new JButton("Add");
btn1.setBounds(480,130,100,30);
btn1.addActionListener(this);
btn1.setActionCommand("Add");
add(btn1);
JButton btn2 = new JButton("Save");
btn2.setBounds(480,170,100,30);
btn2.addActionListener(this);
btn2.setActionCommand("Save");
add(btn2);
JButton btn3 = new JButton("Cancel");
btn3.setBounds(480,210,100,30);
btn3.addActionListener(this);
btn3.setActionCommand("Cancel");
add(btn3);
JButton btn4 = new JButton("Close");
btn4.setBounds(480,250,100,30);
btn4.addActionListener(this);
btn4.setActionCommand("Close");
add(btn4);
public static void main(String[]args)
JFrame frm = new JFrame("Address List");
AddressList panel = new AddressList();
frm.getContentPane().add(panel,"Center");
frm.setSize(700,350);
frm.setVisible(true);
panel.ListDisplay();
public void actionPerformed(ActionEvent e)
String cmd;
cmd = e.getActionCommand();
if(cmd.equals("Add"))
txt1.setText("");
txt2.setText("");
txt3.setText("");
else if(cmd.equals("Save"))
mdl.addElement(txt1.getText());
list.setModel(mdl);
try
RandomAccessFile rand = new RandomAccessFile(fob,"rw");
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
LineNumberReader line = new LineNumberReader(br);
if(fob.exists())
rand.seek(fob.length());
rand.writeBytes("* " + txt1.getText());
rand.writeBytes("\r\n" + "# " + txt2.getText());
rand.writeBytes("\r\n" + "# " + txt3.getText() + "\r\n");
else
System.out.println("No such file..");
txt1.setText("");
txt2.setText("");
txt3.setText("");
catch(IOException a)
System.out.println(a.getMessage());
else if(cmd.equals("Cancel"))
txt1.setText("");
txt2.setText("");
txt3.setText("");
else if(cmd.equals("Close"))
System.exit(0);
class ListInfo implements ListSelectionListener
public void valueChanged(ListSelectionEvent e)
ListSelectionModel lsm = (ListSelectionModel)e.getSource();
int minIndex = lsm.getMinSelectionIndex();
int maxIndex = lsm.getMaxSelectionIndex();
try //*this one should display the info of the person whenever i click the person's name at the list box via textbox.. but i cant seem to get it right since it always display the info of the first person inputed.. i tried to get the program to display them whenever it reads lines with * on them....
File fob = new File("Address3.txt");
RandomAccessFile rand = new RandomAccessFile(fob,"rw");
BufferedReader br = new BufferedReader(new FileReader("Address3.txt"));
LineNumberReader line = new LineNumberReader(br);
if(fob.exists())
for(int i = minIndex; i<=maxIndex; i++)
if(lsm.isSelectedIndex(i))
while((name = rand.readLine()) != null)
chars = name.toCharArray();
if(chars[0] == '#')
continue;
if(chars[0] == '*')
txt1.setText(rand.readLine());
txt2.setText(rand.readLine());
txt3.setText(rand.readLine());
else
System.out.println("No such file..");
catch(IOException a)
System.out.println(a.getMessage());
}the only problem now is about how it should display the right info about the person whenever i click its name on the list.. something about file reading or something, i just cant figure it out.
and also about how to make it scroll once it exceeds the list.. i cant make it work, maybe something about wrong declaration..
thanks in advance..
Edited by: syder on Mar 14, 2008 2:26 AMLike said before, do one thing at a time. At startup, something like:
//put all the content in a list
ArrayList<String> lines = new ArrayList<String>();
while(String line=rand.readLine()!=null) {
lines.add(line);
}If you follow the good advice to create a class to encapsulate the entries, you could populate a list of such entries like this:
static final int ENTRY_SIZE = 3;//you have 3 fields now, better to have a constant if that changes
ArrayList<Entry> entries = new ArrayList<Entry>();
for(int i=0; i<lines.size(); i+=ENTRY_SIZE) {
Entry entry = new Entry(lines.get(i), lines.get(i+1), lines.get(i+2);
entries.add(newEntry);
}You could also do both of the above in one run, but I think you will understand better what's happening if you do one thing at a time.
If you don't want to put the entries in an encapsulating class, you can still access this without looping:
int listStartIdx = <desired_entry_index>*ENTRY_SIZE;
String att1 = lines.get(listStartIdx).substring(1);
String att2 = lines.get(listStartIdx+1).substring(1);
String att3 = lines.get(listStartIdx+2).substring(1); -
URGENT Help With Scientific Calculator!
Hi everybody,
I designed a calculator, and I need help with the rest of the actions. I know I need to use the different Math methods, but I tried tried that and it didn't work. Also, it needs to work as an applet and application, and in the applet, the buttons don't appear in order, how can I fix that?
I will really appreciate your help with this program, I can't get it to work and I'm frustrated, I need to finish this for next Tuesday 16th. Please e-mail me at [email protected].
Below is the code for the calcualtor.
Thanks a lot!
-Maria
// calculator
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
public class calculator extends JApplet implements
ActionListener
private JButton one, two, three, four, five, six, seven,
eight, nine, zero, dec, eq, plus, minus, mult, div, clear,
mem, mrc, sin, cos, tan, asin, acos, atan, x2, sqrt, exp, pi, percent;
private JLabel output, blank;
private Container container;
private String operation;
private double number1, number2, result;
private boolean clear = false;
//GUI
public void init()
container = getContentPane();
//Title
//super("Calculator");
JPanel container = new JPanel();
container.setLayout( new FlowLayout( FlowLayout.CENTER
output = new JLabel("");
output.setBorder(new MatteBorder(2,2,2,2,Color.gray));
output.setPreferredSize(new Dimension(1,26));
getContentPane().setBackground(Color.white);
getContentPane().add( "North",output );
getContentPane().add( "Center",container );
//blank
blank = new JLabel( " " );
container.add( blank );
//clear
clear = new JButton( "CE" );
clear.addActionListener(this);
container.add( clear );
//seven
seven = new JButton( "7" );
seven.addActionListener(this);
container.add( seven );
//eight
eight = new JButton( "8" );
eight.addActionListener(this);
container.add( eight );
//nine
nine = new JButton( "9" );
nine.addActionListener(this);
container.add( nine );
//div
div = new JButton( "/" );
div.addActionListener(this);
container.add( div );
//four
four = new JButton( "4" );
four.addActionListener(this);
container.add( four );
//five
five = new JButton( "5" );
five.addActionListener(this);
container.add( five );
//six
six = new JButton( "6" );
six.addActionListener(this);
container.add( six );
//mult
mult = new JButton( "*" );
mult.addActionListener(this);
container.add( mult );
//one
one = new JButton( "1" );
one.addActionListener(this);
container.add( one );
//two
two = new JButton( "2" );
two.addActionListener(this);
container.add( two );
//three
three = new JButton( "3" );
three.addActionListener(this);
container.add( three );
//minus
minus = new JButton( "-" );
minus.addActionListener(this);
container.add( minus );
//zero
zero = new JButton( "0" );
zero.addActionListener(this);
container.add( zero );
//dec
dec = new JButton( "." );
dec.addActionListener(this);
container.add( dec );
//plus
plus = new JButton( "+" );
plus.addActionListener(this);
container.add( plus );
//mem
mem = new JButton( "MEM" );
mem.addActionListener(this);
container.add( mem );
//mrc
mrc = new JButton( "MRC" );
mrc.addActionListener(this);
container.add( mrc );
//sin
sin = new JButton( "SIN" );
sin.addActionListener(this);
container.add( sin );
//cos
cos = new JButton( "COS" );
cos.addActionListener(this);
container.add( cos );
//tan
tan = new JButton( "TAN" );
tan.addActionListener(this);
container.add( tan );
//asin
asin = new JButton( "ASIN" );
asin.addActionListener(this);
container.add( asin );
//acos
acos = new JButton( "ACOS" );
cos.addActionListener(this);
container.add( cos );
//atan
atan = new JButton( "ATAN" );
atan.addActionListener(this);
container.add( atan );
//x2
x2 = new JButton( "X2" );
x2.addActionListener(this);
container.add( x2 );
//sqrt
sqrt = new JButton( "SQRT" );
sqrt.addActionListener(this);
container.add( sqrt );
//exp
exp = new JButton( "EXP" );
exp.addActionListener(this);
container.add( exp );
//pi
pi = new JButton( "PI" );
pi.addActionListener(this);
container.add( pi );
//percent
percent = new JButton( "%" );
percent.addActionListener(this);
container.add( percent );
//eq
eq = new JButton( "=" );
eq.addActionListener(this);
container.add( eq );
//Set size and visible
setSize( 190, 285 );
setVisible( true );
public static void main(String args[]){
//execute applet as application
//applet's window
JFrame applicationWindow = new JFrame("calculator");
applicationWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//applet instance
calculator appletObject = new calculator();
//init and start methods
appletObject.init();
appletObject.start();
} // end main
public void actionPerformed(ActionEvent ae)
JButton but = ( JButton )ae.getSource();
//dec action
if( but.getText() == "." )
//if dec is pressed, first check to make shure there
is not already a decimal
String temp = output.getText();
if( temp.indexOf( '.' ) == -1 )
output.setText( output.getText() + but.getText() );
//clear action
else if( but.getText() == "CE" )
output.setText( "" );
operation = "";
number1 = 0.0;
number2 = 0.0;
//plus action
else if( but.getText() == "+" )
operation = "+";
number1 = Double.parseDouble( output.getText() );
clear = true;
//output.setText( "" );
//minus action
else if( but.getText() == "-" )
operation = "-";
number1 = Double.parseDouble( output.getText() );
clear = true;
//output.setText( "" );
//mult action
else if( but.getText() == "*" )
operation = "*";
number1 = Double.parseDouble( output.getText() );
clear = true;
//output.setText( "" );
//div action
else if( but.getText() == "/" )
operation = "/";
number1 = Double.parseDouble( output.getText() );
clear = true;
//output.setText( "" );
//eq action
else if( but.getText() == "=" )
number2 = Double.parseDouble( output.getText() );
if( operation == "+" )
result = number1 + number2;
else if( operation == "-" )
result = number1 - number2;
else if( operation == "*" )
result = number1 * number2;
else if( operation == "/" )
result = number1 / number2;
//output result
output.setText( String.valueOf( result ) );
clear = true;
operation = "";
//default action
else
if( clear == true )
output.setText( "" );
clear = false;
output.setText( output.getText() + but.getText() );
}Multiple post:
http://forum.java.sun.com/thread.jsp?forum=31&thread=474370&tstart=0&trange=30 -
Need help with a small application
Hi all, I please need help with a small application that I need to do for a homework assignment.
Here is what I need to do:
"Write an application that creates a frame with one button.
Every time the button is clicked, the button must be changed
to a random color."
I already coded a part of the application, but I don't know what to do further.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ColourButton extends JFrame {
JButton button = new JButton("Change Colour");
public ColourButton() {
super ("Colour Button");
setSize(250, 150);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
panel.add(button);
add(panel);
setVisible(true);
public static void main(String[] args) {
ColourButton cb = new ColourButton();
}The thing is I'm not sure what Event Listener I have to implement and use as well as how to get the button to change to a random color everytime the button is clicked.
Can anyone please help me with this.
Thanks.The listener:
Read this: [http://java.sun.com/docs/books/tutorial/uiswing/components/button.html]
The random color:
[Google this|http://www.google.com/search?q=color+random+java] -
Hi everybody,
I designed a calculator, and I need help with the rest of the scientific actions. I know I need to use the different Math methods, but what exactly? Also, it needs to work as an applet and application, and in the applet, the buttons don't appear in order, how can I fix that?
I will really appreciate your help with this program, I need to finish it ASAP. Please e-mail me at [email protected].
Below is the code for the calcualtor.
Thanks in advance,
-Maria
// calculator
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
public class calculator extends JApplet implements
ActionListener
private JButton one, two, three, four, five, six, seven,
eight, nine, zero, dec, eq, plus, minus, mult, div, clear,
mem, mrc, sin, cos, tan, asin, acos, atan, x2, sqrt, exp, pi, percent;
private JLabel output, blank;
private Container container;
private String operation;
private double number1, number2, result;
private boolean clear = false;
//GUI
public void init()
container = getContentPane();
//Title
//super("Calculator");
JPanel container = new JPanel();
container.setLayout( new FlowLayout( FlowLayout.CENTER
output = new JLabel("");
output.setBorder(new MatteBorder(2,2,2,2,Color.gray));
output.setPreferredSize(new Dimension(1,26));
getContentPane().setBackground(Color.white);
getContentPane().add( "North",output );
getContentPane().add( "Center",container );
//blank
blank = new JLabel( " " );
container.add( blank );
//clear
clear = new JButton( "CE" );
clear.addActionListener(this);
container.add( clear );
//seven
seven = new JButton( "7" );
seven.addActionListener(this);
container.add( seven );
//eight
eight = new JButton( "8" );
eight.addActionListener(this);
container.add( eight );
//nine
nine = new JButton( "9" );
nine.addActionListener(this);
container.add( nine );
//div
div = new JButton( "/" );
div.addActionListener(this);
container.add( div );
//four
four = new JButton( "4" );
four.addActionListener(this);
container.add( four );
//five
five = new JButton( "5" );
five.addActionListener(this);
container.add( five );
//six
six = new JButton( "6" );
six.addActionListener(this);
container.add( six );
//mult
mult = new JButton( "*" );
mult.addActionListener(this);
container.add( mult );
//one
one = new JButton( "1" );
one.addActionListener(this);
container.add( one );
//two
two = new JButton( "2" );
two.addActionListener(this);
container.add( two );
//three
three = new JButton( "3" );
three.addActionListener(this);
container.add( three );
//minus
minus = new JButton( "-" );
minus.addActionListener(this);
container.add( minus );
//zero
zero = new JButton( "0" );
zero.addActionListener(this);
container.add( zero );
//dec
dec = new JButton( "." );
dec.addActionListener(this);
container.add( dec );
//plus
plus = new JButton( "+" );
plus.addActionListener(this);
container.add( plus );
//mem
mem = new JButton( "MEM" );
mem.addActionListener(this);
container.add( mem );
//mrc
mrc = new JButton( "MRC" );
mrc.addActionListener(this);
container.add( mrc );
//sin
sin = new JButton( "SIN" );
sin.addActionListener(this);
container.add( sin );
//cos
cos = new JButton( "COS" );
cos.addActionListener(this);
container.add( cos );
//tan
tan = new JButton( "TAN" );
tan.addActionListener(this);
container.add( tan );
//asin
asin = new JButton( "ASIN" );
asin.addActionListener(this);
container.add( asin );
//acos
acos = new JButton( "ACOS" );
cos.addActionListener(this);
container.add( cos );
//atan
atan = new JButton( "ATAN" );
atan.addActionListener(this);
container.add( atan );
//x2
x2 = new JButton( "X2" );
x2.addActionListener(this);
container.add( x2 );
//sqrt
sqrt = new JButton( "SQRT" );
sqrt.addActionListener(this);
container.add( sqrt );
//exp
exp = new JButton( "EXP" );
exp.addActionListener(this);
container.add( exp );
//pi
pi = new JButton( "PI" );
pi.addActionListener(this);
container.add( pi );
//percent
percent = new JButton( "%" );
percent.addActionListener(this);
container.add( percent );
//eq
eq = new JButton( "=" );
eq.addActionListener(this);
container.add( eq );
//Set size and visible
setSize( 190, 285 );
setVisible( true );
public static void main(String args[]){
//execute applet as application
//applet's window
JFrame applicationWindow = new JFrame("calculator");
applicationWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//applet instance
calculator appletObject = new calculator();
//init and start methods
appletObject.init();
appletObject.start();
} // end main
public void actionPerformed(ActionEvent ae)
JButton but = ( JButton )ae.getSource();
//dec action
if( but.getText() == "." )
//if dec is pressed, first check to make shure there
is not already a decimal
String temp = output.getText();
if( temp.indexOf( '.' ) == -1 )
output.setText( output.getText() + but.getText() );
//clear action
else if( but.getText() == "CE" )
output.setText( "" );
operation = "";
number1 = 0.0;
number2 = 0.0;
//plus action
else if( but.getText() == "+" )
operation = "+";
number1 = Double.parseDouble( output.getText() );
clear = true;
//output.setText( "" );
//minus action
else if( but.getText() == "-" )
operation = "-";
number1 = Double.parseDouble( output.getText() );
clear = true;
//output.setText( "" );
//mult action
else if( but.getText() == "*" )
operation = "*";
number1 = Double.parseDouble( output.getText() );
clear = true;
//output.setText( "" );
//div action
else if( but.getText() == "/" )
operation = "/";
number1 = Double.parseDouble( output.getText() );
clear = true;
//output.setText( "" );
//eq action
else if( but.getText() == "=" )
number2 = Double.parseDouble( output.getText() );
if( operation == "+" )
result = number1 + number2;
else if( operation == "-" )
result = number1 - number2;
else if( operation == "*" )
result = number1 * number2;
else if( operation == "/" )
result = number1 / number2;
//output result
output.setText( String.valueOf( result ) );
clear = true;
operation = "";
//default action
else
if( clear == true )
output.setText( "" );
clear = false;
output.setText( output.getText() + but.getText() );Multiple post:
http://forum.java.sun.com/thread.jsp?forum=31&thread=474370&tstart=0&trange=30 -
Hi, I'm not sure if I'm allowed to post questions on this forum but I can't find anywhere to talk to helpful people about programming.
I'm making a dnd interface for JComponents. So far I've made a simple program that has a Component that can be lifted from a container and braught to the glass pane then later moved to anywhere on the screen and dropped into the container below it. Here's where my problems come:
1) Rite now my 'Movable Component' is a JPanel which is just colored in. I want to either take a Graphic2d from a JComponent/Component and draw it on the JPanel or change the JPanel to the component I want to paint and disable the component.
The problem with getting the Graphics2d is that if the component isn't on the screen it doesn't make a graphic object. I tried messing with the ui delicate and overriding parental methods for paintComponent, repaint, and that repaintChildren(forget name) but I haven't had luck getting a good graphics object. I was thinking of, at the beginning of running the program, putting 1 of each component onto the screen for a second then removing it but I'd rather not. I'd also like to change the graphics dynamicly if someone stretches the component there dropping and what not.
The problem with disabling is that it changes some of the visual features of Components. I want to be able to update the Component myself to change how it looks and I don't want disabling to gray out components.
I mainly just dont want the components to do any of there normal fuctions. This is for a page builder, by the way.
Another problem I'm having is that mouseMotionListener is allowing me to select 2 components that are on top of one another when there edges are near each other. I don't know if theres a fix to this other than changing the Java Class.
My next problem is a drop layout manager, but I'm doing pretty good with that rite now. It'll problem just move components out of the way of the falling component.
One last thing I need help with is that I don't want the object that's being carried to go across the menu bar and certain areas. When I'm having the object being carried I have it braught up to the glass pane which allows it to move anywhere. Does anyone have any idea how I could prevent the component from being over the menu bars and other objects? I might have to make 1 panel is the movable area that can then be broken down into the 'component bank', 'building page' and whatever else I'm gonna need.
This is all just test code to get together for when I make the real program but I need to make sure it'll be possible without a lot of hacking of code.
Sorry for the length. Thanks for any help you can give.The trick to making viewable components that have no behaviour, is to render them onto an image of some sort (eg a BufferedImage). You can then display the Image on a JLabel that can be dragged around the desktop.
Here is a piece of code that does the component rendering for you. This particular example uses a fixed component size, but you can modify that as you choose of course...public class JComponentImage
private static GraphicsConfiguration gConfig;
private static Dimension compSize = new Dimension(80, 22);
private static Image image = null;
public static Image getImage(Class objectClass)
if (gConfig == null)
GraphicsEnvironment gEnv = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice gDevice = gEnv.getDefaultScreenDevice();
gConfig = gDevice.getDefaultConfiguration();
image = gConfig.createCompatibleImage(compSize.width, compSize.height);
JComponent jc = (JComponent) ObjectFactory.instantiate(objectClass);
jc.setSize(compSize);
Graphics g = image.getGraphics();
g.setColor(Color.LIGHT_GRAY);
g.fillRect(0, 0, compSize.width, compSize.height);
g.setColor(Color.BLACK);
jc.paint(g);
return image;
}And here is the class that makes the dragable JLabel using the class above...public class Dragable extends JLabel
private static DragSource dragSource = DragSource.getDefaultDragSource();
private static DragGestureListener dgl = new DragMoveGestureListener();
private static TransferHandler th = new ObjectTransferHandler();
private Class compClass;
private Image image;
Dragable(Class compClass)
this.compClass = compClass;
image = JComponentImage.getImage(compClass);
setIcon(new ImageIcon(image));
setTransferHandler(th);
dragSource.createDefaultDragGestureRecognizer(this,
DnDConstants.ACTION_COPY,
dgl);
public Class getCompClass()
return compClass;
}Oh and here is ObjectFactory which simply instantiates Objects of a given class and sets their text to their classname (very crudely)...public class ObjectFactory
public static Object instantiate(Class objectClass)
Object o = null;
try
o = objectClass.newInstance();
catch (Exception e)
System.out.println("ObjectFactory#instantiate: " + e);
String name = objectClass.getName();
int lastDot = name.lastIndexOf('.');
name = name.substring(lastDot + 1);
if (o instanceof JLabel)
((JLabel)o).setText(name);
if (o instanceof JButton)
((JButton)o).setText(name);
if (o instanceof JTextComponent)
((JTextComponent)o).setText(name);
return o;
}Two more classes required by this codepublic class ObjectTransferHandler extends TransferHandler {
private static DataFlavor df;
* Constructor for ObjectTransferHandler.
public ObjectTransferHandler() {
super();
try {
df = new DataFlavor(DataFlavor.javaJVMLocalObjectMimeType);
} catch (ClassNotFoundException e) {
Debug.trace(e.toString());
public Transferable createTransferable(JComponent jC) {
Transferable t = null;
try {
t = new ObjectTransferable(((Dragable) jC).getCompClass());
} catch (Exception e) {
Debug.trace(e.toString());
return t;
public int getSourceActions(JComponent c) {
return DnDConstants.ACTION_MOVE;
public boolean canImport(JComponent comp, DataFlavor[] flavors) {
if (!(comp instanceof Dragable) && flavors[0].equals(df))
return true;
return false;
public boolean importData(JComponent comp, Transferable t) {
JComponent c = null;
try {
c = (JComponent) t.getTransferData(df);
} catch (Exception e) {
Debug.trace(e.toString());
comp.add(c);
comp.validate();
return true;
public class ObjectTransferable implements Transferable {
private static DataFlavor df = null;
private Class objectClass;
ObjectTransferable(Class objectClass) {
try {
df = new DataFlavor(DataFlavor.javaJVMLocalObjectMimeType);
} catch (ClassNotFoundException e) {
System.out.println("ObjectTransferable: " + e);
this.objectClass = objectClass;
* @see java.awt.datatransfer.Transferable#getTransferDataFlavors()
public DataFlavor[] getTransferDataFlavors() {
return new DataFlavor[] { df };
* @see java.awt.datatransfer.Transferable#isDataFlavorSupported(DataFlavor)
public boolean isDataFlavorSupported(DataFlavor testDF) {
return testDF.equals(df);
* @see java.awt.datatransfer.Transferable#getTransferData(DataFlavor)
public Object getTransferData(DataFlavor arg0)
throws UnsupportedFlavorException, IOException {
return ObjectFactory.instantiate(objectClass);
}And of course the test class:public class DragAndDropTest extends JFrame
JPanel leftPanel = new JPanel();
JPanel rightPanel = new JPanel();
Container contentPane = getContentPane();
Dragable dragableJLabel;
Dragable dragableJButton;
Dragable dragableJTextField;
Dragable dragableJTextArea;
* Constructor DragAndDropTest.
* @param title
public DragAndDropTest(String title)
super(title);
dragableJLabel = new Dragable(JLabel.class);
dragableJButton = new Dragable(JButton.class);
dragableJTextField = new Dragable(JTextField.class);
dragableJTextArea = new Dragable(JTextArea.class);
leftPanel.setBorder(new EtchedBorder());
BoxLayout boxLay = new BoxLayout(leftPanel, BoxLayout.Y_AXIS);
leftPanel.setLayout(boxLay);
leftPanel.add(dragableJLabel);
leftPanel.add(dragableJButton);
leftPanel.add(dragableJTextField);
leftPanel.add(dragableJTextArea);
rightPanel.setPreferredSize(new Dimension(500,500));
rightPanel.setBorder(new EtchedBorder());
rightPanel.setTransferHandler(new ObjectTransferHandler());
contentPane.setLayout(new BorderLayout());
contentPane.add(leftPanel, "West");
contentPane.add(rightPanel, "Center");
public static void main(String[] args)
JFrame frame = new DragAndDropTest("Drag and Drop Test");
frame.pack();
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setVisible(true);
}I wrote this code some time ago, so it won't be perfect but hopefully will give you some good ideas.
Regards,
Tim -
Need help with basic program.....!
I've to write a program that generates a random number, which the user has to try and guess, after each guess they're told whether it's too high or too low etc., I've gotten this far, however, the user has only 10 guesses.... In my program I've used a while loop and the user gets an infinite number of guesses, I know I'm supposed to use a for loop, but can't seem to get it to work properly. Also, when the user guesses the number, the program then has to print out how many guesses it took, and I have no idea how to get it to do this AT ALL!!! I'd really appreciate some help with this, thanks v. much!!!!
I've to write a program that generates a random
number, which the user has to try and guess, after
each guess they're told whether it's too high or too
low etc., I've gotten this far, however, the user has
only 10 guesses.... In my program I've used a while
loop and the user gets an infinite number of guesses,
I know I'm supposed to use a for loop, but can't seem
to get it to work properly. Also, when the user
guesses the number, the program then has to print out
how many guesses it took, and I have no idea how to
get it to do this AT ALL!!! I'd really appreciate some
help with this, thanks v. much!!!!Hey not every book covers every aspect of Java (if you haven't got a book and don't want to buy 1 i recommend an online tutorial) If u want the user to have an infinate number of guesses, use an infinate while loop. Put this in a file called app.java:
import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class app extends Applet implements ActionListener
JLabel lbl=new JLabel("Guess a number between 0 and 10:");
JTextField txtfield=new JTextField(20);
JButton button=new JButton("Guess...");
JLabel lbl2=new JLabel();
int randomnumber=Math.round((float)Math.random()*10);
public void init()
add(lbl);
add(txtfield);
add(button);
button.addActionListener(this);
public void actionPerformed (ActionEvent e)
String s=new String("");
s+=randomnumber;
if (e.getSource().equals(button) && txtfield.getText().equals(s))
setBackground(Color.white);
setForeground(Color.black);
lbl2.setText("Got it!");
add(lbl2);
validate();
else
setBackground(Color.white);
setForeground(Color.black);
if (Integer.parseInt(txtfield.getText())>randomnumber)
lbl2.setText("Too High!");
else
lbl2.setText("Too Low!");
add(lbl2);
validate();
Then create a HTML document in the classes folder:
<HTML>
<HEAD>
<TITLE>APPLET</TITLE>
</HEAD>
<BODY>
<HR>
<CENTER>
<APPLET
CODE=app.class
WIDTH=400
HEIGHT=200 >
</APPLET>
</CENTER>
<HR>
</BODY>
</HTML>
It will do what you wish. If you want to have more then 10 numbers to guess, for example 100, do this:
int randomnumber=Math.round((float)Math.random()*100);
Does that answer your question? -
Help with BufferedImage and JPanel
I have a program that should display some curves, but thats not the problem, the real problem is when i copy the image contained in the JPanel to the buffered image then i draw something there and draw it back to the JPanel. My panel initialy its white but after the operation it gets gray
Please if some one could help with this
here is my code divided in three classes
//class VentanaPrincipal
package gui;
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JSeparator;
import javax.swing.border.LineBorder;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
* This code was edited or generated using CloudGarden's Jigloo
* SWT/Swing GUI Builder, which is free for non-commercial
* use. If Jigloo is being used commercially (ie, by a corporation,
* company or business for any purpose whatever) then you
* should purchase a license for each developer using Jigloo.
* Please visit www.cloudgarden.com for details.
* Use of Jigloo implies acceptance of these licensing terms.
* A COMMERCIAL LICENSE HAS NOT BEEN PURCHASED FOR
* THIS MACHINE, SO JIGLOO OR THIS CODE CANNOT BE USED
* LEGALLY FOR ANY CORPORATE OR COMMERCIAL PURPOSE.
public class VentanaPrincipal extends javax.swing.JFrame {
//Set Look & Feel
try {
javax.swing.UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch(Exception e) {
e.printStackTrace();
private JMenuItem helpMenuItem;
private JMenu jMenu5;
private JMenuItem deleteMenuItem;
private JSeparator jSeparator1;
private JMenuItem pasteMenuItem;
private JLabel jLabel4;
private JLabel jLabel5;
private JLabel jLabel3;
private JLabel jLabel2;
private JLabel jLabel1;
private JButton jSPLineButton;
private JButton jHermiteButton;
private JButton jBezierButton;
private JPanel jPanel2;
private JPanel jPanel1;
private JMenuItem jResetMenuItem1;
private JMenuItem copyMenuItem;
private JMenuItem cutMenuItem;
private JMenu jMenu4;
private JMenuItem exitMenuItem;
private JSeparator jSeparator2;
private JMenu jMenu3;
private JMenuBar jMenuBar1;
* Variables no autogeneradas
private int botonSeleccionado;
* Auto-generated main method to display this JFrame
public static void main(String[] args) {
VentanaPrincipal inst = new VentanaPrincipal();
inst.setVisible(true);
public VentanaPrincipal() {
super();
initGUI();
private void initGUI() {
try {
this.setTitle("Info3 TP 2");
jPanel1 = new pizarra();
getContentPane().add(jPanel1, BorderLayout.WEST);
jPanel1.setPreferredSize(new java.awt.Dimension(373, 340));
jPanel1.setMinimumSize(new java.awt.Dimension(10, 342));
jPanel1.setBackground(new java.awt.Color(0,0,255));
jPanel1.setBorder(BorderFactory.createCompoundBorder(
new LineBorder(new java.awt.Color(0, 0, 0), 1, true),
null));
BufferedImage bufimg = (BufferedImage)jPanel1.createImage(jPanel1.getWidth(), jPanel1.getHeight());
((pizarra) jPanel1).setBufferedImage(bufimg);
jPanel2 = new JPanel();
getContentPane().add(jPanel2, BorderLayout.CENTER);
GridBagLayout jPanel2Layout = new GridBagLayout();
jPanel2Layout.rowWeights = new double[] {0.0, 0.0, 0.0, 0.0};
jPanel2Layout.rowHeights = new int[] {69, 74, 76, 71};
jPanel2Layout.columnWeights = new double[] {0.0, 0.0, 0.1};
jPanel2Layout.columnWidths = new int[] {83, 75, 7};
jPanel2.setLayout(jPanel2Layout);
jBezierButton = new JButton();
jPanel2.add(jBezierButton, new GridBagConstraints(1, 0, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(0, 0, 0, 0), 0, 0));
jBezierButton.setText("Bezier");
jBezierButton.setFont(new java.awt.Font("Tahoma",0,10));
jBezierButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
bezierActionPerformed();
jHermiteButton = new JButton();
jPanel2.add(jHermiteButton, new GridBagConstraints(1, 1, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(0, 0, 0, 0), 0, 0));
jHermiteButton.setText("Hermite");
jHermiteButton.setFont(new java.awt.Font("Tahoma",0,10));
jSPLineButton = new JButton();
jPanel2.add(jSPLineButton, new GridBagConstraints(1, 2, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(0, 0, 0, 0), 0, 0));
jSPLineButton.setText("SP Line");
jSPLineButton.setFont(new java.awt.Font("Tahoma",0,10));
jLabel1 = new JLabel();
jPanel2.add(jLabel1, new GridBagConstraints(0, 3, 1, 1, 0.0, 0.0, GridBagConstraints.CENTER, GridBagConstraints.NONE, new Insets(0, 0, 0, 0), 0, 0));
jLabel1.setText("Posicion Mouse");
jLabel2 = new JLabel();
jPanel2.add(jLabel2, new GridBagConstraints(1, 3, 1, 1, 0.0, 0.0, GridBagConstraints.NORTH, GridBagConstraints.NONE, new Insets(12, 0, 0, 0), 0, 0));
jLabel2.setText("X:");
jLabel3 = new JLabel();
jPanel2.add(jLabel3, new GridBagConstraints(1, 3, 1, 1, 0.0, 0.0, GridBagConstraints.SOUTH, GridBagConstraints.NONE, new Insets(0, 0, 12, 0), 0, 0));
jLabel3.setText("Y:");
jLabel4 = new JLabel();
jPanel2.add(jLabel4, new GridBagConstraints(2, 3, 1, 1, 0.0, 0.0, GridBagConstraints.NORTH, GridBagConstraints.NONE, new Insets(12, 0, 0, 0), 0, 0));
jLabel4.setText("-");
jLabel5 = new JLabel();
jPanel2.add(jLabel5, new GridBagConstraints(2, 3, 1, 1, 0.0, 0.0, GridBagConstraints.SOUTH, GridBagConstraints.NONE, new Insets(0, 0, 12, 0), 0, 0));
jLabel5.setText("-");
this.setSize(600, 400);
jMenuBar1 = new JMenuBar();
setJMenuBar(jMenuBar1);
jMenu3 = new JMenu();
jMenuBar1.add(jMenu3);
jMenu3.setText("Archivo");
jSeparator2 = new JSeparator();
jMenu3.add(jSeparator2);
exitMenuItem = new JMenuItem();
jMenu3.add(exitMenuItem);
exitMenuItem.setText("Exit");
jResetMenuItem1 = new JMenuItem();
jMenu3.add(jResetMenuItem1);
jResetMenuItem1.setText("Reset");
jMenu4 = new JMenu();
jMenuBar1.add(jMenu4);
jMenu4.setText("Edit");
cutMenuItem = new JMenuItem();
jMenu4.add(cutMenuItem);
cutMenuItem.setText("Cut");
copyMenuItem = new JMenuItem();
jMenu4.add(copyMenuItem);
copyMenuItem.setText("Copy");
pasteMenuItem = new JMenuItem();
jMenu4.add(pasteMenuItem);
pasteMenuItem.setText("Paste");
jSeparator1 = new JSeparator();
jMenu4.add(jSeparator1);
deleteMenuItem = new JMenuItem();
jMenu4.add(deleteMenuItem);
deleteMenuItem.setText("Delete");
jMenu5 = new JMenu();
jMenuBar1.add(jMenu5);
jMenu5.setText("Help");
helpMenuItem = new JMenuItem();
jMenu5.add(helpMenuItem);
helpMenuItem.setText("Help");
} catch (Exception e) {
e.printStackTrace();
private void bezierActionPerformed(){
botonSeleccionado = 1;
((pizarra) jPanel1).setTipoFigura(botonSeleccionado);
((pizarra) jPanel1).pintarGrafico();
//class graphUtils
package func;
import java.awt.Image;
import java.awt.Point;
import java.awt.image.BufferedImage;
public class graphUtils {
public static void dibujarPixel(BufferedImage img, int x, int y, int color){
img.setRGB(x, y, color);
public static void dibujarLinea(BufferedImage img, int x0, int y0, int x1, int y1, int color){
int dx = x1 - x0;
int dy = y1 - y0;
if (Math.abs(dx) > Math.abs(dy)) { // Pendiente m < 1
float m = (float) dy / (float) dx;
float b = y0 - m*x0;
if(dx < 0) dx = -1; else dx = 1;
while (x0 != x1) {
x0 += dx;
dibujarPixel(img, x0, Math.round(m*x0 + b), color);
} else
if (dy != 0) { // Pendiente m >= 1
float m = (float) dx / (float) dy;
float b = x0 - m*y0;
if(dy < 0) dy = -1; else dy = 1;
while (y0 != y1) {
y0 += dy;
dibujarPixel(img, Math.round(m*y0 + b), y0, color);
public static void dibujarBezier(BufferedImage img, Point puntos, int color){
//class pizarra
package gui;
import javax.swing.*;
import sun.awt.VerticalBagLayout;
import sun.security.krb5.internal.bh;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import func.graphUtils;
* esta clase pizarra extiende la clase JPanel y se agregan las funciones de pintado
* y rellenado que se muestra en pantalla dentro del panel que se crea con esta clase
* @author victorg
public class pizarra extends JPanel implements MouseListener{
private int tipoFigura;
BufferedImage bufferImagen;
Image img;
Graphics img_gc;
private Color colorRelleno, colorLinea;
private Point puntosBezier[] = new Point[3];
public pizarra(){
super();
addMouseListener(this);
//this.setBackground(Color.BLUE);
colorLinea = Color.BLUE;
public void setTipoFigura(int seleccion){
// se setea para ver si es bezier, hermite, SP line
tipoFigura = seleccion;
public void setTipoRelleno(int seleccion){
public void setColorRelleno(Color relleno){
colorRelleno = relleno;
public void setColorLinea(Color linea){
colorLinea = linea;
public void setBufferedImage(BufferedImage bufimg){
bufferImagen = bufimg;
public void pintarGrafico(){
Graphics g = this.getGraphics();
g.setColor(colorLinea);
//accion ejecutada cuando se selecciona para graficar un poligono
if(tipoFigura == 1){// bezier
if(bufferImagen == null){
//mantiene guardada la imagen cuando la pantalla pasa a segundo plano
bufferImagen = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_RGB);
this.setBackground(Color.WHITE);
bufferImagen = (BufferedImage)createImage(getWidth(), getHeight());
//bufferImagen = this.createImage(getWidth(), getHeight());
//g.drawImage(bufferImagen,0,0,this);
graphUtils.dibujarLinea(bufferImagen,10, 10, 50, 50, colorLinea.getRGB());
g.drawImage(bufferImagen,0,0,this);
protected void paintComponent(Graphics g) { // llamado al repintar
//setBackground(colorFondo);
super.paintComponent(g);
// Graphics2D g2 = (Graphics2D)g;
// g2.drawImage(bufferImagen, 0,0, this);
// g2.dispose();
public void mouseClicked(MouseEvent arg0) {
public void mousePressed(MouseEvent arg0) {
// TODO Auto-generated method stub
public void mouseReleased(MouseEvent arg0) {
// TODO Auto-generated method stub
public void mouseEntered(MouseEvent arg0) {
// TODO Auto-generated method stub
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}1) Swing related questions should be posted in the Swing forum.
Custom painting should be done in the paintComponent(..) method. You created a "pintarGraphico" method to do the custom painting, but that method is only execute once. When Java determines that the panel needs to be repainted, the paintComponent() method is executed which simply does a super.paintComponent(), which in turn simply paints the background of the panel overwriting you custom painting. -
Help with dropdown menu in JCombo box,Pleaseeeeeee
Hi,
I posted earlier but I`II try again. Someone must know how to do this. I have a JComboBox and I want the drop down menu to be a bit wider then the comboBox.
I tried using this method
public void setPreferredSize()
Dimension d = jcbo.getPreferredSize(d);
jcbo.setPreferredSize(new Dimension(20, d.height));
jcbo.setPopupWidth(d.width);
but I recieved a couldn`t resolve symbol error for the last line.
I imported these into the program]
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
Is there something else I should of imported as well to make this work, or is it another problem all together.Any help would be greatly appreciated.Hi , What I want to do is have the dropmenu a bit wider then the comboBox. Here is my code.Please excuse any odd ball mistakes, At this point I have been trying anything.This is an exercise that I have to do fo a java assignment, Hence the weird GUI. In the example pic they gave me.It shows the dropmenu a bit wider than the comboBox, I am sure they through this in to screw with my brain, I have put comment tags Around the stuff I tried to use. Any help with this would be greatly appreciated.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
//import javax.swing.plaf.basic.*;
public class Exercise9_3 extends JFrame implements ActionListener
private JTextField nameField;
private JTextArea nameArea;
private JButton storeButton;
private JComboBox jcbo;
private JPopupMenu popup;
protected int popupWidth;
String newline = "\n";
public Exercise9_3()
createComponets();
addComponets();
setTitle("Exercise9_3");
private void createComponets ()
nameField = new JTextField(19);
nameArea = new JTextArea(10, 15);
storeButton = new JButton("Store");
storeButton.addActionListener(this);
jcbo = new JComboBox();
jcbo.addActionListener(this);
/*8public void setPreferredSize()
Dimension d = jcbo.getPreferredSize(d);
//jcbo.setPreferredSize(new Dimension(20, d.height));
//jcbo.setPopupWidth(d.width);
private void addComponets()
JPanel p1 = new JPanel();
p1.setLayout (new FlowLayout());
p1.add(nameField);
p1.add(nameArea);
p1.add(jcbo);
JPanel p2 = new JPanel();
p2.setLayout (new FlowLayout());
p2.add (storeButton);
getContentPane().setLayout(new BorderLayout());
getContentPane().add(p1, BorderLayout.CENTER);
getContentPane().add(p2, BorderLayout.SOUTH);
public void actionPerformed(ActionEvent e)
if(e.getSource() == storeButton)
String s = nameField.getText();
jcbo.addItem(s);
jcbo.setSelectedItem(s);
String textArea = s ;
String text = nameField.getText();
nameArea.append(text + newline);
nameField.selectAll();
nameField.setText("");
nameField.requestFocus();
if (e.getSource() == jcbo)
/**retrieve the input as a string*/
String selectedName = (String)jcbo.getSelectedItem();
/**set the name that was selected from the ComboBox and add it to textfield*/
nameField.setText(selectedName);
public static void main(String [] args)
Exercise9_3 frame = new Exercise9_3();
frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
int screenWidth = screenSize.width;
int screenHeight = screenSize.height;
// Get dimension of the frame
Dimension frameSize = frame.getSize();
int x = (screenWidth - frameSize.width)/2;
int y = (screenHeight- frameSize.height)/2;
frame.setLocation(x,y);
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