Using Swing in Java I wrote a form containing radio buttons, text fields and so on. In the very end I have a "Submit" button.
Now I want to "send" the information given by the user to the program. How do I do that? Is there a good tutorial about that?
Is it kind of similar to PHP? (I am asking just because I know how to do it in PHP. To avoid confusions I probably need to mention that I do NOT program a web application).
Processing data in Swing is way different from the typical web REQUEST/RESPONSE paradigm.
To Take something you may know, it's more in the fashion of Javascript actions in an HTML page : each time user performs an operation, one or more events are sent, and the application developper can update application content according to it.
In your case, if you register an ActionListener to the button, it will be called each time button is clicked. You'll then have the possibility to perform any operation you want.
But that's not all !
Each time a component is keyboard focused, or receives the mouse, events are sent, as well as when a key is stroked or when widget's model is updated.
I would really suggest you to read documents such as Swing tutorial (which dives in greater details than I could do in 1 month).
Not completely sure what you mean by "send to the program". You are in the program so I assume that you have a dialog that renders this form? Just pass the dialog the object that you want to use to store the data. For example, your dialog's constructor can take an argument.
public class MyDialog extends JPanel {
private UserInfo userInfo;
private JTextField name;
/**
* The main area of the dialog.
*/
protected JPanel panel;
public MyDialog(UserInfo userInfo) {
this.userInfo = userInfo;
}
public showDialog() {
// Some code to create the form which it looks like you already know how to do
// Create a name field
JLabel nameLabel = new JLabel("Name:");
panel.add( nameLabel );
JButton submit = new JButton("Submit");
submit.addActionListener( new ActionListener() {
public void actionPerformed (ActionEvent event)
{
this.userInfo.setName(name.getText().trim());
} } );
panel.add( submit );
}
}
Related
i put text on a JTextfield and i try to use that text in another class
... i have no error but no result
btnEntrez.addActionListener(new AuthentificationListner());
public class AuthentificationListner implements ActionListener{
#Override
public void actionPerformed(ActionEvent e) {
Authentification aut = new Authentification();
String login = aut.txtnom.getText();
System.out.println("Login :"+login);
}
result :
Login : (But no textfield text :/ )
If Authentification is a JFrame, then aut.txtnom.getText() isn't going to return anything (other than what it was initialized with) as the user won't have time to enter anything before you try and grab the value, this is what JDialog is for. See How to make dialogs for more details.
Swing, like most UI frameworks is event driven, something happens, you respond to it, rather the procedural or linear (which your code seems to be trying to do)
Another approach is to use an observer pattern on Authentification, which will notify interested parties that something (they might be interested in) has changed.
I am trying to create a JPanel to display when a user clicks a button within my main JFrame. In Netbeans I first used the wizard to add a new JPanel to my project, I then used the GUI creator to fill in all the content. I am not trying to display the JPanel with the following code
private void m_jbShowSelAccResultsActionPerformed(java.awt.event.ActionEvent evt)
{
Account selAcc = getSelectedAccount();
if(selAcc != null)
{
AccountView accPanel = new AccountView(Account.getDeepCopy(selAcc));
accPanel.setVisible(true);
}
else
ShowMessage("Please select an account to view");
}
But nothing happens, no error is thrown and the JPanel is not shown. So I then changed the JPanel to a JFrame (Netbeans didn't complain). When I try again with the same code I receive the error GroupLayout can only be used with one Container at a time.
How can I display my JPanel/JFrame?
To change views within a Swing GUI, use a CardLayout as this is a much more robust and reliable way to do this.
Don't try to blindly "change a JPanel to a JFrame". It looks like you're just guessing here.
GroupLayout can't be reused as the error message is telling you. Likely this error comes from the point above. If you avoid trying to make a JFrame out of a JPanel, the error message will likely go away. As an aside, GroupLayout is not easily used manually, especially if you're trying to add components to an already rendered GUI.
So for instance, if your program had a JPanel say called cardHolderPanel, that used a CardLayout, this held by a variable say called cardLayout, and you've already added a "card" JPanel to this holder for accounts, say called accPanel, and if the accPanel had a method to set its currently displayed account, say setAccount(Accoint a), you could easily swap views by calling the CardLayout show(...) method, something like:
private void m_jbShowSelAccResultsActionPerformed(java.awt.event.ActionEvent evt) {
Account selAcc = getSelectedAccount();
if(selAcc != null) {
accPanel.setAccount(Account.getDeepCopy(selAcc));
cardLayout.show(cardHolderPanel, "Account View");
}
else {
showErrorMessage("Please select an account to view");
}
}
I have some page that should have dynamic count of check boxes, and inputs depends on data received from database
now I do like this:
make rpc call on component load (getting data for inputs)
onSuccess add inputs dynamically on the form
result: form displayed without content(because it makes call async), only after resizing, it displays content properly
(probably I can fire resize event or redraw with my self, don't know how.. )
question: I am new in GWT, What is the best way to do this task? (Now i am using gwt-ext http://gwt-ext.com/, but I think it's no matter )
update: to refresh panel it's possible to call doLayout();
I'm not familiar with gwt-ext but in "vanilla" gwt you have two options:
Refresh your widget (that should show the result) in the onSuccess method
Proceed with the rest of your code not until the result returned.
To get a bit more precise i would need more of your code.
I had a similar challenge, the content of my widget was loading for a few seconds. I display a ""Loading, please wait ..."" label until the widget is loaded:
final VerticalPanel mainPanel = new VerticalPanel();
initWidget(mainPanel);
mainPanel.add(new Label("Loading, please wait ..."));
mainPanel.add(new myCustomWidget()); // this constructor uses RPC to get content
Timer t = new Timer()
{
public void run()
{
if (!mainPanel.getWidget(1).isVisible()) {
// do nothing
} else {
// remove label "Loading, please wait ..."
mainPanel.remove(0);
// stop timer
cancel();
}
}
};
// repeat every 30 miliseconds until myCustomWidget is visible
t.scheduleRepeating(30);
When a user clicks a JButton in my Java-Swing application, a string is returned from a method and the user then needs to be able to read the string (somehow). The JButton is within a JPanel. My first thought was to create an 'alert' dialogue (thinking this would be easy), I tried to follow this example that looked easy: http://www.java2s.com/Code/Java/SWT-JFace-Eclipse/DialogExample.htm
I have not yet been able to confirm if this works because I do not know how to import the libraries into eclipse. For example import org.eclipse.swt.SWT; gives the error "... cannot be resolved".
So one possible solution is how to import in Eclipse. Another possible solution is to dynamically change the text within the JPanel somehow.
As Ben mentioned in his comment. I would set a jLabel with a blank text to start. Then, when you click your button that triggers the method, simply tack on:
label.setText(value);
Alternatively you could use another pane to popup and display the message.
If you're talking about Swing, an easy solution is to pop a message box with the string:
button.addActionListener(new ActionListener {
public void actionPerformed(ActionEvent e) {
String message = methodThatReturnsYourString();
JOptionPane.showMessageDialog(null, message);
}
}
In this link you will find the information u require in order to add the library and import it:
http://www.eclipsepluginsite.com/swt.html
as well I would not mix SWT with swing and I would stick to swing you can set the label on the event of your button
button.addActionListener(new ActionListener {
public void actionPerformed(ActionEvent e) {
String message = "Test String";
labelMessage.setText(message );
}
}
I am trying to make a program to manage a group of sports players. Each player has an enum Sport, and SportManager has convenient factory methods. What I am trying to do is open a dialog that has a JTextField for a name and a combo box to choose a sport. However, I want to stop the user from closing the dialog while the text field is blank, so I wrote a PropertyChangeListener so that when the text field is blank, it would beep to let the user know. However, if the user puts in something in the text after setting off the beep, it doesn't trigger the listener and you can't close the dialog without pressing cancel because the value is already JOptionPane.OK_OPTION, and cancel is the only way to change JOptionPane.VALUE_PROPERTY. So I tried to add
message.setValue(JOptionPane.UNITIALIZED_VALUE);
within the listener. However this just closes the window right away without giving the user a chance to fill in the text field, presumably because it triggers the listener I just registered. How do I make it so that it will beep more than once and give the user a chance to fill in the field?
FYI newPlayer is the component I'm registering the action to.
Code:
newPlayer.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
Object[] msg = new Object [4];
msg[0] = new JLabel("Name:");
final JTextField nameField = new JTextField();
msg[1]=nameField;
msg[2] = new JLabel("Sport: ");
JComboBox<Sport> major = new JComboBox<Sport>(SportManager.getAllSports());
msg[3]=major;
final JOptionPane message = new JOptionPane();
message.setMessage(msg);
message.setMessageType(JOptionPane.PLAIN_MESSAGE);
message.setOptionType(JOptionPane.OK_CANCEL_OPTION);
final JDialog query = new JDialog(gui,"Create a new player",true);
query.setContentPane(message);
query.setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
message.addPropertyChangeListener(
new PropertyChangeListener() {
public void propertyChange(PropertyChangeEvent e) {
String prop = e.getPropertyName();
if (query.isVisible()&& (e.getSource() == message)&& (prop.equals(JOptionPane.VALUE_PROPERTY))) {
if(nameField.getText().equals("")&&message.getValue().equals(JOptionPane.OK_OPTION)){
Toolkit.getDefaultToolkit().beep();
message.setValue(JOptionPane.UNINITIALIZED_VALUE);
return;
}
query.dispose();
}
}
});
query.pack();
query.setVisible(true);
if(Integer.parseInt(message.getValue().toString())==JOptionPane.OK_OPTION){
players.add(new Player(nameField.getText(),(Sport)major.getSelectedItem()));
edited=true;
}
gui.show(players);
}
});
I don't think you can do it with JOptionPane but you can using using TaskDialog framework and few others.
You can also create a dialog yourself, attach change listeners to your fields and enable/disable OK button based on content of your fields. This process is usually called "form validation"
However, I want to stop the user from closing the dialog while the
text field is blank
I get where you are going, but Java Swing is not very good at this. There is no way you can prevent the listener from being called. A solution would be to ignore the call, but this is complicated to implement.
The way I solved this issue is to let the pop-up disappear, check the returned value and if it is null/empty, beep and re-open it until user fills something.
JOptionPane does not internally support validation of inputs (Bug Reference). Your best bet is to create your own custom JDialog which supports disabling the OK button when the input data is invalid.
I'd recommend reading the bug report since other people talk about it and give workarounds.
However, I want to stop the user from closing the dialog while the text field is blank
The CustomDialog example from the section in the Swing tutorial on Stopping Automatic Dialog Closing has a working example that does this.
After taking a quick look at your code and the working example I think your code should be something like:
if (query.isVisible()
&& (e.getSource() == message)
&& (prop.equals(JOptionPane.VALUE_PROPERTY)))
{
if (message.getValue() == JOptionPane.UNINITIALIZED_VALUE)
return;
if (nameField.getText().equals("")
&& message.getValue().equals(JOptionPane.OK_OPTION))
{
Toolkit.getDefaultToolkit().beep();
message.setValue(JOptionPane.UNINITIALIZED_VALUE);
}
else
query.dispose();
}
Otherwise, I'll let you compare your code with the working code to see what the difference is.
One way to solve this problem is to add a Cancel and Ok button to your dialog. Then, disable closing the popup via the X in the corner, forcing the user to click either Cancel or Ok to finish/close the dialog. Now, simply add a listener to the text field that will disable the Ok button if the text field is blank.
Judging from your code I assume you can figure out how to implement these steps, but if you have trouble let us know! Good luck!