Develop Reference

How to run method in the JFrame by clicking button in JDialog?

I have a JFrame (called FTask) with public void method. Example code:
public void clear() {
jTable1.clearSelection();
jButton1.setEnabled(false);
jButton3.setEnabled(false);
jButton2.setEnabled(false);
jTextArea1.setText(null);
}
Then, I have JDialog with a button. I want when I click the button, frame do the 'clear' method to the frame.
I've tried:
FTask ft = new FTask();
ft.clear();
But it didn't work.

I've tried:
FTask ft = new FTask();
ft.clear();
But it didn't work.
No, it wouldn't. This code is creating a new (2nd instance) of the frame that is not set visible. What you need is a reference to the original frame.
This can be fixed in a number of ways, too broad to go into here, and is Object Oriented Programming 101 that should be mastered before trying to write GUI'd apps. - which add their own complications.

You have to use actionlistener in order to run the code when the button is clicked.
JButton button = new JButton("Click me");
//Add action listener to button
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
//Execute when button is pressed
if(e.getSource() == button){
System.out.println("You clicked the button");
//In your case:
ft.clear();
}
}
});

As #Menno said, you have to use ActionListener in order to detect Button Clicks
Here is the Java 8 Style:
JButton button = new JButton("Click me");
//Add action listener to button
button.addActionListener(
ae -> ft.clear();
);
// Add button to frame
add(button);

Close windows without closing Application

Good afternoon!
I have this code:
private static class ClickListener implements ActionListener {
public ClickListener() {
}
#Override
public void actionPerformed(ActionEvent e) {
JFrame frame = new JFrame();
JLabel label = new JLabel("Opção Indisponivel");
JPanel panel = new JPanel();
frame.add(label, BorderLayout.CENTER);
frame.setSize(300, 400);
JButton button = new JButton("Voltar");
button.addActionListener(new CloseWindowListener());
panel.add(button);
frame.add(panel, BorderLayout.SOUTH);
frame.setVisible(true);
}
}
private static class CloseWindowListener implements ActionListener {
public CloseWindowListener() {
}
#Override
public void actionPerformed(ActionEvent e) {
setVisible(false);
}
}
What I want to do is when i click on the button "voltar" (which is in another window, not on the "main" one as you can see) it closes the windows but not the app itselft. The setVisible line gives me an error about that it cannot be referenced by a static context which I understand because I need the reference of the frame. How do I solve this?
EDIT: Changed JFrame to JDialog but still no sucess. Both windows are shutdown.
Thanks in advance,
Diogo Santos

The setVisible line gives me an error about that it cannot be referenced by a static context which I understand because I need the reference of the frame. How do I solve this?
You can access the component that generated the event. Then you can find the window the component belongs to. This will give you generic code to hide any window:
//setVisible(false);
JButton button = (JButton)e.getSource();
Window window = SwingUtilities.windowForComponent(button);
window.setVisible(false);
You can also check out Closing an Application. The ExitAction can be added to your button. Now when you click the button it will be like clicking the "x" (close) button of the window. That is whatever default close operation your specify for the window will be invoked.

How to open a JDialog

I am creating an application that has 1 JFrame java file and 1 JDialog java file.
In the JFrame, I have a button and when pressed I want it to display what I have designed in the JDialog.
So for example, my JFrame java file is called MMainView.java and my JDialog is called OptionView.java. So when the button in MMainView.java is pressed I want to display the JDialog I have designed in OptionView.java.
So in my MMainView.java file, I have a function that is called when that button is pressed. How do I display the dialog in OptionView.java?
SOLVED
For those wondering. This is what I did:
private JDialog optionView; ~~> JDialog Declaration
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
if (optionView == null) {
JFrame mainFrame = myApp.getApplication().getMainFrame();
optionView = new OptionView(mainFrame, true);
optionView.setLocationRelativeTo(mainFrame);
}
myApp.getApplication().show(optionView);
}

Sounds like you want to create an ActionListener for your button, and set the visibility of the JDialog to true when you press the button.
Something on these lines:
final JButton button = new JButton();
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent actionevent)
{
//set the visibility of the JDialog to true in here
}
});

Let's say your button is called myBtn.
The class should look like this.
public class MMainView extends JFrame
implements ActionListener
You should use a listener for the button.
JButton myBtn = new JButton();
myBtn.addActionListener(this);
And finally:
public void actionPerformed(ActionEvent e) {
if (e.getSource() == myBtn) {
new OptionView();
You don't really need the if, it's just in case you want to add more buttons for the actionPerformed.

First register the button in "MainView.java", like below.
b1.addActionListener(this);
b1.setName("OpenJDialog");
//this is to read in actionperformed method incase you have more than one button
// in action performed method call the dialogue class
public void actionPerformed(ActionEvent ae){
JButton jb = (JButton)ae.getSource();
String str = jb.getName();
if(str.equals("OpenJDialog"){
new OptionView();
//I am assuming u are configuring jdialog content in OptionView constructor
}
}

Pass data via jDialog to another jPanel

I create a jPanel and I open a new jDialog when I click on button (dlgSegments is a JDialog that opened):
JButton btnAddSegment = new JButton("Add GeoSegment");
btnAddSegment.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
dlgSegments.setVisible(true);
}
});
Then in the opened jDialog I want to return the "selected" back to the jPanel which called this jDialog.
How can I implement it?
This is the button listener in the opened jDialog and seleced is the variable that I want to pass to the jPanel:
addButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
GeoSegment selected = lstSegments.getSelectedValue();
// i want to send back the selected value
}
});

One possible solution: If you create your Dialog send an DataObject to the Dialog via his constructor. The DataObject conatins the value you are interested in.
MyDataObject dataObject = new MyDataObject();
MyDialog dialog = new MyDialog(dataObject);
fill the DataObject with the selected value in the dialog.

If you're still working on this problem, your Add button can call getSelectedIndex() or getSelectedIndices() to find out what's selected. Then fire a PropertyChangeEvent like #Hovercraft Full Of Eels shows here. Have you main panel do addPropertyChangeListener() to listen to the dialog.

Performing action when closing JFrame

In my program I have a main JFrame that holds a button. When this button is clicked a new JFrame appears in which I can change some information. Whenever I finish editing I press a save button on the new JFrame which saves the changes and disposes the JFrame. Now when this is done, I'd like to perform an action in the main JFrame as well, but only if something changed. If I open the new JFrame and just close it again without using the save button, I don't want to do anything in the main frame.
I've tried searching the web for a solution, but just don't seem to be anything useful out there..
An example of the code I've got so far:
Main Frame...
public class MainFrame extends JFrame
{
public MainFrame()
{
super("Main Frame");
JButton details = new JButton("Add Detail");
add(details);
details.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
new DetailFrame().setVisible(true);
}
});
}
}
Detail Frame...
public class DetailFrame extends JFrame
{
public DetailFrame()
{
super("Detail Frame");
JButton save = new JButton("Save");
add(save);
save.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
// Save whatever content
dispose();
}
});
}
}
So when I click the "Save" button on the Detail Frame, I want to do something in the Main Frame, whereas when the "x" is clicked on the Detail Frame, I don't want to do anything..
Hope someone is able to help me, and sorry for my english..

You can pass a MainFrame handle to the DetailFrame constructor. Then, on clicking the Save button, the DetailFrame would call a function in MainFrame and pass the changes to it.
Another way is to create a public boolean variable in DetailFrame and set it to true when the Save button is clicked. This way MainFrame will know whether the DetailFrame was closed or Save'd.
EDIT: Some more ideas:
Use JDialog instead of JFrame. JDialog.setVisible is modal, i.e. it will block the calling function until the dialog is closed; this way you can process the results of the dialog in the same "Details" button listener.
To access the dialog after it is called, store the dialog in a separate variable. First construct the dialog, then show it, and then process the result by analyzing its variables.
Store the results of editing in other public variables of DetailFrame (or let's call it DetailDialog). This should happen only when the "Save" button is clicked. This may even allow to go without the boolean variable (depends on the types of values you are editing).
DetailDialog dlg = new DetailDialog();
dlg.setVisible(true);
if(dlg.approvedResult != null) {
// process the result...
}
EDIT: Sorry, JDialog is not modal by default. Need to call a special super constructor to make it modal.
Also, here you will have to pass the reference to MainFrame to the dialog constructor, but you still can declare it as a simple JFrame and avoid unnecessary dependencies.
To get the reference to the enclosing MainFrame from within the anonymous ActionListener, use MainFrame.this.
To be able to change the button text after it was created, you will have to store the button in a member variable.
Main Frame...
public class MainFrame extends JFrame
{
private JButton details = new JButton("Add Detail");
public MainFrame()
{
super("Main Frame");
getContentPane().add(details);
details.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
DetailDialog dlg = new DetailDialog(MainFrame.this);
dlg.setVisible(true);
if(dlg.approved){
details.setText("Edit Detail");
}
}
});
}
}
Detail Dialog... (not Frame)
public class DetailDialog extends JDialog
{
public boolean approved = false;
public DetailDialog(JFrame parent)
{
super(parent,"Detail Dialog",true); // modal dialog parented to the calling frame
JButton save = new JButton("Save");
getContentPane().add(save);
save.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
// Save whatever content
approved = true;
dispose();
}
});
}
}

Create the detail frame in the main frame, and add a windowlistener to it, using the windowadapter class. Implement the windowclosing event by checking for changes, handle those, and then dispose the detail frame. This is all done in the mainframe.
The detail frame should have do nothing on close set to prevent the detail frame being disposed before you recorded the changes.
You may wish to implement checking for changes in the detailframe as a method returning a class holding the interesting data. That way your windowlistener can be small an to the point.

Forget the 2nd JFrame. use a modal dialog instead. It will block input until dismissed. Once dismissed, the only thing to do is decide whether to update the original data. JOptionPane has some inbuilt functionality that makes that easy. If the user presses Cancel or the esc key, the showInputDialog() method will return null as the result.
import java.awt.BorderLayout;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
class EditInfo {
public static void main(String[] args) {
Runnable r = new Runnable() {
public void run() {
final JFrame f = new JFrame("Uneditable");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel p = new JPanel(new BorderLayout(10,10));
final JTextField tf = new JTextField("Hello World!", 20);
tf.setEnabled(false);
p.add(tf, BorderLayout.CENTER);
JButton edit = new JButton("Edit");
edit.addActionListener( new ActionListener(){
public void actionPerformed(ActionEvent ae) {
String result = JOptionPane.showInputDialog(
f,
"Edit text",
tf.getText());
if (result!=null) {
tf.setText(result);
}
}
} );
p.add(edit, BorderLayout.EAST);
p.setBorder(new EmptyBorder(10,10,10,10));
f.setContentPane(p);
f.pack();
f.setLocationByPlatform(true);
f.setVisible(true);
}
};
SwingUtilities.invokeLater(r);
}
}
If it is necessary to edit a number of fields all at once in the JOptionPane, use a JPanel to contain them all, and put them in a showMessageDialog() call. Check the integer based return result to determine if the user OK'd the changes.