Does anyone know how to make a jbutton close a gui? I think it is like System.CLOSE(0); but that didnt work. it also could be exitActionPerformed(evt);, but that didn't work either. just the line of code will work.
EDIT: never mind guys. the answer was System.exit(0);. thanks for the help though!
Add your button:
JButton close = new JButton("Close");
Add an ActionListener:
close.addActionListner(new CloseListener());
Add a class for the Listener implementing the ActionListener interface and override its main function:
private class CloseListener implements ActionListener{
#Override
public void actionPerformed(ActionEvent e) {
//DO SOMETHING
System.exit(0);
}
}
This might be not the best way, but its a point to start. The class for example can be made public and not as a private class inside another one.
By using System.exit(0); you would close the entire process. Is that what you wanted or did you intend to close only the GUI window and allow the process to continue running?
The quickest, easiest and most robust way to simply close a JFrame or JPanel with the click of a JButton is to add an actionListener to the JButton which will execute the line of code below when the JButton is clicked:
this.dispose();
If you are using the NetBeans GUI designer, the easiest way to add this actionListener is to enter the GUI editor window and double click the JButton component. Doing this will automatically create an actionListener and actionEvent, which can be modified manually by you.
See JFrame.setDefaultCloseOperation(DISPOSE_ON_CLOSE)1. You might also use EXIT_ON_CLOSE, but it is better to explicitly clean up any running threads, then when the last GUI element becomes invisible, the EDT & JRE will end.
The 'button' to invoke this operation is already on a frame.
See this answer to How to best position Swing GUIs? for a demo. of the DISPOSE_ON_CLOSE functionality.The JRE will end after all 3 frames are closed by clicking the X button.
You may use Window#dispose() method to release all of the native screen resources, subcomponents, and all of its owned children.
The System.exit(0) will terminates the currently running Java Virtual Machine.
In Java 8, you can use Lambda expressions to make it simpler.
Close application
JButton btnClose = new JButton("Close");
btnClose.addActionListener(e -> System.exit(0));
Close window
JButton btnClose = new JButton("Close");
btnClose.addActionListener(e -> this.dispose());
Create a method and call it to close the JFrame, for example:
public void CloseJframe(){
super.dispose();
}
JButton close = new JButton("Close");
close.addActionListener(this);
public void actionPerformed(ActionEvent closing) {
// getSource() checks for the source of clicked Button , compares with the name of button in which here is close .
if(closing.getSource()==close)
System.exit(0);
// This exit Your GUI
}
/*Some Answers were asking for #override which is overriding the method the super class or the parent class and creating different objects and etc which makes the answer too long . Note : we just need to import java.awt.*; and java.swing.*; and Adding this command : class className implements actionListener{} */
Related
I have my main JFrame and one more JDialog.
If user click on the button, i want JDialog to call method from this JFrame(which contains some operations on ComboBox in this JFrame).
How can I do that?
I don't want to use MyJFrame form = new MyJFrame(); because it will make a new JFrame which i don't want to do, i want to call method from JFrame which is running currently on my computer.
Thanks.
Assuming the JButton is on the JDialog.
If both are in the same class, why not just do this?
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
//I just got clicked
form.doSomething();
}
});
which can be shortened to
button.addActionListener(e -> form.doSomething());
If they aren't, and you're extending JDialog (which I wouldn't recommend) just pass the JFrame in its constructor, then your dialog will have access to it.
It's not possible to add much more without seeing more of your code.
Maybe JOptionPane.showInputDialog() , show a JDialog to take input from User.
I seem to have a fairly unique problem, and I searched for a while for an answer on here without finding one. I have a class that has a simple JFrame with two buttons. Each button calls the Main method of a different class, as such:
checkRuling = new JButton("Check Your Deck's Rulings");
checkRuling.addActionListener(new ActionListener() {
public void actionPerformed (ActionEvent e) {
ReadHtmlCardDatabase.main(null);
}
});
One calls a class that takes a series of inputs into a text field and creates a formatted html document from the inputs, and the other loads the html document into a JEditorPane. My problem is that when I close one of the JFrames for the subclasses (either the input or html loader one), it exits my program completely, and I want to keep the main class (with the two buttons) open. I've tried using:
close = new JButton("CLOSE");
close.addActionListener(new ActionListener() {
public void actionPerformed (ActionEvent e) {
System.exit(1);
}
});
On a button in the subclasses, to no avail. When the button is clicked it simply exits everything. I've also tried using:
JFrame.DISPOSE_ON_EXIT
For the subclasses, but this causes the JFrames to go away without the subclasses actually closing, so the first one that saves the html document never actually saves it, and the second subclass that opens that same html document won't work, because it wasn't saved. Any help would be appreciated, because I can't figure out how to do this.
As Fast Snail says in the comments, you shouldn't be calling a main method. Instantiate a class that does each functonality. Set the frame to visible using setVisible(true) when you start using it, then setVisible(false) when you're done. So, in the action listener, just change the visibility.
Then, assuming you don't have anything too wild going on, the frame you just set to invisible should go out of scope and get freed so that memory isn't chewed up. You just instantiate a new copy of the ReadHtmlCardDatabase class each time you need one. Or you could have one static copy that you set visible/invisible as needed.
one of the JFrames
You should use only one JFrame in Your GUI. For other windows You can use for example JDialog or JWindow.
This should help, if not You can always use frame.setVisible(false) instead of dispose on close, but it' s not very neat.
Thanks to someone who posted a comment and then deleted it, I've figured out my own problem. I just had to replace my main call with this:
setDeck = new JButton("Set Deck");
setDeck.addActionListener(new ActionListener() {
public void actionPerformed (ActionEvent e) {
WriteHtmlCardDatabase w = new WriteHtmlCardDatabase();
w.main(null);
}
});
Thank you!
two JFrames,
JFrame Main; // Main JFrame
JFrame Sub; //Second JFrame that is initialized from within Main via a JMenuItems ActionListener.
mainMenuItem.setActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
try{
Sub subFrame = new Sub();
subFrame.setVisible(true);
}catch(Exception e){}
}
});
}
The problem is whenever i close the second JFrame (Sub) it closes the first aswell.
Both JFrames have:
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Is that part of the problem?
EXIT_ON_CLOSE means to exit the program immediately (System.exit()) when the frame is closed.
You probably want to set this to DISPOSE_ON_CLOSE, then add a WindowListener and close the program only if both frames have been closed.
(Or, perhaps you want only the main frame to have EXIT_ON_CLOSE)
Yes. JFrame.EXIT_ON_CLOSE by definition exits the application. For your second Frame use DISPOSE_ON_CLOSE or HIDE_ON_CLOSE.
Hope this helps!
You state:
JFrame Sub; //Second JFrame that is initialized from within Main via a JMenuItems ActionListener.
This suggests you've a design problem:
Your 2nd "frame" shouldn't even be a JFrame since it is not behaving as a separate independent main program window.
Instead it's acting as a dialog since it is dependent on and shown from a parent window, the main JFrame. So make the secondary window a JDialog not a JFrame, and all these problems will go away.
You will need to consider whether it should be a modal dialog where the main window is not accessable to the user while the dialog is open, or a non-modal dialog.
Having said that, you may even be better off using one window/JFrame and swapping views via a CardLayout.
Please read this link: The Use of Multiple JFrames, Good/Bad Practice?, and in particular please have a look at Andrew Thompson's community wiki answer.
I'm having some trouble figuring out how to make a JButton prompt the user to save the contents in a JTextArea before closing the program. So far, I have some code for the close operation for my button, but even that doesn't seem to work... nothing happens when I click it:
public void actionPerformed(ActionEvent event) {
if(event.getSource() == this.Quit)
this.dispose();
....
the rest are more else/if/try statements for other buttons.
I set my class to extend JFrame and implement ActionListener, so my entire program is in one class... probably not a very neat way to code, but I'm finding it easier to stick everything here for now before I distribute some functions into other classes.
Basically, nothing happens, and I don't know how to add the save prompt along with closing it afterwards. Any help would be great!
Is there any way to tie this into a prompt to save before closing?
See Closing an Application.
Note: you can also add the ExitAction to your JButton. Then when you click on the button it will initiate the closing of the window.
Try this:
MyClass.this.setVisible(false);
Also for a hard application exit do:
System.exit(0);
A more easy way to do what you want is this:
class MyClass extends JFrame{
public MyClass(){
JButton myButton;
//... etc
myButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent event){
MyClass.this.setVisible(false);
}
});
}
}
I'm making a calculator using Swing. So far I have created a GUI that consists of a JFrame with BorderLayout, and in its center I put a JPanel that has a JLabel (representing the screen of the calculator) and some JButtons (representing the keys).
I want the calculator to be able to receive input directly from the keyboard, so I included the method addKeyListener in a class that extends JFrame and I put as an argument a reference to an object of a class that implements KeyListener.
When I run the application it accepts keyboard input until I click on one of the JButtons. After that using the keyboard doesn't work anymore.
I suspect the problem is about focus, but it is not a problem that I could fix by clicking anywhere on the application. I added the following code:
setFocusable(true);
to the JFrame but it did not help. I have read that using Key Bindings maybe a better option than using a KeyListener, but I am not really sure about this approach.
Swing components are lightweight and use KeyBindings, where KeyListeners are for AWT components which are heavyweight. and known to have focus issues when mixed with Swing components. Thus I suggest changing to KeyBindings (but I see you have heard of them). You would use them something like:
final JButton b=..;
//method to add keybindings to a JComponent ie JButton,JPanel,JTextField etc
private void addKeyBindings(JComponent jc) {
//not the getInputMap(..) call it could also be JComponent.WHEN_FOCUSED etc
jc.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("D"), "D pressed");
jc.getActionMap().put("D pressed", new AbstractAction() {
#Override
public void actionPerformed(ActionEvent ae) {
//do something when d is pressed
b.doClick();
}
});
}
For general knowledge a very hacky solution would be calling requestFocusInWindow() on the component to which the listeners are attached whenever focus is lost (like after button click etc)
It's another hacky approach, but you could alter the properties of the JButton when you create it so that it can't take the focus in the first place i.e:
myJbutton.setFocusable(false);
This worked for me.