I have a JDialog that takes a name from the user. Behind the JDialog, is an applet. I dont want the user to access that applet until he has entered the name. I tried JDialog.setAlwaysOnTop(true), but the applet throws an AccessException error. So what I did was keep a while loop that will execute JDialog.setVisible(true) till the JtextField(input for user name) is empty (""). But for some reason this works really slow, meaning the JDialog loads, but it takes time to focus on the JTextField and even when the user types his name, it comes really slow... like one character in 2 seconds... Is there any other way for me to force the user to enter the name before accessing the applet?
Use a modal JDialog. For example the code in your init(...) method of JApplet might include:
JDialog dialog = new JDialog(SwingUtilities.windowForComponent(this));
dialog.setModal(true);
dialog.setSize(...);
dialog.setVisible( true );
Or you can just use a JOptionPane.showInputDialog(). Again you would just specify "this" as the parent component of the option pane.
Another option would be:
frame.setAlwaysOnTop(true);
It forces the dialog on top of any other.
It runs slowly because the program is processing that foo loop
What you can do is to add a window listener and then the jdialog lost it's focus ( or the applet gains it ) return the focus to the jdialog.
This should perform much better than the for loop you're using right now
Related
Is there a possibility to prevent a JOptionPane dialog from blocking the interaction with the rest of the program, especially child JFrames? In my GUI, I launch a JFrame and want a message dialog to pop up after the child is closed to remind the user of something, but they launch parallel and the reminder blocks the child frame from being used.
Like here:
popupObjMan newPopup1 = new popupObjMan(gatewayAbstract, gatewayAbstractID);
JOptionPane.showInternalMessageDialog(this, "REMINDER: DO REFRESH");
I've tried to set the popup always on top, but this doesn't quite do the job.
I have no problem with them launching parallel (I'd even prefer it), but I could not work my head around it yet.
I just started Java programming ,so sorry in case that'd be something obvious.
A JOptionPane normally need to be modal. It shows something important and waits till the user answers with whatever option you give him (e.g. ok-button, yes/no-buttons, ...)
But there are several ways to reach your target.
(a)
Normally a JOptionPane creates a modal window.
You need a modeless window which does not block other windows.
https://docs.oracle.com/javase/tutorial/uiswing/misc/modality.html
(b)
You can start different threads to work for your different windows. They can have windows which are shown whenever the responsible thread commands them to. This is a bit difficult and can lead to memory-troubles.
(c)
You can write your own message-panels (e.g. notificaton) which are shown when and how long you like.
Bigger projects use different of these ways to achieve their goals.
A JOptionPane is a component, just like a JPanel. As a component it can be added to any other panel.
The JOptionPane API provides static methods to create a show the JOptionPane on a modal JDialog by default. You can't change this behaviour.
However, you can manually add the JOptionPane to a non-modal JDialog that you create. This is extra work as you now need to handle the closing of the dialog and processing the clicked button.
If you really want to do this then read the JOptionPane API. There is a section on Direct Use which demonstrates the basic code needed to add the JOptionPane to a JDialog.
In my program it opens a window if an action is happened. After I have filled out information in this window, and entered a button, the window dispose().
The window is picked up in a program outside my main program, but when I close this window, my main program stops. How can I prevent this from happening?
Thanks for your help!
You can set the defalaultCloseOperation property of the second frame to DO_NOTHING_ON_CLOSE or DISPOSE_ON_CLOSE
Don't even use two frames. Use a modal JDialog instead for a secondary frame. See more at How to Use Dialogs. Read more about Modality. And for a good read, see The Use of Multiple JFrames, Good/Bad Practice?
Forget about number 1. and go straight to 2.
If using JFrame or extending it you can use setDefaultCloseOperation() method like:
frame.setDefaultCloseOperation(HIDE_ON_CLOSE);
// or
frame.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
The dispose command is from the AWT Bundle, and this may cause problems, as you are attempting to "close" a swing window with an AWT command.
You can close the window with this command:
windowName.setVisable(false);
windowName is the name of the object representing the window. If you are extending a class, and have no object, you can use this
More Information on the Dispose Method:
"In general java.awt.Window.dispose() is used on a GUI component that is
a subclass of Window, in order for that specific GUI Window object (and
its children) to properly release and destroy native UI resources (such
as the screen). Garbage collection (and the eventual exiting of the
entire VM) may happen as a result of dispose(), but is not directly
connected with the dispose() call itself." From: https://www.java.net/node/684412
windowName.setVisable(false);
doesn't seems to be a good choice. What if user want to exit the program?
check this question - How to hide a JFrame in system tray of taskbar
I have written an application in Java that has a JFrame with options. I now want a certain action to be executed when the user has confirmed the dialog with "Ok". I was recommended to add a return value to JFrame.
Unfortunately, I don't have any experience and need some help. Here are the details.
I want to extend JFrame so that I can have an Enum "DialogResult" when closing a JFrame like in the .Net Framework. Well, the Enum is no problem. My problem is to replicate the ShowDialog method from WinForms of the .Net Framework working in Java for the class JFrame.
Below is an example code in C#:
// DlgOptions : Form
DlgOptions dlg = new DlgOptions();
if(dlg.ShowDialog() == DialogResult.Ok)
{
// do something only when "Ok" was clicked
}
Here's a link from MSDN with the behavior I want to replicate:
https://msdn.microsoft.com/de-de/library/c7ykbedk(v=vs.110).aspx
How can I best implement this? Thanks in advance.
EDIT:
I changed my DlgOptions class so it doesn't extend JFrame but JDialog. I also added an enumeration DialogResult and added a public property of this type in my DlgOptions. But I still have a problem. When I use this code:
// executed when user clicked a JMenuItem in a JMenuBar
DlgOptions dlg = new DlgOptions();
dlg.setModal(true);
dlg.setVisible(true);
if(dlg.DialogResult == DialogResult.OK)
{
// do something
}
the program continues running before the user closed the modal dialog. What can I do?
EDIT 2:
My JDialog contains two JButtons; one to confirm changes that were made and one to abort changing the preferences for the program. I have several JCheckBoxes the user can check or uncheck.
So a JOptionPane would not be what I want / need (as far as I know). That's why I need a modal JDialog. But my Java code above doesn't work as I want it to. I read on a German website of a Java book that a JDialog set to modal with
setModal(true);
would cause the program to wait until the dialog is closed. The problem is, that the code continues too early.
I have a message I want to display with some information in a modeless JDialog. The parent class will call the dispose method to close it at the right point. Here is the code I have:
private static void waitMessage() {
JOptionPane msg=new JOptionPane("Trying to get probes. Please wait ...",
JOptionPane.INFORMATION_MESSAGE,JOptionPane.DEFAULT_OPTION,
null,new Object[]{},null);
waitDialog=msg.createDialog("Probe Scan");
waitDialog.setDefaultCloseOperation(JDialog.DO_NOTHING_ON_CLOSE);
waitDialog.setModalityType(ModalityType.MODELESS);
waitDialog.setSize(300,100);
waitDialog.setVisible(true);
}
The problem is that when I set ModalityType.DOCUMENT_MODAL the message displays as expected. Of course the JDialog blocks which is not what I need.
However, when I set ModalityType.MODELESS, I get this:
The JDialog does not block but the message text does not show up. Can someone explain why the ModalityType munges up the pane? TIA.
Manually adding a JOptionPane as the content for a JDialog, doesn't look right to me.
JOptionPane has a method designed to create a relevant JDialog instance, so better try that :
waitDialog = msg.createDialog("Probe Scan");
The reason you cannot close the dialog programmatically is that you do not keep a reference to the dialog. One way to do that is to have the waitMessage() method return the waitDialog instance. Or you can do as #Berger suggests.
Also,
waitDialog.setSize(300,100);
waitDialog.setVisible(true);
waitDialog.pack();
Why call setSize() and also pack() ? Make up your mind - do you want it a specifie size, or do you want it to appear its preferred size? And you should call setVisible() AFTER calling either setSize or pack.
There is no 'SetDefaultCloseOperation' method.
But there is a setDefaultCloseOperation method. (note the lower case first letter)
In my program it opens a window if an action is happened. After I have filled out information in this window, and entered a button, the window dispose().
The window is picked up in a program outside my main program, but when I close this window, my main program stops. How can I prevent this from happening?
Thanks for your help!
You can set the defalaultCloseOperation property of the second frame to DO_NOTHING_ON_CLOSE or DISPOSE_ON_CLOSE
Don't even use two frames. Use a modal JDialog instead for a secondary frame. See more at How to Use Dialogs. Read more about Modality. And for a good read, see The Use of Multiple JFrames, Good/Bad Practice?
Forget about number 1. and go straight to 2.
If using JFrame or extending it you can use setDefaultCloseOperation() method like:
frame.setDefaultCloseOperation(HIDE_ON_CLOSE);
// or
frame.setDefaultCloseOperation(DISPOSE_ON_CLOSE);
The dispose command is from the AWT Bundle, and this may cause problems, as you are attempting to "close" a swing window with an AWT command.
You can close the window with this command:
windowName.setVisable(false);
windowName is the name of the object representing the window. If you are extending a class, and have no object, you can use this
More Information on the Dispose Method:
"In general java.awt.Window.dispose() is used on a GUI component that is
a subclass of Window, in order for that specific GUI Window object (and
its children) to properly release and destroy native UI resources (such
as the screen). Garbage collection (and the eventual exiting of the
entire VM) may happen as a result of dispose(), but is not directly
connected with the dispose() call itself." From: https://www.java.net/node/684412
windowName.setVisable(false);
doesn't seems to be a good choice. What if user want to exit the program?
check this question - How to hide a JFrame in system tray of taskbar