So I have a main frame that sometimes produces an error frame by pressing on one of the JButtons. I want to make it so when the error frame pops, main frame is inactive and you are unable to press any buttons. Is there an easy way for that?
What you are referring to is modality1, for which case a modal JDialog is more appropriate than a JFrame. See more at How to Use Dialogs
Also, if this is a simple message popup, a simple JOptionPane would be more suitable. You can also see how to use JOptionPanes in the link above.
Here's a simple JOPtionPane example. Though I don't use a frame in the example, if you do have a frame, the JOptionPane will block any user interaction.
import javax.swing.JOptionPane;
public class SimpleErrorMessage {
public static void main(String[] args) {
JOptionPane.showMessageDialog(
null, "Error!", "Error Message", JOptionPane.ERROR_MESSAGE);
}
}
See JOptionPane API for more dialog options.
1. A dialog box can be either modeless or modal. A modal dialog box is one that blocks input to some other top-level windows in the application, except for any windows created with the dialog box as their owner. The modal dialog box captures the window focus until it is closed, usually in response to a button press
You can use a glass pane to make main frame "inactive": http://docs.oracle.com/javase/tutorial/uiswing/components/rootpane.html
Related
When two JFrames are enabled, I want the user to be able to use only one in the top (think of that like an error pop up on your screen, when you can't press anything but the popup itself). I am aware of the class JInternalFrame and I chose not to use it for my program. Thanks in advance :)
Use JDialog, you can set your main frame as the JDialog's parent frame, so that whenever your main frame and JDialog will display, you will be able to click only the JDialog, not your main frame.
You want a modal behaviour, then. I think you can try using JDialog instead of JFrame, something like:
JDialog dialog = new JDialog(parentFrame, title, true); //parameters: owner, title and modal
dialog.getContentPane().add(somePanel);
dialog.pack();
dialog.setVisible(true);
You can read more about it here: http://docs.oracle.com/javase/tutorial/uiswing/misc/modality.html
So I'm fairly new to Java Swing, and I stumbled upon a certain difficulty. I have a main Frame running (main part of the application that is visible throughout the app's execution) which has a button that once clicked, invokes a popup Frame (window) to collect user's information, and that frame has some Components. The problem being is that I don't really know the right approach to invoking the popup window and the main window freezing the execution and waiting until OK, or cancel button is clicked on the popup. Once this happens the main window code collects the returned values from the popup and resumes. I tried using synchronization to accomplish this, however the popup components don't even load, just the JFrame and JPanel (white background) and the popup freezes up on the wait() condition. I know that there is a way of doing it with JDialog and others, my main concern however, is to discover why the popup frame doesn't load the components and freezes up before the wait() condition. (when I get rid of wait() everything loads properly).
//in Main window Class:
frame.setEnabled(false);
Test test = getNewTest(); //should freeze on wait() in popup window
frame.setEnabled(true);
//in Popup Window Class
public Test getNewTest() {
addPanel.setVisible(true);
addFrame.setVisible(true);
synchronized(flag) {
try {
flag.wait();
} catch (InterruptedException e) {}
}
addPanel.setVisible(false);
addFrame.setVisible(false);
if(success)
return new Test(testName, date);
else return null;
}
//When OK or Cancel button clicked appropriate handler sets
//success value and invokes flag.notify();
Get all that synchronized and wait stuff out of your code. All that will do is freeze the Swing event thread, rendering your application useless.
You don't want to use a second JFrame, since an application typically has only one main window or JFrame, not multiple.
You want instead to use a modal dialog such as a JOptionPane (which can hold complex GUI's), or a modal JDialog (which also can hold a complex GUI). Be sure to associate the modal dialog with the parent JFrame. The Swing GUI library will then freeze the main window until the dialog has been dealt with, and the code from the main GUI will resume from the place the dialog was made visible after the dialog is no longer visible.
I have a JOptionPane which appears on top of it's parent JFrame window, but when the application is minimized and restored, only the JOptionPane will show and not the parent JFrame.
How to fix this bug?
JOptionPane is a modal dialog box.
It means first you need to handle/close this dialog box then you will be able to access your main window.
So when you minimize everything and then restore it, it firstly shows the JOptionPane when you will close it or what it is supposed to do ONLY then you will get the main window.
It's not a bug. It is just how modal things work.
You will not be able to even Minimize the main window from icon when JOptionPane is up. You can minimize everything like with Window + D key or Window + M key in Windows PCs.
How do i restrict access to other JFrame?
if I open my main frame and when click the button to display other jframe, the user should not be able to go back to the main frame.
how do I do that?
if i open my main frame and click the add button,
When you click the button you display a modal JDialog. Then until the user closes the dialog they won't be able to access the main frame.
try this method...
this.setEnabled(false);
Your question is not clear to me but as per my understanding I believe You want to open a dialog on button click but when you click the button a new JFrame is displayed and it becomes impossible for you to get back to the original frame.
Use a dialog /pop-up on your button click like JOptionPane.
If you want to open a JFrame on button click, making a HOME button on the newly created/opened JFrame and linking that button to main JFrame might be a good option.Closing the newly created JFrame will display the originally created JFrame anyway.
Use a dialog (JDialog class) instead and make it modal.
Here is some help on how to do this:
http://download.oracle.com/javase/tutorial/uiswing/components/dialog.html
Regards,
I have a piece of code in my program where in I need to display an error message. Code:
String ErrorMsg=" Error to be Diplayed ";
JOptionPane.showMessageDialog(null, ErrorMsg, "Failure", JOptionPane.ERROR_MESSAGE);
Note: Default frame is used.
The message is successfully displayed, but before acknowledging by pressing "OK" button if I try any other successful flow the message box control is lost and message box won't be on foreground blocking even the successive flows.
I want the Message Box to be on the foreground always until the user presses "OK" button, rather losing focus and getting hidden. How to do that?
If you want JOptionPane to behave as it would in a full-fledged GUI, then first create a full-fledged Swing GUI. Forget using "default" frames or whatever you're using (the console perhaps). You are desiring GUI behavior, and so to get this you must create a GUI by displaying your application in a JFrame and have the JFrame launch the JOptionPane.
Pass reference to the parent frame instead of the null (first param).
I want the Message Box to be on the foreground always until the user presses "OK" button, rather losing focus and getting hidden.
Use a JFrame and setAlwaysOnTop(true). You will need to display your own message and button.
A JOptionPane uses a JDialog behind the scenes. A JDialog does not support this property.
Edit:
To get the icon used by the option pane you can use:
Icon icon = UIManager.getIcon("OptionPane.errorIcon");
For a list of the other icons see: UIManager Defaults.
The below code is enough to make a JoptionPane message with default frame to be set on top .
JDialog dialog = new JOptionPane("ErrorMsg",JOptionPane.ERROR_MESSAGE,JOptionPane.DEFAULT_OPTION).createDialog(" Failure");
dialog.setAlwaysOnTop(true);
dialog.setVisible(true);
dialog.dispose();