When I let popup a JPopupMenu without passing the "invoker component", the menu doesn't work: submenu's don't open and isn't getting repainted. But when I create a completely useless JFrame with a JLabel inside, and I pass the JLabal as invoker, it works correctly...
Any suggestions, how to avoid creating a useless frame. And my application really hasn't any frames open, it just has to popup a simple menu.
JPopupMenu.show(null, xOnTheScreen, yOnTheScreen); // Doesn't work
JPopupMenu.show(aStupidJLabelInAStupidJFrame, x, y); // Works
Thanks
Take a look at JPopupMenu source code and you'll see why you have to set an invoker.
Showing a popup menu without any existing component would be very bad usability, in the same league as popup windows from a browser.
Why can't you use JComponent#setComponentPopupMenu, or add a mouse listener to the component in which you want to show popup menu?
Related
I have a Java Swing Dialog with a hidden JLabel above each input component (i.e. JTextField). The purpose of this hidden JLabel is to use it as validation output for its input component.
Let's say, there is an input field for the description of some entity, which has to be non empty, and should contain some special stuff. On error, the action could call the following method:
private void invalidateDescription(String errMessage) {
errDescriptionLabel.setText(errMessage);
errDescriptionLabel.setVisible(true);
descriptionTextField.setBackground(ERR_COLOR);
}
After that, I call pack() and invalidate()
The problem is, that the JDialog still has the same vertical size, so that some of the components (the buttons in the bottom of the dialog) disapear (because they're out of view).
Do you have any suggestion how to fix it?
Best Regards.
edit: I forgott to mention, that the JDialog has a "Free Design" Layout (Netbeans GUI Builder default).
edit 2: I'm looking for a solution which doesn't require kind of a placeholder for (error) JLabel. "Empty Space" is not a desired solution because the dialog doesn't look balanced.
Use CardLayout place your labesl and empty JPanels ans swap thm when necessary.
Instead of using setVisible(), give errDescriptionLabel a background color that matches that of the enclosing panel when the entry is valid.
I have a Java Swing Dialog with a hidden JLabel above each input component
I would not use a hidden component for this. I would change:
private void invalidateDescription(String errMessage)
to
private void invalidateDescription(String errMessage, component inputComponent)
Then I would display a popup with the error message. You could use a non-decorated JDialog as the popup. You might even be able to use a JPopupMenu as the popup.
When you display the popup you would position the popup releative to the input component.
We have an application which, as its first UI action, displays a modal JDialog without a parent frame.
public LoginDialog(Frame owner, Config config, Object... params) {
super((Frame)null, true);
It unfortunately has the annoying characteristic that when it appears, although it comes to the front, it does not grab the focus.
So the user, after launching the application by double-clicking on the start menu, has to use the mouse to select the "login" dialog and type in information.
Is there a way to make this JDialog grab the focus when it appears in the front?
I've tried calls to "requestFocus" before, after and via invokeLater "during" the call to setVisible(true) - but none of these seems to have any effect.
How do we make a modal dialog grab the focus?
UPDATE: The issue was the code used to try to present a background "wait window". This window was displayed "behind" the login dialog as a hack so that when the dialog disappeared the user would see the "Please wait" message. As it was the first window created by the application, it got the focus. I am not sure if there would have been a way to make the dialog gain the focus again inside the event dispatch thread with this hack - but I fixed it by un-hacking it and doing things properly.
First, it a little strange that modal dialog is parent-less. The point in modal dialog is that it is displayed on its parent and does not allow to access parent.
So, the first recommendation is to make it non-modal. I believe it will work.
BTW I have just tried to create such dialog and have not problems with focus. Try probably to simplify your code:
JDialog d = new JDialog();
d.setSize(200, 200);
d.setVisible(true);
This works for me and I believe will work for you. Now start changing this simple code towords your real application code. At some point it will stop working and you will see where the problem is.
If nothing helps try to use the trick I described in this article. Look for title "Portable window activation". I hope it will help.
See Dialog Focus for a potential fix using a RequestFocusListener. I have used it successfully for setting focus in JOptionPane dialogs.
1) you have to create JDialog contents and showing container wrapped inside invokeLater()
or best and safiest way is
2) you have to set for ModalityTypes or Modal for parent
3) only one from containers could be Modal in applications lifecycle
The JXTaskPane used in Java Swing has a title bar. There is a expand/shrink button in it. I would like to be able to add my own actions in the titlebar that would appear beside
the expand/shrink button.
How can I do this? I try myself many times, but do not get the expected result. I made a new JButton and set its location over the title bar coordinates, but it's added in the element.
I have attached a screenshot that shows a help type action in the title bar to show
you what I mean.
That's not possible. I'd recommend perhaps making a new JFrame pop up when you click the button to extend the dropdown menu. Creating your own JFrame popup would also afford you more creativity and customizability when it comes to the components you can put on it. I've not much experienced with this sort of thing, but you could try to do this. It might not be ideal though.
Question about JPopupMenu behavior. I would like the JPopupMenu not to loose focus when it comes up. Also when JPopupMenu is in focus, the user should be able to click/update other parts of the Applet.
Is this possible? Reason is that this JPopupMenu is displaying some codes and it needs to be kept open for reference.
This is what I have now but as soon as the user clicks on the main Applet JPopupMenu looses focus:
JPopupMenu popupMenu = new JPopupMenu();
popupMenu.show(component, x, y);
thanks for your help.
Don't use a JPopupMenu for this purpose.
You can use a non-modal JDialog as the "popup". Make the dialog undecorated and the border will not be painted. Make sure you specify the owner when you create the dialog. You can use the SwingUtilities.windowForComponent(..) method to get the Window to be used as the owner.
"The exact gesture that should bring up a popup menu varies by look and feel." See Bringing Up a Popup Menu for details about doing this in a platform-independent way. Also, consider extending JApplet instead of Applet.
I have a general question. I would like to have a window containing some buttons, radio buttons, text fields and so on. So, user can do something (write text, select options and press buttons). As the result of the user activity window should change it structure/appearance some element should disappear and some appear.
How do I program such "updates"? Should I close an old window and open a new one or I can modify content of window without closing it?
After adding your components or such, calling revalidate() on your container will do the updates