I'm developing the Java Swing application. I'm quite new to Java, so got some questions. I have a modal window with some set of controls (text fields, buttons etc).
I want to handle click on the button in the parent window. I think the most efficient and accurate way is first to handle it in modal window, then raise some another event from the model form and handle it in the parent form.
Is this approach right and what are the best practices on doing that?
Thanks for your help!
In general, the dialog that contains the button should handle the button click.
However, maybe you can use a JOptionPane. It is designed to return which button was clicked and then you can do custom processing based on the clicked button. Check out the section from the Swing tutorial on How to Make Dialogs for some examples. Also not that you can add a panel to an option pane. In this case you may find the Dialog Focus tip usefull.
I suppose what you want is for the action (or an action listener) of a button in the parent window to process a mouse click on a button (or anything) in the modal dialog.
There are infinite ways to do that. You can pass the action to the modal dialog, pass the button and call doClick(), pass an implementation of an interface that can redirect mouse click (or anything), etc.
Or if instead you want to click the actual button in the parent window when the modal dialog is up, look up the definition of modal.
Related
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
I have a JFrame which contains most everything in the application. It has a KeyListener attached, and it also has several buttons and textfield on it. The problem it, when a button is clicked or a textfield is selected, it gets focus and shortcuts don't work. Of course, one can tab out of them, but to do this you must tab through EVERYTHING (each button, each textfield) before giving the window focus again.
Is there a sensible way to only require one tab to return focus to the frame from the textfield, and no tabs to return focus to the frame from a button click?
A WindowListener doesn't seem like the best way to do this, but if it's the only way I suppose I can forge forward there.
Thanks in advance!
It has a KeyboardListener attached
I have never heard of the KeyboardListener class so I can only guess what you are trying to do.
My guess is that you should NOT be using a listener of any kind.
Instead you should be using Key Bindings.
If you only need this for the textfield, you can add a keyListener to the textfield and when the user presses tab use yourJFrame.requestFocus(). Otherwise refer you may want to use a window manager or a key map.
I'm developing a SWT app and in one particular form there are 14 pairs of Yes-No radio buttons. Each of these pairs have a text box associated with them. So if a user selects Yes, the associated textbox should be editable else uneditable. I find writing 28 listeners for the radio buttons really daunting. Since the radio buttons have nothing much to do than just rendering the textbox editable/uneditable I was hoping if there were some generic type of listeners in SWT that would be applicable to a set of radio buttons specified in an array or like that. Are there any frameworks or shall I have to write individual listeners?
Edit
I'm trying to fire an event only when the radio button is selected
rdoExperience.addListener(SWT.CHECK, new RadioButtonSelection(
txtExperience));
but SWT.CHECK is causing the event to be fired on mouse hover over radio button too. I've tried using SWT.SELECTED too but it's not working either and I can't find other suitable SWT constants. W;hat should I use?
Good point. Sorry I don't know such thing.
However, you create one yourself: Instead of writing an anonymous listener for every button, you could write one - say MyButtonListener - and give it the button text box as an argument. Than you instantiate MyButtonListener with the appropriate text box as an argument. Than in the Listeners appropriate callback method you enable or disable the text box.
Edit: My bad. Of course I meant you could give it your text box like radioBtn.addListener(SWT.SELECTED, new MyButtonListener(textfield1));
You could create one SelectionListener and add it to each of the radio buttons. Then you can ascertain which button was pressed from the selection event and map that to a text box. For the mapping you could use an array or hashtable.
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
Does exist in the JDialog class a way to prevent that a child window (JDialog) would be displayed more than once when the button from the main window (JFrame) used to open it, is pressed several times? Many thanks in advance!
Yes, and you don't need to make the box modal to do it (although making it modal would be the easiest way).
Simply do something like the following
In your member delcarations:
private final MyDialog dialog = new MyDialog();
In your code:
private void showDialog() {
dialog.setVisible(true);
dialog.requestFocus(); // May be needed to bring window to front
}
This will ensure that you only instantiate the box once. Simply call showDialog() whenever the button is pressed.
Another way that I've done in the past with Swing is that when the button is pressed the first thing I do is disable the button. Then I use the observable pattern to look at the child window and re-enable the button when the child window is closed. That way if it takes a while to display the child window for some reason the user can't click on it multiple times and mess things up.
You could make the JDialog modal, then the parent window would not react until it is closed.
Or you could initialize the JDialog before, and just make it visible when your button is pressed. Making it visible twice will not display it twice.