 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Java Forum / GUI / November 2004On focuslost ()
Hi there! I'm stuck on a technical difficulty while I was implementing the validation logic for quite a few days. My validation logic is invoked on focuslost event of an editable combo. There are Ok and Apply button on the dialog will save the setting in a file. Now, if I edit the combo setting and then immediately click the OK button. The very first event called is the FocusLost after which it should ideally work on the enqueued event which actually caused it. But it doesn't call my OK button handler. I have to again press an click to save it. Why does it focuslost event eat the ACtionEVent ? Is there any work-around for this ? I'll appreciate any kind of help. Thanks > I'm stuck on a technical difficulty while I was implementing the > validation logic for quite a few days. > > My validation logic is invoked on focuslost event of an editable combo. Have you tried using an InputVerifier?  SignatureRegards, John McGrath Nopes. Can you explain something more about this ? > Nopes. Can you explain something more about this ? <http://java.sun.com/j2se/1.5.0/docs/api/javax/swing/InputVerifier.html> SignatureAndrew Thompson http://www.PhySci.org/codes/ Web & IT Help http://www.PhySci.org/ Open-source software suite http://www.1point1C.org/ Science & Technology http://www.LensEscapes.com/ Images that escape the mundane > Nopes. Can you explain something more about this ? javax.swing.InutVerifier. Check the Sun site for more information. InputVerifier is covered in the Java Tutorial, and one of the sample chapters for a Swing book posted there covers the subject in detail. SignatureRegards, John McGrath Actually, problem is because the validation logic is happening on the server side and hence spawned on a different worker thread. My Event-Dispatch thread needs to wait till this thread returns back as it can't save the settings till then. Some pointers would really help. Thanks > Actually, problem is because the validation logic is happening > on the server side and hence spawned on a different worker thread. That sounds like a very different problem than what you described in your previous message. But it certainly does present some challenges. If you need to connect to a server to do some part of the validation, you do not want to do that at the field level, at least not synchronously. That would slow things down and it would freeze the UI if you have some sort of network slowdown or failure. The easiest solution would be to do these validations at the form level. When the user presses OK or whatever he does to commit the changes, you would then do the server-based validations. As an alternative, you could do these in a background thread and use some sort of indicator in the UI, such as changing the text color to red, to indicate errors in the values. > My Event-Dispatch thread needs to wait till this thread returns back as > it can't save the settings till then. No, you do not want the Event Dispatch Thread waiting on any process that is not guarateed to complete quickly. You should consider your validation to be a "long-running process", so you need to do the validation in a separate thread. SignatureRegards, John McGrath > I'm stuck on a technical difficulty while I was implementing the > validation logic for quite a few days. [quoted text clipped - 12 lines] > Why does it focuslost event eat the ACtionEVent ? > Is there any work-around for this ? I find this hard to believe. Are you sure you aren't getting the ActionEvent from the button ? (Try just putting in some debug println statements in the focuslost as well as the ActionEvent handler). If you're certain you're "losing" the actionevent, please post a code sample that exhibits this behaviour - I'm sure it has to do with something you're doing in your focus handler. And as a general rule of thumb, performing validation in a focusLost handler is generally trouble-prone. Try looking at an InputVerifier as another poster suggested. (though I vaguely recall some discussion about even InputVerifiers not behaving too well in complex components such as a ComboBox : I've never used one on a JComboBox - so cannot offer any feedback on how well it works) BK Free MagazinesGet these publications absolutely FREE for up to 12 months. There are no hidden fees and no obligation. Simply choose a title, complete the application form and submit it. Read more ...
|
Reply to this Message
|
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.