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Java Forum / General / June 2006setVisible "Lost in the weeds"?
Systems: I am using Eclipse 2.1.3 on a Win XP platform to develop a Java 1.3.2 Stand Alone App. The app extends JFrame that then host a set of TAB's designed to provide a user friendly Form Centric App. The app is working well but a new anomaly has appeared. In my main class I instance the app as follows: myApp app = new MyApp(args[0] ...); I follow that line with a "app.setVisible(true);" command. The problem: About 20 % of the time there is no return from the 'setVisible' request and the JFrame of the app is not shown. I used the debugger to follow the 'setVisible' process and deduced that the hang up was in the validate method. Going in there gets me into things that I just do not understand. I then changed the 'app.setVisible(true);' command to 'app.validate()' and placed sysout command before and after. Each time my app hangs up I never see the "Return from 'validate' printout. Comment: Over time my biggest problem with Java has been focus problems. I am looking to produce a stable, robust stand alone app but keep running into problems similar to this one. Over the last few months I have written a precise set of requirements ["Focus Change Event Processing"] and unit test to define focus rules. I was finally confident that I had taken control of the Java environment until the above problem appeared. Question: Any ideas on what can be causing the above irreguality or what else I can be doing to get control over this environment? I do not understand peers very well. Is there a chance that the problem is 'peer' related? I have a Mac OS X [panther] system that I plan to test this app on. Should I run the test on that computer to determine if the problem is platform related. That is a bit of a tangent from my planned development process but could be done if you think it will aid in solving this problem. Please advise! FYI: I have used 'sysout' to write the following 'app' instance parameters following the return from the above 'new' command: peer Name = sun.awt.windows.WFramePeer 'app.isValid' = false 'app.isVisible' = true The above output is the same for the working and the hang up executions. Thanks Jim C. > Systems: > I am using Eclipse 2.1.3 on a Win XP platform to develop a Java 1.3.2 [quoted text clipped - 57 lines] > Thanks > Jim C. Not look at the problem. Right off the top you are using an old version of Eclipse and very old version of JDK.. This will more than likely not be a problem but you can't upgrade Eclipse to at least to 3.1 and Java to 1.5? Thanks in Advance... IchBin, Pocono Lake, Pa, USA http://weconsultants.servebeer.com/JHackerAppManager __________________________________________________________________________ 'If there is one, Knowledge is the "Fountain of Youth"' -William E. Taylor, Regular Guy (1952-) > Not look at the problem. Right off the top you are using an old version > of Eclipse and very old version of JDK.. This will more than likely not > be a problem but you can't upgrade Eclipse to at least to 3.1 and Java > to 1.5? I had a typeO error in my initial message in that I am actually using Java 1.4.2_08. I just checked the Sun site and see that there is a J2SE for 1.4.2_12. I stopped looking for updates after 1.5 was released. I'll update to the latest and greatest 1.4.2 today. Why not 1.5? I do not need any of the new stuff for my app yet and my history has been that a new version update has caused me more work than I expected. Actually the Java 1.4 update went well but I'm still gun shy about updating until I have to. The older Eclipse version is a "my ignorance" problem [once again]. I did the download and insall for 3.1 but found that the Project setup had changed and I could not figure out how to convert my current Project to the new approach. I am developing a Java Package [com.MyPackage] that is designed to produce a Java StandAlone Application. I test it from a class [MyApp] that extends the MyProgram Class. I have the test Java programs in a C:/TestMyPackage/ folder and the 'MyPackage' source in the C:/TestMYPackage/com/MyPackage folder. Ideally I would like to host the 'MyPackage' source in a C:/com.MyPackage/ folder but I could not get that to work even in my Eclipse 2.1.3 setup. I started all this just using the EMacs Editor with the JDE plugin on a Linux platform. FYI: I did EMacs on Windows 98 for awhile but switched to Linux because of Win hangups, EMacs was nice because I was using command line execution and setup the Java environment using classpath, etc. which I could understand. I switched to Elipse and Win XP a couple years ago because I wanted the "Refacturing", JavDoc Comment Tool, etc. capability. I can't seem to get the setup right in the Eclipse 3.1 version so I just stuck with what works, i.e. Eclipse 2.1.3. I have the "The Java Developers Guide to Eclipse" book that I found useful in setting up my 2.1.3 Project. It is written to Eclipse SDK 2.0. Eclipse is nice and I would like to keep up with it's releases but can not afford a lot of learning curve time. Thanks, Jim C. > The problem: > About 20 % of the time there is no return from the 'setVisible' request > and the JFrame of the app is not shown. Have you tried putting all of your initialisation code onto the AWT thread (EDT) ? If not then that might be worth a shot. -- chris > > The problem: > > About 20 % of the time there is no return from the 'setVisible' request > > and the JFrame of the app is not shown. > > Have you tried putting all of your initialisation code onto the AWT thread > (EDT) ? If not then that might be worth a shot. That fixed my problem, many thanks. I used the following approach: public class MyApp { MyApp() { } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { public void run() { new MyApp(); } }); } } I tested it 13 times in a row with no hangups. The only problem I encountered was a 'null' Pointer error when I used the 'KeyboardFocusManager.getCurrentKeyboardFocusManager'.getActiveWindow' method. I added a check for a 'null' Active Window and everything is fine now. The 'null' check should have been programmed anyway. Any idea as to why the KeyBoardFocusManager is affected by the above 'invokeLater' processing? Regards, Jim C. > Any idea as to why the KeyBoardFocusManager is affected by the above > 'invokeLater' processing? None at all, I'm afraid. The best I can offer is the observation that if you treat AWT's internals -- especially the initialisation -- as a massively complicated, bug-riddled, and under-designed muddle, then you won't go far wrong. I'm not suggesting it /is/ that, mind you[*], but it's good working assumption -- in much the same way as it's often sensible to write user-facing code as if the users were all malicious idiots. -- chris [*] From what little I've seen of it, the code looks reasonable enough, and the problems appear to be more about the difficulties of OS integration than [lack of] quality in code or design. > Systems: > I am using Eclipse 2.1.3 on a Win XP platform to develop a Java 1.3.2 [quoted text clipped - 57 lines] > Thanks > Jim C. this looks like a threading issue, but you could try it on the mac, so that it is against the latest JVM. But seriously you should be looking at getting the latest 1.4 jvm onto your system , unless you are specifically tied to 1.3 steve > > Systems: > > I am using Eclipse 2.1.3 on a Win XP platform to develop a Java 1.3.2 [quoted text clipped - 3 lines] > But seriously you should be looking at getting the latest 1.4 jvm onto your > system , unless you are specifically tied to 1.3 Thanks Steve, It was a threading problem. See my response to Chris Uppal. I had a typeO error in my initial message in that I am actually using Java 1.4.2_08. I just checked the Sun site and see that there is a J2SE for 1.4.2_12. I stopped looking for updates after 1.5 was released. I'll update to the latest and greatest 1.4.2 today. Jim C. 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 ...
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