Java Swing Dialog, how to call wait method when capturing WindowClosing event -

i have jruby script opens java dialog report on progress of script.

i capturing windowclosing event, , want dialog wait until cleanup in jruby script has occurred, , dispose. instead, dialog hangs when user presses top right red x button.

how correctly call wait method wait on flag change? using lock object correctly?

a jruby script calls dialog.
if user presses top right red x, dialog captures windowclosing event , sets 'cancelled' flag. script keeps eye on flag, starts shutting down long running tasks , not . when done, updates flag on dialog cleanup has occurred. meanwhile, dialog looping, waiting on flag change. calls dispose().

i've tried using sleep. reason, upsets between jruby , dialog, cleanup occurs okay, dialog not dispose.

using wait, synchronize(this) generates illegalmonitorexception, script cleans , dialog dispose correctly apart exception.

have looked @ bunch of other posts on how synchorize wait method, understand this.

thanks assistance.

dialog class follows:

import javax.swing.*; import java.awt.*;  public class mydialog extends jdialog { private boolean usercancelled; private boolean scriptcleanedup;  //private static object lock = new object();  public mydialog(lock) {     usercancelled = false;     scriptcleanedup = false;     setdefaultcloseoperation(2);      //[..] add various controls dialog     addwindowlistener(new windowadapter() {         public void windowclosing(windowevent we) {             // jruby script keeps eye on flag see if user has cancelled dialog             usercancelled = true;              /* once cancelled, wait script flag has performed cleanup             */              /* here problem area, need synchronize use wait method?             */             while (!scriptcleanedup) {                 try {                       synchronized (lock) {                         lock.wait(1000000000);                     }                     // thread.sleep(1000);                  } catch (interruptedexception e) {                     e.printstacktrace();                 }             }             dispose();         }     });     super.paint(super.getgraphics()); } public boolean user_cancelled() { return usercancelled; } public void setscriptcleaneduptotrue() { this.scriptcleanedup = true; }  public static void forblock(mydialogblockinterface block) {     mydialog dialog = new mydialog(new object());     dialog.setvisible(true);     block.dowork(dialog);     dialog.dispose(); } } 

and if helps, how jruby script calls dialog

mydialog.forblock |dialog|     #do long running jruby task here end 

you've got lot of problems code including:

• you're making long-running calls on swing event thread, tie critical thread , guaranteed freeze gui.
• your calling paint(...) directly, should never done.

i'll bet of problem called making sure dialog modal jdialog, if make long-running calls in background thread such swingworker, , rather trying wait lock released, use call-back mechanism notify dialog shut down.

for example:

import java.awt.dialog.modalitytype; import java.awt.dimension; import java.awt.window; import java.awt.event.actionevent; import java.awt.event.windowadapter; import java.awt.event.windowevent; import java.beans.propertychangeevent; import java.beans.propertychangelistener; import java.util.concurrent.executionexception; import java.util.concurrent.atomic.atomicboolean; import javax.swing.*;  /**  * http://stackoverflow.com/a/29933423/522444  * @author pete  *  */ @suppresswarnings("serial") public class testmydialog2 extends jpanel {    private static final int pref_w = 400;    private static final int pref_h = pref_w;     public testmydialog2() {       add(new jbutton(new mydialogaction("please press button!", this)));    }     @override    public dimension getpreferredsize() {       if (ispreferredsizeset()) {          return super.getpreferredsize();       }       // let's make reasonably big       return new dimension(pref_w, pref_h);    }     private static void createandshowgui() {       testmydialog2 mainpanel = new testmydialog2();        jframe frame = new jframe("testmydialog2");       frame.setdefaultcloseoperation(jframe.dispose_on_close);       frame.getcontentpane().add(mainpanel);       frame.pack();       frame.setlocationbyplatform(true);       frame.setvisible(true);    }     public static void main(string[] args) {       swingutilities.invokelater(new runnable() {          public void run() {             createandshowgui();          }       });    }  }  @suppresswarnings("serial") class mydialogaction extends abstractaction {    private jdialog dialog;    private myworker myworker;    private testmydialog2 testmydialog2;     public mydialogaction(string name, testmydialog2 testmydialog2) {       super(name);       int mnemonic = (int) name.charat(0);       putvalue(mnemonic_key, mnemonic);       this.testmydialog2 = testmydialog2;    }     public void dialogisclosing(windowevent e) {       if (myworker != null && !myworker.isdone()) {          myworker.setkeeprunning(false);       } else {          if (dialog != null && dialog.isvisible()) {             dialog.dispose();          }       }    }     @override    public void actionperformed(actionevent e) {       window maingui = swingutilities.getwindowancestor(testmydialog2);       dialog = new jdialog(maingui, "my dialog", modalitytype.application_modal);       dialog.setdefaultcloseoperation(jdialog.do_nothing_on_close);       dialog.add(box.createrigidarea(new dimension(200, 100)));       dialog.addwindowlistener(new dialogwindowlistener(this));       dialog.pack();        myworker = new myworker();       myworker.addpropertychangelistener(new myworkerlistener(dialog));       myworker.execute();       dialog.setlocationrelativeto(maingui);       dialog.setvisible(true);    } }  class myworker extends swingworker<void, void> {    private volatile atomicboolean keeprunning = new atomicboolean(true);     @override    protected void doinbackground() throws exception {       // emulate long-running code       while (keeprunning.get()) {          thread.sleep(200);          system.out.println("long running background code running");       }        system.out.println("doing shut-down process. close in 10 seconds");       (int = 0; < 10; i++) {          system.out.println("countdown: " + (10 - i));          thread.sleep(1000); // emulate long running shut-down process       }       return null;    }     public void setkeeprunning(boolean newvalue) {       this.keeprunning.getandset(newvalue);    } }  class myworkerlistener implements propertychangelistener {    private jdialog dialog;     public myworkerlistener(jdialog dialog) {       this.dialog = dialog;    }     @override    public void propertychange(propertychangeevent evt) {       if (evt.getnewvalue() == swingworker.statevalue.done) {          dialog.dispose();          try {             ((myworker) evt.getsource()).get();          } catch (interruptedexception e) {             e.printstacktrace();          } catch (executionexception e) {             e.printstacktrace();          }       }    } }  class dialogwindowlistener extends windowadapter {    private mydialogaction mydialogaction;     public dialogwindowlistener(mydialogaction mydialogaction) {       this.mydialogaction = mydialogaction;    }     @override    public void windowclosing(windowevent e) {       mydialogaction.dialogisclosing(e);    } }