java - setOnMouseClicked not working properly -

i've been working on gui part of card game.

what i'm doing show confirmation dialog when player clicks on 1 of card's imageview.

things has been working smoothly there's bug couldn't fix. after repeatedly clicking on imageview , closing alert dialog. dialog somehow fails render body on subsequent calls.

is bug? or doing things wrongly? first question in stackoverflow, hope find soon. thanks!

i took away of game-logic codes may still seem lengthy:

public class game extends application implements igame {     final alert confirmationdialog = new alert(alerttype.confirmation);     final alert errordialog = new alert(alerttype.information);     player currentplayer;      public static void main(string[] args) {         // launch application         launch(args);     }      @override     public void start(stage startstage) throws exception {         // initialization         startstage.settitle("welcome card game");          choicebox<integer> choicebox = new choicebox<integer>();         label promptlabel = new label("number of players:");         promptlabel.setstyle("-fx-font: 30 arial");          choicebox.getitems().addall(2, 3, 4);         choicebox.setvalue(2);         choicebox.setstyle("-fx-font: 20 arial");          vbox outerlayout = new vbox(50);         hbox innerlayout = new hbox(30);         innerlayout.getchildren().addall(promptlabel, choicebox);         innerlayout.setstyle("-fx-alignment: center;");          button buttonstart = new button("start game");         buttonstart.setonaction(e -> {             startgame(choicebox.getvalue());             startstage.close();         });         outerlayout.setstyle("-fx-font: 20 arial; -fx-alignment: center; -fx-padding: 100; -fx-background-color: #993333");         outerlayout.getchildren().addall(innerlayout, buttonstart);          scene scene = new scene(outerlayout);         startstage.setminwidth(700);         startstage.setminheight(500);         startstage.setscene(scene);         startstage.show();     }             void startgame(int numberofplayers) {         // initialize ui components         showmessage("the game has started.");         currentplayer = players[playerindex];         getuserselection();          gamestage.settitle("the card game");         scene scene = new scene(mainlayout);         scene.setfill(null);         gamestage.setscene(scene);         gamestage.show();     }      @override     public void getuserselection() {         showmessage("it player " + (playerindex+1) + "'s turn.");         playerlabel.settext("player " + (playerindex+1));         if (currentplayer.isplayable(piletop)) {             counter=0;             playerhand.getchildren().clear();             for(int i=0; i<currentplayer.hand.size(); i++) {                 card playercard = currentplayer.hand.get(i);                 playerhand.getchildren().add(playercard.imageview);                 playercard.imageview.setonmouseclicked(e -> userselectiondialog(playercard));             }             playtable.setbottom(playerhand);         } else {             counter++;             if (currentplayer.hand.size() < 5) {                 showmessage("player " + (playerindex+1) + " draws card.");                 currentplayer.addcard(stock.remove(stock.size()-1));                 if (stock.isempty()) {                     showmessage("stock pile exhausted, shuffling discard pile..");                     shuffle();                 }             }             showmessage("player " + (playerindex+1) + " passes round.");             if (counter == playerno) end();             else {                 nextplayer();                 getuserselection();             }         }     }      void userselectiondialog(card playercard) {         confirmationdialog.settitle("confirmation dialog");         confirmationdialog.setheadertext("you play " + playercard + ".");         confirmationdialog.setcontenttext("confirm playing card?");         confirmationdialog.getbuttontypes().setall(buttontype.yes, buttontype.cancel);         optional<buttontype> result = confirmationdialog.showandwait();         if (result.get() == buttontype.yes){             if (playercard.match(piletop)) {                 currentplayer.playcard(playercard);                 showmessage("player " + (playerindex+1) + " discarded " + playercard);                 pile.add(playercard);                 piletop = pile.get(pile.size()-1);                 pilepane.getchildren().add(piletop.imageview);                  // end game if player's hand empty                 if (currentplayer.hand.isempty()) end();                 else {                     nextplayer();                     getuserselection();                 }             }             else {                 errordialog.settitle("message");                 errordialog.setheadertext("cannot play card.");                 errordialog.setcontenttext("your card not match rank , suit.");                 errordialog.showandwait();             }         }     } } 

what might problem? tried solve myself, no avail. :(

i realize problem comes after fixed number of mouseclick events. suspect application detaches program after time?

the mouse click event works when i'm doing things non-gui, example:

playercard.imageview.setonmouseclicked(e -> system.out.println("test")); 

however, simple gui functions such adding item listview doesn't work after number of events:

playercard.imageview.setonmouseclicked(e -> listview.add("test")); 

screenshots:

no problem first 10 alerts

alert body becomes blank after that

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edit

it seems me there problems, might memory leaks causes javafx ui hang. add more load ui components, ui seem hang faster.

i.e: added line set stage fullscreen , causes ui hang within 5 seconds application.

 gamestage.setfullscreen(true); 

edit 2

i've tested application method test memory consumption of java program eclipse , showing constant 80 megabytes memory usage. memory might not cause of problem.

apparently, couldn't reproduce problem after restart of java eclipse ide. not sure why, guess question no longer valid.