java - How to override the JPopupMenu method show? -

my goal highlight jlist item after rightclick show jpopupmenu.. read advice overriding method show way.. in case declare jpopupmenu @ beginning of class

     jpopupmenu popupmenu = new jpopupmenu();      jmenuitem masterlist,settings; 

then have method set menuitems

    public void setpopupmenu(int depth//ignore var){     //popupmenu = new jpopupmenu();     popupmenu.removeall();          masterlist = new jmenuitem("masterlist");         settings = new jmenuitem("settings");          //action marsterlist         masterlist.addactionlistener(new actionlistener(){             //stuff here             }         });         //action settings         settings.addactionlistener(new actionlistener(){             //stuff here             }         });          popupmenu.add(masterlist);         popupmenu.add(settings);  } 

and list in different method

list.setselectionmode(listselectionmodel.single_selection); list.setlayoutorientation(jlist.horizontal_wrap); list.setvisiblerowcount(-1); list.setcomponentpopupmenu(popupmenu); 

i tried putting on mouseadapter of list popupmenu fires first , ignores highlighting...

   if ( swingutilities.isrightmousebutton(mouseevent) )//highlight right clicked item                  {                      int row = list.locationtoindex(mouseevent.getpoint());                     list.setselectedindex(row);                      string val = (string)list.getselectedvalue();                     system.out.println(val);                  } 

i know overriding this

  popupmenu = new jpopupmenu(){   @override   public void show(){}   } 

but cant because manipulating menuitems on method... or there other approach can suggest...

rather trying modify state of jpopupmenu, why not modify state of menu item when detect right click...

so, basically, make use of actions api define menu item jpopupmenu, allows register listselectionlistener underlying jlist...

public class showitemaction extends abstractaction {      private jlist list;      public showitemaction(jlist list) {         this.list = new jlist();         putvalue(name, "showing ...");          list.addlistselectionlistener(new listselectionlistener() {             @override             public void valuechanged(listselectionevent e) {                 if (!e.getvalueisadjusting()) {                     int index = list.getselectedindex();                     string value = list.getselectedvalue().tostring();                     putvalue(name, "showing " + value + " @ " + index);                 }             }         });     }      @override     public void actionperformed(actionevent e) {         // actual action performed when selected     }  } 

all is, when selection changed, change text (name) of action, changes text of menu item, based on selected row.

when create jlist, assign jpopupmenu via setcomponentpopupmenu method, means no longer need care , displayed appropriately based on current , feel requirements

jlist list = new jlist(model); jpopupmenu popupmenu = new jpopupmenu(); popupmenu.add(new showitemaction(list)); list.setcomponentpopupmenu(popupmenu); 

i add mouselistener jlist use change row selection when right click on jlist...

list.addmouselistener(new mouseadapter() {     @override     public void mousepressed(mouseevent e) {         jlist list = (jlist)e.getcomponent();         if (swingutilities.isrightmousebutton(e)) {             int row = list.locationtoindex(e.getpoint());             list.setselectedindex(row);         }     } }); 

this not entirely fool proof, if right click jlist while popup visible, mouselistener doesn't appear notified :p

runnable example...

import java.awt.dimension; import java.awt.eventqueue; import java.awt.graphics; import java.awt.graphics2d; import java.awt.event.actionevent; import java.awt.event.mouseadapter; import java.awt.event.mouseevent; import javax.swing.abstractaction; import static javax.swing.action.name; import javax.swing.defaultlistmodel; import javax.swing.jframe; import javax.swing.jlist; import javax.swing.jpanel; import javax.swing.jpopupmenu; import javax.swing.jscrollpane; import javax.swing.swingutilities; import javax.swing.uimanager; import javax.swing.unsupportedlookandfeelexception; import javax.swing.event.listselectionevent; import javax.swing.event.listselectionlistener;  public class test {      public static void main(string[] args) {         new test();     }      public test() {         eventqueue.invokelater(new runnable() {             @override             public void run() {                 try {                     uimanager.setlookandfeel(uimanager.getsystemlookandfeelclassname());                 } catch (classnotfoundexception | instantiationexception | illegalaccessexception | unsupportedlookandfeelexception ex) {                     ex.printstacktrace();                 }                  defaultlistmodel model = new defaultlistmodel();                 model.addelement("one");                 model.addelement("two");                 model.addelement("three");                 model.addelement("four");                 jlist list = new jlist(model);                 jpopupmenu popupmenu = new jpopupmenu();                 popupmenu.add(new showitemaction(list));                 list.setcomponentpopupmenu(popupmenu);                  list.addmouselistener(new mouseadapter() {                      @override                     public void mousepressed(mouseevent e) {                         if (swingutilities.isrightmousebutton(e)) {                             int row = list.locationtoindex(e.getpoint());                             list.setselectedindex(row);                         }                     }                  });                  jframe frame = new jframe("testing");                 frame.setdefaultcloseoperation(jframe.exit_on_close);                 frame.add(new jscrollpane(list));                 frame.pack();                 frame.setlocationrelativeto(null);                 frame.setvisible(true);             }         });     }      public class showitemaction extends abstractaction {          private jlist list;          public showitemaction(jlist list) {             this.list = new jlist();             putvalue(name, "showing ...");              list.addlistselectionlistener(new listselectionlistener() {                 @override                 public void valuechanged(listselectionevent e) {                     if (!e.getvalueisadjusting()) {                         int index = list.getselectedindex();                         string value = list.getselectedvalue().tostring();                         putvalue(name, "showing " + value + " @ " + index);                     }                 }             });         }          @override         public void actionperformed(actionevent e) {         }      }  }