java - How to design a checkbox treeviewer using jface -

i have designed checkbox treeviewer using jface when run program doesnot display thing on ui.i not able find issue is.please me whrer problem new jface.

private void createtreemenu(composite parentcomposite){              /*treeitem = new treeitem(tree, swt.multi | swt.check | swt.virtual |swt.border );             treeitem.settext("(1)test session");             treeitem.setimage(new image(null, treeviewer.class.getclassloader().getresourceasstream("icons/folder-main.jpg")));*/              composite treemenu = new composite(parentcomposite, swt.border);             treemenu.setlayout(new gridlayout(1, false));             treemenu.setlayoutdata(new griddata(griddata.fill, griddata.fill, true, true));              /*tree = new tree (treemenu, swt.multi | swt.check |swt.virtual );             griddata treegd = new griddata(swt.fill, griddata.fill, true, true);             tree.setlayoutdata(treegd);*/               checkboxtreeviewer treeviewer=new checkboxtreeviewer(tree);                   treeviewer.setcontentprovider(new filetreecontentprovider());             treeviewer.setlabelprovider(new filetreelabelprovider1());                    treeviewer.setinput(treeitem);                parameters.add("root");              /*treeitem = new treeitem(tree, swt.multi | swt.check | swt.virtual |swt.border );             treeitem.settext("(1)test session");             treeitem.setimage(new image(null, treeviewer.class.getclassloader().getresourceasstream("icons/folder-main.jpg")));*/              tree.addlistener(swt.selection, new listener() {                 public void handleevent(event e) {                      if(e.item == null)                     {                         return;                     }                      treeselection = tree.getselection();                     }             });              treemenu.addlistener(swt.mousedown, new listener() {                 @override                 public void handleevent(event event) {                     tree.setselection(new treeitem[] {});                     treeselection = null;                 }             });              final menu menu = new menu(tree);             tree.setmenu(menu);             loadmenudetails(menu);         }          public treeitem getinput()         {             treeitem = new treeitem(tree, swt.multi | swt.check | swt.virtual |swt.border );             treeitem.settext("(1)test session");             treeitem.setimage(new image(null, treeviewer.class.getclassloader().getresourceasstream("icons/folder-main.jpg")));              return treeitem;          }          /**          * class provides content tree in filetree          */          class filetreecontentprovider implements itreecontentprovider {           /**            * gets children of specified object            *             * @param arg0            *            parent object            * @return object[]            */           public object[] getchildren(object arg0) {             // return files , subdirectories in directory             //return ((file) arg0).listfiles();               return null;           }            /**            * gets parent of specified object            *             * @param arg0            *            object            * @return object            */           public object getparent(object arg0) {             // return file's parent file             //return ((file) arg0).getparentfile();               return null;           }            /**            * returns whether passed object has children            *             * @param arg0            *            parent object            * @return boolean            */           public boolean haschildren(object arg0) {             // children             object[] obj = getchildren(arg0);              // return whether parent has children             return obj == null ? false : obj.length > 0;           }        /**        * gets root element(s) of tree        *         * @param arg0        *            input data        * @return object[]        */       /*public object[] getelements(object arg0) {         // these root elements of tree         // don't care arg0 is, because want         // root nodes in file system         return file.listroots();         //return "new root";       }*/        public object[] getelements(object inputelement) {              //treeitem rootitem = new treeitem((tree) arg0, swt.check);             //rootitem.settext("root");         //    return new object[] { "session root" }; // root item want display           treeitem = new treeitem(tree, swt.multi | swt.check | swt.virtual |swt.border );             treeitem.settext("(1)test session");             treeitem.setimage(new image(null, treeviewer.class.getclassloader().getresourceasstream("icons/folder-main.jpg")));           if (inputelement instanceof treeitem)           {               system.out.println("getelements");               return ((list<string>)inputelement).toarray();           }             return new object[] {parameters.toarray()};         }        /**        * disposes created resources        */       public void dispose() {         // nothing dispose       }        /**        * called when input changes        *         * @param arg0        *            viewer        * @param arg1        *            old input        * @param arg2        *            new input        */       public void inputchanged(viewer arg0, object arg1, object arg2) {         // nothing change       }     }  class filetreelabelprovider1 implements ilabelprovider {       // listeners       private list listeners;        // images tree nodes       private image file;        private image dir;        // label provider state: preserve case of file names/directories         /**        * constructs filetreelabelprovider        */       public filetreelabelprovider1() {         // create list hold listeners         listeners = new arraylist();          // create images         try {           file = new image(null, new fileinputstream("images/file.gif"));           dir = new image(null, new fileinputstream("images/directory.gif"));         } catch (filenotfoundexception e) {           // swallow it; we'll without images         }       }          /**        * gets image display node in tree        *         * @param arg0        *            node        * @return image        */       public image getimage(object arg0) {         // if node represents directory, return directory image.         // otherwise, return file image.         return ((file) arg0).isdirectory() ? dir : file;       }        /**        * gets text display node in tree        *         * @param arg0        *            node        * @return string        */       public string gettext(object arg0) {         // name of file         string text = ((file) arg0).getname();          // if name blank, path         if (text.length() == 0) {           text = ((file) arg0).getpath();         }          // check case settings before returning text         return text ;       }        /**        * adds listener label provider        *         * @param arg0        *            listener        */       public void addlistener(ilabelproviderlistener arg0) {         listeners.add(arg0);       }        /**        * called when labelprovider being disposed        */       public void dispose() {         // dispose images         if (dir != null)           dir.dispose();         if (file != null)           file.dispose();       }        /**        * returns whether changes specified property on specified        * element affect label element        *         * @param arg0        *            element        * @param arg1        *            property        * @return boolean        */       public boolean islabelproperty(object arg0, string arg1) {         return false;       }        /**        * removes listener        *         * @param arg0        *            listener remove        */       public void removelistener(ilabelproviderlistener arg0) {         listeners.remove(arg0);       }     } 

try giving tree object parent composite , flags (swt.border | swt.check) worked me way

tree = new tree(treemenu, swt.border | swt.check);