android - dynamically hide or show TextView in ListView's rows corresponding to title's first character -

i need hide or show label of listview's row if first character of title matched first time in list. attach picture can understand clearly.

i tried when create arraylist of contacts :

public arraylist<contactitem> getdisplaycontacts(context context)     {            arraylist<contactitem> contactslist = null;         databasehandler db = new databasehandler(context.getapplicationcontext());          try {             dao<contactitem,integer> daosubject = db.getcontactdao();             contactslist = (arraylist<contactitem>) daosubject.queryforall();          }          catch(exception e)          {e.printstacktrace();}          collections.sort(contactslist, new comparator<contactitem>() {                 @override                 public int compare(contactitem lhs, contactitem rhs) {                     return lhs.getname().compareto(rhs.getname());                 }             });          (int =0; i< contactslist.size()-1;i++)          {              if (!contactslist.get(i).getname().substring(0,1).equalsignorecase(contactslist.get(i+1).getname().substring(0,1)))                  contactslist.get(i).setcontactlabel(true);              else                   contactslist.get(i).setcontactlabel(false);          }         return contactslist;      } 

but didn't proper result. tried put views in custom arrayadapter , change after listview created, didn't help. check title , show/hide label in getview didn't help. grateful help.

first of - remember positions 'letter-item' should be. 'a' 0, 'b' = number of 'a'-started names, 'c' = 'b' postition + number of 'b'-started items , on. let sparsearray string type.

when got of this, should put data sparsearray, each item inex adjusted previous calculation. example, alex - 1(0 'a'-label,), bob - 3(2 'b'-label) , on.

then write custom adapter , override method

public view getview(int position, view convertview, viewgroup parent) 

so, if 'position' contains in first array, return 'label'-view proper latter, otherwise, common row item accessing second array.

english not native, might hard understand - don't hesitate ask questions.