android - How to start fragment from a specific position and be able to go to previous positions? -

i have listview. when click on element of listview pass 2 string arrays , list position. use information start pager of fragments. working fine. information, displayed. let's click on listitem-5, new fragment start @ 5 , i'll able go 6,7,8 etc., won't able go left @ 4,3,2,1.how can achieve ?

public class viewpagerfragment extends fragmentactivity {      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_view_pager_fragment);         arraylist<string> email=getintent().getextras().getstringarraylist("email");         arraylist<string> about=getintent().getextras().getstringarraylist("about");         int listposition = getintent().getextras().getint("position");           viewpager vppager = (viewpager) findviewbyid(r.id.vppager);         adapterviewpager = new mypageradapter(getsupportfragmentmanager(),email,about,listposition);         vppager.setadapter(adapterviewpager);     }      private smartfragmentstatepageradapter adapterviewpager;      // extend smartfragmentstatepageradapter instead more dynamic viewpager items     public static class mypageradapter extends smartfragmentstatepageradapter {         private final arraylist<string> email;         private final arraylist<string> about;         private int listposition;          public mypageradapter(fragmentmanager fragmentmanager,arraylist<string> email,arraylist<string> about,int lposition) {             super(fragmentmanager);             this.email=email;             this.about = about;             listposition = lposition;         }          // returns total number of pages         @override         public int getcount() {             return email.size();         }          // returns fragment display page         @override         public fragment getitem(int position) {             return firstfragment.newinstance(email.get(listposition+position), about.get(listposition+position));         }          // returns page title top indicator         @override         public charsequence getpagetitle(int position) {             return "page " + position;         }      } } 

i not understanding code design. allow me understand sample scenario. if click on listitem-5, perhaps used code:

adapterviewpager.getitem(0); 

if need see fragment 4, need go backwards. hence use code:

adapterviewpager.getitem(-1); 

otherwise, use code:

adapterviewpager = new mypageradapter(getsupportfragmentmanager(),email,about, 0); 

note value 0 4th parameter start first fragment.