android - Reset CirclePageIndicator library -

i wanted have image lazy loading in listview. put images in viewpager, , set circlepageindicator viewpager:

public void fetchdrawableonthread(final viewpager viewpager, final circlepageindicator indicator) {               final handler handler = new handler() {             @override             public void handlemessage(message message) {                 imagepageradapter adapter = new imagepageradapter((drawable[]) message.obj);                 viewpager.setadapter(adapter);                  indicator.setviewpager(viewpager);             }         };          thread thread = new thread() {             @override             public void run() {                   drawable[] drawables = fetchdrawables();                  message message = handler.obtainmessage(1, drawables);                 handler.sendmessage(message);             }         };         thread.start();     } 

this custom adapter class in main activity:

private class multiadapter extends arrayadapter<string> {       public multiadapter(context context, arraylist<string> mstrings) {         super(context, r.layout.list_main, mstrings);     }      @override     public view getview(int position, view convertview, viewgroup parent) {          view row;          if (convertview == null)  {             layoutinflater inflater = getlayoutinflater();             row = inflater.inflate(r.layout.list_main, parent, false);         } else             row = convertview;          viewpager viewpager = (viewpager) row.findviewbyid(r.id.pager);         circlepageindicator indicator = (circlepageindicator)row.findviewbyid(r.id.indicator);          if(scroll_is_idle)             drawablemng.fetchdrawableonthread(viewpager, indicator);          else {             viewpager.setadapter(null);         }          return row;     } } 

in getview method, want set viewpager adapter null, when scroll not in idle mode , makes problem in pageindicator library (nullpointerexception). know how can reset pageindicator avoid problem?

i know logic may not good:

if(scroll_is_idle)       drawablemng.fetchdrawableonthread(viewpager, indicator);  else        viewpager.setadapter(null); 

but way made problem in ondraw method in viewpageindicator library, nullponiterexception.

i solved problem editing ondraw , add mviewpager.getadapter() == null condition:

@override     protected void ondraw(canvas canvas) {         super.ondraw(canvas);          if (mviewpager == null || mviewpager.getadapter() == null) {             return;         }