Memory leak with view pager and fragment - memory-management

Question

In this part of my application there is a ViewPager contents in a fragment,
when i replace the fragment contains the viewpager android doesn't clear the memory.
How can I clear the memory?
this is the adapter for the listview:
public class LineeAdapter extends ArrayAdapter<Linea> {
private final List<Linea> list;
private final Activity context;
private final int layout;
public LineeAdapter(Activity context,int layout, List<Linea> list) {
super(context, layout, list);
this.context = context;
this.list = list;
this.layout=layout;
}
static class ViewHolder {
protected TextView text;
protected TextView text1;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = null;
if (convertView == null) {
LayoutInflater inflator = context.getLayoutInflater();
view = inflator.inflate(layout, null);
final ViewHolder viewHolder = new ViewHolder();
viewHolder.text = (TextView) view.findViewById(R.id.cod_linea);
viewHolder.text1 = (TextView) view.findViewById(R.id.descrizione_linea);
view.setTag(viewHolder);
} else {
view = convertView;
}
ViewHolder holder = (ViewHolder) view.getTag();
holder.text.setText(list.get(position).getCod_Linea());
holder.text1.setText(list.get(position).getDesc_Linea());
return view;
}
this is the fragmet contain in the view pager
public class TempiAtt_Linee extends Fragment
{
View view;
ListView lw;
int dati;
LineeAdapter adapter;
List<Linea> linee ;
static TempiAtt_Linee newInstance(int num)
{
TempiAtt_Linee f = new TempiAtt_Linee();
return f;
}
#Override
public void onDestroyView()
{
super.onDestroyView();
getView().destroyDrawingCache();
linee.clear();
adapter.notifyDataSetChanged();
adapter.clear();
view = null;
lw = null;
linee = null;
System.gc();
}
#Override
public void onActivityCreated(Bundle savedInstanceState)
{
super.onActivityCreated(savedInstanceState);
linee= new ArrayList<Linea>();
for (int i = 0; i < Main.GeneralObject.getLinee().size(); i++)
{
this.linee.add(Main.GeneralObject.getLinee().get(i));
}
lw = (ListView) getView().findViewById(R.id.list_view);
adapter = new LineeAdapter(getActivity(), R.layout.row_linea, linee);
lw.setAdapter(adapter);
lw.setOnItemClickListener(new OnItemClickListener()
{
#Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int position, long arg3)
{
ArrayList<Percorso> tratte = linee.get(position).getPercorsi();
Fragment fragment = new TempiAtt_Percorsi();
FragmentManager fragmentManager = getActivity()
.getSupportFragmentManager();
Bundle temp = new Bundle();
temp.putString("linea", linee.get(position).getCod_Linea()
.replace(" ", "_"));
temp.putSerializable("tratte",
SerializerClass.serializeObject(tratte));
fragment.setArguments(temp);
fragmentManager.beginTransaction().addToBackStack(null)
.replace(R.id.content_frame, fragment).commit();
}
});
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
{
view = inflater.inflate(R.layout.generic_listview, container, false);
return view;
}
}
and this is the fragment of the viewpager:
public class TempiAtt extends Fragment {
// list contains fragments to instantiate in the viewpager
List<Fragment> fragments = null;
int NUM = 3;
List<String> fragmentTitles = null;
// page adapter between fragment list and view pager
private MyAdapter mPagerAdapter = null;
// view pager
private ViewPager mViewPager;
private Handler handler;
View view;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
view = inflater.inflate(R.layout.main_prova, container, false);
return view;
}
public void clear() {
if (null != mViewPager) {
mViewPager.removeAllViews();
}
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mViewPager = (ViewPager) getView().findViewById(R.id.pager);
fragments = new Vector<Fragment>();
setRetainInstance(true);
fragmentTitles = new Vector<String>();
Bundle scheda = new Bundle();
scheda.putInt("scheda", 0);
// creating fragments and adding to list
fragments.add(Fragment.instantiate(getActivity(),
TempiAtt_Linee.class.getName(), scheda));
fragmentTitles.add(getActivity().getResources().getString(
R.string.urbana_como));
Bundle scheda1 = new Bundle();
scheda1.putInt("scheda", 1);
fragments.add(Fragment.instantiate(getActivity(),
TempiAtt_Linee.class.getName(), scheda1));
fragmentTitles.add(getActivity().getResources().getString(
R.string.extraurbana));
Bundle scheda2 = new Bundle();
scheda2.putInt("scheda", 2);
fragments.add(Fragment.instantiate(getActivity(),
TempiAtt_Linee.class.getName(), scheda2));
fragmentTitles.add(getActivity().getResources().getString(
R.string.urbana_cantu));
View pagerStrip = super.getView().findViewById(R.id.pagerTabStrip);
if (pagerStrip instanceof PagerTabStrip) {
PagerTabStrip pagerTabStrip = (PagerTabStrip) pagerStrip;
pagerTabStrip.setDrawFullUnderline(true);
pagerTabStrip.setTabIndicatorColorResource(R.color.bianco);
} else if (pagerStrip instanceof PagerTitleStrip) {
PagerTitleStrip pagerTitleStrip = (PagerTitleStrip) pagerStrip;
pagerTitleStrip.setTextColor(getResources().getColor(
android.R.color.white));
}
/*
* this.mPagerAdapter = new PagerAdapter(getChildFragmentManager(),
* fragments, fragmentTitles);
* mViewPager.setAdapter(this.mPagerAdapter);
* mViewPager.setCurrentItem(0);
*/
mPagerAdapter = new MyAdapter(getChildFragmentManager());
handler = new Handler();
handler.post(new Runnable() {
#Override
public void run() {
mViewPager.setAdapter(mPagerAdapter);
}
});
mViewPager.setOffscreenPageLimit(2);
}
#Override
public void onDestroyView() {
super.onDestroyView();
onDestroy();
deleteCard();
clear();
view = null;
System.gc();
}
public void deleteCard() {
// Reduce the card counter by one
NUM -= 3;
for (int i = 0; i < fragments.size(); i++) {
fragments.remove(i);
Log.e("SONO IO", fragments.size() + "");
}
mPagerAdapter.notifyDataSetChanged();
}
private class MyAdapter extends FragmentPagerAdapter {
private SparseArray<WeakReference<TempiAtt_Linee>> mPageReferenceMap = new SparseArray<WeakReference<TempiAtt_Linee>>();;
public MyAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int index) {
return getFragment(index);
}
#Override
public int getCount() {
return NUM;
}
public int getItemPosition(Object object) {
return POSITION_NONE;
}
public TempiAtt_Linee getFragment(int key) {
WeakReference<TempiAtt_Linee> weakReference = mPageReferenceMap
.get(key);
if (null != weakReference) {
return (TempiAtt_Linee) weakReference.get();
} else {
return null;
}
}
public Object instantiateItem(ViewGroup container, int position) {
TempiAtt_Linee tempiAttLinee = TempiAtt_Linee.newInstance(position);
mPageReferenceMap.put(Integer.valueOf(position),
new WeakReference<TempiAtt_Linee>(tempiAttLinee));
return super.instantiateItem(container, position);
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
super.destroyItem(container, position, object);
mPageReferenceMap.remove(Integer.valueOf(position));
}
}
}