FragmentPagerAdapter + BaseAdapter + UIL not Updating

Question

I am trying to setup a tab title strip using swipes to switch between the fragments as demoed in the documentation here. It works, up to a point. The gridview shows all the images as required however, both fragment 1 and fragment 2 are showing the same images. It appears that fragment 2 is overwriting the images because if you click on the image in fragment 1, the fragment 1 details screen pops up (even though it shows an image from fragment 2).

Basically, I need my ImageAdapter (BaseAdapter) to show the correct images for each separate fragment. I don't see how the second fragment is interacting with the first if there are no static elements.

Edit: I tried changing to Picasso and the same error occurred so there has to be something in my code.

Edit2: I found this answer and it does let me redraw the grid when a fragment becomes visible but that causes a noticeable flicker and it is obvious the images were wrong. The problem has to lie somwhere with UIL/Picasso thinking the gridview in the separate fragments are the same object (they do have the same images but in different orders).

public void setupFragmentSwipes() {
    mDemoCollectionPagerAdapter =
            new DemoCollectionPagerAdapter(
                    getFragmentManager());
    mViewPager = (ViewPager) mRootView.findViewById(R.id.pager);
    mViewPager.setAdapter(mDemoCollectionPagerAdapter);
}

  public class DemoCollectionPagerAdapter extends FragmentStatePagerAdapter {
    String[] array = getResources().getStringArray(R.array.SortOptions);
    public DemoCollectionPagerAdapter(FragmentManager fm) {
        super(fm);
    }
    @Override
    public Fragment getItem(int i) {
        Fragment fragment = new FragmentGrid();
        Bundle args = new Bundle();

        args.putInt("mMode", mMode);
        args.putInt("mSortAorD", mSortAorD);
        args.putInt("mSortType", i);
        fragment.setArguments(args);
        return fragment
    }

    @Override
    public int getCount() {
        return array.length;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return array[position];
    }
}

FragmentGrid

public class FragmentGrid extends Fragment {
public int mode;
private ArrayList<Theme> mThemes;
private GridView listView;
private static DisplayImageOptions options;
protected ImageLoader imageLoader = ImageLoader.getInstance();
protected int mSavedPosition;
private int sortType;
private int sortAorD;
@Override
    public View onCreateView(LayoutInflater inflater,
                         ViewGroup container, Bundle savedInstanceState) {
    // The last two arguments ensure LayoutParams are inflated
    // properly.
    View rootView = inflater.inflate(
            R.layout.fragment_collection_object, container, false);
    Bundle args = getArguments();

    mode = args.getInt("mMode", BaseConstants.ViewModes.NORMAL);

    sortType = args.getInt("mSortType", BaseConstants.Sort.POPULAR);
    sortAorD = args.getInt("mSortAorD", BaseConstants.Sort.DESC);
    listView = (GridView) rootView.findViewById(R.id.gridview2);



    options = new DisplayImageOptions.Builder()
            .showStubImage(R.drawable.ic_stub)
            .showImageForEmptyUri(R.drawable.ic_error)
            .showImageOnFail(R.drawable.ic_error)
            .cacheOnDisc(true)
            .imageScaleType(ImageScaleType.EXACTLY)
            .bitmapConfig(Bitmap.Config.RGB_565)
            .build();



    return rootView;
}
@Override
public void onResume() {
    super.onResume();
    listView.setSelection(mSavedPosition);
    ThemeManager tm = new ThemeManager(getActivity().getApplicationContext());
    mThemes = tm.getModifiedThemeList(mode);
    mThemes = tm.compare(sortType, sortAorD, checkIfTesting());
    listView.setAdapter(new ImageAdapter(mThemes));
    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            mSavedPosition = position;
            Intent intent = new Intent(getActivity(), ImagePagerActivity.class);
            intent.putExtra("mMode", mode);
            intent.putExtra("mSortAorD", sortAorD);
            intent.putExtra("mSortType", sortType);
            intent.putExtra("mPosition", position);
            startActivity(intent);
        }
    });

}
public class ImageAdapter extends BaseAdapter {
    ArrayList<Theme> imageAdapterThemeList;
    public ImageAdapter(ArrayList<Theme> themes) {
        imageAdapterThemeList = themes;
    }
    @Override
    public int getCount() {
        int result = 0;
        if (imageAdapterThemeList != null) {
            result = imageAdapterThemeList.size();
        }
        return result;
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
         ImageView imageView;

        if (convertView == null) {
            imageView = (ImageView) getActivity().getLayoutInflater().inflate(R.layout.item_grid_image, parent, false);
        } else {
            imageView = (ImageView) convertView;
        }

        Theme theme = imageAdapterThemeList.get(position);

        imageLoader.displayImage(theme.getImageURL(), imageView, options);

        return imageView;
    }
}

fragment_collection_object.xml

<GridView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/gridview2"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center"
android:horizontalSpacing="4dip"
android:numColumns="auto_fit"
android:columnWidth="150dip"
android:scrollbars="vertical"
android:stretchMode="columnWidth"
android:verticalSpacing="4dip"
android:padding="4dip" />

Answer 1

Ok, I found the answer but I don't know why. I had to change the following from:

ArrayList<Theme> imageAdapterThemeList;
public ImageAdapter(ArrayList<Theme> themes) {
    imageAdapterThemeList = themes;
}

to:

ArrayList<Theme> imageAdapterThemeList = new ArrayList<Theme>();

    public ImageAdapter(ArrayList<Theme> themes) {

        for (int i = 0; i< themes.size() ;i++) {
            imageAdapterThemeList.add(i, themes.get(i));
        }

    }

I think, rather than creating a new ArrayList I was merely pointing to the old one. This new method actually recreates it but I'm sure it's not very efficient.