how to perform test to the GridView in onclick position

I write a testing to the Grid View to count the number of items in the grid. i want to perform onclick to the grid view

here is a my mainActivity class

public class MainActivity extends AppCompatActivity {

GridView gridView;


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

    gridView = (GridView) findViewById(R.id.gridview1);

    gridView.setAdapter(new ImageAdapter(this));

    gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
            // Send intent to SingleViewActivity
            Intent i = new Intent(getApplicationContext(), SingleViewActivity.class);

            // Pass image index
            i.putExtra("id", position);
            startActivity(i);
        }
    });

}
}

SingleViewActivity.Java

public class SingleViewActivity extends Activity{

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.single_view);

    // Get intent data
    Intent i = getIntent();

    // Selected image id
    int position = i.getExtras().getInt("id");
    ImageAdapter imageAdapter = new ImageAdapter(this);

    ImageView imageView = (ImageView) findViewById(R.id.SingleView);
    imageView.setImageResource(imageAdapter.mThumbIds[position]);
}
}

ImageAdapter.java

public class ImageAdapter extends BaseAdapter {
private Context mContext;

// Constructor
public ImageAdapter(Context c) {
    mContext = c;
}

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

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

@Override
public long getItemId(int position) {
    return 0;
}

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

    if (convertView == null) {
        imageView = new ImageView(mContext);
        imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setPadding(8, 8, 8, 8);
    }
    else
    {
        imageView = (ImageView) convertView;
    }
    imageView.setImageResource(mThumbIds[position]);
    return imageView;
}


public Integer[] mThumbIds = {
        R.drawable.images, R.drawable.asdawe,
        R.drawable.bokey, R.drawable.assd,
        R.drawable.download, R.drawable.ew,
        R.drawable.lilly, R.drawable.jh,
        R.drawable.rose, R.drawable.we,
        R.drawable.lilly1, R.drawable.images,
        R.drawable.bokey, R.drawable.asdawe,
        R.drawable.download, R.drawable.ew,
        R.drawable.jh, R.drawable.lilly,
        R.drawable.rose, R.drawable.we,
        R.drawable.lilly1, R.drawable.images
};
}

MainActivityTest.java

public class MainActivityTest extends ActivityInstrumentationTestCase<MainActivity> {

private MainActivity mActivity;
private GridView mGridView;
private Instrumentation mInstrumentation;
public MainActivityTest() {
    super("com.android.frameworks.coretests", MainActivity.class);
}

@Override
protected void setUp() throws Exception {
    super.setUp();

    mActivity = getActivity();
    mGridView = (GridView) mActivity.findViewById(R.id.gridview1);
    mInstrumentation = getInstrumentation();
}
@MediumTest
public void testPreconditions() {
    assertNotNull(mActivity);
    assertNotNull(mGridView);
}
@LargeTest
public void testSetSelection() {
    mGridView = new GridView(mActivity);
    mGridView.setSelection(0);
    assertEquals(0, mGridView.getSelectedItemPosition());
    mGridView.setSelection(-1);
    assertEquals(-1, mGridView.getSelectedItemPosition());
    mGridView.setSelection(mGridView.getCount());
    assertEquals(mGridView.getCount(), mGridView.getSelectedItemPosition());
}

@Test
public void testSetSelectionone() {
    TouchUtils.dragQuarterScreenDown(this);
    TouchUtils.dragQuarterScreenUp(this);

    // Nothing should be selected
    assertEquals("Selection still available after touch", -1,
            mGridView.getSelectedItemPosition());

    final int targetPosition = mGridView.getAdapter().getCount() ;

    assertEquals(22,targetPosition);
}


}

i want a test for the on click on the Grid View