You'll have to add numbering to each of the cells and only display it when it is the leftmost cell.
Cell layout
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<TextView
android:id="@+id/row_number"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:gravity="center"/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<!-- The rest of your layout -->
</LinearLayout>
</LinearLayout>
In your Adapter
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = LayoutInflater.from(context).inflate(R.layout.grid_cell);
TextView rowNumber = (TextView) v.findViewById(R.id.row_number);
if (position % colNum == 0) { // colNum: number of columns
int row = position / colNum + 1; // get the row number
rowNumber.setText(String.valueOf(row));
rowNumber.setVisibility(View.VISIBLE);
} else {
rowNumber.setVisibility(View.GONE);
}
return v;
}
Note: For the sake of simplicity I am not using the ViewHolder pattern. But you should!