Question

I have a activity displaying call logs in a ListView. The adapter used here to populate listview extends CursorAdapter. Listview is set to onItemClickListener(..). My Question is whenever an item is clicked how does cursor get the data? how does cursor know which position is clicked and need to get data from clicked position only? I have provided a code snippnet.

public class CallLog extends Activity
{
   ListView mListView;
   Cursor cursor;

   //other variables


   public void OnCreate()
   {
        setContentView(R.layout.calllog);

        //SQLiteDatabaseInstance db
        cursor = db.query(...parameters to get all call logs...);
        mListView.setOnItemClickListener(this);
   }

   public void OnItemClick( // all arguments... )
   {
         //there is a column name 'NAME' in call log table in database 
         String name = cursor.getString(cursor.getColumnIndex(Database.NAME))

         //here name is obtained of the clicked item.
   }

Cursor is a result set. how does the cursor know which item is clicked? What can be the methods implicitly called by cursor that gives it position of clicked item?

If there are any links of similar question then pls provide.

I hope I am able to make you understand the question. Thank you

Answer 1

Specifically it is NOT the Cursor that knows who clicked on what. This is actually handled by the Adapter. The adapter is used to group elements together and allow abstraction as such that they can be handled in a uniform way.

Any form of list, always has an adapter, and this is exactly why the adapter works so well. If you look at a Custom Listview with a Custom Adapter, you’ll see exactly how this is done.

Example:

http://android.vexedlogic.com/2011/04/02/android-lists-listactivity-and-listview-ii-%E2%80%93-custom-adapter-and-list-item-view/