Question

i have been having this issue for some time now, and have not gotten an answer for it yet. i have this custom Cursor adapter which i use to populate a list view from an sqlite database. Now my issue is that i want to populate the listview based on certain conditions.An example is if the condition is important, the listview should display only data that fits into that criteria and so on. I already have working methods that query the database accordingly.

now my problem is that, i can’t seem to populate the listviews based on those methods and conditions without:

1) creating a copy of the exact same custom cursor adapter and just changing the names variables.
2) creating a copy of the exact xml layout and changing the id’s.

As i say, its working this way, but i feel am having unnecessary classes and xml layout since its exactly the same thing. I know am doing something wrong, i just don’t know what. Please any help and explanation would be appreciated. here is the necessary part of the code Code for the CustomCursorAdapter:

 public class ViewItems extends ListActivity implements OnItemClickListener{

     DBAdapter adapter;
     Cursor cursor;
     ListView list;

     public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.view_list);
      adapter = new DBAdapter(this);
      adapter.open();
      fillData();

      list = (ListView)findViewById(android.R.id.list); // default android listView id
      list.setOnItemClickListener(this);


     }

     // Different method calls
     protected void fillImportantData() {
      Cursor cursor = adapter.retrieveImportant();
      startManagingCursor(cursor);

        String[] from = new String[]{DBAdapter.NAME, DBAdapter.DATE, DBAdapter.TIME, DBAdapter.PRIORITY};
        int[] to = new int[]{R.id.viewNameId, R.id.viewDateId, R.id.viewTimeId};

        customCursorAdapter items = new customCursorAdapter(this, R.layout.view_items, cursor, from, to);
        setListAdapter(items);   
     }



     public class customCursorAdapter extends SimpleCursorAdapter {
      private int layout;
      Context context;

      public customCursorAdapter(Context context, int layout, Cursor cursor, String[]from, int[] to) {
       super(context, layout, cursor, from, to);
       this.layout = layout;
       this.context = context;

      }


      @Override
      public void bindView(View view, Context context, Cursor cursor) {
       ViewHolder holder;

       if(view != null){
        holder = new ViewHolder();
        holder.viewName = (TextView)view.findViewById(R.id.viewNameId);
        holder.viewStartDate = (TextView)view.findViewById(R.id.viewDateId);
        holder.viewStartTime = (TextView)view.findViewById(R.id.viewTimeId);

        view.setTag(holder);
       }else{
        holder = (ViewHolder)view.getTag();
       }

       int namecol = cursor.getColumnIndex(DBAdapter.NAME); 
       String name = cursor.getString(namecol);


       if(holder.viewName != null){
       holder.viewName.setText(name);
       holder.viewName.setTextColor(Color.RED);
       }

       String startDate = cursor.getString(cursor.getColumnIndex(DBAdapter.DATE));
       holder.viewStartDate.setText(startDate);

       String startTime = cursor.getString(cursor.getColumnIndex(DBAdapter.TIME));
       holder.viewStartTime.setText(startTime);
      }


      @Override
      public View newView(Context context, Cursor cursor, ViewGroup parent) {

       LayoutInflater inflater = LayoutInflater.from(context);
       final View view = inflater.inflate(layout, parent, false);

       return view;
      }


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


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

     }

     static class ViewHolder{
      TextView viewName;
      TextView viewStartDate;
      TextView viewStartTime;

     }

    }


// methods in database

public Cursor retrieveAll(){
  String[] resultColumns = new String[] {KEY_ID, NAME DATE, TIME, PRIORITY};
    Cursor cursor = db.query(DATABASE_TABLE, resultColumns, null, , null, null, null);
     return cursor; 
    }

public Cursor retrieveImportant(){
  String[] resultColumns = new String[] {KEY_ID, NAME DATE, TIME, PRIORITY};
  String[] condition = {"important"};
  Cursor cursor = db.query(DATABASE_TABLE, resultColumns, PRIORITY + "=" + "?", condition, null, null, null);
     return cursor; 
    }

Answer 1

1. If you change the data you wish to display, you will need to run a fresh query on the database and get a Cursor back that reflects that changed data. Depending on the nature of the changes, this may require a fresh CursorAdapter or merely a call to changeCursor(). If the new query returns the same columns and you want them displayed the same way, changeCursor() is probably sufficient. Otherwise, you will need to create a new CursorAdapter and call setAdapter() on your ListView to switch over to it.

2. You only need a different row layout if you are truly changing the row layout. You do not need to change IDs just for grins. Since you are not doing this in the code you have shown above, I am unclear what specifically you are worried about.