Question

I’ve implemented a custom CursorAdapter. This adapter takes data from a Cursor and deposits most of it into a ListView. One of the fields in the ListView needs data from a different table, so I need to query the database again to set that piece in the view. My ListView seems to be working, as before I had no data in the db it was properly displaying my empty tag, "no data in the db". Now that there is data in the db, the ListView shows nothing! Here is my custom adapter:

    public class ScheduleAdapter extends CursorAdapter {

    private LayoutInflater mInflater;
    private int mHomeAway, mOppFK, mLocation, mWhen, mOutcome, mType, mPlayed;
    private String teamName;

    public ScheduleAdapter(Context context, Cursor c) {
        super(context, c);
        // TODO Auto-generated constructor stub

        mHomeAway = c.getColumnIndex(ScoreMasterDB.KEY_SCHHOMEAWAY);
        mOppFK = c.getColumnIndex(ScoreMasterDB.KEY_SCHOPPFK);
        mLocation = c.getColumnIndex(ScoreMasterDB.KEY_SCHLOCATION);
        mWhen = c.getColumnIndex(ScoreMasterDB.KEY_SCHWHEN);
        mOutcome = c.getColumnIndex(ScoreMasterDB.KEY_SCHOUTCOME);
        mType = c.getColumnIndex(ScoreMasterDB.KEY_SCHTYPE);
        mPlayed = c.getColumnIndex(ScoreMasterDB.KEY_SCHPLAYED);

        mInflater = LayoutInflater.from(context);
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        // TODO Auto-generated method stub
        return mInflater.inflate(R.layout.schedule_main_list, parent);
    }

    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        // TODO Auto-generated method stub

        TextView homeAway = (TextView) view.findViewById(R.id.tvVsAt);
        TextView oppName = (TextView) view.findViewById(R.id.tvScheduleListOpponent);
        TextView location = (TextView) view.findViewById(R.id.tvScheduleListLocation);
        TextView outcomeWhen = (TextView) view.findViewById(R.id.tvScheduleDateTimeResult);
        TextView gameType = (TextView) view.findViewById(R.id.tvScheduleType);

        ScoreMasterDB dbInfo = new ScoreMasterDB(context);
        try {
            dbInfo.open();
            teamName = dbInfo.getTeamName(cursor.getInt(mOppFK));
            dbInfo.close();

        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        homeAway.setText(cursor.getString(mHomeAway));
        oppName.setText(teamName);
        location.setText(cursor.getString(mLocation));

        //set game time or outcome
        if(cursor.getInt(mPlayed) == 0){
            outcomeWhen.setText(cursor.getString(mWhen));

            //set text style for outcome
            if(cursor.getInt(mOutcome) == 1){
                outcomeWhen.setTextAppearance(context, R.style.greenWinText);
            }
        }

        gameType.setText(cursor.getString(mType));

    }
}

Here is my call to this adapter:

// get schedule cursor
            scheduleInfo = dbInfo.getScheduleCursor(teamID, seasonID);
            startManagingCursor(scheduleInfo);

            ScheduleAdapter scheduleAdapter = new ScheduleAdapter(ScheduleMain.this, scheduleInfo);
            setListAdapter(scheduleAdapter);

EDIT:
The activity that is calling the custom adapter is supposed to display the team’s schedule. It does so by first showing a dialog to select the team, then showing another dialog to choose the appropriate season. It then queries the db for the schedule with the matching teamID and seasonID. The reason for the custom adapter is that the schedule will list the opponent as an integer foreign key, so I need to query the db in the adapter to grab the appropriate team name for the opponent.

Here is the activity (its quite a lot of code)

    package com.scoremaster.pro;

import android.app.Dialog;
import android.app.ListActivity;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemLongClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.TextView;
import android.widget.Toast;

public class ScheduleMain extends ListActivity implements OnItemClickListener,
        OnClickListener, OnItemLongClickListener {

    Dialog selectTeam, selectSeason, newSeason;
    Cursor teamInfo, seasons, scheduleInfo;
    ScoreMasterDB dbInfo;
    ListView diaList, diaSeason;
    int teamID, seasonID;
    String teamNameG;
    Button addNewSeason;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

        setContentView(R.layout.schedule_main);

        selectTeam = new Dialog(ScheduleMain.this);
        selectTeam.setContentView(R.layout.schedule_main_dialog);
        selectTeam.setTitle("Select Team");

        dbInfo = new ScoreMasterDB(this);
        try {
            dbInfo.open();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        teamInfo = dbInfo.getTeamsCursor();
        startManagingCursor(teamInfo);

        if (teamInfo.getCount() == 0) {
            Intent createTeamIntent = new Intent(
                    "com.scoremaster.pro.CREATETEAM");
            createTeamIntent.putExtra("fromSchedule", true);
            startActivity(createTeamIntent);
        }

        String[] columns = { ScoreMasterDB.KEY_TEAMNAME };
        int[] to = { R.id.tvTeamSelectList };

        //Bundle scheduleBundle = getIntent().getExtras();
        //int whatToDo = scheduleBundle.getInt(")

        diaList = (ListView) selectTeam.findViewById(R.id.lvScheduleDialog);
        SimpleCursorAdapter teamListAdapter = new SimpleCursorAdapter(
                ScheduleMain.this, R.layout.team_select_list, teamInfo,
                columns, to);
        diaList.setAdapter(teamListAdapter);
        diaList.setOnItemClickListener(this);
        selectTeam.show();

    }

    // listview onClick events
    public void onItemClick(AdapterView<?> parent, View view, int position,
            long id) {
        // TODO Auto-generated method stub
        switch (parent.getId()) {
        case R.id.lvScheduleDialog:
            selectTeam.dismiss();
            teamInfo.moveToPosition(position);

            // set data on ScheduleMain
            TextView teamName = (TextView) findViewById(R.id.tvScheduleTeam);
            TextView teamAbbrev = (TextView) findViewById(R.id.tvScheduleAbbrev);
            TextView teamLevel = (TextView) findViewById(R.id.tvScheduleLevel);
            LinearLayout layTeam = (LinearLayout) findViewById(R.id.layScheduleTeam);
            Button bAddSchedule = (Button) findViewById(R.id.bAddGame);

            teamNameG = teamInfo.getString(1);

            teamName.setText(teamInfo.getString(1));
            teamAbbrev.setText(teamInfo.getString(2));
            teamLevel.setText(teamInfo.getString(3));
            bAddSchedule.setText("Add Game to Schedule");
            bAddSchedule.setClickable(true);

            teamID = teamInfo.getInt(0);

            // set button if no team
            if (teamInfo.getCount() == 0) {

            }

            // set listeners for bAddGame and laySheduleTeam
            bAddSchedule.setOnClickListener(this);
            layTeam.setOnClickListener(this);

            // get season information
            selectSeason = new Dialog(ScheduleMain.this);
            selectSeason.setContentView(R.layout.schedule_season_dialog);
            selectSeason.setTitle("Select Season");
            seasons = dbInfo.getSeasonsCursor(teamID);
            startManagingCursor(seasons);

            String[] columns = { ScoreMasterDB.KEY_SEANAME };
            int[] to = { R.id.tvTeamSelectList };

            // set select season dialog listview elements
            diaSeason = (ListView) selectSeason
                    .findViewById(R.id.lvSeasonDialog);
            SimpleCursorAdapter seasonListAdapter = new SimpleCursorAdapter(
                    ScheduleMain.this, R.layout.team_select_list, seasons,
                    columns, to);
            diaSeason.setAdapter(seasonListAdapter);
            diaSeason.setOnItemClickListener(this);
            diaSeason.setOnItemLongClickListener(this);

            // set add button listenter
            Button addSeason = (Button) selectSeason
                    .findViewById(R.id.bAddSeason);
            addSeason.setOnClickListener(this);

            // show dialog
            selectSeason.show();
            break;
        case R.id.lvSeasonDialog:
            // get seasonID
            selectSeason.dismiss();
            seasons.moveToPosition(position);
            seasonID = seasons.getInt(0);

            // get schedule cursor
            scheduleInfo = dbInfo.getScheduleCursor(teamID, seasonID);
            startManagingCursor(scheduleInfo);
            //scheduleInfo.moveToFirst();

            //String[] columns1 = {ScoreMasterDB.KEY_SEANAME};
            //int[] to1 = {R.id.tvScheduleAddVsAt};
            //SimpleCursorAdapter scheduleAdapter = new SimpleCursorAdapter(ScheduleMain.this, R.layout.schedule_main_list, seasons, columns1, to1);
            ScheduleAdapter scheduleAdapter = new ScheduleAdapter(ScheduleMain.this, scheduleInfo);
            setListAdapter(scheduleAdapter);
            break;

        }

    }

    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch (v.getId()) {
        case R.id.bAddSeason:
            selectSeason.dismiss();
            newSeason = new Dialog(ScheduleMain.this);
            newSeason.setContentView(R.layout.schedule_new_season);
            newSeason.setTitle("New Season");

            TextView teamName = (TextView) newSeason
                    .findViewById(R.id.tvNewSeasonTeamName);
            teamName.setText("Create new season for the " + teamNameG);

            addNewSeason = (Button) newSeason
                    .findViewById(R.id.bSubmitNewSeason);
            addNewSeason.setOnClickListener(this);
            newSeason.show();
            break;
        case R.id.bSubmitNewSeason:
            TextView seasonName = (TextView) newSeason
                    .findViewById(R.id.etNewSeasonName);
            String submitSeason = seasonName.getText().toString();
            if (submitSeason.equalsIgnoreCase("")) {
                Toast.makeText(ScheduleMain.this, "Please enter a season name",
                        Toast.LENGTH_SHORT).show();
            } else {
                try {
                    dbInfo.insertSeason(teamID, submitSeason);
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    Intent intent = getIntent();
                    finish();
                    startActivity(intent);

                }
            }

            break;
        case R.id.bAddGame:
            Intent addGame = new Intent("com.scoremaster.pro.ADDGAME");
            addGame.putExtra("teamID", teamID);
            addGame.putExtra("seasonID", seasonID);
            startActivity(addGame);

            break;
        case R.id.layScheduleTeam:
            selectTeam.show();
            break;
        }

    }

    public boolean onItemLongClick(AdapterView<?> parent, View view,
            int position, long id) {
        // TODO Auto-generated method stub
        if (parent.getId() == R.id.lvSeasonDialog) {
            seasons.moveToPosition(position);
            int rowID = seasons.getInt(0);
            dbInfo.removeSeason(rowID);
            selectSeason.dismiss();
            Intent intent = getIntent();
            finish();
            startActivity(intent);
            return true;

        } else {
            return false;

        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        super.onActivityResult(requestCode, resultCode, data);
    }

}

Here is the getScheduleCursor() method in the DB class

    public Cursor getScheduleCursor(int teamID, int seasonID){
    String[] columnsSch = {KEY_ROWID, KEY_SCHHOMEAWAY, KEY_SCHOPPFK, KEY_SCHLOCATION,  KEY_SCHWHEN, KEY_SCHOUTCOME, KEY_SCHTYPE, KEY_SCHPLAYED}; 
    Cursor c = scoreMasterDB.query(DB_SCHEDULE_TABLE, columnsSch, KEY_SCHTEAMFK + "=" + teamID + " AND " + KEY_SCHSEASON + "=" + seasonID, null, null, null, null); 

    return c;
}

Answer 1

In ScheduleAdapter, when inflating the view, use the version of inflate() that does not attach to the root view:

@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
    // TODO Auto-generated method stub
    return mInflater.inflate(R.layout.schedule_main_list, parent, false);
}

Also note, it would be better if you include the teamName in the original cursor (along with or replacing mOppFK) rather than creating a new connection to the database to get it when binding the view, cause you’re making a new connection and query the DB for every item added to the ListView.

EDIT: things you can improve:

A) Instead of made your activity to implement OnItemClickListener (and the other interfaces), use an anonymous type when you need to pass it to setOnItemClickListener:

diaList.setOnItemClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {

                }
            });

B) To perform a JOIN (and avoid open a new connection inside the adapter), use a SQLiteQueryBuilder to build your query expression:

SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
qb.setTables("foo LEFT OUTER JOIN bar ON (foo.id = bar.foo_id)")

Cursor cursor = qb.query(...);

C) Not sure what you’re trying to do here:

Intent intent = getIntent();
finish();
startActivity(intent);

You want to restart your activity? Why not just open the first dialog again?

D) I feel more comfortable creating a new Intent in this way:

Intent createTeamIntent = new Intent(this, CREATETEAM.class));

If you’re inside a listener, you can’t use this to pass as context (as it doesn’t refer to the activity). In such cases, you can declare an atributte in the activity:

Context context;

Initialize it in OnCreate:

this.context = this;

And then use it whenever you need it, by simply calling context.