How do i send data to my custom adapter

Question

After several tries to get a custom adapter working I am almost there. Now I have one problem left: get data in the adapter. This is what I do.

I have a CustomListAdapter class for the adapter, a sqLiteHelper class to CRUD data and a mainActivity class. In the mainActivity i load the customlist like this:

ListView list;
CustomListAdapter adapter;
public  MainActivity CustomListView = null;
public  ArrayList<Players> CustomListViewValuesArr = new ArrayList<Players>();

//button handlers newmatch_players_home
public void addSpelerNu(View button) {

    Log.d("WedstrijdID buiten de create", ""+wedstrijdId);
    Log.d("id return team thuis", ""+thuisTeamId);
    //thuisteam
    final EditText shirtNummer = (EditText) findViewById(R.id.shirtThuis);
    String nummerShirt = shirtNummer.getText().toString();
    int shirtSpeler = Integer.parseInt(nummerShirt);
    final EditText spelerNaam = (EditText) findViewById(R.id.naamThuis);
    String naamSpeler = spelerNaam.getText().toString();

    Integer wedstrijdSpelerId = (int) (long) wedstrijdId;
    SqLiteHelper db = new SqLiteHelper(this);
    db.addSpeler(new Players(shirtSpeler, naamSpeler, thuisTeamId, wedstrijdSpelerId));
    Log.d("Toevoegen speler THUIS", ">> BEGIN");
    Log.d("Toevoegen speler", "Shirt = "+nummerShirt+" Naam = "+naamSpeler +" Team ="+thuisTeamId+" Wedstrijd ="+wedstrijdSpelerId);
     Log.d("Toevoegen speler", ">> EIND");

     shirtNummer.setText(null);
     spelerNaam.setText(null);


     CustomListView = this;

     /******** Take some data in Arraylist ( CustomListViewValuesArr ) ***********/

     ArrayList <Players> CustomListViewValuesArr = new ArrayList<Players>();    

    Resources res =getResources();
     list=  ( ListView )findViewById( R.id.listHome );  

     /**************** Create Custom Adapter *********/
     adapter=new CustomListAdapter( CustomListView, CustomListViewValuesArr);
     list.setAdapter( adapter );



}

This works except for the data. The data I want to use is in my sqlitehelper

public ArrayList<Players> getPlayersForTeam(int teamNumber,int matchNumber) {
        ArrayList<Players> speler = new ArrayList<Players>();

        String query = "SELECT  * FROM " + TABLE_SPELERS + " WHERE team=? AND wedstrijd =?";

        SQLiteDatabase db = this.getWritableDatabase();
        String[] selectionArgs = new String[] { Integer.toString(teamNumber), Integer.toString(matchNumber) };
        Cursor cursor = db.rawQuery(query, selectionArgs);

        Players spelers = null;
        if (cursor.moveToFirst()) {
            do {
             spelers = new Players();
             spelers.setIdSpeler(Integer.parseInt(cursor.getString(0)));
             spelers.setShirt(Integer.parseInt(cursor.getString(1)));
             spelers.setSpeler(cursor.getString(2));
             spelers.setTeam(Integer.parseInt(cursor.getString(3)));
             spelers.setSpelerWedstrijd(Integer.parseInt(cursor.getString(4)));


                speler.add(spelers);
            } while (cursor.moveToNext());
        }


        Log.d("Alle spelers in DB for team:" + teamNumber, speler.toString());

        // return wedstrijden
        return speler;
    }

If I load this data like this

List <Players> list = new ArrayList<Players>(); 
list=db.getPlayersForTeam(thuisTeamId,wedstrijdSpelerId);    

I will see the log.d in logcat. But I just can't get that data into my CustomListViewValuesArr.

What should I do?

This is the customListAdapter class

package com.jd.wedstrijdkaart;

import java.util.ArrayList;

import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

public class CustomListAdapter extends BaseAdapter {

             /*********** Declare Used Variables *********/
             private Activity activity;
             private ArrayList data;
             private static LayoutInflater inflater=null;
             Players tempValues=null;
             int i=0;

             /*************  CustomAdapter Constructor 
             * @return *****************/
             public CustomListAdapter(Activity a, ArrayList d) {

                    /********** Take passed values **********/
                     activity = a;
                     data=d;

                     /***********  Layout inflator to call external xml layout () ***********/
                      inflater = ( LayoutInflater )activity.
                                                  getSystemService(Context.LAYOUT_INFLATER_SERVICE);

             }

             /******** What is the size of Passed Arraylist Size ************/
             public int getCount() {

                 if(data.size()<=0)
                     return 1;
                 return data.size();
             }

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

             public long getItemId(int position) {
                 return position;
             }

             /********* Create a holder Class to contain inflated xml file elements *********/
             public static class ViewHolder{

                 public TextView shirt;
                 public TextView name;

             }

             /****** Depends upon data size called for each row , Create each ListView row *****/
             public View getView(int position, View convertView, ViewGroup parent) {

                 View vi = convertView;
                 ViewHolder holder;

                 if(convertView==null){

                     /****** Inflate tabitem.xml file for each row ( Defined below ) *******/
                     vi = inflater.inflate(R.layout.adapter_players, null);

                     /****** View Holder Object to contain tabitem.xml file elements ******/

                     holder = new ViewHolder();
                     holder.shirt = (TextView) vi.findViewById(R.id.shirt);
                     holder.name=(TextView)vi.findViewById(R.id.name);

                    /************  Set holder with LayoutInflater ************/
                     vi.setTag( holder );
                 }
                 else 
                     holder=(ViewHolder)vi.getTag();

                 if(data.size()<=0)
                 {
                     holder.name.setText("No Data");

                 }
                 else
                 {
                     /***** Get each Model object from Arraylist ********/
                    tempValues = null;
                     tempValues = ( Players ) data.get( position );

                     /************  Set Model values in Holder elements ***********/

                      holder.shirt.setText( tempValues.getShirt() );
                      holder.name.setText( tempValues.getSpeler() );



                 }
                 return vi;
             }


         }

Answer 1

Typically, when building custom adapters you want to pass your ArrayList into the constructor for your CustomListAdapter. It is relatively straight forward.

 // Create a reference to your custom adapter as a Class Member and arraylist
 CustomListAdapter mAdapter = null;
 ArrayList<MyObjects> mArrayList = null;


 // Initialize the adapter somewhere in onCreate 
 // After you have retrieved the data out of sql and created your custom object


 mArrayList = new ArrayList<MyObjects>();
 // Fill your array list with data

 // ******* THIS IS WHERE YOU WANT TO RETRIEVE THE ITEM FROM SQLITE

 // Then Each time your get a new cursor object
 // You should create a new MyObject object and add it to the ArrayList

 // Intialize the custom list adapter using the context, and your array list
 mAdpater = new CustomListAdapter(getBaseContext(), mArrayList);


 // Set ListView adapter
 listView.setAdapter(mAdapter);

Then Create the Custom Adapter And use the constructor to pass the data

 // Custom Adapter Class

public class CustomListAdapter extends BaseAdapter {


private ArrayList<MyObjects> mObjects = null;
private LayoutInflater mInflater = null;

    // Private class to hold information about the row content UI Items
private class RowContent{
    // Reference the UI Widgets for each row
        TextView mTextView;
        // etc.
}

// Constructor
public CustomListAdapter(Context context, ArrayList<MyObject> objects){
    this.mInflater = LayoutInflater.from(context);
    this.mObjects = objects;

}


// --------------------------------------------------
// BaseAdapter Overrides
// --------------------------------------------------
    // Returns the count of your arrayList
@Override
public int getCount() {
    int count = 0;

    if(mObjects!=null && mObjects.length() >= 1){

        count = mObjects.length();

    }

    return count;
}
    // Returns object at position
@Override
public Object getItem(int position) {
    // TODO Auto-generated method stub
    return mOjbects[position];
}
    // returns position
@Override
public long getItemId(int position) {
    // TODO Auto-generated method stub
    return position;
}
    // This is where all the magic happens
    // Creates a new row for each item in your arraylist
@Override
public View getView(int position, View convertView, ViewGroup parent) {

    RowContent theRow;

    // If ConvertVIew is null
    if(convertView == null){
        // Create a reference to the class holding the UI Elements
        theRow= new RowContent ();
        // set the view using your XML layout for a custom list item
        convertView = mInflater.inflate(R.layout.custom_list_item, null);
        // reference the UI widgets in the XML by their ID's            
        theRow.mTextView = (TextView) convertView.findViewById(R.id.textView);
        // set the Tag for the View         
        convertView.setTag(theRow);

    }else{
                  // If there is already an item, recycle it
        theRow= (RowContent) convertView.getTag();
    }

    // Set the Text or arrays For UI Widgets
    theRow.mtextView.setText(mObjects.get(position).text);

            // return the view
    return convertView;
}

}

Answer 2

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

         public long getItemId(int position) {
             return position;
         } 

is totally wrong. Here is where you should return the objects at the specified position in your ArrayList.

Answer 3

In onCreate() you do this:

ArrayList <Players> CustomListViewValuesArr = new ArrayList<Players>();
...
adapter=new CustomListAdapter( CustomListView, CustomListViewValuesArr);

You are initializing your adapter with an empty list of items (CustomListViewValuesArr is empty).

You have 2 choices:

1. You can get the data from your database and pass it to the adapter when you initialize it.

2. You can initialize the adapter with an empty array and then later pass the data to the adapter. To do that you'll need to provide a setter method in the adapter, something like this:

   public void setData(ArrayList d) { data = d; // Tell the views that the data has changed so they can refresh notifyDataSetChanged(); }