ListView: setItemChecked only works with standard ArrayAdapter - does NOT work when using customized ArrayAdapter?

user387184 picture user387184 · Dec 3, 2011 · Viewed 41.3k times · Source

This is really weird.

When I use the standard ArrayAdapter for a ListView calling setItemChecked works OK

But when using a custom made ArrayAdapter it does not.

What would be the reason? Is this a bug? Or am I missing something?

public class Test_Activity extends Activity {

    /** Called when the activity is first created. */
    private List<Model> list;
    private ListView lView;

    public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    // Create an array of Strings, that will be put to our ListActivity
    setContentView(R.layout.main);
    lView = (ListView) findViewById(R.id.ListView01);
    lView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);

    list = getModel();

    //with this adapter setItemChecked works OK
    lView.setAdapter(new ArrayAdapter<Model>(this,
        android.R.layout.simple_list_item_multiple_choice, list));


  //**************************
    //PROBLEM: with this adapter it does not check any items on the screen
    // ArrayAdapter<Model> adapter = new Test_Class1(this, list);
    // lView.setAdapter(adapter);



    }

    private List<Model> getModel() {
       List<Model> list = new ArrayList<Model>();
       list.add(get("0"));
       list.add(get("1"));
       list.add(get("2"));
       list.get(1).setSelected(true);
       Model m = list.get(1);
       list.add(get("3"));
       list.add(get("4"));
       list.add(get("5"));
       list.add(get("6"));
       list.add(get("7"));
       // Initially select one of the items
       return list;
    }

    private Model get(String s) {
       return new Model(s);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
       MenuInflater inflater = getMenuInflater();
       inflater.inflate(R.menu.results_screen_option_menu, menu);
       return true;
    }

    /**
     * @category OptionsMenu
     */
    @Override
 public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case R.id.select_all: {

        int size = lView.getAdapter().getCount();

        for (int i = 0; i <= size; i++) {

            //************************** PROBLEM
        lView.setItemChecked(i, true); // selects the item only for standard ArrayAdapter

    Log.i("xxx", "looping " + i);
        }
    }
        return true;
    case R.id.select_none:
        return true;
    }
    return false;
    }
}

//------------------------------------------------------------

public class Test_Class1 extends ArrayAdapter<Model> {

    private final List<Model> list;
    private final Activity context;

 public Test_Class1(Activity context, List<Model> list) {
    super(context, R.layout.rowbuttonlayout2, list);
    this.context = context;
    this.list = list;
    }

  static class ViewHolder {
    protected TextView text;
    protected CheckBox checkbox;
    }

    @Override
 public View getView(int position, View convertView, ViewGroup parent) {
    View view = null;
    Log.i("xxx", "-> getView " + position);
    if (convertView == null) {
        LayoutInflater inflator = context.getLayoutInflater();
        view = inflator.inflate(R.layout.rowbuttonlayout, null);
        final ViewHolder viewHolder = new ViewHolder();
        viewHolder.text = (TextView) view.findViewById(R.id.label);
        viewHolder.checkbox = (CheckBox) view.findViewById(R.id.check);
        viewHolder.checkbox
            .setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

            @Override
            public void onCheckedChanged(CompoundButton buttonView,
                boolean isChecked) {
                Model element = (Model) viewHolder.checkbox
                    .getTag();
                Log.i("xxx", "-> onCheckedChanged");
                element.setSelected(buttonView.isChecked());
                Log.i("xxx", "<- onCheckedChanged");

            }
            });
        view.setTag(viewHolder);
        viewHolder.checkbox.setTag(list.get(position));
    } else {
        view = convertView;
        ((ViewHolder) view.getTag()).checkbox.setTag(list.get(position));
    }
    ViewHolder holder = (ViewHolder) view.getTag();
    holder.text.setText(list.get(position).getName());
    Log.i("xxx", "holder.checkbox.setChecked: " + position);

    holder.checkbox.setChecked(list.get(position).isSelected());
    Log.i("xxx", "<-  getView " + position);

    return view;
    }

}

Answer

CommonsWare picture CommonsWare · Dec 3, 2011

Your row layout needs to be Checkable for setItemChecked() to work, in which case Android will manage calling setChecked() on your Checkable as the user clicks on the row. You would not need to be setting up your own OnCheckedChangeListener.

For more, see: