android spinner dropdown checkbox

Question

I have Spinner like this :

Answer 1

For that you have to Create Custom Adapter and set TextView and CheckBox inside that below way.

Define Spinner in xml

<Spinner
        android:id="@+id/spinner"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="10dp" />

Create spinner_item.xml file in layout folder.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="20dp"
        android:text="text"
        android:textAlignment="gravity" />

    <CheckBox
        android:id="@+id/checkbox"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true" />
</RelativeLayout>

Now create StateVO.java class that can contain the TextView and CheckBox value.

public class StateVO {
    private String title;
    private boolean selected;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public boolean isSelected() {
        return selected;
    }

    public void setSelected(boolean selected) {
        this.selected = selected;
    }
}

Now in your Activity inititlize the Spinner and set CustomAdapter below way.

 final String[] select_qualification = {
                "Select Qualification", "10th / Below", "12th", "Diploma", "UG",
                "PG", "Phd"};
        Spinner spinner = (Spinner) findViewById(R.id.spinner);

        ArrayList<StateVO> listVOs = new ArrayList<>();

        for (int i = 0; i < select_qualification.length; i++) {
            StateVO stateVO = new StateVO();
            stateVO.setTitle(select_qualification[i]);
            stateVO.setSelected(false);
            listVOs.add(stateVO);
        }
        MyAdapter myAdapter = new MyAdapter(Main2Activity.this, 0,
                listVOs);
        spinner.setAdapter(myAdapter);

And Finally Create CustomAdapter class like below way.

MyAdapter.java

public class MyAdapter extends ArrayAdapter<StateVO> {
    private Context mContext;
    private ArrayList<StateVO> listState;
    private MyAdapter myAdapter;
    private boolean isFromView = false;

    public MyAdapter(Context context, int resource, List<StateVO> objects) {
        super(context, resource, objects);
        this.mContext = context;
        this.listState = (ArrayList<StateVO>) objects;
        this.myAdapter = this;
    }

    @Override
    public View getDropDownView(int position, View convertView,
                                ViewGroup parent) {
        return getCustomView(position, convertView, parent);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        return getCustomView(position, convertView, parent);
    }

    public View getCustomView(final int position, View convertView,
                              ViewGroup parent) {

        final ViewHolder holder;
        if (convertView == null) {
            LayoutInflater layoutInflator = LayoutInflater.from(mContext);
            convertView = layoutInflator.inflate(R.layout.spinner_item, null);
            holder = new ViewHolder();
            holder.mTextView = (TextView) convertView
                    .findViewById(R.id.text);
            holder.mCheckBox = (CheckBox) convertView
                    .findViewById(R.id.checkbox);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        holder.mTextView.setText(listState.get(position).getTitle());

        // To check weather checked event fire from getview() or user input
        isFromView = true;
        holder.mCheckBox.setChecked(listState.get(position).isSelected());
        isFromView = false;

        if ((position == 0)) {
            holder.mCheckBox.setVisibility(View.INVISIBLE);
        } else {
            holder.mCheckBox.setVisibility(View.VISIBLE);
        }
        holder.mCheckBox.setTag(position);
        holder.mCheckBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                int getPosition = (Integer) buttonView.getTag();

                if (!isFromView) {
                    listState.get(position).setSelected(isChecked);
                }
            }
        });
        return convertView;
    }

    private class ViewHolder {
        private TextView mTextView;
        private CheckBox mCheckBox;
    }
}

Output :

Answer 2

This post is a great resource. For anyone interested, I made a generic adapter based on the other answer that has worked well for multiple data types. Also lets you click the text to toggle the checkbox.

public class CheckableSpinnerAdapter<T> extends BaseAdapter {

    static class SpinnerItem<T> {
        private String txt;
        private T item;

        SpinnerItem(T t, String s) {
            item = t;
            txt = s;
        }
    }

    private Context context;
    private Set<T> selected_items;
    private List<SpinnerItem<T>> all_items;
    private String headerText;

    CheckableSpinnerAdapter(Context context,
                            String headerText,
                            List<SpinnerItem<T>> all_items,
                            Set<T> selected_items) {
        this.context = context;
        this.headerText = headerText;
        this.all_items = all_items;
        this.selected_items = selected_items;
    }

    @Override
    public int getCount() {
        return all_items.size() + 1;
    }

    @Override
    public Object getItem(int position) {
        if( position < 1 ) {
            return null;
        }
        else {
            return all_items.get(position-1);
        }
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    @SuppressWarnings({"unchecked"})
    @NonNull
    public View getView(int position, View convertView, @NonNull ViewGroup parent) {

        final ViewHolder holder;
        if (convertView == null ) {
            LayoutInflater layoutInflator = LayoutInflater.from(context);
            convertView = layoutInflator.inflate(R.layout.checkable_spinner_item, parent, false);

            holder = new ViewHolder();
            holder.mTextView = convertView.findViewById(R.id.text);
            holder.mCheckBox = convertView.findViewById(R.id.checkbox);
            convertView.setTag(holder);
        }
        else {
            holder = (ViewHolder) convertView.getTag();
        }

        if( position < 1 ) {
            holder.mCheckBox.setVisibility(View.GONE);
            holder.mTextView.setText(headerText);
        }
        else {
            final int listPos = position - 1;
            holder.mCheckBox.setVisibility(View.VISIBLE);
            holder.mTextView.setText(all_items.get(listPos).txt);

            final T item = all_items.get(listPos).item;
            boolean isSel = selected_items.contains(item);

            holder.mCheckBox.setOnCheckedChangeListener(null);
            holder.mCheckBox.setChecked(isSel);

            holder.mCheckBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    if( isChecked ) {
                        selected_items.add(item);
                    }
                    else {
                        selected_items.remove(item);
                    }
                }
            });

            holder.mTextView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    holder.mCheckBox.toggle();
                }
            });
        }

        return convertView;
    }

    private class ViewHolder {
        private TextView mTextView;
        private CheckBox mCheckBox;
    }
} 

And the layout checkable_spinner_item.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <CheckBox
        android:id="@+id/checkbox"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="@id/text"
        app:layout_constraintBottom_toBottomOf="@id/text"/>

    <TextView
        android:id="@+id/text"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="8dp"
        android:layout_marginBottom="8dp"
        android:textSize="16sp"
        android:textColor="#000000"
        app:layout_constraintStart_toEndOf="@id/checkbox"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:textAlignment="gravity" />

</android.support.constraint.ConstraintLayout>

You would use it by creating a list of items to show, a Set, which will contain the selected items, and the header row text. For example:

private final List<CheckableSpinnerAdapter.SpinnerItem<MyObject>> spinner_items = new ArrayList<>();
private final Set<MyObject> selected_items = new HashSet<>();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // fill the 'spinner_items' array with all items to show
    List<MyObject> all_objects = getMyObjects(); // from wherever
    for(MyObject o : all_objects) {
        spinner_items.add(new CheckableSpinnerAdapter.SpinnerItem<>(o, o.getName()));
    }

    // to start with any pre-selected, add them to the `selected_items` set

    String headerText = "Click an Item";

    Spinner spinner = findViewById(R.id.my_spinner);
    CheckableSpinnerAdapter adapter = new CheckableSpinnerAdapter<>(this, headerText, spinner_items, selected_items);
    spinner.setAdapter(adapter);

    // when you want to see what the user has selected, look in the `selected_items`
    // set anywhere in your activity
}

An example in use:

EDIT: MyObject can be any class or enum, whatever you want to associate with the spinner items. If you are copying this example directly it would have to implement a String getName() method. Here's a simple example:

class MyObject {
    private String mName;
    private String mAddr;

    MyObject(String name, String address) {
        mName = name;
        mAddr = address;
    }

    String getName() { return mName; }
    String getAddress() { return mAddr; }
}