Android: Custom ArrayAdapter for SmoothCheckBox

I'm trying to get a grid of SmoothCheckboxes (can be found here http://ift.tt/2nnWIcT), and the grid populates with everything I throw at it successfully, besides the SmoothCheckBox itself. What am I doing wrong here?

My Custom Adapter:

    public class ExercisesAdapter extends BaseAdapter {

private Context context;
private final SmoothCheckBox[] checkboxes;

public ExercisesAdapter(Context context, SmoothCheckBox[] checkboxes) {
    this.context = context;
    this.checkboxes = checkboxes;
}

@Override
public int getCount() {
    return checkboxes.length;
}

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

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

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View gridView;

        gridView = new View(context);
        // get layout from mobile.xml
        gridView = inflater.inflate(R.layout.exercise, null);
        TextView number = (TextView) gridView.findViewById(R.id.tv_exerciseName);
        number.setText("No. " + position);
        SmoothCheckBox checkBox = checkboxes[position];

        return gridView;

}}

My layout for the checkboxes:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://ift.tt/nIICcg"
    xmlns:app="http://ift.tt/GEGVYd"
    xmlns:tools="http://ift.tt/LrGmb4"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/tv_exerciseName"
        android:layout_width="31dp"
        android:layout_height="22dp"
        android:textAlignment="center"
        tools:layout_editor_absoluteX="1dp"
        tools:layout_editor_absoluteY="2dp" />

    <cn.refactor.library.SmoothCheckBox
        android:id="@+id/checkBox"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="14dp"
        android:checked="false"
        app:layout_constraintTop_toBottomOf="@+id/tv_exerciseName"
        tools:layout_editor_absoluteX="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginBottom="8dp" />
</android.support.constraint.ConstraintLayout>