app/src/main/res/layout/activity_create_group.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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".activities.CreateGroupActivity"
tools:layout_editor_absoluteY="25dp">
<AutoCompleteTextView
android:id="@+id/courseComplete2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="47dp"
android:layout_marginEnd="16dp"
android:hint="Please select a Course"
android:imeOptions="actionDone"
android:inputType="text"
android:maxLines="1"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Spinner
android:id="@+id/spinnerLanguage"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="151dp"
android:layout_marginEnd="8dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<NumberPicker
android:id="@+id/numberPicker"
android:layout_width="0dp"
android:layout_height="114dp"
android:layout_marginEnd="155dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/textView2"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/confirmGroupCreation"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="27dp"
android:onClick="addtoGroups"
android:text=" Create Group"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/numberPicker" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="32dp"
android:layout_marginEnd="34dp"
android:text="Maximum \n Participants"
android:textAlignment="center"
app:layout_constraintEnd_toStartOf="@+id/numberPicker"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="@+id/numberPicker" />
</android.support.constraint.ConstraintLayout>