How to modify chain length in constraint layout?

Question

Here is my code

<?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"
android:background="@color/nav_and_action_bar_color"
 >

<ImageView
    android:id="@+id/some_person"
    android:layout_width="100dp"
    android:layout_height="100dp"
    android:src="@drawable/some_person"
    app:layout_constraintBottom_toTopOf="@+id/et_username"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.5"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />


<EditText
    android:id="@+id/et_username"
    android:layout_width="@dimen/login_page_text_fields_width"
    android:layout_height="wrap_content"
    android:layout_margin="10dp"
    android:background="@android:color/white"
    android:hint="@string/email_hint"
    android:padding="10dp"
    app:layout_constraintBottom_toTopOf="@+id/et_password"
    app:layout_constraintHorizontal_bias="0.5"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/some_person" />

<EditText
    android:id="@+id/et_password"
    android:layout_width="@dimen/login_page_text_fields_width"
    android:layout_height="wrap_content"
    android:layout_margin="10dp"
    android:background="@android:color/white"
    android:hint="@string/password_hint"
    android:inputType="textPassword"
    android:padding="10dp"
    app:layout_constraintBottom_toTopOf="@+id/login_button"
    app:layout_constraintHorizontal_bias="0.5"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@id/et_username" />

<Button
    android:id="@+id/login_button"
    android:layout_width="@dimen/login_button_width"
    android:layout_height="wrap_content"
    android:layout_margin="10dp"
    android:background="@color/colorAccent"
    android:elevation="5dp"
    android:onClick="clickedOnLogin"
    android:text="@string/login_button"
    android:textColor="@android:color/white"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintHorizontal_bias="0.5"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@id/et_password" />
</android.support.constraint.ConstraintLayout>

and i seem to be getting this as a result

How do i bring the elements together? I want them to be close together.

Answer 1

You need to define variable for every view, where you want to apply chaining logic. Pick just one:

app:layout_constraintVertical_chainStyle="packed"
app:layout_constraintVertical_chainStyle="spread"
app:layout_constraintVertical_chainStyle="spread_inside"