KdanLoginRegisterUI/src/main/res/layout/activity_bind_account.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=".screen.BindAccountActivity">

    <ScrollView
        android:fillViewport="true"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        >

        <android.support.constraint.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <android.support.constraint.Guideline
                android:id="@+id/guideLine_bindAccount_centerHorizontal"
                android:orientation="vertical"
                android:layout_width="0dp"
                android:layout_height="0dp"
                app:layout_constraintGuide_percent="0.5"
                />

            <android.widget.Space
                android:id="@+id/anchor_bindAccount_left"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginRight="136dp"
                android:layout_marginEnd="136dp"
                app:layout_constraintRight_toRightOf="@id/guideLine_bindAccount_centerHorizontal"
                />

            <android.widget.Space
                android:id="@+id/anchor_bindAccount_right"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="136dp"
                android:layout_marginStart="136dp"
                app:layout_constraintLeft_toLeftOf="@id/guideLine_bindAccount_centerHorizontal"
                />

            <ImageButton
                android:id="@+id/btn_bindAccount_back"
                android:background="?android:attr/selectableItemBackground"
                android:src="@drawable/ic_arrow_back_blue_24dp"
                android:contentDescription="@string/emptyImageContextDescription"
                android:layout_width="48dp"
                android:layout_height="48dp"
                android:layout_marginTop="4dp"
                android:layout_marginLeft="16dp"
                android:layout_marginStart="16dp"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                />

            <TextView
                android:visibility="gone"
                android:id="@+id/tv_bindAccount_createNew"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_marginTop="24dp"
                android:gravity="center_vertical|left"
                android:text="@string/bind_account_create_new_text"
                app:layout_constraintBottom_toTopOf="@id/btn_bindAccount_create"
                app:layout_constraintLeft_toLeftOf="@id/anchor_bindAccount_left"
                app:layout_constraintRight_toRightOf="@id/anchor_bindAccount_right"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_constraintVertical_chainStyle="packed" />

            <Button
                android:visibility="gone"
                android:id="@+id/btn_bindAccount_create"
                android:text="@string/bind_account_create_new_btn"
                android:textSize="14sp"
                android:textColor="@android:color/white"
                android:background="@drawable/bg_bind_account_create_btn"
                android:layout_width="0dp"
                android:layout_height="40dp"
                android:layout_marginTop="12dp"
                app:layout_constraintLeft_toLeftOf="@id/anchor_bindAccount_left"
                app:layout_constraintRight_toRightOf="@id/anchor_bindAccount_right"
                app:layout_constraintTop_toBottomOf="@id/tv_bindAccount_createNew"
                app:layout_constraintBottom_toTopOf="@id/tv_bindAccount_orDivider"
                />

            <TextView
                android:visibility="gone"
                android:id="@+id/tv_bindAccount_orDivider"
                android:text="@string/or"
                android:textSize="@dimen/or_divider_text_size"
                android:textColor="@color/or_diver"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="20dp"
                app:layout_constraintTop_toBottomOf="@id/btn_bindAccount_create"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintBottom_toTopOf="@+id/tv_bindAccount_bind"
                />

            <View
                android:visibility="gone"
                android:background="@color/or_diver"
                android:layout_width="0dp"
                android:layout_height="1dp"
                android:layout_marginRight="16dp"
                android:layout_marginEnd="16dp"
                app:layout_constraintTop_toTopOf="@id/tv_bindAccount_orDivider"
                app:layout_constraintBottom_toBottomOf="@id/tv_bindAccount_orDivider"
                app:layout_constraintLeft_toLeftOf="@id/anchor_bindAccount_left"
                app:layout_constraintRight_toLeftOf="@id/tv_bindAccount_orDivider"
                />

            <View
                android:visibility="gone"
                android:background="@color/or_diver"
                android:layout_width="0dp"
                android:layout_height="1dp"
                android:layout_marginLeft="16dp"
                android:layout_marginStart="16dp"
                app:layout_constraintTop_toTopOf="@id/tv_bindAccount_orDivider"
                app:layout_constraintBottom_toBottomOf="@id/tv_bindAccount_orDivider"
                app:layout_constraintLeft_toRightOf="@id/tv_bindAccount_orDivider"
                app:layout_constraintRight_toRightOf="@id/anchor_bindAccount_right"
                />

            <TextView
                android:visibility="gone"
                android:id="@+id/tv_bindAccount_bind"
                android:text="@string/bind_account_bind_text"
                android:gravity="center_vertical|left"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginTop="20dp"
                app:layout_constraintLeft_toLeftOf="@id/anchor_bindAccount_left"
                app:layout_constraintRight_toRightOf="@id/anchor_bindAccount_right"
                app:layout_constraintTop_toBottomOf="@id/tv_bindAccount_orDivider"
                app:layout_constraintBottom_toTopOf="@id/et_bindAccount_email"
                />

            <EditText
                android:id="@+id/et_bindAccount_email"
                style="@style/EmailLoginRegisterFormEditText"
                android:inputType="textEmailAddress"
                android:hint="@string/email_input_hint"
                android:layout_width="0dp"
                android:layout_height="44dp"
                android:layout_marginTop="12dp"
                app:layout_constraintLeft_toLeftOf="@id/anchor_bindAccount_left"
                app:layout_constraintRight_toRightOf="@id/anchor_bindAccount_right"
                app:layout_constraintTop_toBottomOf="@id/tv_bindAccount_bind"
                app:layout_constraintBottom_toTopOf="@+id/et_bindAccount_pwd"
                />

            <EditText
                android:id="@+id/et_bindAccount_pwd"
                style="@style/EmailLoginRegisterFormEditText"
                android:inputType="textPassword"
                android:hint="@string/pwd_input_hint"
                android:layout_width="0dp"
                android:layout_height="44dp"
                android:layout_marginTop="8dp"
                app:layout_constraintLeft_toLeftOf="@id/anchor_bindAccount_left"
                app:layout_constraintRight_toRightOf="@id/anchor_bindAccount_right"
                app:layout_constraintTop_toBottomOf="@id/et_bindAccount_email"
                app:layout_constraintBottom_toTopOf="@id/btn_bindAccount_bind"
                />

            <Button
                android:id="@+id/btn_bindAccount_bind"
                android:text="@string/bind_account_bind_btn"
                android:textSize="14sp"
                android:textColor="@android:color/white"
                android:background="@drawable/bg_bind_account_bind_btn"
                android:layout_width="0dp"
                android:layout_height="40dp"
                android:layout_marginTop="8dp"
                app:layout_constraintLeft_toLeftOf="@id/anchor_bindAccount_left"
                app:layout_constraintRight_toRightOf="@id/anchor_bindAccount_right"
                app:layout_constraintTop_toBottomOf="@id/et_bindAccount_pwd"
                app:layout_constraintBottom_toTopOf="@id/tv_bindAccount_bindExplanation"
                />

            <TextView
                android:id="@+id/tv_bindAccount_bindExplanation"
                android:text="@string/bind_account_bind_explanation"
                android:gravity="center_vertical|left"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginTop="12dp"
                android:layout_marginBottom="24dp"
                app:layout_constraintLeft_toLeftOf="@id/anchor_bindAccount_left"
                app:layout_constraintRight_toRightOf="@id/anchor_bindAccount_right"
                app:layout_constraintTop_toBottomOf="@id/btn_bindAccount_bind"
                app:layout_constraintBottom_toBottomOf="parent"
                />
        </android.support.constraint.ConstraintLayout>
    </ScrollView>
</android.support.constraint.ConstraintLayout>