crystal-wallet-android/app/src/main/res/layout/send_transaction.xml

<?xml version="1.0" encoding="utf-8"?>
<ScrollView
    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="wrap_content"
    android:background="@color/white">

    <android.support.constraint.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="24dp">

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

        <android.support.constraint.Guideline
            android:id="@+id/cameraVerticalGuideline"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            app:layout_constraintGuide_percent="0.65"/>

        <View
            android:id="@+id/topView"
            android:layout_width="match_parent"
            android:background="@drawable/send_transaction_top_view"
            android:layout_height="120dp"
            android:layout_marginEnd="0dp"
            android:layout_marginStart="0dp"
            android:layout_marginTop="0dp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="24dp"
            android:layout_marginTop="24dp"
            android:text="@string/title_capital"
            android:textColor="@color/white"
            android:textSize="20sp"
            android:textStyle="bold"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <ImageView
            android:id="@+id/btnCancel"
            android:layout_width="24dp"
            android:layout_height="24dp"
            android:layout_marginTop="12dp"
            android:layout_marginEnd="12dp"
            android:background="@drawable/ic_close"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintEnd_toEndOf="parent"/>

        <cy.agorise.crystalwallet.util.CircularImageView
            android:id="@+id/gravatar"
            android:layout_width="60dp"
            android:layout_height="60dp"
            android:layout_marginStart="32dp"
            android:layout_marginTop="90dp"
            android:src="@drawable/avatar_placeholder"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <!--<com.jaredrummler.materialspinner.MaterialSpinner-->
        <Spinner
            android:id="@+id/spFrom"
            android:layout_width="0dp"
            android:layout_height="40dp"
            android:layout_marginEnd="24dp"
            android:layout_marginStart="16dp"
            android:textColor="@color/white"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toEndOf="@id/gravatar"
            app:layout_constraintBottom_toBottomOf="@+id/topView"/>

        <TextView
            android:id="@+id/tvFromError"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:textColor="@color/red"
            app:layout_constraintEnd_toEndOf="@+id/spFrom"
            app:layout_constraintStart_toStartOf="@+id/spFrom"
            app:layout_constraintTop_toBottomOf="@+id/topView" />

        <EditText
            android:id="@+id/etTo"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginEnd="24dp"
            android:layout_marginStart="24dp"
            android:layout_marginTop="24dp"
            android:gravity="top"
            android:inputType="text"
            android:textSize="20sp"
            android:hint="@string/to_capital"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/gravatar" />

        <ImageView
            android:id="@+id/ivPeople"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:layout_marginEnd="5dp"
            app:srcCompat="@drawable/ic_people"
            android:layout_marginBottom="15dp"
            app:layout_constraintEnd_toEndOf="@id/etTo"
            app:layout_constraintBottom_toBottomOf="@id/etTo"
            android:contentDescription="@string/people_icon" />

        <TextView
            android:id="@+id/tvToError"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:textColor="@color/red"
            app:layout_constraintEnd_toEndOf="@+id/etTo"
            app:layout_constraintStart_toStartOf="@+id/etTo"
            app:layout_constraintTop_toBottomOf="@+id/etTo" />

        <EditText
            android:id="@+id/etAmount"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:layout_marginStart="24dp"
            android:layout_marginEnd="12dp"
            android:inputType="numberDecimal"
            android:textSize="20sp"
            android:hint="@string/amount"
            app:layout_constraintTop_toBottomOf="@+id/tvToError"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toStartOf="@id/centeredVerticalGuideline"/>

        <TextView
            android:id="@+id/tvAmountError"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:textColor="@color/red"
            app:layout_constraintEnd_toEndOf="@+id/etAmount"
            app:layout_constraintStart_toStartOf="@+id/etAmount"
            app:layout_constraintTop_toBottomOf="@+id/etAmount" />

        <Spinner
            android:id="@+id/spAsset"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginTop="8dp"
            android:layout_marginEnd="24dp"
            android:layout_marginStart="12dp"
            android:gravity="top"
            app:layout_constraintTop_toTopOf="@+id/etAmount"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toEndOf="@id/centeredVerticalGuideline"/>

        <View
            android:id="@+id/viewSpinner"
            android:layout_width="0dp"
            android:layout_height="1dp"
            android:layout_marginBottom="7dp"
            android:background="@color/darkGray"
            app:layout_constraintEnd_toEndOf="@+id/spAsset"
            app:layout_constraintStart_toStartOf="@+id/spAsset"
            app:layout_constraintBottom_toBottomOf="@id/etAmount" />

        <TextView
            android:id="@+id/tvAssetError"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:textColor="@color/red"
            app:layout_constraintBottom_toBottomOf="@+id/tvAmountError"
            app:layout_constraintEnd_toEndOf="@+id/spAsset"
            app:layout_constraintStart_toStartOf="@+id/spAsset" />

        <EditText
            android:id="@+id/etMemo"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginEnd="24dp"
            android:layout_marginStart="24dp"
            android:layout_marginTop="8dp"
            android:inputType="textMultiLine"
            android:hint="@string/memo_capital"
            android:textSize="20sp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/tvAmountError" />

        <TextView
            android:id="@+id/tvMemoError"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:textColor="@color/red"
            app:layout_constraintEnd_toEndOf="@+id/etMemo"
            app:layout_constraintStart_toStartOf="@+id/etMemo"
            app:layout_constraintTop_toBottomOf="@+id/etMemo" />

        <TextView
            android:id="@+id/tvScan"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="4dp"
            android:layout_marginStart="24dp"
            android:text="@string/scan_capital"
            android:textSize="14sp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/tvMemoError" />

        <View
            android:id="@+id/viewCamera"
            android:background="@color/black"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:layout_marginTop="16dp"
            android:layout_marginStart="@dimen/activity_horizontal_margin"
            android:visibility="visible"
            app:layout_constraintDimensionRatio="1:1"
            app:layout_constraintTop_toBottomOf="@+id/tvScan"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toStartOf="@id/cameraVerticalGuideline"/>

        <android.support.design.widget.FloatingActionButton
            android:id="@+id/fabCloseCamera"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:backgroundTint="@color/send_strong_orange"
            app:fabCustomSize="32dp"
            app:layout_constraintStart_toEndOf="@id/cameraVerticalGuideline"
            app:layout_constraintTop_toBottomOf="@+id/tvScan"
            app:srcCompat="@drawable/ok" />

        <me.dm7.barcodescanner.zxing.ZXingScannerView
            android:id="@+id/ivCamera"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:contentDescription="@string/camera_feed_to_scan_qr"
            app:layout_constraintDimensionRatio="w,3:4"
            app:layout_constraintTop_toTopOf="@+id/viewCamera"
            app:layout_constraintBottom_toBottomOf="@id/viewCamera"
            app:layout_constraintStart_toStartOf="@id/viewCamera"
            app:layout_constraintEnd_toEndOf="@id/viewCamera" />

        <View
            android:id="@+id/viewSend"
            android:layout_width="120dp"
            android:layout_height="140dp"
            android:layout_marginEnd="0dp"
            android:background="@drawable/send_transaction_send_view"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="@id/viewCamera"
            app:layout_constraintBottom_toBottomOf="@id/viewCamera"/>

        <android.support.design.widget.FloatingActionButton
            android:id="@+id/btnSend"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="24dp"
            app:fabCustomSize="90dp"
            app:maxImageSize="70dp"
            app:backgroundTint="@color/send_strong_orange"
            app:srcCompat="@drawable/ic_arrow_forward"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="@+id/viewSend" />

    </android.support.constraint.ConstraintLayout>

</ScrollView>