session-android/res/layout/media_keyboard.xml

<?xml version="1.0" encoding="utf-8"?>

<merge
    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"
    tools:parentTag="org.thoughtcrime.securesms.components.emoji.MediaKeyboard">

    <android.support.constraint.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="?emoji_drawer_background">

        <ImageView
            android:id="@+id/media_keyboard_search"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="6dp"
            android:padding="6dp"
            android:src="@drawable/ic_search_white_24dp"
            android:tint="?media_keyboard_button_color"
            android:background="?selectableItemBackgroundBorderless"
            android:visibility="invisible"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="@id/media_keyboard_provider_tabs"
            app:layout_constraintBottom_toBottomOf="@id/media_keyboard_provider_tabs"
            tools:visibility="visible"/>

        <LinearLayout
            android:id="@+id/media_keyboard_provider_tabs"
            android:layout_width="0dp"
            android:layout_height="40dp"
            android:layout_marginStart="8dp"
            android:gravity="center"
            android:orientation="horizontal"
            app:layout_constraintEnd_toStartOf="@id/media_keyboard_backspace"
            app:layout_constraintStart_toEndOf="@id/media_keyboard_search"
            app:layout_constraintTop_toTopOf="parent" />

        <org.thoughtcrime.securesms.components.RepeatableImageKey
            android:id="@+id/media_keyboard_backspace"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginEnd="6dp"
            android:padding="6dp"
            android:src="@drawable/ic_backspace_grey600_24dp"
            android:background="?selectableItemBackgroundBorderless"
            android:visibility="invisible"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="@id/media_keyboard_provider_tabs"
            app:layout_constraintBottom_toBottomOf="@id/media_keyboard_provider_tabs"
            tools:visibility="visible"/>

        <org.thoughtcrime.securesms.components.ControllableViewPager
            android:id="@+id/media_keyboard_pager"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:visibility="visible"
            app:layout_constraintTop_toBottomOf="@id/media_keyboard_provider_tabs"
            app:layout_constraintBottom_toTopOf="@id/media_keyboard_tabs"/>

        <View
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:background="?emoji_tab_strip_background"
            app:layout_constraintBottom_toBottomOf="@id/media_keyboard_tabs"
            app:layout_constraintTop_toTopOf="@+id/media_keyboard_tabs" />

        <android.support.v7.widget.RecyclerView
            android:id="@+id/media_keyboard_tabs"
            android:layout_width="0dp"
            android:layout_height="40dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toStartOf="@id/media_keyboard_add"
            tools:layout_height="40dp"/>

        <org.thoughtcrime.securesms.components.RepeatableImageKey
            android:id="@+id/media_keyboard_backspace_backup"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginEnd="6dp"
            android:padding="6dp"
            android:src="@drawable/ic_backspace_grey600_24dp"
            android:background="?selectableItemBackgroundBorderless"
            android:visibility="invisible"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="@id/media_keyboard_tabs"
            app:layout_constraintBottom_toBottomOf="@id/media_keyboard_tabs"
            tools:visibility="visible"/>

        <ImageView
            android:id="@+id/media_keyboard_add"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginEnd="12dp"
            android:scaleType="fitCenter"
            android:tint="?media_keyboard_button_color"
            android:visibility="gone"
            android:background="?selectableItemBackground"
            app:srcCompat="@drawable/ic_plus_24"
            app:layout_constraintBottom_toBottomOf="@id/media_keyboard_tabs"
            app:layout_constraintTop_toTopOf="@id/media_keyboard_tabs"
            app:layout_constraintEnd_toStartOf="@id/media_keyboard_backspace_backup"
            tools:visibility="visible"/>

    </android.support.constraint.ConstraintLayout>

</merge>