linphone-android/app/src/main/res/layout/conversation_fragment.xml

<?xml version="1.0" encoding="utf-8"?>
<layout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <data>
        <import type="android.view.View" />
        <variable
            name="backClickListener"
            type="View.OnClickListener" />
        <variable
            name="viewModel"
            type="org.linphone.ui.main.conversations.viewmodel.ConversationViewModel" />
    </data>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/white">

        <ImageView
            android:id="@+id/back"
            android:onClick="@{backClickListener}"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@drawable/back"
            android:padding="20dp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <ImageView
            android:id="@+id/avatar"
            android:layout_width="wrap_content"
            android:layout_height="36dp"
            android:layout_marginTop="5dp"
            android:layout_marginBottom="5dp"
            android:adjustViewBounds="true"
            android:src="@{viewModel.isOneToOne ? @drawable/contact_avatar : @drawable/group_avatar, default=@drawable/contact_avatar}"
            coilContact="@{viewModel.contactData}"
            app:layout_constraintStart_toEndOf="@id/back"
            app:layout_constraintTop_toTopOf="@id/back"
            app:layout_constraintBottom_toBottomOf="@id/back"/>

        <androidx.appcompat.widget.AppCompatTextView
            android:id="@+id/title"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginStart="12dp"
            android:text="@{viewModel.isOneToOne ? viewModel.contactName : viewModel.subject, default=`John Doe`}"
            android:textColor="@color/black"
            android:textSize="14sp"
            android:maxLines="1"
            android:ellipsize="end"
            app:layout_constraintStart_toEndOf="@id/avatar"
            app:layout_constraintEnd_toStartOf="@id/phone_call"
            app:layout_constraintTop_toTopOf="@id/avatar" />

        <androidx.appcompat.widget.AppCompatTextView
            android:id="@+id/presence"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginStart="12dp"
            android:text="Online"
            android:textColor="@color/green_online"
            android:textSize="14sp"
            android:textStyle=""
            android:maxLines="1"
            android:ellipsize="end"
            app:layout_constraintStart_toEndOf="@id/avatar"
            app:layout_constraintEnd_toStartOf="@id/phone_call"
            app:layout_constraintTop_toBottomOf="@id/title"
            app:layout_constraintBottom_toBottomOf="@id/avatar"/>

        <ImageView
            android:id="@+id/info"
            android:layout_width="wrap_content"
            android:layout_height="0dp"
            android:src="@drawable/info"
            android:padding="10dp"
            android:layout_marginEnd="5dp"
            app:layout_constraintTop_toTopOf="@id/back"
            app:layout_constraintBottom_toBottomOf="@id/back"
            app:layout_constraintEnd_toEndOf="parent" />

        <ImageView
            android:id="@+id/video_call"
            android:layout_width="wrap_content"
            android:layout_height="0dp"
            android:src="@drawable/video_call"
            android:padding="10dp"
            app:layout_constraintTop_toTopOf="@id/back"
            app:layout_constraintBottom_toBottomOf="@id/back"
            app:layout_constraintEnd_toStartOf="@id/info" />

        <ImageView
            android:id="@+id/phone_call"
            android:layout_width="wrap_content"
            android:layout_height="0dp"
            android:src="@drawable/phone_call"
            android:padding="10dp"
            app:layout_constraintTop_toTopOf="@id/back"
            app:layout_constraintBottom_toBottomOf="@id/back"
            app:layout_constraintEnd_toStartOf="@id/video_call" />

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/messages_list"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:layout_marginTop="5dp"
            android:layout_marginBottom="5dp"
            app:layout_constraintTop_toBottomOf="@id/back"
            app:layout_constraintBottom_toTopOf="@id/messages_bottom_barrier"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toEndOf="parent" />

        <androidx.constraintlayout.widget.Barrier
            android:id="@+id/messages_bottom_barrier"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:constraint_referenced_ids="composing_text, bottom_background"
            app:barrierDirection="top" />

        <androidx.appcompat.widget.AppCompatTextView
            android:id="@+id/composing_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="... est en train d’écrire"
            android:textSize="12sp"
            android:textColor="#73000000"
            android:layout_marginStart="10dp"
            android:layout_marginBottom="15dp"
            android:visibility="@{viewModel.isComposing ? View.VISIBLE : View.GONE}"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintBottom_toTopOf="@id/bottom_background" />

        <View
            android:id="@+id/bottom_background"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:background="@color/gray_7"
            android:layout_marginTop="-15dp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="@id/message"
            app:layout_constraintBottom_toBottomOf="parent" />

        <androidx.appcompat.widget.AppCompatTextView
            android:id="@+id/emoji_picker"
            android:layout_width="wrap_content"
            android:layout_height="0dp"
            android:text="🙂"
            android:textSize="18sp"
            android:padding="5dp"
            android:gravity="center"
            android:layout_marginStart="10dp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="@id/message"
            app:layout_constraintBottom_toBottomOf="@id/message" />

        <ImageView
            android:id="@+id/attach_file"
            android:layout_width="wrap_content"
            android:layout_height="0dp"
            android:src="@drawable/add_file"
            android:padding="5dp"
            android:layout_marginStart="10dp"
            app:layout_constraintStart_toEndOf="@id/emoji_picker"
            app:layout_constraintTop_toTopOf="@id/message"
            app:layout_constraintBottom_toBottomOf="@id/message" />

        <EditText
            android:id="@+id/message"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:hint="Dites quelque chose..."
            android:layout_marginBottom="15dp"
            android:layout_marginStart="10dp"
            android:layout_marginEnd="10dp"
            android:paddingStart="24dp"
            android:paddingTop="5dp"
            android:paddingBottom="5dp"
            android:maxLines="5"
            android:textSize="14sp"
            android:background="@drawable/shape_edittext_white_background"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toEndOf="@id/attach_file"
            app:layout_constraintEnd_toStartOf="@id/voice_message"/>

        <ImageView
            android:id="@+id/voice_message"
            android:layout_width="wrap_content"
            android:layout_height="0dp"
            android:src="@drawable/voice_message"
            android:padding="5dp"
            android:layout_marginEnd="10dp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="@id/message"
            app:layout_constraintBottom_toBottomOf="@id/message" />

    </androidx.constraintlayout.widget.ConstraintLayout>

</layout>