Quelle  activity_image_paint.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:id="@+id/image_paint_root"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    android:orientation="vertical"
    tools:context="ch.threema.app.activities.ImagePaintActivity">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1">

        <com.google.android.material.appbar.AppBarLayout
            android:id="@+id/appbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:layout_constraintTop_toTopOf="parent">

            <com.google.android.material.appbar.MaterialToolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:theme="@style/ThemeOverlay.AppCompat.ActionBar" />

        </com.google.android.material.appbar.AppBarLayout>

        <ch.threema.app.ui.LockableScrollView
            android:id="@+id/content_scroll_view"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            app:layout_constraintBottom_toTopOf="@id/bottom_panel"
            app:layout_constraintTop_toBottomOf="@id/appbar">

            <FrameLayout
                android:id="@+id/content_frame"
                android:layout_width="match_parent"
                android:layout_height="wrap_content">

                <ImageView
                    android:id="@+id/preview_image"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center"
                    android:adjustViewBounds="true" />

                <com.google.android.material.progressindicator.CircularProgressIndicator
                    android:id="@+id/progress"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center"
                    android:indeterminate="true"
                    android:visibility="gone" />

                <ch.threema.app.motionviews.widget.MotionView
                    android:id="@+id/motion_view"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:layout_gravity="center" />

                <ch.threema.app.ui.PaintView
                    android:id="@+id/paint_view"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:layout_gravity="center" />

            </FrameLayout>

        </ch.threema.app.ui.LockableScrollView>

        <FrameLayout
            android:id="@+id/bottom_panel"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom"
            android:background="#77000000"
            android:paddingBottom="4dp"
            android:paddingLeft="8dp"
            android:paddingRight="8dp"
            android:paddingTop="4dp"
            android:visibility="gone"
            app:layout_constraintBottom_toBottomOf="parent">

            <ch.threema.app.ui.ComposeEditText
                android:id="@+id/caption_edittext"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="bottom"
                android:layout_marginRight="56dp"
                android:background="@drawable/bubble_compose_dark_outline"
                android:ellipsize="end"
                android:hint="@string/add_caption_hint"
                android:maxLength="1000"
                android:maxLines="@integer/message_edittext_max_lines"
                android:minHeight="@dimen/input_text_height"
                android:nextFocusLeft="@+id/emoji_button"
                android:nextFocusRight="@+id/attach_button"
                android:paddingBottom="4dp"
                android:paddingLeft="@dimen/emoji_button_width"
                android:paddingRight="45dp"
                android:paddingTop="3dp"
                android:scrollHorizontally="false"
                android:textSize="16sp">

                <requestFocus />
            </ch.threema.app.ui.ComposeEditText>

            <ch.threema.app.emojis.EmojiButton
                android:id="@+id/emoji_button"
                style="?android:attr/borderlessButtonStyle"
                android:layout_width="@dimen/emoji_button_width"
                android:layout_height="@dimen/emoji_button_width"
                android:layout_gravity="left|bottom"
                android:layout_marginBottom="5dp"
                android:background="@drawable/selector_compose_button"
                android:contentDescription="@string/select_emoji"
                android:drawablePadding="0dip"
                android:focusable="true"
                android:nextFocusRight="@+id/caption_edittext"
                android:padding="8dp" />

            <ch.threema.app.ui.SendButton
                android:id="@+id/send_button"
                android:layout_width="@dimen/input_text_height"
                android:layout_height="@dimen/input_text_height"
                android:layout_gravity="bottom|right"
                android:clickable="true"
                android:focusable="true"
                android:foreground="@drawable/selector_avatar"
                app:buttonTheme="1" />

        </FrameLayout>

    </androidx.constraintlayout.widget.ConstraintLayout>

    <ViewStub
        android:id="@+id/emoji_stub"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inflatedId="@+id/emoji_picker"
        android:layout="@layout/emoji_picker_layout" />

</LinearLayout>