Quelle  activity_media_attach.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout 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/coordinator"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:elevation="1dp">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/permission_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:paddingLeft="16dp"
        android:paddingRight="16dp"
        android:visibility="gone"
        app:layout_constraintBottom_toBottomOf="@id/media_grid_recycler"
        app:layout_constraintLeft_toLeftOf="@id/media_grid_recycler"
        app:layout_constraintRight_toRightOf="@id/media_grid_recycler"
        app:layout_constraintTop_toTopOf="@id/media_grid_recycler">

        <TextView
            android:id="@+id/permission_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:gravity="center_horizontal"
            android:shadowColor="@android:color/black"
            android:shadowDx="2"
            android:shadowDy="2"
            android:shadowRadius="3"
            android:text="@string/enable_storage_access_for_media"
            android:textAlignment="center"
            android:textAppearance="@style/Threema.TextAppearance.EmptyView"
            android:textColor="@android:color/white"
            app:layout_constraintBottom_toTopOf="@+id/permission_button"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_chainStyle="packed" />

        <com.google.android.material.button.MaterialButton
            android:id="@+id/permission_button"
            style="@style/Threema.MaterialButton.Elevated"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:text="@string/take_me_there"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toBottomOf="@id/permission_text" />

    </androidx.constraintlayout.widget.ConstraintLayout>

    <androidx.coordinatorlayout.widget.CoordinatorLayout
        android:id="@+id/grid_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <androidx.coordinatorlayout.widget.CoordinatorLayout
            android:id="@+id/bottom_sheet_container"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginTop="20dp">

            <androidx.constraintlayout.widget.ConstraintLayout
                android:id="@id/bottom_sheet"
                style="?attr/bottomSheetStyle"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_gravity="center"
                android:clipToPadding="false"
                android:elevation="1dp"
                app:behavior_hideable="true"
                app:behavior_saveFlags="all"
                app:layout_behavior="@string/bottom_sheet_behavior">

                <ImageView
                    android:id="@+id/drag_handle"
                    style="@style/Threema.BottomSheet.DragHandle"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:importantForAccessibility="no"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintRight_toRightOf="parent"
                    app:layout_constraintTop_toTopOf="parent" />

                <include
                    android:id="@+id/select_media_permission_notice_container"
                    layout="@layout/notice_select_media_permission"
                    android:layout_width="0dp"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="8dp"
                    android:layout_marginTop="@dimen/notice_views_vertical_margin"
                    android:layout_marginRight="8dp"
                    android:layout_marginBottom="@dimen/notice_views_vertical_margin"
                    android:visibility="gone"
                    app:layout_constraintBottom_toTopOf="@id/media_grid_recycler"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintRight_toRightOf="parent"
                    app:layout_constraintTop_toBottomOf="@id/drag_handle" />

                <ch.threema.app.ui.EmptyRecyclerView
                    android:id="@+id/media_grid_recycler"
                    android:layout_width="0dp"
                    android:layout_height="0dp"
                    android:clipToPadding="false"
                    android:paddingHorizontal="@dimen/grid_unit_x1"
                    android:paddingTop="8dp"
                    app:layout_constraintBottom_toBottomOf="parent"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintRight_toRightOf="parent"
                    app:layout_constraintTop_toBottomOf="@id/select_media_permission_notice_container" />

            </androidx.constraintlayout.widget.ConstraintLayout>

        </androidx.coordinatorlayout.widget.CoordinatorLayout>

        <com.google.android.material.appbar.AppBarLayout
            android:id="@+id/appbar_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/colorSurface"
            android:visibility="invisible"
            app:elevation="0dp"
            tools:visibility="visible">

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

                <com.google.android.material.appbar.MaterialToolbar
                    android:id="@+id/toolbar"
                    style="@style/Threema.ToolbarStyle"
                    android:layout_width="match_parent"
                    android:layout_height="?attr/actionBarSize"
                    app:menu="@menu/activity_media_attach"
                    app:navigationIcon="@drawable/ic_chevron_down_slightly_bigger"
                    app:navigationIconTint="?attr/colorOnSurface">

                    <LinearLayout
                        android:id="@+id/toolbar_title"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:background="?attr/selectableItemBackgroundBorderless"
                        android:clickable="false"
                        android:focusable="true"
                        android:orientation="horizontal">

                        <TextView
                            android:id="@+id/toolbar_title_textview"
                            style="@style/Threema.TextAppearance.Toolbar.Title"
                            android:layout_width="wrap_content"
                            android:layout_height="match_parent"
                            android:ellipsize="middle"
                            android:textColor="?attr/colorOnBackground"
                            android:textSize="20sp"
                            tools:text="Gallery" />

                        <ImageView
                            android:id="@+id/dropdown_icon"
                            android:layout_width="wrap_content"
                            android:layout_height="match_parent"
                            android:contentDescription="@string/filter_by_album"
                            android:visibility="invisible"
                            app:srcCompat="@drawable/ic_arrow_down_filled"
                            app:tint="?attr/colorOnBackground"
                            tools:visibility="visible" />

                    </LinearLayout>

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

            </FrameLayout>

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

        <ViewStub
            android:id="@+id/stub"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom"
            android:inflatedId="@+id/control_panel" />

    </androidx.coordinatorlayout.widget.CoordinatorLayout>

    <androidx.coordinatorlayout.widget.CoordinatorLayout
        android:id="@+id/pager_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="gone">

        <androidx.viewpager2.widget.ViewPager2
            android:id="@+id/pager"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/gallery_background" />

        <com.google.android.material.appbar.AppBarLayout
            android:id="@+id/appbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@color/preview_navigation_area_bg"
            app:elevation="0dp">

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

                <com.google.android.material.appbar.MaterialToolbar
                    android:id="@+id/preview_toolbar"
                    style="@style/Threema.ToolbarStyle"
                    android:layout_width="match_parent"
                    android:layout_height="?attr/actionBarSize"
                    android:background="@android:color/transparent"
                    app:navigationIcon="@drawable/ic_arrow_left"
                    app:navigationIconTint="@android:color/white">

                    <ch.threema.app.ui.CheckableView
                        android:id="@+id/check_box"
                        android:layout_width="32dp"
                        android:layout_height="32dp"
                        android:layout_gravity="top|right"
                        android:layout_marginTop="12dp"
                        android:layout_marginRight="16dp"
                        android:background="@drawable/selector_grid_checkbox" />

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

            </FrameLayout>

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

        <include layout="@layout/bottom_sheet_media_preview" />

    </androidx.coordinatorlayout.widget.CoordinatorLayout>

</androidx.coordinatorlayout.widget.CoordinatorLayout>