mTHMMY/app/src/main/res/layout/activity_upload.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/main_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context=".activities.upload.UploadActivity">

    <com.google.android.material.appbar.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingTop="@dimen/appbar_padding_top"
        android:theme="@style/ToolbarTheme">

        <androidx.appcompat.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/ToolbarTheme" />
    </com.google.android.material.appbar.AppBarLayout>

    <androidx.core.widget.NestedScrollView
        android:id="@+id/upload_outer_scrollview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="top|start"
        android:background="@color/background"
        android:paddingEnd="@dimen/activity_horizontal_margin"
        android:paddingStart="@dimen/activity_horizontal_margin"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        tools:context="gr.thmmy.mthmmy.activities.upload.UploadActivity">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@color/background"
            android:focusableInTouchMode="true"
            android:orientation="vertical">

            <LinearLayout
                android:id="@+id/upload_spinners"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:background="@color/background"
                android:orientation="vertical">

                <gr.thmmy.mthmmy.utils.AppCompatSpinnerWithoutDefault
                    android:id="@+id/upload_spinner_category_root"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginBottom="6dp"
                    android:layout_marginTop="6dp"
                    android:popupBackground="@color/primary"
                    android:prompt="@string/upload_spinners_hint" />
            </LinearLayout>

            <com.google.android.material.textfield.TextInputLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginBottom="6dp"
                android:layout_marginTop="6dp">

                <EditText
                    android:id="@+id/upload_title"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:hint="@string/upload_title_hint"
                    android:inputType="text"
                    android:maxLength="500" />
            </com.google.android.material.textfield.TextInputLayout>

            <com.google.android.material.textfield.TextInputLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginBottom="6dp"
                android:layout_marginTop="6dp">

                <EditText
                    android:id="@+id/upload_description"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:hint="@string/upload_description_hint"
                    android:inputType="textMultiLine" />
            </com.google.android.material.textfield.TextInputLayout>

            <androidx.appcompat.widget.AppCompatButton
                android:id="@+id/upload_title_description_builder"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginBottom="6dp"
                android:gravity="center"
                android:text="@string/upload_title_description_builder"
                android:textAlignment="center"
                android:textColor="@color/accent" />

            <androidx.appcompat.widget.AppCompatTextView
                android:id="@+id/upload_filename"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginBottom="6dp"
                android:layout_marginTop="6dp"
                android:drawablePadding="5dp"
                android:ellipsize="marquee"
                android:singleLine="true"
                android:textColor="@color/primary_text"
                android:visibility="gone" />

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content">

                <View
                    android:layout_width="0dp"
                    android:layout_height="0dp"
                    android:layout_weight="1" />

                <androidx.appcompat.widget.AppCompatButton
                    android:id="@+id/upload_select_file_button"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="end"
                    android:layout_marginEnd="16dp"
                    android:drawablePadding="5dp"
                    android:gravity="center_vertical"
                    android:text="@string/upload_select_file"
                    android:textColor="@color/primary_text" />

                <View
                    android:layout_width="0dp"
                    android:layout_height="0dp"
                    android:layout_weight="1" />

                <androidx.appcompat.widget.AppCompatButton
                    android:id="@+id/upload_take_photo_button"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="end"
                    android:layout_marginEnd="16dp"
                    android:drawablePadding="5dp"
                    android:gravity="center_vertical"
                    android:text="@string/upload_take_photo"
                    android:textColor="@color/primary_text" />
            </LinearLayout>
        </LinearLayout>
    </androidx.core.widget.NestedScrollView>

    <me.zhanghai.android.materialprogressbar.MaterialProgressBar
        android:id="@+id/progressBar"
        style="@style/Widget.MaterialProgressBar.ProgressBar.Horizontal.NoPadding"
        android:layout_width="match_parent"
        android:layout_height="@dimen/progress_bar_height"
        android:indeterminate="true"
        android:visibility="invisible"
        app:layout_anchor="@id/appbar"
        app:layout_anchorGravity="bottom|center"
        app:mpb_indeterminateTint="@color/accent"
        app:mpb_progressStyle="horizontal" />

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/upload_fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_marginBottom="@dimen/fab_margins"
        android:layout_marginEnd="@dimen/fab_margins"
        app:layout_behavior="gr.thmmy.mthmmy.utils.ScrollAwareFABBehavior"
        app:srcCompat="@drawable/ic_file_upload_white_24dp" />

</androidx.coordinatorlayout.widget.CoordinatorLayout>