activity_formatting.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="20dp"
    tools:context=".FormattingActivity">

    <dev.olaore.workingwithtext.views.CustomTextView
        android:id="@+id/custom_text_view"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        app:layout_constraintTop_toTopOf="parent" />

    <LinearLayout
        android:id="@+id/text_spacing_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp"
        android:orientation="vertical"
        app:layout_constraintTop_toBottomOf="@id/custom_text_view">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/text_spacing"
            android:textSize="24sp" />

        <SeekBar
            android:id="@+id/spacing_seekbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:max="5"
            android:progress="0" />

    </LinearLayout>

    <LinearLayout
        android:id="@+id/text_formatting_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="30dp"
        android:orientation="vertical"
        app:layout_constraintTop_toBottomOf="@id/text_spacing_container">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/text_formatting"
            android:textSize="24sp" />

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

            <CheckBox
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:id="@+id/bold_checkbox"
                android:text="@string/bold" />

            <CheckBox
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:id="@+id/underline_checkbox"
                android:text="@string/underline" />

            <CheckBox
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:id="@+id/strikethrough_checkbox"
                android:text="@string/strikethrough" />

        </LinearLayout>

    </LinearLayout>

    <LinearLayout
        android:id="@+id/text_fill_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:orientation="vertical"
        app:layout_constraintTop_toBottomOf="@id/text_formatting_container">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/text_fill"
            android:textSize="24sp" />

        <RadioGroup
            android:id="@+id/text_fill_radio_group"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:orientation="horizontal">

            <RadioButton
                android:id="@+id/apply_fill"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:fontFamily="casual"
                android:checked="true"
                android:text="@string/fill_text"
                tools:ignore="TouchTargetSizeCheck" />

            <RadioButton
                android:id="@+id/apply_stroke"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:fontFamily="casual"
                android:text="@string/stroke_text"
                tools:ignore="TouchTargetSizeCheck" />

            <RadioButton
                android:id="@+id/apply_fill_and_stroke"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:fontFamily="casual"
                android:text="@string/fill_and_stroke_text"
                tools:ignore="TouchTargetSizeCheck" />

        </RadioGroup>

    </LinearLayout>

    <LinearLayout
        android:id="@+id/text_fonts_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:orientation="vertical"
        app:layout_constraintTop_toBottomOf="@id/text_fill_container">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/text_fonts"
            android:textSize="24sp" />

        <RadioGroup
            android:id="@+id/text_fonts_radio_group"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:orientation="horizontal">

            <RadioButton
                android:id="@+id/apply_serif"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:fontFamily="casual"
                android:text="@string/serif_text"
                android:checked="true"
                tools:ignore="TouchTargetSizeCheck" />

            <RadioButton
                android:id="@+id/apply_sans_serif"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:fontFamily="casual"
                android:text="@string/sans_serif_text"
                tools:ignore="TouchTargetSizeCheck" />

            <RadioButton
                android:id="@+id/apply_monospace"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:fontFamily="casual"
                android:text="@string/monospace_text"
                tools:ignore="TouchTargetSizeCheck" />

        </RadioGroup>

    </LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>