PinPoint/app/src/main/res/layout/activity_bowling_camera.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
  Portrait (default) button arrangement: record button in a bottom bar,
  back/switch-camera in the top corners. See res/layout-land/ for the
  landscape variant, which moves the record button to a side column instead
  - Android picks whichever of the two matches the current orientation
  automatically, no code needed.
-->
<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:keepScreenOn="true"
    tools:context=".bowling.BowlingCameraActivity">

    <androidx.camera.view.PreviewView
        android:id="@+id/camera_preview"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

    <com.example.jnicpp.bowling.PoseOverlayView
        android:id="@+id/pose_overlay"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintTop_toTopOf="@id/camera_preview"
        app:layout_constraintBottom_toBottomOf="@id/camera_preview"
        app:layout_constraintStart_toStartOf="@id/camera_preview"
        app:layout_constraintEnd_toEndOf="@id/camera_preview" />

    <!--
      Recording indicator: red dot + elapsed timer, only visible while
      recording. Anchored below btn_back (rather than parent's top) so the
      two never overlap - btn_back is declared later in this file so it
      draws on top, but ConstraintLayout resolves constraint references
      regardless of declaration order, so this forward reference is fine.
    -->
    <LinearLayout
        android:id="@+id/layout_recording_indicator"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center_vertical"
        android:background="@color/overlay_scrim"
        android:paddingHorizontal="12dp"
        android:paddingVertical="6dp"
        android:visibility="gone"
        tools:visibility="visible"
        app:layout_constraintTop_toBottomOf="@id/btn_back"
        app:layout_constraintStart_toStartOf="parent"
        android:layout_marginTop="8dp"
        android:layout_marginStart="16dp">

        <View
            android:id="@+id/view_recording_dot"
            android:layout_width="12dp"
            android:layout_height="12dp"
            android:background="@drawable/shape_recording_dot" />

        <TextView
            android:id="@+id/text_timer"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="8dp"
            android:text="@string/recording_timer_placeholder"
            android:textColor="@color/white"
            android:textSize="16sp"
            android:fontFamily="monospace" />
    </LinearLayout>

    <!-- Live pose overlay + baked-in-recording toggle. Only togglable while
         not recording (see BowlingCameraActivity#renderRecordingState) since
         the recording pipeline picks its pose mode once at start. -->
    <com.google.android.material.switchmaterial.SwitchMaterial
        android:id="@+id/switch_pose"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="32dp"
        android:layout_marginEnd="8dp"
        android:text="@string/toggle_pose"
        android:textColor="@color/white"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toStartOf="@id/btn_record"
        app:layout_constraintHorizontal_chainStyle="packed" />

    <Button
        android:id="@+id/btn_record"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="32dp"
        android:layout_marginStart="8dp"
        android:text="@string/record"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toEndOf="@id/switch_pose"
        app:layout_constraintEnd_toEndOf="parent" />

    <!-- Overlaid on the preview itself so it's reachable while the camera UI is showing. -->
    <Button
        android:id="@+id/btn_switch_camera"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:text="@string/switch_camera"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

    <!-- Shown instead of the camera UI when CAMERA/RECORD_AUDIO aren't granted -->
    <LinearLayout
        android:id="@+id/layout_permission_rationale"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:gravity="center"
        android:padding="24dp"
        android:background="@color/black"
        android:visibility="gone"
        tools:visibility="visible"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent">

        <TextView
            android:id="@+id/text_permission_message"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/permission_rationale_message"
            android:textColor="@color/white"
            android:textSize="16sp"
            android:gravity="center"
            android:layout_marginBottom="16dp" />

        <Button
            android:id="@+id/btn_grant_permissions"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/grant_permissions" />
    </LinearLayout>

    <!-- Declared last so it draws above the permission rationale screen too,
         keeping a way back out of this Activity available in every state. -->
    <Button
        android:id="@+id/btn_back"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:layout_marginStart="16dp"
        android:text="@string/back"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>