Is fling gesture not supported by the Frame Layout?

I have included the Java and XML files for your ready reference. I was aiming to put a keypad into a fragment into a frame layout. The frame Layout would then have a fling-able feature across the entire available screen.

In my experiment I found that fling gesture won't work on a frame layout. It will work on the button however. Also, a point of interest, if you implement a long press on the frame layout, that will work then.

package com.example.framelayoutexperiment;

import androidx.appcompat.app.AppCompatActivity;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    public static final int SWIPE_THRESHOLD = 100;
    public static final int SWIPE_VELOCITY_THRESHOLD = 100;
    FrameLayout fr1;
    Button btn1;

    @SuppressLint("ClickableViewAccessibility")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        fr1 = (FrameLayout) findViewById(R.id.this_frameLayout);
        btn1 = findViewById(R.id.this_button);

        btn1.setOnTouchListener(new View.OnTouchListener() {
            GestureDetector gestureDetector = new GestureDetector(getApplicationContext(), new GestureDetector.SimpleOnGestureListener() {

                @Override
                public boolean onFling(MotionEvent downEvent, MotionEvent moveEvent, float velocityX, float velocityY) {

                    boolean result = false;
                    float diffY = moveEvent.getY() - downEvent.getY();
                    float diffX = moveEvent.getX() - downEvent.getX();

                    if (Math.abs(diffX) > Math.abs(diffY)) {
                        // right or left swipe
                        if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                            if (diffX > 0) {
                                onSwipeRight();
                            } else {
                                onSwipeLeft();
                            }
                        }

                    } else {
                        // up or down swipe
                        if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                            if (diffY > 0) {
                                onSwipeBottom() ;
                            } else {
                                oNSwipeTop() ;
                            }
                        }
                    }
                    return true;
                }

                private void onSwipeBottom() {
                    Toast.makeText(getApplicationContext(), "Swipe Bottom", Toast.LENGTH_LONG).show();
                }

                private void oNSwipeTop() {
                    Toast.makeText(getApplicationContext(), "Swipe Top", Toast.LENGTH_LONG).show();
                }

                private void onSwipeLeft() {
                    Toast.makeText(getApplicationContext(), "Swipe Left", Toast.LENGTH_LONG).show();
                }

                private void onSwipeRight() {
                    Toast.makeText(getApplicationContext(), "Swipe Right", Toast.LENGTH_LONG).show();
                }
            });

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                gestureDetector.onTouchEvent(event);
                return false;
            }
        });

        fr1.setOnTouchListener(new View.OnTouchListener() {
            GestureDetector gestureDetector = new GestureDetector(getApplicationContext(), new GestureDetector.SimpleOnGestureListener() {

                @Override
                public boolean onFling(MotionEvent downEvent, MotionEvent moveEvent, float velocityX, float velocityY) {

                    boolean result = false;
                    float diffY = moveEvent.getY() - downEvent.getY();
                    float diffX = moveEvent.getX() - downEvent.getX();

                    if (Math.abs(diffX) > Math.abs(diffY)) {
                        // right or left swipe
                        if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                            if (diffX > 0) {
                                onSwipeRight();
                            } else {
                                onSwipeLeft();
                            }
                        }

                    } else {
                        // up or down swipe
                        if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                            if (diffY > 0) {
                                onSwipeBottom() ;
                            } else {
                                oNSwipeTop() ;
                            }
                        }
                    }
                    return true;
                }

                private void onSwipeBottom() {
                    Toast.makeText(getApplicationContext(), "Swipe Bottom", Toast.LENGTH_LONG).show();
                }

                private void oNSwipeTop() {
                    Toast.makeText(getApplicationContext(), "Swipe Top", Toast.LENGTH_LONG).show();
                }

                private void onSwipeLeft() {
                    Toast.makeText(getApplicationContext(), "Swipe Left", Toast.LENGTH_LONG).show();
                }

                private void onSwipeRight() {
                    Toast.makeText(getApplicationContext(), "Swipe Right", Toast.LENGTH_LONG).show();
                }
            });

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                gestureDetector.onTouchEvent(event);
                return false;
            }
        });
    }
}

<?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"
    tools:context=".MainActivity">

    <FrameLayout
        android:id="@+id/this_frameLayout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="185dp"
        android:background="@color/colorAccent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent">

        <Button
            android:id="@+id/this_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="279dp"
            android:text="Example"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

    </FrameLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

Add android:clickable="true" and android:focusable="true" for your FrameLayout.

<?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"
    tools:context=".MainActivity">

    <FrameLayout
        android:id="@+id/this_frameLayout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:clickable="true"
        android:focusable="true"
        android:layout_marginBottom="185dp"
        android:background="@color/teal_200"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent">

        <Button
            android:id="@+id/this_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="279dp"
            android:text="Example"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

    </FrameLayout>
</androidx.constraintlayout.widget.ConstraintLayout>