floating action button m3 example

different files

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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">

    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentEnd="true"
        android:layout_marginBottom="16dp"
        android:layout_marginEnd="16dp"
        app:srcCompat="@android:drawable/ic_dialog_email" />
</RelativeLayout>

==========================================================================================

MainActivity.java:

package com.sunmeat.myapplication;

import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import androidx.appcompat.app.AppCompatActivity;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;

public class MainActivity extends AppCompatActivity {

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

        FloatingActionButton fab = findViewById(R.id.fab);
        fab.setOnClickListener(view -> {
            Snackbar snackbar = Snackbar.make(view, "FAB был нажат", Snackbar.LENGTH_SHORT);
            View snackbarView = snackbar.getView();
            Snackbar.SnackbarLayout.LayoutParams params = (Snackbar.SnackbarLayout.LayoutParams) snackbarView.getLayoutParams();
            params.gravity = Gravity.TOP;
            snackbarView.setLayoutParams(params);
            snackbar.show();
        });
    }
}

==========================================================================================

build.gradle.kts: (уже и так должно быть по дефолту)

dependencies {
    ...
    implementation("com.google.android.material:material:1.11.0")
    ...
}