examples/platform_view/android/app/src/main/java/io/flutter/examples/platform_view/CountActivity.java

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package io.flutter.examples.platform_view;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import com.google.android.material.floatingactionbutton.FloatingActionButton;

public class CountActivity extends AppCompatActivity {
  public static final String EXTRA_COUNTER = "counter";
  private int counter;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.android_full_screen_layout);
    Toolbar myToolbar = findViewById(R.id.my_toolbar);
    myToolbar.setTitle("Platform View");
    setSupportActionBar(myToolbar);

    counter = getIntent().getIntExtra(EXTRA_COUNTER, 0);
    updateText();

    FloatingActionButton fab = findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        counter++;
        updateText();
      }
    });

    Button switchViewButton = findViewById(R.id.button);
    switchViewButton.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        returnToFlutterView();
      }
    });
  }

  private void updateText() {
    TextView textView = findViewById(R.id.button_tap);
    String value = "Button tapped " + counter + (counter == 1 ? " time" : " times");
    textView.setText(value);
  }

  private void returnToFlutterView() {
    Intent returnIntent = new Intent();
    returnIntent.putExtra(EXTRA_COUNTER, counter);
    setResult(Activity.RESULT_OK, returnIntent);
    finish();
  }

  public void onBackPressed() {
    returnToFlutterView();
  }
}