packages/google_maps_flutter/android/src/main/java/io/flutter/plugins/googlemaps/GoogleMapsPlugin.java

// Copyright 2018 The Chromium 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.plugins.googlemaps;

import android.app.Activity;
import android.app.Application;
import android.os.Bundle;
import io.flutter.plugin.common.PluginRegistry.Registrar;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Plugin for controlling a set of GoogleMap views to be shown as overlays on top of the Flutter
 * view. The overlay should be hidden during transformations or while Flutter is rendering on top of
 * the map. A Texture drawn using GoogleMap bitmap snapshots can then be shown instead of the
 * overlay.
 */
public class GoogleMapsPlugin implements Application.ActivityLifecycleCallbacks {
  static final int CREATED = 1;
  static final int STARTED = 2;
  static final int RESUMED = 3;
  static final int PAUSED = 4;
  static final int STOPPED = 5;
  static final int DESTROYED = 6;
  private final AtomicInteger state = new AtomicInteger(0);
  private final int registrarActivityHashCode;

  public static void registerWith(Registrar registrar) {
    if (registrar.activity() == null) {
      // When a background flutter view tries to register the plugin, the registrar has no activity.
      // We stop the registration process as this plugin is foreground only.
      return;
    }
    final GoogleMapsPlugin plugin = new GoogleMapsPlugin(registrar);
    registrar.activity().getApplication().registerActivityLifecycleCallbacks(plugin);
    registrar
        .platformViewRegistry()
        .registerViewFactory(
            "plugins.flutter.io/google_maps", new GoogleMapFactory(plugin.state, registrar));
  }

  @Override
  public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
    if (activity.hashCode() != registrarActivityHashCode) {
      return;
    }
    state.set(CREATED);
  }

  @Override
  public void onActivityStarted(Activity activity) {
    if (activity.hashCode() != registrarActivityHashCode) {
      return;
    }
    state.set(STARTED);
  }

  @Override
  public void onActivityResumed(Activity activity) {
    if (activity.hashCode() != registrarActivityHashCode) {
      return;
    }
    state.set(RESUMED);
  }

  @Override
  public void onActivityPaused(Activity activity) {
    if (activity.hashCode() != registrarActivityHashCode) {
      return;
    }
    state.set(PAUSED);
  }

  @Override
  public void onActivityStopped(Activity activity) {
    if (activity.hashCode() != registrarActivityHashCode) {
      return;
    }
    state.set(STOPPED);
  }

  @Override
  public void onActivitySaveInstanceState(Activity activity, Bundle outState) {}

  @Override
  public void onActivityDestroyed(Activity activity) {
    if (activity.hashCode() != registrarActivityHashCode) {
      return;
    }
    activity.getApplication().unregisterActivityLifecycleCallbacks(this);
    state.set(DESTROYED);
  }

  private GoogleMapsPlugin(Registrar registrar) {
    this.registrarActivityHashCode = registrar.activity().hashCode();
  }
}