Mercury-IM/app/src/main/java/org/mercury_im/messenger/MercuryImApplication.java

package org.mercury_im.messenger;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.Application;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.content.Context;
import android.content.Intent;
import android.os.Build;

import org.mercury_im.messenger.di.component.AppComponent;
import org.mercury_im.messenger.di.component.DaggerAppComponent;
import org.mercury_im.messenger.di.module.AppModule;
import org.mercury_im.messenger.service.MercuryConnectionService;
import org.mercury_im.messenger.util.AbstractActivityLifecycleCallbacks;

import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;


public class MercuryImApplication extends Application {

    static {
        // Initialize Smack etc.
        // new MercuryConfiguration();
    }

    private static MercuryImApplication INSTANCE;
    AppComponent appComponent;

    // Keep track of activities in "started" state.
    // This will come in handy for CSI
    // see https://medium.com/@iamsadesh/android-how-to-detect-when-app-goes-background-foreground-fd5a4d331f8a
    private AtomicInteger activityReferences = new AtomicInteger(0);
    private AtomicBoolean isActivityChangingConfiguration = new AtomicBoolean(false);

    public static MercuryImApplication getApplication() {
        return INSTANCE;
    }


    @Override
    public void onCreate() {

        super.onCreate();
        registerActivityLifecycleCallbacks(lifecycleCallbacks);

        INSTANCE = this;

        appComponent = createAppComponent();

        initializeNotificationChannels(this);

        Intent serviceIntent = new Intent(getApplicationContext(), MercuryConnectionService.class);

        serviceIntent.setAction(MercuryConnectionService.ACTION_START);
        if (Build.VERSION.SDK_INT < 26) {
            startService(serviceIntent);
        } else {
            startForegroundService(serviceIntent);
        }
    }

    /**
     * Create the Dependency Injection graph.
     * For testing, overwrite this method with custom modules.
     */
    public AppComponent createAppComponent() {
        AppComponent appComponent = DaggerAppComponent.builder()
                .appModule(new AppModule(this))
                .build();

        appComponent.inject(this);

        return appComponent;
    }

    public void initializeNotificationChannels(Context context) {
        // Only necessary on Android O and upwards.
        if (Build.VERSION.SDK_INT < 26) {
            return;
        }

        NotificationManager notificationManager =
                (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);

        // Foreground notification channel
        String fName = getResources().getString(R.string.channel_name_foreground);
        String fDescription = getResources().getString(R.string.channel_description_foreground);

        @SuppressLint("WrongConstant")
        NotificationChannel foreground = new NotificationChannel(Notifications.NOTIFICATION_CHANNEL__FOREGROUND_SERVICE,
                fName, NotificationManager.IMPORTANCE_MIN);
        foreground.setDescription(fDescription);
        foreground.setShowBadge(false);
        notificationManager.createNotificationChannel(foreground);

        // Incoming Messages notification channel
        String mName = getResources().getString(R.string.channel_name_message);
        String mDescription = getResources().getString(R.string.channel_description_message);

        @SuppressLint("WrongConstant")
        NotificationChannel messages = new NotificationChannel(Notifications.NOTIFICATION_CHANNEL__NEW_MESSAGE,
                mName, NotificationManager.IMPORTANCE_DEFAULT);
        messages.setDescription(mDescription);
        notificationManager.createNotificationChannel(messages);
    }

    public AppComponent getAppComponent() {
        return appComponent;
    }

    private final AbstractActivityLifecycleCallbacks lifecycleCallbacks = new AbstractActivityLifecycleCallbacks() {

        @Override
        public void onActivityStarted(Activity activity) {
            if (activityReferences.incrementAndGet() == 1 && !isActivityChangingConfiguration.get()) {
                // App enters foreground
                //connectionCenter.clientStateActive();
            }
        }

        @Override
        public void onActivityStopped(Activity activity) {
            isActivityChangingConfiguration.set(activity.isChangingConfigurations());
            if (activityReferences.decrementAndGet() == 0 && !isActivityChangingConfiguration.get()) {
                // App enters background
                //connectionCenter.clientStateInactive();
            }
        }
    };
}