add notification for download progress

app/src/main/java/com/dkanada/gramophone/service/DownloadService.java

@@ -10,6 +10,7 @@ import com.dkanada.gramophone.App;
 import com.dkanada.gramophone.BuildConfig;
 import com.dkanada.gramophone.database.Cache;
 import com.dkanada.gramophone.model.Song;
+import com.dkanada.gramophone.service.notifications.DownloadNotification;
 import com.dkanada.gramophone.util.MusicUtil;
 import com.dkanada.gramophone.util.PreferenceUtil;
 
@@ -30,6 +31,7 @@ public class DownloadService extends Service {
 
     private Executor executor;
     private Handler handler;
+    private DownloadNotification notification;
 
     @Override
     public void onCreate() {
@@ -42,6 +44,7 @@ public class DownloadService extends Service {
 
         executor = Executors.newFixedThreadPool(4);
         handler = new Handler(looper);
+        notification = new DownloadNotification(this);
     }
 
     @Override
@@ -68,11 +71,13 @@ public class DownloadService extends Service {
 
                 connection.connect();
 
-                byte[] data = new byte[262144];
+                byte[] data = new byte[1048576];
                 int count;
 
+                notification.start(song, connection.getContentLength());
                 while ((count = input.read(data)) != -1) {
                     output.write(data, 0, count);
+                    notification.update(count);
                 }
 
                 input.close();
@@ -90,6 +95,7 @@ public class DownloadService extends Service {
 
                 download.delete();
                 App.getDatabase().cacheDao().insertCache(new Cache(song));
+                notification.stop(song);
             } catch (Exception e) {
                 e.printStackTrace();
             }

app/src/main/java/com/dkanada/gramophone/service/notifications/DownloadNotification.java

@@ -0,0 +1,108 @@
+package com.dkanada.gramophone.service.notifications;
+
+import android.app.NotificationChannel;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Build;
+
+import androidx.annotation.RequiresApi;
+import androidx.core.app.NotificationCompat;
+
+import com.dkanada.gramophone.R;
+import com.dkanada.gramophone.activities.MainActivity;
+import com.dkanada.gramophone.model.Song;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static android.content.Context.NOTIFICATION_SERVICE;
+
+public class DownloadNotification {
+    private static final String CHANNEL_ID = DownloadNotification.class.getSimpleName();
+    private static final int NOTIFICATION_ID = 2;
+
+    private final Context context;
+    private final NotificationManager notificationManager;
+
+    private final List<Song> songs;
+
+    private int current;
+    private int maximum;
+
+    public DownloadNotification(Context context) {
+        this.notificationManager = (NotificationManager) context.getSystemService(NOTIFICATION_SERVICE);
+        this.context = context;
+
+        this.songs = new ArrayList<>();
+    }
+
+    public synchronized void start(Song song, int maximum) {
+        this.songs.add(song);
+
+        this.maximum += maximum;
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            createNotificationChannel();
+        }
+    }
+
+    public synchronized void update(int current) {
+        this.current += current;
+
+        Intent action = new Intent(context, MainActivity.class).setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        PendingIntent clickIntent = PendingIntent.getActivity(context, 0, action, 0);
+
+        NotificationCompat.InboxStyle style = new NotificationCompat.InboxStyle();
+        for (Song item : songs.stream().limit(5).collect(Collectors.toList())) {
+            style.addLine(item.title);
+        }
+
+        NotificationCompat.Builder builder = new NotificationCompat.Builder(context, CHANNEL_ID)
+            .setSmallIcon(R.drawable.ic_notification)
+            .setContentIntent(clickIntent)
+            .setContentTitle(String.format(context.getString(R.string.downloading_x_songs), songs.size()))
+            .setProgress(maximum, this.current, false)
+            .setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
+            .setStyle(style)
+            .setShowWhen(false);
+
+        notificationManager.notify(NOTIFICATION_ID, builder.build());
+    }
+
+    public synchronized void stop(Song song) {
+        if (song != null) {
+            songs.remove(song);
+        }
+
+        if (songs.size() != 0) {
+            return;
+        }
+
+        current = 0;
+        maximum = 0;
+
+        notificationManager.cancel(NOTIFICATION_ID);
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            notificationManager.deleteNotificationChannel(CHANNEL_ID);
+        }
+    }
+
+    @RequiresApi(Build.VERSION_CODES.O)
+    private void createNotificationChannel() {
+        NotificationChannel notificationChannel = notificationManager.getNotificationChannel(CHANNEL_ID);
+
+        if (notificationChannel == null) {
+            notificationChannel = new NotificationChannel(CHANNEL_ID, context.getString(R.string.action_download), NotificationManager.IMPORTANCE_LOW);
+
+            notificationChannel.setDescription(context.getString(R.string.playing_notification_description));
+            notificationChannel.enableLights(false);
+            notificationChannel.enableVibration(false);
+
+            notificationManager.createNotificationChannel(notificationChannel);
+        }
+    }
+}