Add support for picture attachments in notifications

Also adds a local cache for pictures which is handled by the NotificationListener itself.

If the picture is hosted in a third party content provider it gets queried.
If the Bitmap is embedded in the notification, the local cache is used.

In any case the NotificationSpec just holds a String to the absolute file path

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/externalevents/NotificationListener.java

@@ -25,9 +25,11 @@ package nodomain.freeyourgadget.gadgetbridge.externalevents;
 import android.app.Notification;
 import android.app.PendingIntent;
 import android.content.BroadcastReceiver;
+import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
+import android.database.Cursor;
 import android.graphics.Bitmap;
 import android.graphics.Color;
 import android.graphics.drawable.Drawable;
@@ -38,6 +40,7 @@ import android.os.Handler;
 import android.os.PowerManager;
 import android.os.Process;
 import android.os.UserHandle;
+import android.provider.MediaStore;
 import android.service.notification.NotificationListenerService;
 import android.service.notification.StatusBarNotification;
 
@@ -51,6 +54,10 @@ import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
 import java.time.LocalTime;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -123,6 +130,17 @@ public class NotificationListener extends NotificationListenerService {
     public static final ArrayList<String> notificationStack = new ArrayList<>();
     private static final ArrayList<Integer> notificationsActive = new ArrayList<>();
 
+    private static final Set<String> supportedPictureMimeTypes = new HashSet<String>() {{
+        add("image/"); //for im.vector.app
+        add("image/jpeg");
+        add("image/png");
+        add("image/gif");
+        add("image/bmp");
+        add("image/webp");
+    }};
+
+    private File notificationPictureCacheDirectory;
+
     private long activeCallPostTime;
     private int mLastCallCommand = CallSpec.CALL_UNDEFINED;
 
@@ -244,6 +262,8 @@ public class NotificationListener extends NotificationListenerService {
         filterLocal.addAction(ACTION_MUTE);
         filterLocal.addAction(ACTION_REPLY);
         LocalBroadcastManager.getInstance(this).registerReceiver(mReceiver, filterLocal);
+        createNotificationPictureCacheDirectory();
+        cleanUpNotificationPictureProvider();
     }
 
     @Override
@@ -251,6 +271,7 @@ public class NotificationListener extends NotificationListenerService {
         LocalBroadcastManager.getInstance(this).unregisterReceiver(mReceiver);
         notificationStack.clear();
         notificationsActive.clear();
+        cleanUpNotificationPictureProvider();
         super.onDestroy();
     }
 
@@ -674,6 +695,41 @@ public class NotificationListener extends NotificationListenerService {
             notificationSpec.body = sanitizeUnicode(contentCS.toString());
         }
 
+        NotificationCompat.MessagingStyle messagingStyle = NotificationCompat.MessagingStyle.extractMessagingStyleFromNotification(notification);
+        if (messagingStyle != null) {
+            List<NotificationCompat.MessagingStyle.Message> messages = messagingStyle.getMessages();
+            if (!messages.isEmpty()) {
+                // Get the last message (assumed to be the most recent)
+                NotificationCompat.MessagingStyle.Message lastMessage = messages.get(messages.size() - 1);
+
+                if (supportedPictureMimeTypes.contains(lastMessage.getDataMimeType())) {
+                    ContentResolver contentResolver = getContentResolver();
+                    try (Cursor cursor = contentResolver.query(lastMessage.getDataUri(), null, null, null, null)) {
+                        if (cursor != null && cursor.moveToFirst()) {
+                            int dataIndex = cursor.getColumnIndex(MediaStore.Images.Media.DATA);
+                            notificationSpec.picturePath = cursor.getString(dataIndex);
+                        }
+                    } catch (Exception e) {
+                        LOG.error(e.getMessage());
+                    }
+                }
+            }
+        }
+
+        if (extras.containsKey(NotificationCompat.EXTRA_PICTURE)) {
+            final Bitmap bmp = (Bitmap) extras.get(NotificationCompat.EXTRA_PICTURE);
+            File pictureFile = new File(this.notificationPictureCacheDirectory, String.valueOf(notificationSpec.getId()));
+
+            try (FileOutputStream fos = new FileOutputStream(pictureFile)) {
+                bmp.compress(Bitmap.CompressFormat.PNG, 100, fos);
+                notificationSpec.picturePath = pictureFile.getAbsolutePath();
+            } catch (IOException e) {
+                LOG.error("Failed to save picture to notification cache: {}", e.getMessage());
+            } finally {
+                bmp.recycle();
+            }
+        }
+
         if (notificationSpec.type == NotificationType.COL_REMINDER
                 && notificationSpec.body == null
                 && notificationSpec.title != null) {
@@ -792,6 +848,7 @@ public class NotificationListener extends NotificationListenerService {
         for (int notificationId : notificationsActive) {
             if (!activeNotificationsIds.contains(notificationId)) {
                 notificationsToRemove.add(notificationId);
+                deleteNotificationPicture(notificationId);
             }
         }
 
@@ -815,6 +872,27 @@ public class NotificationListener extends NotificationListenerService {
         }
     }
 
+    private void deleteNotificationPicture(int notificationId) {
+        File pictureFile = new File(this.notificationPictureCacheDirectory, String.valueOf(notificationId));
+        if (pictureFile.exists())
+            pictureFile.delete();
+    }
+
+    private void cleanUpNotificationPictureProvider() {
+        File[] pictureFiles = this.notificationPictureCacheDirectory.listFiles();
+        if (pictureFiles == null)
+            return;
+
+        for (File pictureFile : pictureFiles) {
+            pictureFile.delete();
+        }
+    }
+
+    private void createNotificationPictureCacheDirectory() {
+        final File cacheDir = getApplicationContext().getExternalCacheDir();
+        this.notificationPictureCacheDirectory = new File(cacheDir, "notification-pictures");
+        this.notificationPictureCacheDirectory.mkdir();
+    }
     private void logNotification(StatusBarNotification sbn, boolean posted) {
         LOG.debug(
                 "Notification {} {}: packageName={}, when={}, priority={}, category={}",

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/impl/GBDeviceService.java

@@ -179,6 +179,7 @@ public class GBDeviceService implements DeviceService {
                 .putExtra(EXTRA_NOTIFICATION_PEBBLE_COLOR, notificationSpec.pebbleColor)
                 .putExtra(EXTRA_NOTIFICATION_SOURCEAPPID, notificationSpec.sourceAppId)
                 .putExtra(EXTRA_NOTIFICATION_ICONID, notificationSpec.iconId)
+                .putExtra(NOTIFICATION_PICTURE_PATH, notificationSpec.picturePath)
                 .putExtra(EXTRA_NOTIFICATION_DNDSUPPRESSED, notificationSpec.dndSuppressed);
         invokeService(intent);
     }

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/model/DeviceService.java

@@ -99,6 +99,7 @@ public interface DeviceService extends EventHandler {
     String EXTRA_NOTIFICATION_ACTIONS = "notification_actions";
     String EXTRA_NOTIFICATION_PEBBLE_COLOR = "notification_pebble_color";
     String EXTRA_NOTIFICATION_ICONID = "notification_iconid";
+    String NOTIFICATION_PICTURE_PATH = "notification_picture_path";
     String EXTRA_NOTIFICATION_DNDSUPPRESSED = "notification_dndsuppressed";
     String EXTRA_FIND_START = "find_start";
     String EXTRA_VIBRATION_INTENSITY = "vibration_intensity";

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/model/NotificationSpec.java

@@ -48,6 +48,7 @@ public class NotificationSpec {
      */
     public int iconId;
 
+    public String picturePath;
     /**
      * The color that should be assigned to this notification when displayed on a Pebble
      */

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/DeviceCommunicationService.java

@@ -862,6 +862,7 @@ public class DeviceCommunicationService extends Service implements SharedPrefere
                 notificationSpec.flags = intentCopy.getIntExtra(EXTRA_NOTIFICATION_FLAGS, 0);
                 notificationSpec.sourceAppId = intentCopy.getStringExtra(EXTRA_NOTIFICATION_SOURCEAPPID);
                 notificationSpec.iconId = intentCopy.getIntExtra(EXTRA_NOTIFICATION_ICONID, 0);
+                notificationSpec.picturePath = intent.getStringExtra(NOTIFICATION_PICTURE_PATH);
                 notificationSpec.dndSuppressed = intentCopy.getIntExtra(EXTRA_NOTIFICATION_DNDSUPPRESSED, 0);
 
                 if (notificationSpec.type == NotificationType.GENERIC_SMS && notificationSpec.phoneNumber != null) {