add optional mediumType parameter of getAlbumThumbnail api method to display video thumbnail correctly

android/src/main/kotlin/com/morbit/photogallery/PhotoGalleryPlugin.kt

@@ -122,10 +122,11 @@ class PhotoGalleryPlugin : FlutterPlugin, MethodCallHandler {
             }
             "getAlbumThumbnail" -> {
                 val albumId = call.argument<String>("albumId")
+                val mediumType = call.argument<String>("mediumType")
                 val width = call.argument<Int>("width")
                 val height = call.argument<Int>("height")
                 BackgroundAsyncTask({
-                    getAlbumThumbnail(albumId!!, width, height)
+                    getAlbumThumbnail(albumId!!, mediumType, width, height)
                 }, { v ->
                     result.success(v)
                 })
@@ -461,7 +462,22 @@ class PhotoGalleryPlugin : FlutterPlugin, MethodCallHandler {
         return byteArray
     }
 
-    private fun getAlbumThumbnail(albumId: String, width: Int?, height: Int?): ByteArray? {
+    private fun getAlbumThumbnail(albumId: String, mediumType: String?, width: Int?, height: Int?): ByteArray? {
+        return when (mediumType) {
+            imageType -> {
+                getImageAlbumThubnail(albumId, width, height)
+            }
+            videoType -> {
+                getVideoAlbumThubnail(albumId, width, height)
+            }
+            else -> {
+                getImageAlbumThubnail(albumId, width, height)
+                    ?: getVideoAlbumThubnail(albumId, width, height)
+            }
+        }
+    }
+
+    private fun getImageAlbumThubnail(albumId: String, width: Int?, height: Int?): ByteArray? {
         return this.context?.run {
             val imageCursor = this.contentResolver.query(
                 MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
@@ -478,6 +494,12 @@ class PhotoGalleryPlugin : FlutterPlugin, MethodCallHandler {
                 }
             }
 
+            return null
+        }
+    }
+
+    private fun getVideoAlbumThubnail(albumId: String, width: Int?, height: Int?): ByteArray? {
+        return this.context?.run {
             val videoCursor = this.contentResolver.query(
                 MediaStore.Video.Media.EXTERNAL_CONTENT_URI,
                 arrayOf(MediaStore.Video.Media._ID),
@@ -493,7 +515,7 @@ class PhotoGalleryPlugin : FlutterPlugin, MethodCallHandler {
                 }
             }
 
-            return@run null
+            return null
         }
     }
 

ios/Classes/SwiftPhotoGalleryPlugin.swift

@@ -52,11 +52,13 @@ public class SwiftPhotoGalleryPlugin: NSObject, FlutterPlugin {
     else if(call.method == "getAlbumThumbnail") {
       let arguments = call.arguments as! Dictionary<String, AnyObject>
       let albumId = arguments["albumId"] as! String
+      let mediumType = arguments["mediumType"] as? String
       let width = arguments["width"] as? Int
       let height = arguments["height"] as? Int
       let highQuality = arguments["highQuality"] as? Bool
       getAlbumThumbnail(
         albumId: albumId,
+        mediumType: mediumType,
         width: width,
         height: height,
         highQuality: highQuality,
@@ -251,6 +253,7 @@ public class SwiftPhotoGalleryPlugin: NSObject, FlutterPlugin {
   
   private func getAlbumThumbnail(
     albumId: String,
+    mediumType: String?,
     width: Int?,
     height: Int?,
     highQuality: Bool?,
@@ -258,6 +261,9 @@ public class SwiftPhotoGalleryPlugin: NSObject, FlutterPlugin {
   ) {
     let manager = PHImageManager.default()
     let fetchOptions = PHFetchOptions()
+    if (mediumType != nil) {
+      fetchOptions.predicate = self.predicateFromMediumType(mediumType: mediumType!)
+    }
     fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]
     if #available(iOS 9, *) {
       fetchOptions.fetchLimit = 1

lib/photo_gallery.dart

@@ -85,6 +85,7 @@ class PhotoGallery {
   /// Get album thumbnail by album id
   static Future<List<dynamic>> getAlbumThumbnail({
     @required String albumId,
+    MediumType mediumType,
     int width,
     int height,
     bool highQuality,
@@ -92,6 +93,7 @@ class PhotoGallery {
     assert(albumId != null);
     final bytes = await _channel.invokeMethod('getAlbumThumbnail', {
       'albumId': albumId,
+      'mediumType': mediumTypeToJson(mediumType),
       'width': width,
       'height': height,
       'highQuality': highQuality,

lib/src/image_providers/album_thumbnail_provider.dart

@@ -4,12 +4,14 @@ part of photogallery;
 class AlbumThumbnailProvider extends ImageProvider<AlbumThumbnailProvider> {
   const AlbumThumbnailProvider({
     @required this.albumId,
+    this.mediumType,
     this.height,
     this.width,
     this.highQuality = false,
   }) : assert(albumId != null);
 
   final String albumId;
+  final MediumType mediumType;
   final int height;
   final int width;
   final bool highQuality;
@@ -30,6 +32,7 @@ class AlbumThumbnailProvider extends ImageProvider<AlbumThumbnailProvider> {
     assert(key == this);
     final bytes = await PhotoGallery.getAlbumThumbnail(
       albumId: albumId,
+      mediumType: mediumType,
       height: height,
       width: width,
       highQuality: highQuality,

lib/src/models/album.dart

@@ -51,6 +51,7 @@ class Album {
   }) {
     return PhotoGallery.getAlbumThumbnail(
       albumId: id,
+      mediumType: this.mediumType,
       width: width,
       height: height,
       highQuality: highQuality,