Make it possible to pass bytes

packages/firebase_ml_vision/lib/firebase_ml_vision.dart

@@ -7,6 +7,7 @@ library firebase_ml_vision;
 import 'dart:async';
 import 'dart:io';
 import 'dart:math';
+import 'dart:typed_data';
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';

packages/firebase_ml_vision/lib/src/barcode_detector.dart

@@ -189,7 +189,9 @@ class BarcodeDetector extends FirebaseVisionDetector {
     final List<dynamic> reply = await FirebaseVision.channel.invokeMethod(
       'BarcodeDetector#detectInImage',
       <String, dynamic>{
-        'path': visionImage.imageFile.path,
+        'type': _enumToString(visionImage._type),
+        'path': visionImage._imageFile.path,
+        'bytes': visionImage._bytes,
         'options': <String, dynamic>{
           'barcodeFormats': options.barcodeFormats.value,
         },

packages/firebase_ml_vision/lib/src/face_detector.dart

@@ -44,7 +44,9 @@ class FaceDetector extends FirebaseVisionDetector {
     final List<dynamic> reply = await FirebaseVision.channel.invokeMethod(
       'FaceDetector#detectInImage',
       <String, dynamic>{
-        'path': visionImage.imageFile.path,
+        'type': _enumToString(visionImage._type),
+        'path': visionImage._imageFile.path,
+        'bytes': visionImage._bytes,
         'options': <String, dynamic>{
           'enableClassification': options.enableClassification,
           'enableLandmarks': options.enableLandmarks,

packages/firebase_ml_vision/lib/src/firebase_vision.dart

@@ -4,6 +4,8 @@
 
 part of firebase_ml_vision;
 
+enum _FirebaseVisionImageType { file, bytes }
+
 /// The Firebase machine learning vision API.
 ///
 /// You can get an instance by calling [FirebaseVision.instance] and then get
@@ -56,22 +58,44 @@ class FirebaseVision {
 ///
 /// Create an instance by calling one of the factory constructors.
 class FirebaseVisionImage {
-  FirebaseVisionImage._(this.imageFile);
+  FirebaseVisionImage._({
+    @required _FirebaseVisionImageType type,
+    File imageFile,
+    Uint8List bytes,
+  })  : _imageFile = imageFile,
+        _bytes = bytes,
+        _type = type;
 
   /// Construct a [FirebaseVisionImage] from a file.
   factory FirebaseVisionImage.fromFile(File imageFile) {
     assert(imageFile != null);
-    return FirebaseVisionImage._(imageFile);
+    return FirebaseVisionImage._(
+      type: _FirebaseVisionImageType.file,
+      imageFile: imageFile,
+    );
   }
 
   /// Construct a [FirebaseVisionImage] from a file path.
   factory FirebaseVisionImage.fromFilePath(String imagePath) {
     assert(imagePath != null);
-    return FirebaseVisionImage._(File(imagePath));
+    return FirebaseVisionImage._(
+      type: _FirebaseVisionImageType.file,
+      imageFile: File(imagePath),
+    );
+  }
+
+  /// Construct a [FirebaseVisionImage] from a list of bytes.
+  factory FirebaseVisionImage.fromBytes(Uint8List bytes) {
+    assert(bytes != null);
+    return FirebaseVisionImage._(
+      type: _FirebaseVisionImageType.bytes,
+      bytes: bytes,
+    );
   }
 
-  /// The file location of the image.
-  final File imageFile;
+  final File _imageFile;
+  final Uint8List _bytes;
+  final _FirebaseVisionImageType _type;
 }
 
 /// Abstract class for detectors in [FirebaseVision] API.

packages/firebase_ml_vision/lib/src/label_detector.dart

@@ -34,7 +34,9 @@ class LabelDetector extends FirebaseVisionDetector {
     final List<dynamic> reply = await FirebaseVision.channel.invokeMethod(
       'LabelDetector#detectInImage',
       <String, dynamic>{
-        'path': visionImage.imageFile.path,
+        'type': _enumToString(visionImage._type),
+        'path': visionImage._imageFile.path,
+        'bytes': visionImage._bytes,
         'options': <String, dynamic>{
           'confidenceThreshold': options.confidenceThreshold,
         },
@@ -80,7 +82,9 @@ class CloudLabelDetector extends FirebaseVisionDetector {
     final List<dynamic> reply = await FirebaseVision.channel.invokeMethod(
       'CloudLabelDetector#detectInImage',
       <String, dynamic>{
-        'path': visionImage.imageFile.path,
+        'type': _enumToString(visionImage._type),
+        'path': visionImage._imageFile.path,
+        'bytes': visionImage._bytes,
         'options': options._toMap(),
       },
     );

packages/firebase_ml_vision/lib/src/text_recognizer.dart

@@ -22,7 +22,9 @@ class TextRecognizer implements FirebaseVisionDetector {
         await FirebaseVision.channel.invokeMethod(
       'TextRecognizer#processImage',
       <String, dynamic>{
-        'path': visionImage.imageFile.path,
+        'type': _enumToString(visionImage._type),
+        'path': visionImage._imageFile.path,
+        'bytes': visionImage._bytes,
         'options': <String, dynamic>{},
       },
     );