Added image picker

lib/utils/files_utils.dart

@@ -0,0 +1,50 @@
+import 'dart:io';
+
+import 'package:comunic/utils/intl_utils.dart';
+import 'package:flutter/material.dart';
+import 'package:image_picker/image_picker.dart';
+
+/// Files utilities
+///
+/// @author Pierre HUBERT
+
+enum _ChooseImageSource { GALLERY, CAMERA }
+
+/// Ask the user to choose an image, either from the gallery or using the camera
+///
+/// Returns null in case of failure
+Future<File> pickImage(BuildContext context) async {
+  /// First, we ask the user to choose between image picker and camera
+  final result = await showDialog<_ChooseImageSource>(
+    context: context,
+    builder: (c) {
+      return AlertDialog(
+        title: Text(tr("Choose an image")),
+        actions: <Widget>[
+          //Gallery
+          FlatButton(
+            onPressed: () => Navigator.pop(context, _ChooseImageSource.GALLERY),
+            child: Text(
+              tr("Image gallery").toUpperCase(),
+            ),
+          ),
+
+          // Camera
+          FlatButton(
+            onPressed: () => Navigator.pop(context, _ChooseImageSource.CAMERA),
+            child: Text(
+              tr("Camera").toUpperCase(),
+            ),
+          ),
+        ],
+      );
+    },
+  );
+
+  if (result == null) return null;
+
+  return await ImagePicker.pickImage(
+      source: result == _ChooseImageSource.CAMERA
+          ? ImageSource.camera
+          : ImageSource.gallery);
+}