use correct folder on android platform

lib/home_page.dart

@@ -1,3 +1,5 @@
+import 'dart:io';
+
 import 'package:flutter/material.dart';
 import 'package:gallery/data_provider/data_provider.dart';
 import 'package:gallery/image_grid.dart';
@@ -20,23 +22,28 @@ enum Page { local, remote }
 class _MyHomePageState extends State<MyHomePage> {
   Page page = Page.local;
 
-  final DataProvider localProvider = LocalDataProvider(getApplicationDocumentsDirectory());
+  Future<Directory> _getLocalDir() async {
+    Directory dir;
+    if (Theme.of(context).platform == TargetPlatform.android) {
+      dir = Directory("/storage/emulated/0/DCIM/");
+    } else {
+      dir = (await getDownloadsDirectory())?.parent ??
+          await getApplicationDocumentsDirectory();
+    }
+    return dir;
+  }
 
   Widget _buildPage() {
     DataProvider provider;
 
     switch (page) {
       case Page.local:
-        provider = localProvider;
+        provider = LocalDataProvider(_getLocalDir());
         break;
       case Page.remote:
         // todo do not generate a new provider on each tab switch
         provider = SSHDataProvider(
-            initialPath: "/",
-            host: "",
-            password: "",
-            port: 0,
-            username: "");
+            initialPath: "/", host: "", password: "", port: 0, username: "");
         break;
     }
     return ImageGrid(dProvider: provider);