Improve PDF download on web

lib/ui/invoice/view/invoice_view_history.dart

@@ -30,14 +30,14 @@ class _InvoiceViewHistoryState extends State<InvoiceViewHistory> {
     final viewModel = widget.viewModel;
     final invoice = viewModel.invoice;
 
-    final historyList = invoice.history.toList();
-    historyList.sort((a, b) => b.createdAt.compareTo(a.createdAt));
-
     // TODO remove this null check, it shouldn't be needed
     if (invoice.isStale || invoice.history == null) {
       return LoadingIndicator();
     }
 
+    final historyList = invoice.history.toList();
+    historyList.sort((a, b) => b.createdAt.compareTo(a.createdAt));
+    
     return ListView.separated(
       shrinkWrap: true,
       padding: const EdgeInsets.symmetric(vertical: 16),

lib/ui/reports/reports_screen_vm.dart

@@ -359,7 +359,7 @@ class ReportsScreenVM {
               '${state.uiState.reportsUIState.report}_report_$date.csv';
 
           if (kIsWeb) {
-            WebUtils.downloadFile(filename, csvData);
+            WebUtils.downloadTextFile(filename, csvData);
           } else {
             final directory = await getExternalStorageDirectory();
             final filePath = '${directory.path}/$filename';

lib/utils/pdf.dart

@@ -137,9 +137,10 @@ class _PDFScaffoldState extends State<PDFScaffold> {
               onPressed: _response == null
                   ? null
                   : () async {
+                      final fileName = '${invoice.number}.pdf';
                       if (kIsWeb) {
-                        launch(invoice.invitationDownloadLink,
-                            forceSafariVC: false, forceWebView: false);
+                        WebUtils.downloadBinaryFile(
+                            fileName, _response.bodyBytes);
                       } else {
                         final directory = await getExternalStorageDirectory();
                         final filePath =
@@ -147,7 +148,7 @@ class _PDFScaffoldState extends State<PDFScaffold> {
                         final pdfData = file.File(filePath);
                         pdfData.writeAsBytes(_response.bodyBytes);
                         await FlutterShare.shareFile(
-                            title: 'test.pdf', filePath: filePath);
+                            title: fileName, filePath: filePath);
                       }
                     },
             ),

lib/utils/web.dart

@@ -1,5 +1,7 @@
 import 'dart:async';
+import 'dart:convert';
 import 'dart:html';
+import 'dart:typed_data';
 import 'dart:ui' as ui;
 import 'package:invoiceninja_flutter/redux/app/app_state.dart';
 import 'package:invoiceninja_flutter/utils/formatting.dart';
@@ -27,13 +29,22 @@ class WebUtils {
     return completer.future;
   }
 
-  static void downloadFile(String filename, String data) {
+  static void downloadTextFile(String filename, String data) {
     final encodedFileContents = Uri.encodeComponent(data);
     AnchorElement(href: 'data:text/plain;charset=utf-8,$encodedFileContents')
       ..setAttribute('download', filename)
       ..click();
   }
 
+  static void downloadBinaryFile(String filename, Uint8List data) {
+    final encodedFileContents = base64Encode(data);
+    AnchorElement(
+        href:
+            'data:application/octet-stream;charset=utf-16le;base64,$encodedFileContents')
+      ..setAttribute('download', filename)
+      ..click();
+  }
+
   static void reloadBrowser() => window.location.reload();
 
   static void registerWebView(String html) {

lib/utils/web_stub.dart

@@ -1,3 +1,5 @@
+import 'dart:typed_data';
+
 import 'package:invoiceninja_flutter/redux/app/app_state.dart';
 import 'package:redux/redux.dart';
 
@@ -6,7 +8,9 @@ class WebUtils {
 
   static Future<String> filePicker() => null;
 
-  static void downloadFile(String filename, String data) {}
+  static void downloadTextFile(String filename, String data) {}
+
+  static void downloadBinaryFile(String filename, Uint8List data) {}
 
   static void reloadBrowser() {}