Fix flutter lints

Makefile

@@ -83,7 +83,7 @@ node_modules:
 
 printing/example/.metadata:
 	cd printing/example; flutter create -t app --no-overwrite --org net.nfet --project-name example .
-	rm -rf printing/example/test
+	rm -rf printing/example/test printing/example/integration_test
 
 pdf/pubspec.lock: pdf/pubspec.yaml
 	cd pdf; dart pub get

pdf/lib/src/exif.dart

@@ -257,11 +257,11 @@ orientation: $orientation''';
           return <int>[numerator, denominator];
         }
         final offset = valueOffset;
-        final result = List<List<int>>(numValues);
+        final result = <List<int>>[];
         for (var i = 0; i < result.length; ++i) {
           final numerator = file.getUint32(offset + i * 8, bigEnd);
           final denominator = file.getUint32(offset + i * 8 + 4, bigEnd);
-          result[i] = <int>[numerator, denominator];
+          result.add(<int>[numerator, denominator]);
         }
         return result;
       case 9: // slong, 32 bit signed int
@@ -281,11 +281,11 @@ orientation: $orientation''';
           return <int>[numerator, denominator];
         }
         final offset = valueOffset;
-        final result = List<List<int>>(numValues);
+        final result = <List<int>>[];
         for (var i = 0; i < result.length; ++i) {
           final numerator = file.getInt32(offset + i * 8, bigEnd);
           final denominator = file.getInt32(offset + i * 8 + 4, bigEnd);
-          result[i] = <int>[numerator, denominator];
+          result.add(<int>[numerator, denominator]);
         }
         return result;
       case 11: // single float, 32 bit float

pdf/lib/widgets/partitions.dart

@@ -80,7 +80,8 @@ class Partition implements SpanningWidget {
 }
 
 class _PartitionsContext extends WidgetContext {
-  _PartitionsContext(int count) : partitionContext = List<WidgetContext>(count);
+  _PartitionsContext(int count)
+      : partitionContext = List<WidgetContext>.filled(count, null);
 
   final List<WidgetContext> partitionContext;
 

printing/lib/src/printing_web.dart

@@ -15,7 +15,6 @@
  */
 
 import 'dart:async';
-import 'dart:convert';
 import 'dart:html' as html;
 import 'dart:html';
 import 'dart:io';