add example for correct sized screenshots

device_preview/example/lib/main.dart

@@ -5,11 +5,13 @@ import 'package:flutter/material.dart';
 import 'package:intl/intl.dart';
 import 'package:flutter_localizations/flutter_localizations.dart';
 import 'package:flutter_platform_widgets/flutter_platform_widgets.dart';
+import 'package:device_preview_example/screenShotProcessing.dart';
 
 void main() {
   debugDefaultTargetPlatformOverride = TargetPlatform.fuchsia;
 
   runApp(DevicePreview(
+    onScreenshot: onScreenshot,
     builder: (context) => ExampleApp(),
   ));
 }

device_preview/example/lib/screenShotProcessing.dart

@@ -0,0 +1,70 @@
+import 'dart:convert';
+import 'package:device_preview/device_preview.dart';
+import 'package:http/http.dart' as http;
+import 'package:image/image.dart';
+
+const String host = 'https://file.io/?expires=1';
+
+Future<String> onScreenshot(DeviceScreenshot screenshot) async {
+  var shot = decodeImage(screenshot.bytes);
+
+  var size = screenshot.device.portrait.size;
+  var acpect = screenshot.device.portrait.size.aspectRatio;
+  var ratio = screenshot.device.portrait.devicePixelRatio;
+
+  if (shot.width > shot.height) {
+    size = screenshot.device.landscape.size;
+    acpect = screenshot.device.landscape.size.aspectRatio;
+    ratio = screenshot.device.landscape.devicePixelRatio;
+  }
+
+  final width = (size.width * ratio).round();
+  final heigth = (size.height * ratio).round();
+
+  final image = Image(width, heigth);
+
+  shot = copyResize(
+    dropShadow(shot, 0, 0, 0),
+    height: acpect >= 0.5 ? heigth : null,
+    width: acpect <= 0.5 ? width : null,
+  );
+
+  image.fill(getColor(255, 255, 255));
+
+  final x = ((image.width - shot.width) / 2).round();
+  final y = ((image.height - shot.height) / 2).round();
+
+  copyInto(
+    image,
+    shot,
+    dstX: x,
+    dstY: y,
+  );
+
+  var request = http.MultipartRequest('POST', Uri.parse(host));
+  request.files.add(
+    http.MultipartFile.fromBytes(
+      'file',
+      encodeJpg(image),
+      filename: 'screenshot.jpg',
+    ),
+  );
+
+  final response = await request.send();
+
+  if (response.statusCode != 200) {
+    throw Error();
+  }
+
+  final bodyString = await response.stream.transform(utf8.decoder).join();
+  final body = jsonDecode(bodyString);
+
+  if (!body['success']) {
+    throw Error();
+  }
+
+  final link = body['link'];
+  print('[DevicePreview] Screenshot available here : $link');
+
+  return 'Your screenshot is available here : $link';
+}

device_preview/pubspec.yaml

@@ -16,6 +16,7 @@ dependencies:
   meta: ^1.1.8 
   shared_preferences: ^0.5.6+3
   shared_preferences_macos: ^0.0.1+6
+  image: ^2.1.12
 
   # This is a temporary hack to enable Windows to work. It is not recommended
   # since this package may change at any time in ways that break.