Made build portable

dependencies/bitsdojo_window-0.1.5/lib/src/app_window.dart

@@ -0,0 +1,43 @@
+import 'package:bitsdojo_window_platform_interface/bitsdojo_window_platform_interface.dart';
+import 'package:bitsdojo_window_platform_interface/method_channel_bitsdojo_window.dart';
+import 'package:bitsdojo_window_windows/bitsdojo_window_windows.dart';
+import 'package:bitsdojo_window_macos/bitsdojo_window_macos.dart';
+import 'package:bitsdojo_window_linux/bitsdojo_window_linux.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter/foundation.dart' show kIsWeb;
+import 'dart:io' show Platform;
+
+bool _platformInstanceNeedsInit = true;
+
+void initPlatformInstance() {
+  if (!kIsWeb) {
+    if (BitsdojoWindowPlatform.instance is MethodChannelBitsdojoWindow) {
+      if (Platform.isWindows) {
+        BitsdojoWindowPlatform.instance = BitsdojoWindowWindows();
+      } else if (Platform.isMacOS) {
+        BitsdojoWindowPlatform.instance = BitsdojoWindowMacOS();
+      } else if (Platform.isLinux) {
+        BitsdojoWindowPlatform.instance = BitsdojoWindowLinux();
+      }
+    }
+  } else {
+    BitsdojoWindowPlatform.instance = BitsdojoWindowPlatformNotImplemented();
+  }
+}
+
+BitsdojoWindowPlatform get _platform {
+  var needsInit = _platformInstanceNeedsInit;
+  if (needsInit) {
+    initPlatformInstance();
+    _platformInstanceNeedsInit = false;
+  }
+  return BitsdojoWindowPlatform.instance;
+}
+
+void doWhenWindowReady(VoidCallback callback) {
+  _platform.doWhenWindowReady(callback);
+}
+
+DesktopWindow get appWindow {
+  return _platform.appWindow;
+}