docs: demonstrate integration with leanflutter/contextual_menu

closes #4

example/README.md

@@ -94,6 +94,13 @@ BetrayalLogConfig.level = "OFF";
 
 To learn more about logging in *betrayal* have a look at the implementation in [logging.dart](https://github.com/benthillerkus/betrayal/blob/main/lib/src/logging.dart).
 
+## Why is there no built-in method for opening a context menu?
+
+Because it's unrelated from displaying and managing a tray icon.
+
+There are already great plugins for doing so, such as [leanflutter/contextual_menu](https://github.com/leanflutter/contextual_menu)!<br>
+In the [select_image](https://github.com/benthillerkus/betrayal/blob/main/example/select_image) example you can see that it plays well with *betrayal*
+
 ## Why are my icons still there after restarting the app?
 
 There is no hook for plugin devs to detect a hot restart. The best we can do is to reset state once the restarted app starts to interact with the library again and to provide an optional reset method users can call before `runApp` runs.

example/select_image/README.md

@@ -4,6 +4,7 @@ This example shows you how…
 
 - …to use the imperative api in a more complex application
 - …use the `image` library to set any image from disk as a tray icon
+- …use the `contextual_menu` library to create a context menu
 
 ## WTF is going on in the code?
 

example/select_image/lib/main.dart

@@ -3,10 +3,11 @@
 import 'dart:io';
 
 import 'package:betrayal/betrayal.dart';
+import 'package:contextual_menu/contextual_menu.dart';
 import 'package:select_image/view/view.dart';
 import 'package:file_picker/file_picker.dart';
 import 'package:flutter/foundation.dart';
-import 'package:flutter/material.dart';
+import 'package:flutter/material.dart' hide MenuItem;
 import 'package:image/image.dart' as img;
 
 void main() {
@@ -152,8 +153,16 @@ class _HomeScreenState extends State<HomeScreen> {
   }
 
   void _setTrayIcon(MyData element) {
-    _icon.setTooltip(element.name ?? element.key.toString());
+    final name = element.name ?? element.key.toString();
+    _icon.setTooltip(name);
     _icon.setImage(delegate: element.delegate);
+    _icon.onSecondaryTap = (_) => popUpContextualMenu(
+        Menu(items: [
+          MenuItem(label: "select_image example app", sublabel: name),
+          MenuItem.separator(),
+          MenuItem(label: "Exit")
+        ]),
+        placement: Placement.bottomLeft);
     _icon.show();
   }
 }

example/select_image/pubspec.lock

@@ -57,6 +57,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.16.0"
+  contextual_menu:
+    dependency: "direct main"
+    description:
+      name: contextual_menu
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.1.1"
   crypto:
     dependency: transitive
     description:
@@ -156,6 +163,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.1.4"
+  menu_base:
+    dependency: transitive
+    description:
+      name: menu_base
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.1.0"
   meta:
     dependency: transitive
     description:

example/select_image/pubspec.yaml

@@ -19,6 +19,7 @@ dependencies:
     path: ../../
   file_picker: ^4.5.1
   image: ^3.1.3
+  contextual_menu: ^0.1.1
 
 dev_dependencies:
   flutter_test:

example/select_image/windows/flutter/generated_plugin_registrant.cc

@@ -7,8 +7,11 @@
 #include "generated_plugin_registrant.h"
 
 #include <betrayal/betrayal_plugin.h>
+#include <contextual_menu/contextual_menu_plugin.h>
 
 void RegisterPlugins(flutter::PluginRegistry* registry) {
   BetrayalPluginRegisterWithRegistrar(
       registry->GetRegistrarForPlugin("BetrayalPlugin"));
+  ContextualMenuPluginRegisterWithRegistrar(
+      registry->GetRegistrarForPlugin("ContextualMenuPlugin"));
 }

example/select_image/windows/flutter/generated_plugins.cmake

@@ -4,6 +4,7 @@
 
 list(APPEND FLUTTER_PLUGIN_LIST
   betrayal
+  contextual_menu
 )
 
 list(APPEND FLUTTER_FFI_PLUGIN_LIST