From 312c4c5c063e99967674d9f897ee632a67ccb042 Mon Sep 17 00:00:00 2001
From: Chris Kaczor <chris@kaczorzoo.net>
Date: Mon, 20 Dec 2021 16:21:01 -0500
Subject: [PATCH] Handle device removal/addition

---
 App.xaml.cs          | 19 +++++-----------
 Common               |  2 +-
 Common.Wpf           |  2 +-
 LightController.cs   | 14 ++++++++++++
 UsbService.cs        | 52 ++++++++++++++++++++++++++++++++++++++++++++
 WorkIndicator.csproj |  1 +
 6 files changed, 74 insertions(+), 16 deletions(-)
 create mode 100644 UsbService.cs

diff --git a/App.xaml.cs b/App.xaml.cs
index 34192a9..80e10fe 100644
--- a/App.xaml.cs
+++ b/App.xaml.cs
@@ -59,22 +59,13 @@ namespace WorkIndicator
             // Initialize the tray icon
             TrayIcon.Initialize();
 
-            Task.Factory.StartNew(CheckUpdate).ContinueWith(task => StartApplication(task.Result.Result));
-        }
+            // Set automatic start into the registry
+            Current.SetStartWithWindows(Settings.Default.StartWithWindows);
 
-        private void StartApplication(bool updateRequired)
-        {
-            if (updateRequired)
-                return;
+            // Initialize the light controller
+            LightController.Initialize();
 
-            Task.Factory.StartNew(() =>
-            {
-                // Set automatic start into the registry
-                Current.SetStartWithWindows(Settings.Default.StartWithWindows);
-
-                // Initialize the light controller
-                LightController.Initialize();
-            });
+            Task.Factory.StartNew(CheckUpdate);
         }
 
         private void HandleCommandLine(object sender, InterprocessMessageListener.InterprocessMessageEventArgs e)
diff --git a/Common b/Common
index 81856b2..4da8f42 160000
--- a/Common
+++ b/Common
@@ -1 +1 @@
-Subproject commit 81856b27001b1e271184f8dce84e7e061fe4d557
+Subproject commit 4da8f426c0f23f7734aec7c1172a9832afc3a44d
diff --git a/Common.Wpf b/Common.Wpf
index 8a82786..a71af7d 160000
--- a/Common.Wpf
+++ b/Common.Wpf
@@ -1 +1 @@
-Subproject commit 8a82786166d49271b22e48aba0ca34cf8d366872
+Subproject commit a71af7de8e59b35c02040735728076b00a6402a3
diff --git a/LightController.cs b/LightController.cs
index f49c7d0..8193ae0 100644
--- a/LightController.cs
+++ b/LightController.cs
@@ -15,11 +15,15 @@ namespace WorkIndicator
     public static class LightController
     {
         private static StoplightIndicator _stoplightIndicator;
+        private static UsbService _usbService;
         private static bool _initialized;
         private static Status _status = Status.Auto;
 
         public static void Initialize()
         {
+            _usbService = new UsbService();
+            _usbService.DevicesChanged += DevicesChanged;
+
             _stoplightIndicator = new StoplightIndicator();
             _stoplightIndicator.SetLight(StoplightIndicator.Light.Yellow, StoplightIndicator.LightState.On);
 
@@ -29,6 +33,14 @@ namespace WorkIndicator
             _initialized = true;
         }
 
+        private static void DevicesChanged()
+        {
+            _stoplightIndicator?.Dispose();
+            _stoplightIndicator = new StoplightIndicator();
+    
+            UpdateLights();
+        }
+
         private static void AudioWatcher_MicrophoneInUseChanged(bool microphoneInUse)
         {
             UpdateLights();
@@ -44,6 +56,8 @@ namespace WorkIndicator
             _stoplightIndicator.SetLights(StoplightIndicator.LightState.Off, StoplightIndicator.LightState.Off, StoplightIndicator.LightState.Off);
             _stoplightIndicator.Dispose();
 
+            _usbService.Dispose();
+
             _initialized = false;
         }
 
diff --git a/UsbService.cs b/UsbService.cs
new file mode 100644
index 0000000..9cd0075
--- /dev/null
+++ b/UsbService.cs
@@ -0,0 +1,52 @@
+using System;
+using System.Windows.Forms;
+
+namespace WorkIndicator
+{
+    internal class UsbService : NativeWindow, IDisposable
+    {
+        public event Action DevicesChanged;
+
+        private const int WM_DEVICECHANGE = 0x0219;
+        private const int DBT_DEVICEARRIVAL = 0x8000;
+        private const int DBT_DEVICEREMOVECOMPLETE = 0x8004;
+        private const int DBT_DEVNODES_CHANGED = 0x0007;
+
+        private bool _isDisposed;
+
+        internal UsbService()
+        {
+            base.CreateHandle(new CreateParams());
+        }
+
+
+        protected override void WndProc(ref Message msg)
+        {
+            base.WndProc(ref msg);
+
+            if (msg.Msg == WM_DEVICECHANGE)
+            {
+                switch (msg.WParam.ToInt32())
+                {
+                    case DBT_DEVNODES_CHANGED:
+                    case DBT_DEVICEARRIVAL:
+                    case DBT_DEVICEREMOVECOMPLETE:
+                        DevicesChanged?.Invoke();
+                        break;
+                }
+            }
+        }
+
+        public void Dispose()
+        {
+            if (!_isDisposed)
+            {
+                base.DestroyHandle();
+
+                _isDisposed = true;
+
+                GC.SuppressFinalize(this);
+            }
+        }
+    }
+}
diff --git a/WorkIndicator.csproj b/WorkIndicator.csproj
index 607d63e..7e42f81 100644
--- a/WorkIndicator.csproj
+++ b/WorkIndicator.csproj
@@ -144,6 +144,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="UpdateCheck.cs" />
+    <Compile Include="UsbService.cs" />
     <Page Include="App.xaml">
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>