From ae5527471cf8c07cce6f4b609fbcdd2e2c903500 Mon Sep 17 00:00:00 2001
From: Ryan <fauxpark@gmail.com>
Date: Wed, 21 Jul 2021 17:30:42 +1000
Subject: [PATCH] [Windows] Improve USB device detection (#282)

---
 windows/QMK Toolbox/MainWindow.cs | 17 +++-----------
 windows/QMK Toolbox/USB.cs        | 37 +++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 14 deletions(-)

diff --git a/windows/QMK Toolbox/MainWindow.cs b/windows/QMK Toolbox/MainWindow.cs
index 9216e87192..4d6a020cf9 100644
--- a/windows/QMK Toolbox/MainWindow.cs	
+++ b/windows/QMK Toolbox/MainWindow.cs	
@@ -120,7 +120,7 @@ public MainWindow(string path) : this()
             _usb = new Usb(_flasher, _printer);
             _flasher.Usb = _usb;
 
-            StartListeningForDeviceEvents();
+            _usb.StartListeningForDeviceEvents(DeviceEvent);
         }
 
         private void MainWindow_FormClosing(object sender, FormClosingEventArgs e)
@@ -129,6 +129,8 @@ private void MainWindow_FormClosing(object sender, FormClosingEventArgs e)
             Settings.Default.hexFileCollection = arraylist;
             Settings.Default.targetSetting = mcuBox.GetItemText(mcuBox.SelectedItem);
             Settings.Default.Save();
+
+            _usb.StopListeningForDeviceEvents();
         }
 
         private void MainWindow_Load(object sender, EventArgs e)
@@ -565,19 +567,6 @@ private void DeviceEvent(object sender, EventArrivedEventArgs e)
             }
         }
 
-        private void StartListeningForDeviceEvents()
-        {
-            StartManagementEventWatcher("__InstanceCreationEvent");
-            StartManagementEventWatcher("__InstanceDeletionEvent");
-        }
-
-        private void StartManagementEventWatcher(string eventType)
-        {
-            var watcher = new ManagementEventWatcher($"SELECT * FROM {eventType} WITHIN 2 WHERE TargetInstance ISA 'Win32_PnPEntity' AND TargetInstance.DeviceID LIKE 'USB%'");
-            watcher.EventArrived += DeviceEvent;
-            watcher.Start();
-        }
-
         private void autoflashCheckbox_CheckedChanged(object sender, EventArgs e)
         {
             if (autoflashCheckbox.Checked)
diff --git a/windows/QMK Toolbox/USB.cs b/windows/QMK Toolbox/USB.cs
index 5acbe32cbf..ad9b97be68 100644
--- a/windows/QMK Toolbox/USB.cs	
+++ b/windows/QMK Toolbox/USB.cs	
@@ -16,12 +16,49 @@ public class Usb
         private readonly Printing _printer;
         private readonly Regex DeviceIdRegex = new Regex(@"USB\\VID_([0-9A-F]+).*PID_([0-9A-F]+).*REV_([0-9A-F]+).*");
 
+        private ManagementEventWatcher deviceConnectedWatcher;
+        private ManagementEventWatcher deviceDisconnectedWatcher;
+
         public Usb(Flashing flasher, Printing printer)
         {
             _flasher = flasher;
             _printer = printer;
         }
 
+        public  void StartListeningForDeviceEvents(EventArrivedEventHandler handler)
+        {
+            if (deviceConnectedWatcher == null)
+            {
+                deviceConnectedWatcher = StartManagementEventWatcher("__InstanceCreationEvent", handler);
+            }
+
+            if (deviceDisconnectedWatcher == null)
+            {
+                deviceDisconnectedWatcher = StartManagementEventWatcher("__InstanceDeletionEvent", handler);
+            }
+        }
+
+        public void StopListeningForDeviceEvents()
+        {
+            if (deviceConnectedWatcher != null)
+            {
+                deviceConnectedWatcher.Stop();
+            }
+
+            if (deviceDisconnectedWatcher != null)
+            {
+                deviceDisconnectedWatcher.Stop();
+            }
+        }
+
+        private ManagementEventWatcher StartManagementEventWatcher(string eventType, EventArrivedEventHandler handler)
+        {
+            var watcher = new ManagementEventWatcher($"SELECT * FROM {eventType} WITHIN 2 WHERE TargetInstance ISA 'Win32_PnPEntity' AND TargetInstance.DeviceID LIKE 'USB%'");
+            watcher.EventArrived += handler;
+            watcher.Start();
+            return watcher;
+        }
+
         public bool DetectBootloaderFromCollection(ManagementObjectCollection collection, bool connected = true)
         {
             var found = false;