Fix: Plugin GUI X button now closes window — custom DocumentWindow with closeButtonPressed override

Source/Helper/HelperPluginHost.cpp

@@ -4,6 +4,21 @@
 #include <pthread.h>
 #include <sched.h>
 
+// Custom window that actually closes when you click X
+class PluginGuiWindow : public juce::DocumentWindow
+{
+public:
+    PluginGuiWindow(const juce::String& name)
+        : DocumentWindow(name, juce::Colour(0xff1a1a2e),
+                         DocumentWindow::closeButton | DocumentWindow::minimiseButton)
+    {}
+
+    void closeButtonPressed() override
+    {
+        setVisible(false);
+    }
+};
+
 HelperPluginHost::HelperPluginHost()
 {
     #if JUCE_PLUGINHOST_VST3
@@ -119,7 +134,6 @@ void HelperPluginHost::stopProcessing()
 
 void HelperPluginHost::audioProcessingLoop()
 {
-    // Set realtime thread priority using native macOS/POSIX API
     struct sched_param param;
     param.sched_priority = sched_get_priority_max(SCHED_FIFO);
     pthread_setschedparam(pthread_self(), SCHED_FIFO, &param);
@@ -227,20 +241,23 @@ bool HelperPluginHost::setParams(const std::map<int, float>& values)
 void HelperPluginHost::showGui()
 {
     if (!plugin || !plugin->hasEditor()) return;
-    if (guiWindow) return;
 
     juce::MessageManager::callAsync([this]()
     {
         if (!plugin) return;
 
+        // If window exists but hidden, just show it again
+        if (guiWindow)
+        {
+            guiWindow->setVisible(true);
+            guiWindow->toFront(true);
+            return;
+        }
+
         auto* editor = plugin->createEditor();
         if (!editor) return;
 
-        guiWindow = std::make_unique<juce::DocumentWindow>(
-            plugin->getName(),
-            juce::Colour(0xff1a1a2e),
-            juce::DocumentWindow::closeButton | juce::DocumentWindow::minimiseButton);
-
+        guiWindow = std::make_unique<PluginGuiWindow>(plugin->getName());
         guiWindow->setContentOwned(editor, true);
         guiWindow->setResizable(true, true);
         guiWindow->centreWithSize(editor->getWidth(), editor->getHeight());