UZDoom · the-phinet · May 31, 2026 · May 30, 2026
diff --git a/include/zwidget/core/widget.h b/include/zwidget/core/widget.h
@@ -19,7 +19,8 @@ enum class WidgetType
 {
 	Child,
 	Window,
-	Popup
+	Popup,
+	Utility
 };
 
 enum class WidgetEvent
@@ -192,6 +193,9 @@ class Widget : DisplayWindowHost
 	virtual void OnSetFocus() { }
 	virtual void OnLostFocus() { }
 	virtual void OnEnableChanged() { }
+	void OnWindowNotified() override {};
+
+	void NotifyWindow(); // used to wake up a window from another thread
 
 	virtual void Notify(Widget* source, const WidgetEvent type) { };
 

diff --git a/include/zwidget/window/window.h b/include/zwidget/window/window.h
@@ -145,13 +145,14 @@ class DisplayWindowHost
 	virtual void OnWindowActivated() = 0;
 	virtual void OnWindowDeactivated() = 0;
 	virtual void OnWindowDpiScaleChanged() = 0;
+	virtual void OnWindowNotified() = 0;
 	virtual bool OnFileDrop(std::string path) = 0;
 };
 
 class DisplayWindow
 {
 public:
-	static std::unique_ptr<DisplayWindow> Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable);
+	static std::unique_ptr<DisplayWindow> Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable, bool utility);
 
 	static void ProcessEvents();
 	static void RunLoop();
@@ -209,6 +210,8 @@ class DisplayWindow
 
 	virtual std::vector<std::string> GetVulkanInstanceExtensions() = 0;
 	virtual VkSurfaceKHR CreateVulkanSurface(VkInstance instance) = 0;
+
+	virtual void NotifyWindow() = 0;
 };
 
 class DisplayBackend
@@ -227,7 +230,7 @@ class DisplayBackend
 	virtual bool IsWin32() { return false; }
 	virtual bool IsSDL2() { return false; }
 
-	virtual std::unique_ptr<DisplayWindow> Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable) = 0;
+	virtual std::unique_ptr<DisplayWindow> Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable, bool utility) = 0;
 	virtual void ProcessEvents() = 0;
 	virtual void RunLoop() = 0;
 	virtual void ExitLoop() = 0;

diff --git a/src/core/widget.cpp b/src/core/widget.cpp
@@ -11,7 +11,7 @@ Widget::Widget(Widget* parent, WidgetType type, RenderAPI renderAPI, bool window
 	if (type != WidgetType::Child)
 	{
 		Widget* owner = parent ? parent->Window() : nullptr;
-		DispWindow = DisplayWindow::Create(this, type == WidgetType::Popup, owner ? owner->DispWindow.get() : nullptr, renderAPI, windowResizable);
+		DispWindow = DisplayWindow::Create(this, type == WidgetType::Popup, owner ? owner->DispWindow.get() : nullptr, renderAPI, windowResizable, type == WidgetType::Utility);
 		if (renderAPI == RenderAPI::Unspecified || renderAPI == RenderAPI::Bitmap)
 		{
 			DispCanvas = Canvas::create();
@@ -1051,3 +1051,10 @@ Colorf Widget::GetStyleColor(const std::string& propertyName) const
 	WidgetStyle* style = WidgetTheme::GetTheme()->GetStyle(StyleClass);
 	return style ? style->GetColor(StyleState, propertyName) : Colorf::transparent();
 }
+
+void Widget::NotifyWindow()
+{
+	Widget* w = Window();
+	if (w && w->DispWindow)
+		w->DispWindow->NotifyWindow();
+}
diff --git a/src/window/sdl2/sdl2_display_backend.cpp b/src/window/sdl2/sdl2_display_backend.cpp
@@ -61,9 +61,9 @@ SDL2DisplayBackend::SDL2DisplayBackend()
 	}
 }
 
-std::unique_ptr<DisplayWindow> SDL2DisplayBackend::Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable)
+std::unique_ptr<DisplayWindow> SDL2DisplayBackend::Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable, bool utility)
 {
-	return std::make_unique<SDL2DisplayWindow>(windowHost, popupWindow, static_cast<SDL2DisplayWindow*>(owner), renderAPI, UIScale, resizable);
+	return std::make_unique<SDL2DisplayWindow>(windowHost, popupWindow, static_cast<SDL2DisplayWindow*>(owner), renderAPI, UIScale, resizable, utility);
 }
 
 void SDL2DisplayBackend::ProcessEvents()

diff --git a/src/window/sdl2/sdl2_display_backend.h b/src/window/sdl2/sdl2_display_backend.h
@@ -7,7 +7,7 @@ class SDL2DisplayBackend : public DisplayBackend
 public:
 	SDL2DisplayBackend();
 
-	std::unique_ptr<DisplayWindow> Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable) override;
+	std::unique_ptr<DisplayWindow> Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable, bool utility) override;
 	void ProcessEvents() override;
 	void RunLoop() override;
 	void ExitLoop() override;

diff --git a/src/window/sdl2/sdl2_display_window.cpp b/src/window/sdl2/sdl2_display_window.cpp
@@ -1,15 +1,19 @@
 #include "sdl2_display_window.h"
 #include <SDL2/SDL_events.h>
+#include <SDL2/SDL_video.h>
 #include <stdexcept>
 #include <SDL2/SDL_vulkan.h>
+#include <SDL2/SDL_hints.h>
+
+#define EVENT_NOTIFY_WINDOW SDL_USEREVENT + 100
 
 Uint32 SDL2DisplayWindow::PaintEventNumber = 0xffffffff;
 bool SDL2DisplayWindow::ExitRunLoop;
 std::unordered_map<int, SDL2DisplayWindow*> SDL2DisplayWindow::WindowList;
 
-SDL2DisplayWindow::SDL2DisplayWindow(DisplayWindowHost* windowHost, bool popupWindow, SDL2DisplayWindow* owner, RenderAPI renderAPI, double uiscale, bool resizable) : WindowHost(windowHost), UIScale(uiscale)
+SDL2DisplayWindow::SDL2DisplayWindow(DisplayWindowHost* windowHost, bool popupWindow, SDL2DisplayWindow* owner, RenderAPI renderAPI, double uiscale, bool resizable, bool utility) : WindowHost(windowHost), UIScale(uiscale)
 {
-	unsigned int flags = resizable ? (SDL_WINDOW_HIDDEN | SDL_WINDOW_RESIZABLE) : SDL_WINDOW_HIDDEN /*| SDL_WINDOW_ALLOW_HIGHDPI*/;
+	unsigned int flags = SDL_WINDOW_HIDDEN /*| SDL_WINDOW_ALLOW_HIGHDPI*/;
 	if (renderAPI == RenderAPI::Vulkan)
 		flags |= SDL_WINDOW_VULKAN;
 	else if (renderAPI == RenderAPI::OpenGL)
@@ -18,20 +22,34 @@ SDL2DisplayWindow::SDL2DisplayWindow(DisplayWindowHost* windowHost, bool popupWi
 	else if (renderAPI == RenderAPI::Metal)
 		flags |= SDL_WINDOW_METAL;
 #endif
+
+	if (resizable)
+		flags |= SDL_WINDOW_RESIZABLE;
 	if (popupWindow)
 		flags |= SDL_WINDOW_BORDERLESS;
-
-	if (renderAPI == RenderAPI::Vulkan || renderAPI == RenderAPI::OpenGL || renderAPI == RenderAPI::Metal)
+	if (utility)
 	{
-		Handle.window = SDL_CreateWindow("", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 320, 200, flags);
-		if (!Handle.window)
-			throw std::runtime_error(std::string("Unable to create SDL window:") + SDL_GetError());
+		Owner = owner;
+		flags |= (SDL_WINDOW_UTILITY | SDL_WINDOW_ALWAYS_ON_TOP | SDL_WINDOW_SKIP_TASKBAR);
 	}
-	else
+
+	Handle.window = SDL_CreateWindow("", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 320, 200, flags);
+	if (!Handle.window)
+		throw std::runtime_error(std::string("Unable to create SDL window:") + SDL_GetError());
+
+	switch (renderAPI)
 	{
-		int result = SDL_CreateWindowAndRenderer(320, 200, flags, &Handle.window, &RendererHandle);
-		if (result != 0)
-			throw std::runtime_error(std::string("Unable to create SDL window:") + SDL_GetError());
+		case RenderAPI::Vulkan:
+		case RenderAPI::OpenGL:
+		case RenderAPI::Metal:
+			break;
+		default: {
+			RendererHandle = SDL_CreateRenderer(Handle.window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
+			if (!RendererHandle)
+				RendererHandle = SDL_CreateRenderer(Handle.window, -1, SDL_RENDERER_SOFTWARE);
+			if (!RendererHandle)
+				throw std::runtime_error(std::string("Unable to create renderer: ") + SDL_GetError());
+		}
 	}
 
 	WindowList[SDL_GetWindowID(Handle.window)] = this;
@@ -78,6 +96,14 @@ VkSurfaceKHR SDL2DisplayWindow::CreateVulkanSurface(VkInstance instance)
 	return surfaceHandle;
 }
 
+void SDL2DisplayWindow::NotifyWindow()
+{
+	SDL_Event e;
+	SDL_zero(e);
+	e.type = EVENT_NOTIFY_WINDOW;
+	SDL_PushEvent(&e);
+}
+
 void SDL2DisplayWindow::SetWindowTitle(const std::string& text)
 {
 	SDL_SetWindowTitle(Handle.window, text.c_str());
@@ -112,7 +138,21 @@ void SDL2DisplayWindow::SetClientFrame(const Rect& box)
 
 void SDL2DisplayWindow::Show()
 {
+	if (Owner)
+	{
+		SDL_SetWindowModalFor(Handle.window, Owner->Handle.window);
+		SDL_SetWindowAlwaysOnTop(Handle.window, SDL_TRUE);
+	}
+
+	// this is a hack, but it seems to prevent unpainted windows on my pc
 	SDL_ShowWindow(Handle.window);
+	SDL_RaiseWindow(Handle.window);
+	SDL_Delay(10);
+	WindowHost->OnWindowGeometryChanged();
+	WindowHost->OnWindowPaint();
+	SDL_Delay(10);
+	Update();
+	ProcessEvents();
 }
 
 void SDL2DisplayWindow::Restore()
@@ -210,8 +250,14 @@ bool SDL2DisplayWindow::GetKeyState(InputKey key)
 	const Uint8* state = SDL_GetKeyboardState(&numkeys);
 	if (!state) return false;
 
-	SDL_Scancode index = InputKeyToScancode(key);
-	return (index < numkeys) ? state[index] != 0 : false;
+	auto test = [numkeys, state](InputKey key) {
+		SDL_Scancode index = InputKeyToScancode(key);
+		return (index < numkeys) ? state[index] != 0 : false;
+	};
+
+	if (key == InputKey::Ctrl) return test(key) || test(InputKey::LControl) || test(InputKey::RControl);
+	if (key == InputKey::Shift) return test(key) || test(InputKey::LShift) || test(InputKey::RShift);
+	return test(key);
 }
 
 Rect SDL2DisplayWindow::GetWindowFrame() const
@@ -495,6 +541,9 @@ void SDL2DisplayWindow::OnWindowEvent(const SDL_WindowEvent& event)
 {
 	switch (event.event)
 	{
+		case EVENT_NOTIFY_WINDOW:
+			WindowHost->OnWindowNotified();
+			break;
 		case SDL_WINDOWEVENT_CLOSE:
 			WindowHost->OnWindowClose();
 			break;

diff --git a/src/window/sdl2/sdl2_display_window.h b/src/window/sdl2/sdl2_display_window.h
@@ -8,7 +8,7 @@
 class SDL2DisplayWindow : public DisplayWindow
 {
 public:
-	SDL2DisplayWindow(DisplayWindowHost* windowHost, bool popupWindow, SDL2DisplayWindow* owner, RenderAPI renderAPI, double uiscale, bool resizable);
+	SDL2DisplayWindow(DisplayWindowHost* windowHost, bool popupWindow, SDL2DisplayWindow* owner, RenderAPI renderAPI, double uiscale, bool resizable, bool utility);
 	~SDL2DisplayWindow();
 
 	void SetWindowTitle(const std::string& text) override;
@@ -55,6 +55,8 @@ class SDL2DisplayWindow : public DisplayWindow
 
 	std::vector<std::string> GetVulkanInstanceExtensions() override;
 	VkSurfaceKHR CreateVulkanSurface(VkInstance instance) override;
+
+	virtual void NotifyWindow() override;
 
 	static void DispatchEvent(const SDL_Event& event);
 	static SDL2DisplayWindow* FindEventWindow(const SDL_Event& event);
@@ -95,6 +97,7 @@ class SDL2DisplayWindow : public DisplayWindow
 	static Uint32 ExecTimer(Uint32 interval, void* id);
 
 	DisplayWindowHost* WindowHost = nullptr;
+	SDL2DisplayWindow* Owner = nullptr;
 	SDL2NativeHandle Handle;
 	SDL_Renderer* RendererHandle = nullptr;
 	SDL_Texture* BackBufferTexture = nullptr;

diff --git a/src/window/win32/win32_display_backend.cpp b/src/window/win32/win32_display_backend.cpp
@@ -5,9 +5,9 @@
 #include "win32_save_file_dialog.h"
 #include "win32_open_folder_dialog.h"
 
-std::unique_ptr<DisplayWindow> Win32DisplayBackend::Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable)
+std::unique_ptr<DisplayWindow> Win32DisplayBackend::Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable, bool utility)
 {
-	return std::make_unique<Win32DisplayWindow>(windowHost, popupWindow, static_cast<Win32DisplayWindow*>(owner), renderAPI, resizable);
+	return std::make_unique<Win32DisplayWindow>(windowHost, popupWindow, static_cast<Win32DisplayWindow*>(owner), renderAPI, resizable, utility);
 }
 
 void Win32DisplayBackend::ProcessEvents()

diff --git a/src/window/win32/win32_display_backend.h b/src/window/win32/win32_display_backend.h
@@ -5,7 +5,7 @@
 class Win32DisplayBackend : public DisplayBackend
 {
 public:
-	std::unique_ptr<DisplayWindow> Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable) override;
+	std::unique_ptr<DisplayWindow> Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable, bool utility) override;
 	void ProcessEvents() override;
 	void RunLoop() override;
 	void ExitLoop() override;

diff --git a/src/window/win32/win32_display_window.cpp b/src/window/win32/win32_display_window.cpp
@@ -10,6 +10,8 @@
 
 #pragma comment(lib, "dwmapi.lib")
 
+#define MESSAGE_NOTIFY_WINDOW (WM_APP + 100)
+
 #ifndef HID_USAGE_PAGE_GENERIC
 #define HID_USAGE_PAGE_GENERIC		((USHORT) 0x01)
 #endif
@@ -78,7 +80,7 @@ static double DelayLoadGetDpiScale(HWND hwnd)
 	}
 }
 
-Win32DisplayWindow::Win32DisplayWindow(DisplayWindowHost* windowHost, bool popupWindow, Win32DisplayWindow* owner, RenderAPI renderAPI, bool resizable) : WindowHost(windowHost), PopupWindow(popupWindow)
+Win32DisplayWindow::Win32DisplayWindow(DisplayWindowHost* windowHost, bool popupWindow, Win32DisplayWindow* owner, RenderAPI renderAPI, bool resizable, bool utility) : WindowHost(windowHost), PopupWindow(popupWindow)
 {
 	Windows.push_front(this);
 	WindowsIterator = Windows.begin();
@@ -585,6 +587,10 @@ LRESULT Win32DisplayWindow::OnWindowMessage(UINT msg, WPARAM wparam, LPARAM lpar
 		}
 		return 0;
 	}
+	else if (msg == MESSAGE_NOTIFY_WINDOW)
+	{
+		WindowHost->OnWindowNotified();
+	}
 	else if (msg == WM_ACTIVATE)
 	{
 		WindowHost->OnWindowActivated();
@@ -949,6 +955,11 @@ VkSurfaceKHR Win32DisplayWindow::CreateVulkanSurface(VkInstance instance)
 	return surface;
 }
 
+void Win32DisplayWindow::NotifyWindow()
+{
+	PostMessageA(WindowHandle.hwnd, MESSAGE_NOTIFY_WINDOW, 0, 0);
+}
+
 std::vector<std::string> Win32DisplayWindow::GetVulkanInstanceExtensions()
 {
 	return { "VK_KHR_surface", "VK_KHR_win32_surface" };

diff --git a/src/window/win32/win32_display_window.h b/src/window/win32/win32_display_window.h
@@ -10,7 +10,7 @@
 class Win32DisplayWindow : public DisplayWindow
 {
 public:
-	Win32DisplayWindow(DisplayWindowHost* windowHost, bool popupWindow, Win32DisplayWindow* owner, RenderAPI renderAPI, bool resizable);
+	Win32DisplayWindow(DisplayWindowHost* windowHost, bool popupWindow, Win32DisplayWindow* owner, RenderAPI renderAPI, bool resizable, bool utility);
 	~Win32DisplayWindow();
 
 	void SetWindowTitle(const std::string& text) override;
@@ -62,6 +62,8 @@ class Win32DisplayWindow : public DisplayWindow
 	std::vector<std::string> GetVulkanInstanceExtensions() override;
 	VkSurfaceKHR CreateVulkanSurface(VkInstance instance) override;
 
+	virtual void NotifyWindow() override;
+
 	static void ProcessEvents();
 	static void RunLoop();
 	static void ExitLoop();

diff --git a/src/window/window.cpp b/src/window/window.cpp
@@ -7,9 +7,9 @@
 #include "core/widget.h"
 #include <stdexcept>
 
-std::unique_ptr<DisplayWindow> DisplayWindow::Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable)
+std::unique_ptr<DisplayWindow> DisplayWindow::Create(DisplayWindowHost* windowHost, bool popupWindow, DisplayWindow* owner, RenderAPI renderAPI, bool resizable, bool utility)
 {
-	return DisplayBackend::Get()->Create(windowHost, popupWindow, owner, renderAPI, resizable);
+	return DisplayBackend::Get()->Create(windowHost, popupWindow, owner, renderAPI, resizable, utility);
 }
 
 void DisplayWindow::ProcessEvents()