Add functionality to hide windows from taskbar (Windows only).

core/config/project_settings.cpp

@@ -1487,6 +1487,7 @@ ProjectSettings::ProjectSettings() {
 	GLOBAL_DEF("display/window/size/extend_to_title", false);
 	GLOBAL_DEF("display/window/size/no_focus", false);
 	GLOBAL_DEF("display/window/size/sharp_corners", false);
+	GLOBAL_DEF("display/window/size/skip_taskbar", false);
 
 	GLOBAL_DEF(PropertyInfo(Variant::INT, "display/window/size/window_width_override", PROPERTY_HINT_RANGE, "0,7680,1,or_greater"), 0); // 8K resolution
 	GLOBAL_DEF(PropertyInfo(Variant::INT, "display/window/size/window_height_override", PROPERTY_HINT_RANGE, "0,4320,1,or_greater"), 0); // 8K resolution

doc/classes/DisplayServer.xml

@@ -2145,7 +2145,11 @@
 			[b]Note:[/b] This flag is implemented on macOS and Windows.
 			[b]Note:[/b] Setting this flag will [b]NOT[/b] prevent other apps from capturing an image, it should not be used as a security measure.
 		</constant>
-		<constant name="WINDOW_FLAG_MAX" value="10" enum="WindowFlags">
+		<constant name="WINDOW_FLAG_SKIP_TASKBAR" value="10" enum="WindowFlags">
+			Window won't be visible in the taskbar or in the system's window manager's window list.
+			[b]Note:[/b] This flag is implemented only on Windows.
+		</constant>
+		<constant name="WINDOW_FLAG_MAX" value="11" enum="WindowFlags">
 			Max value of the [enum WindowFlags].
 		</constant>
 		<constant name="WINDOW_EVENT_MOUSE_ENTER" value="0" enum="WindowEvent">

doc/classes/ProjectSettings.xml

@@ -892,6 +892,10 @@
 			If [code]true[/code], the main window uses sharp corners by default.
 			[b]Note:[/b] This property is implemented only on Windows (11).
 		</member>
+		<member name="display/window/size/skip_taskbar" type="bool" setter="" getter="" default="false">
+			If [code]true[/code], the main window won't be visible in the taskbar or in the system's window manager's window list.
+			[b]Note:[/b] This property is implemented only on Windows.
+		</member>
 		<member name="display/window/size/transparent" type="bool" setter="" getter="" default="false">
 			If [code]true[/code], enables a window manager hint that the main window background [i]can[/i] be transparent. This does not make the background actually transparent. For the background to be transparent, the root viewport must also be made transparent by enabling [member rendering/viewport/transparent_background].
 			[b]Note:[/b] To use a transparent splash screen, set [member application/boot_splash/bg_color] to [code]Color(0, 0, 0, 0)[/code].

doc/classes/Window.xml

@@ -670,6 +670,11 @@
 		<member name="size" type="Vector2i" setter="set_size" getter="get_size" default="Vector2i(100, 100)">
 			The window's size in pixels.
 		</member>
+		<member name="skip_taskbar" type="bool" setter="set_flag" getter="get_flag" default="false">
+			If [code]true[/code], the [Window] won't be visible in the taskbar or in the system's window manager's window list.
+			[b]Note:[/b] This property is implemented only on Windows.
+			[b]Note:[/b] This property only works with native windows.
+		</member>
 		<member name="theme" type="Theme" setter="set_theme" getter="get_theme">
 			The [Theme] resource this node and all its [Control] and [Window] children use. If a child node has its own [Theme] resource set, theme items are merged with child's definitions having higher priority.
 			[b]Note:[/b] [Window] styles will have no effect unless the window is embedded.
@@ -861,7 +866,12 @@
 			[b]Note:[/b] This flag is implemented on macOS and Windows.
 			[b]Note:[/b] Setting this flag will [b]NOT[/b] prevent other apps from capturing an image, it should not be used as a security measure.
 		</constant>
-		<constant name="FLAG_MAX" value="10" enum="Flags">
+		<constant name="FLAG_SKIP_TASKBAR" value="10" enum="Flags">
+			Window won't be visible in the taskbar or in the system's window manager's window list.
+			[b]Note:[/b] This flag has no effect in embedded windows.
+			[b]Note:[/b] This flag is implemented only on Windows.
+		</constant>
+		<constant name="FLAG_MAX" value="11" enum="Flags">
 			Max value of the [enum Flags].
 		</constant>
 		<constant name="CONTENT_SCALE_MODE_DISABLED" value="0" enum="ContentScaleMode">

main/main.cpp

@@ -2461,6 +2461,9 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 		if (bool(GLOBAL_GET("display/window/size/sharp_corners"))) {
 			window_flags |= DisplayServer::WINDOW_FLAG_SHARP_CORNERS_BIT;
 		}
+		if (bool(GLOBAL_GET("display/window/size/skip_taskbar"))) {
+			window_flags |= DisplayServer::WINDOW_FLAG_SKIP_TASKBAR_BIT;
+		}
 		window_mode = (DisplayServer::WindowMode)(GLOBAL_GET("display/window/size/mode").operator int());
 		int initial_position_type = GLOBAL_GET("display/window/size/initial_position_type").operator int();
 		if (initial_position_type == 0) { // Absolute.

platform/windows/display_server_windows.cpp

@@ -1557,6 +1557,9 @@ DisplayServer::WindowID DisplayServerWindows::create_sub_window(WindowMode p_mod
 	if (p_flags & WINDOW_FLAG_SHARP_CORNERS_BIT) {
 		wd.sharp_corners = true;
 	}
+	if (p_flags & WINDOW_FLAG_SKIP_TASKBAR_BIT) {
+		wd.skip_taskbar = true;
+	}
 	if (p_flags & WINDOW_FLAG_NO_FOCUS_BIT) {
 		wd.no_focus = true;
 	}
@@ -2491,6 +2494,22 @@ void DisplayServerWindows::window_set_flag(WindowFlags p_flag, bool p_enabled, W
 			ERR_FAIL_COND_MSG(IsWindowVisible(wd.hWnd) && (wd.is_popup != p_enabled), "Popup flag can't changed while window is opened.");
 			wd.is_popup = p_enabled;
 		} break;
+		case WINDOW_FLAG_SKIP_TASKBAR: {
+			if (wd.skip_taskbar != p_enabled) {
+				wd.skip_taskbar = p_enabled;
+				ITaskbarList *tbl = nullptr;
+				if (SUCCEEDED(CoCreateInstance(CLSID_TaskbarList, nullptr, CLSCTX_INPROC_SERVER, IID_ITaskbarList, (LPVOID *)&tbl))) {
+					if (SUCCEEDED(tbl->HrInit())) {
+						if (p_enabled) {
+							tbl->DeleteTab(wd.hWnd);
+						} else {
+							tbl->AddTab(wd.hWnd);
+						}
+					}
+					SAFE_RELEASE(tbl)
+				}
+			}
+		} break;
 		default:
 			break;
 	}
@@ -2529,6 +2548,9 @@ bool DisplayServerWindows::window_get_flag(WindowFlags p_flag, WindowID p_window
 		case WINDOW_FLAG_POPUP: {
 			return wd.is_popup;
 		} break;
+		case WINDOW_FLAG_SKIP_TASKBAR: {
+			return wd.skip_taskbar;
+		} break;
 		default:
 			break;
 	}
@@ -5988,6 +6010,16 @@ DisplayServer::WindowID DisplayServerWindows::_create_window(WindowMode p_mode,
 			SetWindowPos(wd.hWnd, HWND_TOP, srect.position.x, srect.position.y, srect.size.width, srect.size.height, SWP_NOZORDER | SWP_NOACTIVATE);
 		}
 
+		if (p_flags & WINDOW_FLAG_SKIP_TASKBAR_BIT) {
+			ITaskbarList *tbl = nullptr;
+			if (SUCCEEDED(CoCreateInstance(CLSID_TaskbarList, nullptr, CLSCTX_INPROC_SERVER, IID_ITaskbarList, (LPVOID *)&tbl))) {
+				if (SUCCEEDED(tbl->HrInit())) {
+					tbl->DeleteTab(wd.hWnd);
+				}
+				SAFE_RELEASE(tbl)
+			}
+		}
+
 		wd.create_completed = true;
 		window_id_counter++;
 	}

platform/windows/display_server_windows.h

@@ -490,6 +490,7 @@ class DisplayServerWindows : public DisplayServer {
 		bool mpass = false;
 		bool sharp_corners = false;
 		bool hide_from_capture = false;
+		bool skip_taskbar = false;
 
 		// Used to transfer data between events using timer.
 		WPARAM saved_wparam;

scene/main/window.cpp

@@ -3009,6 +3009,7 @@ void Window::_bind_methods() {
 	ADD_PROPERTYI(PropertyInfo(Variant::BOOL, "mouse_passthrough"), "set_flag", "get_flag", FLAG_MOUSE_PASSTHROUGH);
 	ADD_PROPERTYI(PropertyInfo(Variant::BOOL, "sharp_corners"), "set_flag", "get_flag", FLAG_SHARP_CORNERS);
 	ADD_PROPERTYI(PropertyInfo(Variant::BOOL, "exclude_from_capture"), "set_flag", "get_flag", FLAG_EXCLUDE_FROM_CAPTURE);
+	ADD_PROPERTYI(PropertyInfo(Variant::BOOL, "skip_taskbar"), "set_flag", "get_flag", FLAG_SKIP_TASKBAR);
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "force_native"), "set_force_native", "get_force_native");
 
 	ADD_GROUP("Limits", "");
@@ -3064,6 +3065,7 @@ void Window::_bind_methods() {
 	BIND_ENUM_CONSTANT(FLAG_MOUSE_PASSTHROUGH);
 	BIND_ENUM_CONSTANT(FLAG_SHARP_CORNERS);
 	BIND_ENUM_CONSTANT(FLAG_EXCLUDE_FROM_CAPTURE);
+	BIND_ENUM_CONSTANT(FLAG_SKIP_TASKBAR);
 	BIND_ENUM_CONSTANT(FLAG_MAX);
 
 	BIND_ENUM_CONSTANT(CONTENT_SCALE_MODE_DISABLED);

scene/main/window.h

@@ -65,6 +65,7 @@ class Window : public Viewport {
 		FLAG_MOUSE_PASSTHROUGH = DisplayServer::WINDOW_FLAG_MOUSE_PASSTHROUGH,
 		FLAG_SHARP_CORNERS = DisplayServer::WINDOW_FLAG_SHARP_CORNERS,
 		FLAG_EXCLUDE_FROM_CAPTURE = DisplayServer::WINDOW_FLAG_EXCLUDE_FROM_CAPTURE,
+		FLAG_SKIP_TASKBAR = DisplayServer::WINDOW_FLAG_SKIP_TASKBAR,
 		FLAG_MAX = DisplayServer::WINDOW_FLAG_MAX,
 	};
 

servers/display_server.cpp

@@ -1141,6 +1141,7 @@ void DisplayServer::_bind_methods() {
 	BIND_ENUM_CONSTANT(WINDOW_FLAG_MOUSE_PASSTHROUGH);
 	BIND_ENUM_CONSTANT(WINDOW_FLAG_SHARP_CORNERS);
 	BIND_ENUM_CONSTANT(WINDOW_FLAG_EXCLUDE_FROM_CAPTURE);
+	BIND_ENUM_CONSTANT(WINDOW_FLAG_SKIP_TASKBAR);
 	BIND_ENUM_CONSTANT(WINDOW_FLAG_MAX);
 
 	BIND_ENUM_CONSTANT(WINDOW_EVENT_MOUSE_ENTER);

servers/display_server.h

@@ -390,6 +390,7 @@ class DisplayServer : public Object {
 		WINDOW_FLAG_MOUSE_PASSTHROUGH,
 		WINDOW_FLAG_SHARP_CORNERS,
 		WINDOW_FLAG_EXCLUDE_FROM_CAPTURE,
+		WINDOW_FLAG_SKIP_TASKBAR,
 		WINDOW_FLAG_MAX,
 	};
 
@@ -405,6 +406,7 @@ class DisplayServer : public Object {
 		WINDOW_FLAG_MOUSE_PASSTHROUGH_BIT = (1 << WINDOW_FLAG_MOUSE_PASSTHROUGH),
 		WINDOW_FLAG_SHARP_CORNERS_BIT = (1 << WINDOW_FLAG_SHARP_CORNERS),
 		WINDOW_FLAG_EXCLUDE_FROM_CAPTURE_BIT = (1 << WINDOW_FLAG_EXCLUDE_FROM_CAPTURE),
+		WINDOW_FLAG_SKIP_TASKBAR_BIT = (1 << WINDOW_FLAG_SKIP_TASKBAR),
 	};
 
 	virtual WindowID create_sub_window(WindowMode p_mode, VSyncMode p_vsync_mode, uint32_t p_flags, const Rect2i &p_rect = Rect2i(), bool p_exclusive = false, WindowID p_transient_parent = INVALID_WINDOW_ID);