Import combined Enhanced viewport: zoom out, overlays & tooltips (r53_27127) patch

https://www.tt-forums.net/viewtopic.php?f=33&t=53394

src/vehicle_gui.h

@@ -18,6 +18,7 @@
 #include "station_type.h"
 #include "engine_type.h"
 #include "company_type.h"
+#include "widgets/dropdown_func.h"
 
 void ShowVehicleRefitWindow(const Vehicle *v, VehicleOrderID order, Window *parent, bool auto_refit = false);
 
@@ -101,4 +102,33 @@ Vehicle *CheckClickOnVehicle(const struct ViewPort *vp, int x, int y);
 
 void DrawVehicleImage(const Vehicle *v, int left, int right, int y, VehicleID selection, EngineImageType image_type, int skip);
 
+/**
+ * Tell if the focused window concerns the specified vehicle.
+ * @param vid Vehicle id to check.
+ * @param ref_window The window to check against.
+ * @return True if the focused window is about specified vehicle.
+ */
+static inline bool HasFocusedVehicleChanged(const VehicleID vid, Window *ref_window)
+{
+	if (ref_window) {
+		WindowClass wc = ref_window->window_class;
+		WindowNumber wn = ref_window->window_number;
+
+		if (wc == WC_DROPDOWN_MENU) GetParentWindowInfo(ref_window, wc, wn);
+
+		switch (wc) {
+			default:
+				break;
+			case WC_VEHICLE_DETAILS:
+			case WC_VEHICLE_REFIT:
+			case WC_VEHICLE_ORDERS:
+			case WC_VEHICLE_TIMETABLE:
+			case WC_VEHICLE_VIEW:
+				return ((uint32) wn != vid);
+		}
+	}
+
+	return true;
+}
+
 #endif /* VEHICLE_GUI_H */