Operating System Simulator

This reference documents the C++ surface of the Operating System Simulator plugin — classes, structs, enums, and their members as declared in the plugin source. Use it when you extend the simulator in C++, subclass core types, or need exact signatures and inheritance without opening the engine.

If you are new to the plugin, start with the Getting Started guide and Plugin Classes overview. Come back here when you need method-level detail on a specific type.

How to browse

Use the sidebar to drill into categories. Each page lists inheritance, members, parameters, and return types for one type.

Category	What you will find
Actors	World-placed device actors that boot and host a virtual OS
Core	Operating system, hardware, filesystem, and session types
Programs	Built-in and extensible program implementations
Widgets	UMG widgets for desktop, taskbar, terminal, and UI chrome
Objects	UObject-based helpers and data holders
Types	Shared structs, typedefs, and header-level definitions
Enums	Enumerations used across the plugin API
Viewport Worlds	Viewport-world integration types
Implementation	Internal implementation details (advanced)
Miscellaneous	Everything else that does not fit a folder above

Architecture diagrams

Diagrams on this reference are Mermaid (no Graphviz images), generated from the same Doxygen XML as the signatures unless noted as conceptual below.

Diagram	Where
Inheritance	Every class and struct page — direct bases and subclasses
Collaboration	Class pages — owned and referenced types via member variables
Class detail	Busier class pages — key members in one card
Caller impact	Hub methods — who inside the plugin calls them
Include map	Below — what the core public header pulls in
Category map	Below — how API types group by folder

Device lifecycle

EOperatingSystemDeviceState on UOperatingSystemBaseDevice tracks boot and runtime:

stateDiagram-v2
  [*] --> None
  None --> Starting : power on
  Starting --> BIOS : firmware
  BIOS --> Running : OS ready
  Running --> Restarting : reboot
  Running --> ShuttingDown : shutdown
  Restarting --> Starting
  ShuttingDown --> None
  Running --> BSOD : fatal error
  BSOD --> ShuttingDown

Program window focus

EOperatingSystemProgramViewState on UOperatingSystemBaseProgram drives taskbar and window chrome:

stateDiagram-v2
  [*] --> NotFocused
  NotFocused --> Focused : activate
  Focused --> NotFocused : blur
  Focused --> Minimized : minimize
  Minimized --> Focused : restore
  Minimized --> MinimizedAndNotFocused : blur
  MinimizedAndNotFocused --> Minimized : focus

OS installation flow

Typical install sequence on a device actor (conceptual — not derived from source):

sequenceDiagram
  participant D as AOperatingSystemDeviceActor
  participant O as UOperatingSystem
  participant W as UOperatingSystemWidget
  D->>O: BeginInstallation
  O->>O: FinalizePreInstallation
  O->>W: Show progress
  O->>O: FinishInstallation
  O-->>D: InstallationCompleted

Category map

Top-level folders in the sidebar and a representative type in each:

flowchart TD
  OS["Operating System Simulator"]
  Actors["Actors"]
  OS --> Actors
  AOperatingSystemCCTVActor["AOperatingSystemCCTVActor"]
  Actors --> AOperatingSystemCCTVActor
  Core["Core"]
  OS --> Core
  UOperatingSystem["UOperatingSystem"]
  Core --> UOperatingSystem
  Programs["Programs"]
  OS --> Programs
  UOperatingSystemStore["UOperatingSystemStore"]
  Programs --> UOperatingSystemStore
  Widgets["Widgets"]
  OS --> Widgets
  UOperatingSystemWidget["UOperatingSystemWidget"]
  Widgets --> UOperatingSystemWidget
  Devices["Devices"]
  OS --> Devices
  EOperatingSystemWidgetSet["EOperatingSystemWidgetSet"]
  Devices --> EOperatingSystemWidgetSet
  Enums["Enums"]
  OS --> Enums
  EOperatingSystemWindowStartupState["EOperatingSystemWindowStartupState"]
  Enums --> EOperatingSystemWindowStartupState

For a narrative map of core types, see Plugin Classes in the Guide.

Tips

• Search — use the site search bar to jump straight to a class name (e.g. UOperatingSystem, AOperatingSystemDeviceActor).
• Blueprint users — many types are UCLASS / USTRUCT and appear in Blueprint; this reference shows the underlying C++ API.
• AI assistant — the docs chat widget can answer questions about classes and methods using this reference as context.

Source updates in the operating-system-simulator repository are reflected here on each docs deploy.