This change replaces fixed callback protocols (e.g., ViewerGuiHook, ViewerUpdateHook, SimEventHandler) with a general-purpose, priority-based message and event handling mechanism.
Key changes:
- Handler decorator and registry: Introduced the `@messages.handler(priority=...)` decorator and `HandlerRegistry` (`handler_registry.py`). Methods marked as handlers are automatically discovered and dispatched by priority (CRITICAL, USER, LIBRARY, INTERNAL) or method resolution order.
- Local lifecycle events: Added `ViewerAppInitEvent`, `BuildGuiEvent`, and `UpdateEvent` to `messages.py`. Custom GUI rendering and per-frame update logic can now be implemented as standard event handlers without needing separate interface protocols.
- Streamlined launch and app APIs: Replaced individual hook and handler arguments in `launch_passive`, `ViewerApp`, and `ViewerHandle` with unified `viewer_handlers` and `sim_handlers` lists.
- Module restructuring: Extracted simulation-side message handling and `ViewerHandle` from `sim_app.py` into a dedicated `viewer_handle.py` module, removing `sim_app.py`.
- Sample updates: Migrated existing examples (such as `implot.py`) to use the new handler pattern and lifecycle events.
PiperOrigin-RevId: 941729322
Change-Id: I93e7c0edf0a13a8dc854f9e2083451f7c25a1825
The ViewerEndpoint can now send Snapshot messages to the SimEndpoint. The SimEndpoint has a new method, `get_viewer_snapshots`, to retrieve these. Thsi channel will be used for UI state needed for the simulation (e.g., `MjOption` and `StepControl`).
PiperOrigin-RevId: 940981799
Change-Id: Ib9bd6ad848cd5479bc49492a34fddd82569cb09f
StepControl methods SetSpeed, SetNoiseParameters, and SetPauseState now return a boolean indicating whether the state was actually changed. The GUI functions NoiseGui and StepControlGui also return a boolean reflecting if any parameters were modified. Noise parameters are now directly managed by StepControl rather than being stored in UxState. The StepControlEvent message has been expanded to include all step control parameters. Keyboard event handling has been slightly refactored to better align with event-based updates.
PiperOrigin-RevId: 940656342
Change-Id: I3701623a2fdcfc4c084b5db0ae19048669040de4
- `messages.py`: Defines base classes for `Message`, `Snapshot`, and `Event`, along with `SnapshotChannel` and `EventChannel` protocols. It also includes concrete message types for state, reset, model, perturbation, pause state, and exit events.
- `endpoints.py`: Provides `ViewerEndpoint` and `SimEndpoint` classes to manage message routing between the simulation and the viewer via the defined channels. A `make_endpoints` function is included to create both endpoints.
PiperOrigin-RevId: 939659912
Change-Id: I61a52a7d25431bc4ed38a184813882145eb421d1
Matija Kecman