Ken Van Hoeylandt
ab75d2022d
Event handling: - Added unified event handling for application, system, and Wi‑Fi events. - Updated all apps to reflect event handling changes Wi-Fi: - Refactored event handling from listener interface to task & event group. - Added direct Wi‑Fi radio controls and improved event subscriptions. - Wi‑Fi screens now refresh asynchronously and handle unavailable devices more gracefully. - Enabled Wi‑Fi by default on in dts files, but radio on/off is still done by code. The main reason was reliable event subscription and consistent devicetree states. - Improved Wi‑Fi shutdown cleanup and radio-state handling. Other: - Renamed the Kernel Display app to Display.
19 lines
1.8 KiB
Markdown
19 lines
1.8 KiB
Markdown
# Architecture: App Framework
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Apps are event-driven, C API (`app-module`, `<app/*.h>`), not a C++ class. Each app has an `AppManifest` (`id`, `name`, `category`, `location`, `flags`) and a `main(argc, argv)` entry point (`AppMainFn`), modelled on a C program's `main()`. Every app instance gets its own dedicated task for its whole lifetime, and blocks in that task until it returns. Use `app_scheduler_current_app_id()` (`app/scheduler.h`) to identify the running instance - it's not passed as a parameter.
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Lifecycle and inter-app communication go through `app_manager_*()` (`app/manager.h`) and `app_event_*()` (`app/event.h`):
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- `app_manager_start()`/`app_manager_start_with_parameters()` launch a plain instance; `app_manager_start_for_result()` launches a modal child that reports back to a parent instance.
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- An app subscribes with `app_event_subscribe()` (registers for its own instance's events, no id argument needed), blocks via `task_event_group_wait()`/`task_event_group_wait_any()`, and drains with `app_event_poll()`, reacting to `APP_EVENT_CLOSE` (terminate now) and `APP_EVENT_RESULT` (a child it started reported back).
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- An app closes itself by calling `app_manager_finish()` right before returning from `main()`; another instance is closed via `app_manager_stop()`.
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Apps are registered at startup via `app_manager_add()`. External apps can be loaded from SD card via `manifest.properties` files, or side-loaded as ELF binaries on ESP32 (see `app/loader.h`'s `AppLoaderApi`).
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Apps can be loaded from:
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- memory (`APP_LOCATION_MEMORY`)
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- a path pointing to an install folder where an `.app` file was installed (`APP_LOCATION_PATH`)
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- a path pointing to an `.elf` file (`APP_LOCATION_PATH`)
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An app can build an optional UI via the LVGL window-manager module (see `lvgl.md`).
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