This crate is part of the [`zng`](https://github.com/zng-ui/zng?tab=readme-ov-file#crates) project.
## Cargo Features
This crate provides 10 feature flags, 0 enabled by default.
#### `"inspector"`
Instrument each widget instance to retain build information.
#### `"dyn_app_extension"`
Use dynamic dispatch at the app-extension level.
This speeds-up compilation time at the cost of runtime.
#### `"test_util"`
Like `cfg(test)` but also visible in docs and integration tests.
#### `"multi_app"`
Allows multiple app instances per-process.
This feature allows multiple apps, one app per thread at a time. The `LocalContext` tracks
what app is currently running in each thread and `app_local!` statics switch to the value of each app
depending on the current thread.
Not enabled by default, but enabled by `feature="test_util"`.
#### `"trace_widget"`
Instrument every widget outer-most node to trace UI methods.
#### `"trace_wgt_item"`
Instrument every property and intrinsic node to trace UI methods.
Note that this can cause very large trace files and bad performance.
#### `"crash_handler"`
Allow app-process crash handler.
Only enables in `not(any(target_arch = "wasm32", target_os = "android", target_os = "ios"))` builds.
#### `"trace_recorder"`
Enable trace recording.
Note that this does not auto start recording, to do that run with the `ZNG_RECORD_TRACE` env var set.
#### `"ipc"`
Enables IPC tasks and pre-build views and connecting to views running in another process.
#### `"deadlock_detection"`
Spawns a thread on app creation that checks and prints `parking_lot` deadlocks.
Not enabled by default, but enabled by `feature="test_util"`.