Crate zng_app

Source
Expand description

App process implementation.

§Widget Instantiation

See enable_widget_macros! if you want to instantiate widgets without depending on the zng crate.

§Crate

This crate is part of the zng project.

§Cargo Features

This crate provides 12 feature flags, 2 enabled by default.

§"debug_default"

Enable the "dyn_*" and "inspector" features in debug builds.

Enabled by default.

§"dyn_node"

Use dynamic dispatch at the node level by placing each property node in a BoxedUiNode and enabling UiNode::cfg_boxed.

This speeds-up compilation time at the cost of runtime.

§"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.

§"dyn_closure"

Box closures at opportune places, such as Var::map, reducing the number of monomorphised types.

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.

§"ipc"

Enables IPC tasks and pre-build views and connecting to views running in another process.

Enabled by default.

§"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".

Modules§

access
Accessibility/automation events.
crash_handler
App-process crash handler.
event
App event and commands API.
handler
Handler types and macros.
render
Frame render and metadata API.
shortcut
Key combination types.
third_party
Third party licenses service and types.
timer
App timers, deadlines and timeouts.
update
App updates API.
view_process
View process connection and other types.
widget
Widget, UI node API.
window
Window context API.

Structs§

APP
Start and manage an app process.
AppEventSender
A sender that can awake apps and insert events into the main loop.
AppExtReceiver
Represents a channel receiver in an app extension.
AppExtSender
Represents a channel sender that causes an extensions update for each value transferred.
AppExtSenderDisconnected
Error when the app connected to a sender/receiver channel has disconnected.
AppExtended
Application builder.
AppExtensionInfo
Info about an app-extension.
AppExtensionsInfo
List of app-extensions that are part of an app.
AppStartArgs
Arguments for on_app_start handlers.
DInstant
Duration elapsed since an epoch.
Deadline
Represents a timeout instant.
ExitCancelled
Cancellation message of an exit request.
ExitRequestedArgs
Arguments for EXIT_REQUESTED_EVENT.
HeadlessApp
A headless app controller.
INSTANT
Instant service.

Enums§

AppControlFlow
Desired next step of app main loop.
InstantMode
Defines how the INSTANT.now value updates in the app.

Statics§

EXIT_CMD
Represents the app process exit request.
EXIT_REQUESTED_EVENT
Cancellable event raised when app process exit is requested.

Traits§

AppEventObserver
Observer for HeadlessApp::update_observed.
AppExtension
An app extension.

Functions§

on_app_start
Register a handler to run when an APP starts running in the process.
print_tracing
Enables tracing events printing if a subscriber is not already set.
print_tracing_filter
Filter used by print_tracing, removes some log noise from dependencies.
test_log
Modifies the print_tracing subscriber to panic for error logs in the current app.