Crate zng_app 

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 11 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.

See zng::app::trace_recorder for more details.

"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".

See zng::app::spawn_deadlock_detection for more details.

"memory_profiler"

Enable instrumented allocator and record allocations.

Note that this replaces the #[global_allocator] and has an impact in performance.

See zng::app::memory_profiler for more details.

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.

trace_recorder

Trace recording and data model.

update

App updates API.

view_process

View process connection and other types.

widget

Widget, UI node API.

window

Window context API.

Macros

async_hn

Declare an async clone-move event handler.

async_hn_once

Declare an async clone-move event handler that is only called once.

command

Declares new Command static items.

crash_handler_config

Register a FnOnce(&mut CrashConfig) closure to be called on process init to configure the crash handler.

enable_widget_macros

Enable widget instantiation in crates that can’t depend on the zng crate.

event_args

Declares new EventArgs types.

event_macro

Declares new Event<A> static items.

hn

Declare a mutable clone-move event handler.

hn_once

Declare a clone-move event handler that is only called once.

property_args

New Box<PropertyArgs> box from a property and value.

property_id

New PropertyId that represents the type and name.

property_info

New PropertyInfo from property path.

property_input_types

Gets the strong input storage types from a property path.

shortcut_macro

Creates a Shortcut.

source_location

New SourceLocation that represents the location you call this macro.

static_id

Declares a static unique ID that is lazy inited.

ui_vec

Creates an UiVec containing the arguments.

widget_impl

Implement a property on the widget to strongly associate it with the widget.

widget_set

Sets properties and when condition on a widget builder.

widget_type

Gets the WidgetType info of a widget.

Structs

APP

Start and manage an app process.

AppEventSender

A sender that can awake apps and insert events into the main loop.

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.

spawn_deadlock_detection

When compiled with "deadlock_detection" spawns a thread that monitors for parking_lot deadlocks.

test_log

Modifies the print_tracing subscriber to panic for error logs in the current app.