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 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.

Macros

app_hn

Declare a mutable clone-move app event handler.

app_hn_once

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

async_app_hn

Declare an async clone-move app event handler.

async_app_hn_once

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

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.

AppExtReceiver

Represents a channel receiver in an app extension.

AppExtSender

Represents a channel sender that causes an extensions update for each value transferred.

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

AppChannelError

Error during send or receive of app channels.

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.