Module zng::update

App update service and other types.

The UPDATES service can execute arbitrary futures and setup update handlers. It can also be used to request update, info rebuild, layout and render for any widget. Note that from inside the widget you should use the WIDGET service instead, as it is more efficient.

The example below setups a handler that is called every app update.

use zng::prelude::*;

zng::update::UPDATES
  .on_pre_update(app_hn!(|args: &zng::update::UpdateArgs, _| {
      println!("pre_update #{}", args.count);
  }))
  .perm();

Updates are coalesced, multiple requests for the same widget will cause it to only update once, and multiple widgets can update on the same pass. See the Main Loop docs in the app module for more details.

Full API

See zng_app::update for the full update API.

Structs

• ContextUpdates
  Updates that must be reacted by an app owner.
• EventUpdate
  Represents a single event update.
• InfoUpdates
  Widget info updates of the current cycle.
• LayoutUpdates
  Widget layout updates of the current cycle.
• OnUpdateHandle
  Represents an on_pre_update or on_update handler.
• RenderUpdates
  Widget render updates of the current cycle.
• UPDATES
  Update schedule service.
• UpdateArgs
  Arguments for an on_pre_update, on_update or run handler.
• UpdateDeliveryList
  Represents all the widgets and windows marked to receive an update.
• WeakOnUpdateHandle
  Weak OnUpdateHandle.
• WidgetUpdates
  Widget updates of the current cycle.

Enums

• UpdateOp
  Identify node and app-extension operations that can be requested.

Traits

• UpdateSubscribers
  Represents a set of widgets that subscribe to an event source.
• UpdatesTraceUiNodeExt
  Extension methods for infinite loop diagnostics.