Cairn.Input

The context-menu key: Shift-F10, or a PC keyboard's Menu key. It opens the focused control's menu (ControlMenu).

Committed text from the input system (typing, IME commit, dictation). With replace, the text replaces that range [a, b) of the focused field (scalar indices) instead of the selection.

IME composition: the marked text and the selection within it, optionally replacing the range replace of the focused field.

Backing scale × 100 (200 on a Retina display).

The host's time. The host sends one first in every batch, and before any later event that arrived a millisecond or more later (docs/effects.md).

The host's answer to request id.

An event from the subscription the runtime started as id.

A surface-local event (pointer, key, text, resize, scale, focus) for the surface whose place claim is place (docs/surfaces.md). A bare local event is the window's, as in M1.

The status item place's menu is opening (menuWillOpen).

The status item place's menu closed (menuDidClose); with the window's place, the control menu open in the window closed.

The person chose the item ref in the menu of surface place: a status item's menu, the app's items in the menu bar (Surface.menuBar), or, with the window's place, the control menu open in the window (UI.menu).

The runtime's own, never the host's (it has no encoding): the end of a batch, before the frame is drawn. Runtime.steps runs it after every batch; it compares what is on screen with the last frame and delivers Action.appear (docs/runtime.md, "Appear").

The control c, marked Control.appear, came on screen: at the end of a batch it has a visible part, and at the end of the last batch it had none or wasn't there. The runtime's, not a person's: no pointer or key makes it directly (docs/runtime.md, "Appear").

Offset 0: the content's start.

The furthest the offset goes: the content's end at the box's end.

A virtual list's row with key k at the top of the box. Nothing on a plain scroll box, or for a key the list doesn't have.

Move keyboard focus to the control c. The runtime runs this one, not the host: after the step's actions it sets ui.focus := some c, and keeps it only if c is a focusable control of the new tree (docs/runtime.md). No blur is delivered for a field it takes focus from. The host decodes it and does nothing.

Start (or restart) the timer name, due ms milliseconds from now. The runtime keeps timers; the host only wakes it (docs/effects.md).

Forget the timer name; nothing if it isn't set.

Ask the host to do r; it answers with Msg.reply id _, exactly once. At most App.maxInFlight requests of capped kinds (Request.Kind.capped) are with the host at a time; the runtime holds the rest and sends them, oldest first, as slots free.

Withdraw request id (docs/effects.md, "Requests in flight"). Its reply never reaches the app. A request still waiting for a slot is dropped and never sent; one already sent is cancelled on the host (URLSessionTask.cancel), and its id stays taken until the host's one reply to it arrives, which the runtime swallows. Nothing if id is not pending.

End the app. The host terminates after running the frame's other effects.

Move the scroll box or virtual list box (its Style.scrollRef) to to, clamped as every offset is. The runtime runs this one, like focus: after the step's deliveries and layout it sets the offset against the tree just laid and lays out again (docs/runtime.md, "Scrolling"). A box not on screen is left alone. The host decodes it and does nothing.

Set the Dock tile's badge to label; none clears it (docs/effects.md, "The Dock badge and announcements"). The host shows exactly the label; Lean decides what it says.

Ask assistive apps (VoiceOver) to speak text, for news that has no focus of its own ("Couldn't like the post; it's back as it was"). Posted once, with exactly this text.