Show a confirm dialog and act on the answer

Dialogs.confirm returns an Overlay value — it does not take callbacks. The app owns the dialog's open/closed state and the focused button; key events route to whichever side owns focus.

Pattern

1. Add a flag (or sealed case class) to your model that says "the confirm dialog is open and waiting for an answer".
2. In view, when that flag is set, append the Dialogs.confirm overlay to RootNode.overlays.
3. In update, route key events to the dialog when it's open: arrow keys flip the focused button, Enter/Space commits, Escape cancels.

Code

import termflow.tui.{Dialogs, Theme}
import termflow.tui.KeyDecoder.InputKey.*

final case class Model(
  /* … domain fields … */,
  confirm: Option[ConfirmState]
)

enum ConfirmState:
  case Open(yesFocused: Boolean)   // dialog visible, button focus tracked here

enum Msg:
  case AskDelete             // user requested the destructive action
  case ConfirmYes
  case ConfirmNo
  case ConfirmKey(k: InputKey)

def update(m: Model, msg: Msg, ctx: RuntimeCtx[Msg]): Tui[Model, Msg] =
  msg match
    case Msg.AskDelete =>
      m.copy(confirm = Some(ConfirmState.Open(yesFocused = false))).tui

    case Msg.ConfirmKey(k) =>
      m.confirm match
        case Some(ConfirmState.Open(yesFocused)) =>
          k match
            case ArrowLeft | ArrowRight | Tab | BackTab =>
              m.copy(confirm = Some(ConfirmState.Open(!yesFocused))).tui
            case Enter | CharKey(' ') =>
              if yesFocused then m.copy(confirm = None).gCmd(Msg.ConfirmYes)
              else              m.copy(confirm = None).gCmd(Msg.ConfirmNo)
            case Escape =>
              m.copy(confirm = None).gCmd(Msg.ConfirmNo)
            case _ => m.tui
        case None => m.tui

    case Msg.ConfirmYes =>  /* perform the destructive action */
    case Msg.ConfirmNo  =>  m.tui /* no-op */

def view(m: Model): RootNode =
  given Theme = Theme.dark
  val baseChildren = /* … */
  val overlays = m.confirm match
    case Some(ConfirmState.Open(yesFocused)) =>
      List(Dialogs.confirm(
        prompt     = "Delete this file?",
        yesFocused = yesFocused,
        title      = "Confirm delete",
        yesLabel   = "Yes",
        noLabel    = "No"
      ))
    case None => Nil

  RootNode(80, 24, children = baseChildren, input = None, overlays = overlays)

Notes

• Why Option[ConfirmState] and not just Boolean? It scales — add Open(yesFocused, prompt: String) later and any caller of AskDelete can pass its own prompt.
• Always re-route keys when a dialog is open. Don't forget to intercept the global keymap so q doesn't quit while the dialog is modal. The simplest pattern is: if m.confirm.isDefined, route the whole keystream into ConfirmKey and skip your normal handlers.
• Mouse clicks on overlays. Dialogs.confirm is mouse-aware in the renderer; if you want clicks on the buttons to flip focus, pair the dialog with Layout.resolveTracked and dispatch ConfirmKey from the hit-test result.

For a working example, see the showcase's Dialogs tab — Stage1ShowcaseApp.scala.