Panes and overlays

Pane

mayflyPanes supports header, left, right, and bottom placement, and views for a view of the status row (see Views of the status row).

export const inject = ['mayflyPanes']

export function apply(ctx: Context): void {
  const pane = ctx.mayflyPanes.register({
    id: 'acme.inspector',
    title: 'Inspector',
    placement: 'right',
    size: { min: 20, preferred: 30, max: 40 },
    narrow: 'bottom',
  }, { kind: 'text', content: 'healthy' })

  // Call after domain state changes:
  pane.set({ kind: 'text', content: 'updated' })
}

narrow may be bottom, overlay, or hidden. set(null) releases the lane until the next non-null snapshot.

size counts columns for left/right panes and rows for bottom panes. Bottom panes stack in one dock that takes at most a third of the terminal height: each pane first receives size.min rows (default 1, its head row), nearest the editor first, and the remaining rows are shared round-robin up to size.max. A pane that gets fewer rows than it rendered keeps its head and ends in a muted … +K more rows, so put the most important row first. When several passive bottom panes begin with a plain divider, the dock paints a single rule for all of them. Use overflow: 'truncate' on dense rows so one entry never costs two dock rows.

Views

A views pane has no lane of its own: it declares a summary that joins the status row and updates it with setSummary() (null takes the view out of the row). set(node) publishes the panel that opens under the row while the view is entered with Alt+↓, F5, or F6. size and narrow do not apply.

Overlay

export const inject = ['commands', 'mayflyOverlays']

export function apply(ctx: Context): void {
  ctx.commands.register({
    name: 'health',
    description: 'Open health details',
    handler: () => {
      ctx.mayflyOverlays.close('acme.health')
      ctx.mayflyOverlays.open({
        id: 'acme.health',
        title: 'Health',
        capturing: true,
        anchor: 'center',
        width: '70%',
      }, { kind: 'text', content: 'healthy' })
      return { kind: 'success', text: 'opened health details' }
    },
  })
}

A capturing overlay receives focus and is Escape-dismissible by default. Only explicit dismissible: false disables this. A non-capturing overlay may not contain interactive controls.

Pane and overlay ids are unique within their registry. Core still admits snapshot and event output. Fiber unload removes panes and closes overlays opened by that Fiber.