Files
claude-code/packages/@ant/ink/src/components/AlternateScreen.tsx
2026-04-07 16:17:48 +08:00

88 lines
3.1 KiB
TypeScript

import React, {
type PropsWithChildren,
useContext,
useInsertionEffect,
} from 'react'
import instances from '../core/instances.js'
import {
DISABLE_MOUSE_TRACKING,
ENABLE_MOUSE_TRACKING,
ENTER_ALT_SCREEN,
EXIT_ALT_SCREEN,
} from '../core/termio/dec.js'
import { TerminalWriteContext } from '../hooks/useTerminalNotification.js'
import Box from './Box.js'
import { TerminalSizeContext } from './TerminalSizeContext.js'
type Props = PropsWithChildren<{
/** Enable SGR mouse tracking (wheel + click/drag). Default true. */
mouseTracking?: boolean
}>
/**
* Run children in the terminal's alternate screen buffer, constrained to
* the viewport height. While mounted:
*
* - Enters the alt screen (DEC 1049), clears it, homes the cursor
* - Constrains its own height to the terminal row count, so overflow must
* be handled via `overflow: scroll` / flexbox (no native scrollback)
* - Optionally enables SGR mouse tracking (wheel + click/drag) — events
* surface as `ParsedKey` (wheel) and update the Ink instance's
* selection state (click/drag)
*
* On unmount, disables mouse tracking and exits the alt screen, restoring
* the main screen's content. Safe for use in ctrl-o transcript overlays
* and similar temporary fullscreen views — the main screen is preserved.
*
* Notifies the Ink instance via `setAltScreenActive()` so the renderer
* keeps the cursor inside the viewport (preventing the cursor-restore LF
* from scrolling content) and so signal-exit cleanup can exit the alt
* screen if the component's own unmount doesn't run.
*/
export function AlternateScreen({
children,
mouseTracking = true,
}: Props): React.ReactNode {
const size = useContext(TerminalSizeContext)
const writeRaw = useContext(TerminalWriteContext)
// useInsertionEffect (not useLayoutEffect): react-reconciler calls
// resetAfterCommit between the mutation and layout commit phases, and
// Ink's resetAfterCommit triggers onRender. With useLayoutEffect, that
// first onRender fires BEFORE this effect — writing a full frame to the
// main screen with altScreen=false. That frame is preserved when we
// enter alt screen and revealed on exit as a broken view. Insertion
// effects fire during the mutation phase, before resetAfterCommit, so
// ENTER_ALT_SCREEN reaches the terminal before the first frame does.
// Cleanup timing is unchanged: both insertion and layout effect cleanup
// run in the mutation phase on unmount, before resetAfterCommit.
useInsertionEffect(() => {
const ink = instances.get(process.stdout)
if (!writeRaw) return
writeRaw(
ENTER_ALT_SCREEN +
'\x1b[2J\x1b[H' +
(mouseTracking ? ENABLE_MOUSE_TRACKING : ''),
)
ink?.setAltScreenActive(true, mouseTracking)
return () => {
ink?.setAltScreenActive(false)
ink?.clearTextSelection()
writeRaw((mouseTracking ? DISABLE_MOUSE_TRACKING : '') + EXIT_ALT_SCREEN)
}
}, [writeRaw, mouseTracking])
return (
<Box
flexDirection="column"
height={size?.rows ?? 24}
width="100%"
flexShrink={0}
>
{children}
</Box>
)
}