Files
claude-code/packages/@ant/ink/src/components/AlternateScreen.tsx
2026-05-01 21:55:51 +08:00

72 lines
3.0 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>
);
}