1 files changed, 405 insertions, 0 deletions
diff --git a/packages/cli/src/ui/contexts/KeypressContext.tsx b/packages/cli/src/ui/contexts/KeypressContext.tsx
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+++ b/packages/cli/src/ui/contexts/KeypressContext.tsx
@@ -0,0 +1,405 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  Config,
+  KittySequenceOverflowEvent,
+  logKittySequenceOverflow,
+} from '@google/gemini-cli-core';
+import { useStdin } from 'ink';
+import React, {
+  createContext,
+  useCallback,
+  useContext,
+  useEffect,
+  useRef,
+} from 'react';
+import readline from 'readline';
+import { PassThrough } from 'stream';
+import {
+  BACKSLASH_ENTER_DETECTION_WINDOW_MS,
+  KITTY_CTRL_C,
+  MAX_KITTY_SEQUENCE_LENGTH,
+} from '../utils/platformConstants.js';
+
+import { FOCUS_IN, FOCUS_OUT } from '../hooks/useFocus.js';
+
+const ESC = '\u001B';
+export const PASTE_MODE_PREFIX = `${ESC}[200~`;
+export const PASTE_MODE_SUFFIX = `${ESC}[201~`;
+
+export interface Key {
+  name: string;
+  ctrl: boolean;
+  meta: boolean;
+  shift: boolean;
+  paste: boolean;
+  sequence: string;
+  kittyProtocol?: boolean;
+}
+
+export type KeypressHandler = (key: Key) => void;
+
+interface KeypressContextValue {
+  subscribe: (handler: KeypressHandler) => void;
+  unsubscribe: (handler: KeypressHandler) => void;
+}
+
+const KeypressContext = createContext<KeypressContextValue | undefined>(
+  undefined,
+);
+
+export function useKeypressContext() {
+  const context = useContext(KeypressContext);
+  if (!context) {
+    throw new Error(
+      'useKeypressContext must be used within a KeypressProvider',
+    );
+  }
+  return context;
+}
+
+export function KeypressProvider({
+  children,
+  kittyProtocolEnabled,
+  config,
+}: {
+  children: React.ReactNode;
+  kittyProtocolEnabled: boolean;
+  config?: Config;
+}) {
+  const { stdin, setRawMode } = useStdin();
+  const subscribers = useRef<Set<KeypressHandler>>(new Set()).current;
+
+  const subscribe = useCallback(
+    (handler: KeypressHandler) => {
+      subscribers.add(handler);
+    },
+    [subscribers],
+  );
+
+  const unsubscribe = useCallback(
+    (handler: KeypressHandler) => {
+      subscribers.delete(handler);
+    },
+    [subscribers],
+  );
+
+  useEffect(() => {
+    setRawMode(true);
+
+    const keypressStream = new PassThrough();
+    let usePassthrough = false;
+    const nodeMajorVersion = parseInt(process.versions.node.split('.')[0], 10);
+    if (
+      nodeMajorVersion < 20 ||
+      process.env['PASTE_WORKAROUND'] === '1' ||
+      process.env['PASTE_WORKAROUND'] === 'true'
+    ) {
+      usePassthrough = true;
+    }
+
+    let isPaste = false;
+    let pasteBuffer = Buffer.alloc(0);
+    let kittySequenceBuffer = '';
+    let backslashTimeout: NodeJS.Timeout | null = null;
+    let waitingForEnterAfterBackslash = false;
+
+    const parseKittySequence = (sequence: string): Key | null => {
+      const kittyPattern = new RegExp(`^${ESC}\\[(\\d+)(;(\\d+))?([u~])$`);
+      const match = sequence.match(kittyPattern);
+      if (!match) return null;
+
+      const keyCode = parseInt(match[1], 10);
+      const modifiers = match[3] ? parseInt(match[3], 10) : 1;
+      const modifierBits = modifiers - 1;
+      const shift = (modifierBits & 1) === 1;
+      const alt = (modifierBits & 2) === 2;
+      const ctrl = (modifierBits & 4) === 4;
+
+      if (keyCode === 27) {
+        return {
+          name: 'escape',
+          ctrl,
+          meta: alt,
+          shift,
+          paste: false,
+          sequence,
+          kittyProtocol: true,
+        };
+      }
+
+      if (keyCode === 13) {
+        return {
+          name: 'return',
+          ctrl,
+          meta: alt,
+          shift,
+          paste: false,
+          sequence,
+          kittyProtocol: true,
+        };
+      }
+
+      if (keyCode >= 97 && keyCode <= 122 && ctrl) {
+        const letter = String.fromCharCode(keyCode);
+        return {
+          name: letter,
+          ctrl: true,
+          meta: alt,
+          shift,
+          paste: false,
+          sequence,
+          kittyProtocol: true,
+        };
+      }
+
+      return null;
+    };
+
+    const broadcast = (key: Key) => {
+      for (const handler of subscribers) {
+        handler(key);
+      }
+    };
+
+    const handleKeypress = (_: unknown, key: Key) => {
+      if (key.name === 'return' && waitingForEnterAfterBackslash) {
+        if (backslashTimeout) {
+          clearTimeout(backslashTimeout);
+          backslashTimeout = null;
+        }
+        waitingForEnterAfterBackslash = false;
+        broadcast({
+          ...key,
+          shift: true,
+          sequence: '\r', // Corrected escaping for newline
+        });
+        return;
+      }
+
+      if (key.sequence === '\\' && !key.name) {
+        // Corrected escaping for backslash
+        waitingForEnterAfterBackslash = true;
+        backslashTimeout = setTimeout(() => {
+          waitingForEnterAfterBackslash = false;
+          backslashTimeout = null;
+          broadcast(key);
+        }, BACKSLASH_ENTER_DETECTION_WINDOW_MS);
+        return;
+      }
+
+      if (waitingForEnterAfterBackslash && key.name !== 'return') {
+        if (backslashTimeout) {
+          clearTimeout(backslashTimeout);
+          backslashTimeout = null;
+        }
+        waitingForEnterAfterBackslash = false;
+        broadcast({
+          name: '',
+          sequence: '\\',
+          ctrl: false,
+          meta: false,
+          shift: false,
+          paste: false,
+        });
+      }
+
+      if (['up', 'down', 'left', 'right'].includes(key.name)) {
+        broadcast(key);
+        return;
+      }
+
+      if (
+        (key.ctrl && key.name === 'c') ||
+        key.sequence === `${ESC}${KITTY_CTRL_C}`
+      ) {
+        kittySequenceBuffer = '';
+        if (key.sequence === `${ESC}${KITTY_CTRL_C}`) {
+          broadcast({
+            name: 'c',
+            ctrl: true,
+            meta: false,
+            shift: false,
+            paste: false,
+            sequence: key.sequence,
+            kittyProtocol: true,
+          });
+        } else {
+          broadcast(key);
+        }
+        return;
+      }
+
+      if (kittyProtocolEnabled) {
+        if (
+          kittySequenceBuffer ||
+          (key.sequence.startsWith(`${ESC}[`) &&
+            !key.sequence.startsWith(PASTE_MODE_PREFIX) &&
+            !key.sequence.startsWith(PASTE_MODE_SUFFIX) &&
+            !key.sequence.startsWith(FOCUS_IN) &&
+            !key.sequence.startsWith(FOCUS_OUT))
+        ) {
+          kittySequenceBuffer += key.sequence;
+          const kittyKey = parseKittySequence(kittySequenceBuffer);
+          if (kittyKey) {
+            kittySequenceBuffer = '';
+            broadcast(kittyKey);
+            return;
+          }
+
+          if (config?.getDebugMode()) {
+            const codes = Array.from(kittySequenceBuffer).map((ch) =>
+              ch.charCodeAt(0),
+            );
+            console.warn('Kitty sequence buffer has char codes:', codes);
+          }
+
+          if (kittySequenceBuffer.length > MAX_KITTY_SEQUENCE_LENGTH) {
+            if (config) {
+              const event = new KittySequenceOverflowEvent(
+                kittySequenceBuffer.length,
+                kittySequenceBuffer,
+              );
+              logKittySequenceOverflow(config, event);
+            }
+            kittySequenceBuffer = '';
+          } else {
+            return;
+          }
+        }
+      }
+
+      if (key.name === 'paste-start') {
+        isPaste = true;
+      } else if (key.name === 'paste-end') {
+        isPaste = false;
+        broadcast({
+          name: '',
+          ctrl: false,
+          meta: false,
+          shift: false,
+          paste: true,
+          sequence: pasteBuffer.toString(),
+        });
+        pasteBuffer = Buffer.alloc(0);
+      } else {
+        if (isPaste) {
+          pasteBuffer = Buffer.concat([pasteBuffer, Buffer.from(key.sequence)]);
+        } else {
+          if (key.name === 'return' && key.sequence === `${ESC}\r`) {
+            key.meta = true;
+          }
+          broadcast({ ...key, paste: isPaste });
+        }
+      }
+    };
+
+    const handleRawKeypress = (data: Buffer) => {
+      const pasteModePrefixBuffer = Buffer.from(PASTE_MODE_PREFIX);
+      const pasteModeSuffixBuffer = Buffer.from(PASTE_MODE_SUFFIX);
+
+      let pos = 0;
+      while (pos < data.length) {
+        const prefixPos = data.indexOf(pasteModePrefixBuffer, pos);
+        const suffixPos = data.indexOf(pasteModeSuffixBuffer, pos);
+        const isPrefixNext =
+          prefixPos !== -1 && (suffixPos === -1 || prefixPos < suffixPos);
+        const isSuffixNext =
+          suffixPos !== -1 && (prefixPos === -1 || suffixPos < prefixPos);
+
+        let nextMarkerPos = -1;
+        let markerLength = 0;
+
+        if (isPrefixNext) {
+          nextMarkerPos = prefixPos;
+        } else if (isSuffixNext) {
+          nextMarkerPos = suffixPos;
+        }
+        markerLength = pasteModeSuffixBuffer.length;
+
+        if (nextMarkerPos === -1) {
+          keypressStream.write(data.slice(pos));
+          return;
+        }
+
+        const nextData = data.slice(pos, nextMarkerPos);
+        if (nextData.length > 0) {
+          keypressStream.write(nextData);
+        }
+        const createPasteKeyEvent = (
+          name: 'paste-start' | 'paste-end',
+        ): Key => ({
+          name,
+          ctrl: false,
+          meta: false,
+          shift: false,
+          paste: false,
+          sequence: '',
+        });
+        if (isPrefixNext) {
+          handleKeypress(undefined, createPasteKeyEvent('paste-start'));
+        } else if (isSuffixNext) {
+          handleKeypress(undefined, createPasteKeyEvent('paste-end'));
+        }
+        pos = nextMarkerPos + markerLength;
+      }
+    };
+
+    let rl: readline.Interface;
+    if (usePassthrough) {
+      rl = readline.createInterface({
+        input: keypressStream,
+        escapeCodeTimeout: 0,
+      });
+      readline.emitKeypressEvents(keypressStream, rl);
+      keypressStream.on('keypress', handleKeypress);
+      stdin.on('data', handleRawKeypress);
+    } else {
+      rl = readline.createInterface({ input: stdin, escapeCodeTimeout: 0 });
+      readline.emitKeypressEvents(stdin, rl);
+      stdin.on('keypress', handleKeypress);
+    }
+
+    return () => {
+      if (usePassthrough) {
+        keypressStream.removeListener('keypress', handleKeypress);
+        stdin.removeListener('data', handleRawKeypress);
+      } else {
+        stdin.removeListener('keypress', handleKeypress);
+      }
+
+      rl.close();
+
+      // Restore the terminal to its original state.
+      setRawMode(false);
+
+      if (backslashTimeout) {
+        clearTimeout(backslashTimeout);
+        backslashTimeout = null;
+      }
+
+      // Flush any pending paste data to avoid data loss on exit.
+      if (isPaste) {
+        broadcast({
+          name: '',
+          ctrl: false,
+          meta: false,
+          shift: false,
+          paste: true,
+          sequence: pasteBuffer.toString(),
+        });
+        pasteBuffer = Buffer.alloc(0);
+      }
+    };
+  }, [stdin, setRawMode, kittyProtocolEnabled, config, subscribers]);
+
+  return (
+    <KeypressContext.Provider value={{ subscribe, unsubscribe }}>
+      {children}
+    </KeypressContext.Provider>
+  );
+}