Class KeyEncoder

lib/ghostty.ts:161–244

 * Key Encoder - converts keyboard events into terminal escape sequences
 */
export class KeyEncoder {
  private exports: GhosttyWasmExports;
  private encoder: number = 0;

  constructor(exports: GhosttyWasmExports) {
    this.exports = exports;
    const encoderPtrPtr = this.exports.ghostty_wasm_alloc_opaque();
    const result = this.exports.ghostty_key_encoder_new(0, encoderPtrPtr);
    if (result !== 0) throw new Error(`Failed to create key encoder: ${result}`);
    const view = new DataView(this.exports.memory.buffer);
    this.encoder = view.getUint32(encoderPtrPtr, true);
    this.exports.ghostty_wasm_free_opaque(encoderPtrPtr);
  }

  setOption(option: KeyEncoderOption, value: boolean | number): void {
    const valuePtr = this.exports.ghostty_wasm_alloc_u8();
    const view = new DataView(this.exports.memory.buffer);
    view.setUint8(valuePtr, typeof value === 'boolean' ? (value ? 1 : 0) : value);
    this.exports.ghostty_key_encoder_setopt(this.encoder, option, valuePtr);
    this.exports.ghostty_wasm_free_u8(valuePtr);
  }

  setKittyFlags(flags: KittyKeyFlags): void {
    this.setOption(KeyEncoderOption.KITTY_KEYBOARD_FLAGS, flags);
  }

  encode(event: KeyEvent): Uint8Array {
    const eventPtrPtr = this.exports.ghostty_wasm_alloc_opaque();
    const createResult = this.exports.ghostty_key_event_new(0, eventPtrPtr);
    if (createResult !== 0) throw new Error(`Failed to create key event: ${createResult}`);

    const view = new DataView(this.exports.memory.buffer);
    const eventPtr = view.getUint32(eventPtrPtr, true);
    this.exports.ghostty_wasm_free_opaque(eventPtrPtr);

    this.exports.ghostty_key_event_set_action(eventPtr, event.action);
    this.exports.ghostty_key_event_set_key(eventPtr, event.key);
    this.exports.ghostty_key_event_set_mods(eventPtr, event.mods);

    if (event.utf8) {
      const encoder = new TextEncoder();
      const utf8Bytes = encoder.encode(event.utf8);
      const utf8Ptr = this.exports.ghostty_wasm_alloc_u8_array(utf8Bytes.length);
      new Uint8Array(this.exports.memory.buffer).set(utf8Bytes, utf8Ptr);
      this.exports.ghostty_key_event_set_utf8(eventPtr, utf8Ptr, utf8Bytes.length);
      this.exports.ghostty_wasm_free_u8_array(utf8Ptr, utf8Bytes.length);
    }

    const bufferSize = 32;
    const bufPtr = this.exports.ghostty_wasm_alloc_u8_array(bufferSize);
    const writtenPtr = this.exports.ghostty_wasm_alloc_usize();

    const encodeResult = this.exports.ghostty_key_encoder_encode(
      this.encoder,
      eventPtr,
      bufPtr,
      bufferSize,
      writtenPtr