Class InputSystem

packages/engine-core/src/Input/InputSystem.ts:71–264

 */
@ECSSystem('InputSystem', { updateOrder: -1000 }) // 最先更新 | Update first
export class InputSystem extends EntitySystem {
    private _inputManager: InputManager;
    private _inputSubsystem: IPlatformInputSubsystem | null = null;
    private _disableInEditor: boolean;
    private _isInitialized: boolean = false;

    constructor(config: InputSystemConfig = {}) {
        // 不匹配任何实体，只用于生命周期 | Match no entities, only for lifecycle
        super(Matcher.nothing());

        this._inputManager = config.inputManager ?? Input;
        this._disableInEditor = config.disableInEditor ?? false;
    }

    /**
     * 设置平台输入子系统
     * Set platform input subsystem
     *
     * @param subsystem 平台输入子系统 | Platform input subsystem
     */
    setInputSubsystem(subsystem: IPlatformInputSubsystem): void {
        // 如果已有子系统，先解绑 | Unbind if already has subsystem
        if (this._inputSubsystem && this._isInitialized) {
            this.unbindEvents();
        }

        this._inputSubsystem = subsystem;

        // 如果已初始化，立即绑定 | Bind immediately if initialized
        if (this._isInitialized) {
            this.bindEvents();
        }
    }

    /**
     * 获取输入管理器
     * Get input manager
     */
    get inputManager(): InputManager {
        return this._inputManager;
    }

    protected override onInitialize(): void {
        this._isInitialized = true;

        if (this._inputSubsystem) {
            this.bindEvents();
        }
    }

    /**
     * 绑定平台输入事件
     * Bind platform input events
     */
    private bindEvents(): void {
        if (!this._inputSubsystem) return;

        const sub = this._inputSubsystem;