Method setLanguage

src/core/nodeviews/code-block.ts:1399–1430

* 设置语言

(language: string)

   * 设置语言
   */
  private setLanguage(language: string): void {
    const pos = this.getPos();
    if (pos === undefined) return;

    const prevLanguage = this.node.attrs.language;

    // 更新 ProseMirror 节点属性
    this.view.dispatch(
      this.view.state.tr.setNodeMarkup(pos, null, {
        ...this.node.attrs,
        language,
      })
    );

    // 更新 CodeMirror 语言扩展
    this.cm.dispatch({
      effects: this.languageCompartment.reconfigure(getLanguageExtension(language)),
    });

    // 更新头部（添加或移除 Mermaid 模式选择器）
    if ((prevLanguage === "mermaid") !== (language === "mermaid")) {
      this.updateHeader(language);
    }

    // 更新 Mermaid 预览
    if (language === "mermaid") {
      this.createMermaidPreview(this.cm.state.doc.toString());
    } else if (this.mermaidPreview) {
      this.mermaidPreview.remove();
      this.mermaidPreview = null;
    }
  }

  /**
   * 更新头部