Method updateLoopPlaybackUI

js/ReadingSystem.js:772–797

* 更新循环播放 UI

()

   * 更新循环播放 UI
   */
  updateLoopPlaybackUI() {
    if (!this.dom.loopToggleBtn) return;

    const mode = this.state.loopMode;
    const isList = mode === 'list';
    const isSentence = mode === 'sentence';
    const isActive = isList || isSentence;

    this.dom.loopToggleBtn.setAttribute('aria-pressed', isActive ? 'true' : 'false');
    toggleClass(this.dom.loopToggleBtn, 'active', isList);
    toggleClass(this.dom.loopToggleBtn, 'sentence', isSentence);

    let title = '列表循环';
    let label = '列表循环';

    if (isList) {
      title = '关闭循环播放';
      label = '关闭循环播放';
    } else if (isSentence) {
      title = '关闭单句循环';
      label = '关闭单句循环';
    }

    this.dom.loopToggleBtn.title = title;
    this.dom.loopToggleBtn.setAttribute('aria-label', label);
  }

  // =========================================================================
  // 翻译显示控制