copyLayers method

List<TextLayerData> copyLayers()

深拷贝所有图层（用于历史记录）

Implementation

List<TextLayerData> copyLayers() {
  return _layers.values.map((layer) {
    return TextLayerData(
      id: layer.id,
      text: layer.text,
      position: layer.position,
      color: layer.color,
      fontSize: layer.fontSize,
      isSelected: layer.isSelected,
    );
  }).toList();
}