How to change opacity of text widget to 0.7 with flutter extension?

Question

I need change style of Text Widget in flutter with an extension. this extension must be change opacity of Text Widget to 0.7 . when i used in on Text widget , i can change opacity of widget to 0.7.

UPDATE: if Text widget has style and color, this ok . but when not have style receive null error .

extension TextStyleOpacity on Text {
  Text  opacity70(){
    return Text("A", style:this.style!.copyWith(color:this.style?.color!.withOpacity(0.3) ) ,) ;
  }
}

Answer 1

ok. I change this extension for text style and solved , answer is :

    extension TextStyleOpacity on TextStyle?{
  TextStyle colorOpacity ({required BuildContext context}){
    Color? color =this==null?DefaultTextStyle.of(context).style.color: this?.color;
    if(this==null){
      return DefaultTextStyle.of(context).style.copyWith(color: color!.withOpacity(0.7));
    }else{
      return this!.copyWith(color: color!.withOpacity(0.7));
    }
  }
}

And is used like this example:

Text(textWidget.data! ,style:textWidget.style.colorOpacity(context: context),);