Qfyilyi

I have the following object structure:

class Annotation;

class LabelAnnotation: inherits Annotation;

class TextAnnotation: inherits LabelAnnotation;

I would like to use "creator" objects to do some initialization on these object (This initialization depends on external settings so I don't want to do it in the constructor of these objects.)

In particular, when creating a LabelAnnotation I would like to do:

fontSize = AppDefaults.fontSize

So I'm writing a "creator":

class LabelAnnotationCreator {

    LabelAnnotation create() {

        annotation = LabelAnnotation()

        annotation.fontSize = AppDefaults.fontSize

        return annotation;

    }

}

Now, I would like to create a TextAnnotationCreator. This is where I'm stuck: I can't use the LabelAnnotationCreator because it would create an instance of a LabelAnnotation, but on the other hand, I want to benefit from the initialization performed by the LabelAnnotationCreator.

class TextAnnotationCreator {

    TextAnnotation create() {

        annotation = TextAnnotation()

        // I'm stuck here:

        // can't do LabelAnnotationCreator().create()… ???

        return annotation;

    }

}

Obviously, this isn't the right pattern but I'm not sure how to find the correct one.

Thanks!

what do you think about this:

class TextAnnotation {

    private final int someOtherArgs;

    private final int fontSize;



    public TextAnnotation(LabelAnnotation labelAnnotation, int someOtherArgs) {

        this(someOtherArgs, labelAnnotation.getFontSize());

    }



    public TextAnnotation(int someOtherArgs, int fontSize) {

        this.someOtherArgs= someOtherArgs;

        this.fontSize = fontSize;

    }

}

create a constructor on TextAnnotation that builds a object from a LabelAnnotation configuration. Then you can use it like this:

TextAnnotation text = new TextAnnotation(someArgs,fontSize);

or using your creator

class TextAnnotationCreator {

    TextAnnotation create() {

        return 

           new TextAnnotation(

               new LabelAnnotationCreator().create(),

               someOtherArgs

           );

    }

}