CODEWITHSUNDEEP
javaandroidkotlin
Codedruid13
Codedruid13

Reputation: 43

Projections are not allowed for immediate arguments of a supertype Kotlin

I converted a Java class to kotlin and am getting the mentioned the error Projections are not allowed for immediate arguments of a supertype

The Java class is

public class RecipeViewHolder extends ParentViewHolder {

    private static final float INITIAL_POSITION = 0.0f;
    private static final float ROTATED_POSITION = 180f;

    @NonNull
    private final ImageView mArrowExpandImageView;
    private TextView mRecipeTextView;
    private TextView position;
    private TextView total;

    public RecipeViewHolder(@NonNull View itemView) {
        super(itemView);
        mRecipeTextView = (TextView) itemView.findViewById(R.id.recipe_textview);
        position = (TextView) itemView.findViewById(R.id.textViewPosition);
        total = (TextView) itemView.findViewById(R.id.textViewTotal);

        mArrowExpandImageView = (ImageView) itemView.findViewById(R.id.arrow_expand_imageview);
    }

    public void bind(@NonNull Recipe recipe) {
        mRecipeTextView.setText(recipe.getName());

        try {

            position.setText("Position: " + recipe.getJson().getString("position"));
            total.setText("Total Bid Amount: " + recipe.getJson().getString("type"));

        } catch (JSONException e) {
            e.printStackTrace();
        }
    }

}

The converted Kotlin class is 

//Error occurs here in Parentvireholder<*,*>

class RecipeViewHolder(itemView: View) : ParentViewHolder<*, *>(itemView) {

    private val mArrowExpandImageView: ImageView
    private val mRecipeTextView: TextView
    private val position: TextView
    private val total: TextView

    init {

        mRecipeTextView = itemView.findViewById<View>(R.id.recipe_textview) as TextView
        position = itemView.findViewById<View>(R.id.textViewPosition) as TextView
        total = itemView.findViewById<View>(R.id.textViewTotal) as TextView

        mArrowExpandImageView = itemView.findViewById<View>(R.id.arrow_expand_imageview) as ImageView

    }

    fun bind(recipe: Recipe) {

        mRecipeTextView.text = recipe.name

        try {

            position.text = "Position: " + recipe.json!!.getString("position")
            total.text = "Total Bid Amount: " + recipe.json!!.getString("type")

        } catch (e: JSONException) {
            e.printStackTrace()
        }

    }

}

Error occurs in shown comment. I.ve tried the Any fix but that shows Type arguments is not within its bounds

Upvotes: 1

Views: 1208

Answers (1)

Jacob Ellis
Jacob Ellis

Reputation: 358

Kotlin requires you to specify the generic arguments of the superclass.

You need to replace the *'s in the superclass generic types with an explicit type or specify generic type's for the subclass.

You can't use Any if the super class generic types are restricted to a particular type. Have a look at the class definition of ParentViewHolder and declare the same types as that does:

RecipeViewHolder<P extends Parent<C>, C>(itemView: View) : ParentViewHolder<P, C>

or

RecipeViewHolder(itemView: View) : ParentViewHolder<MyParent, MyChild>

Upvotes: 1

Related Questions