Summary

To modify return type of public API StyleConverter.getEnumConverter()

Problem

StyleConverter.getEnumConverter() returns an instance of converting in "StyleConverter<String,? extends Enum>" type, whereas constructor of CssMetaData expects "StyleConverter<?, V>" where V is the type of the enum.

This forces the developer to cast the converter returned from StyleConverter.getEnumConverter() method. without cast code gives compile time error.

Solution

To change the return type of StyleConverter.getEnumConverter() from StyleConverter<String, ? extends Enum<?>> to StyleConverter<String, E>.

Specification

/**
 * Return a {@code StyleConverter} that converts a String representation
 * of an {@code Enum} to an {@code Enum}.
 * @param <E> the type of the {@code Enum}
 * @param enumClass the enum Class
 * @return A {@code StyleConverter} that converts a String representation
 * of an {@code Enum} to an {@code Enum}
 * @see Enum#valueOf(java.lang.Class, java.lang.String)
 */
public static <E extends Enum<E>> StyleConverter<String, E> getEnumConverter(Class<E> enumClass) { }