Keep reference to type of SimpleNode value

[pfroud]

This is for my idea to add different colored icons for different data types, mentioned in issue #8.

The value field in SimpleNode.java is an Object, so when it is null we cannot tell what type it is. This PR adds field Class classOfValue.

KSY to easily get a null value:

meta:
  id: null_enum_test
seq:
  - id: null_enum
    enum: my_enum
enums:
   my_enum:
    1: one

Screenshot:

The code in ListNode.java is kind of gross. We can't check the generic type of an ArrayList at runtime because of type erasure. So, I look for a non-null element in the List and check its type.

[Mingun]

I agree that class of object need to store . I'm not thrilled to have to figure out the type of list item by specific objects, there may still be another way. Could you investigate this?

[Mingun]

Suggested change

	public Class<?> getClassOfValue() { return classOfValue; }
	public Class<?> getValueClass() { return valueClass; }

I bet, that this name is better.

[Mingun]

Suggested change

	/** Replace value.getClass() when value==null. */
	private final Class<?> classOfValue;
	/** Class of property, represented by the getter return value. */
	private final Class<?> valueClass;

value.getClass() is slightly incorrect, because it is dynamic type, but in fact the static type is stored here. For example ArrayList vs List

[Mingun]

I think it is better to avoid null in that field:

Suggested change

	valueClass = null;
	valueClass = Object.class;

[Mingun]

I don't really like the idea of looking at the content, because the type will depend on the specific object. Probably it is possible to extract some type from generic boundaries? I remember, that this should be possible.

[pfroud]

Regarding ListNode.java, I agree, the way I did it is dissatisfying.

I read some StackOverflow. Type erasure does apply here, if you do:

new ArrayList<Integer>().getClass().getTypeParameters()[0].getBounds()

it just returns:

[class java.lang.Object]

But we can do what we want using the Field or Method. Overview:

1. Call myField.getGenericType() or myMethod.getGenericReturnType()
2. Cast to java.lang.reflect.ParameterizedType
3. Call getActualTypeArguments()[0]

Via https://stackoverflow.com/a/1942680/7376577

I will push some more changes to this branch

[Mingun]

Thanks!