Show JTree children in correct order

[pfroud]

The GUI uses the getDeclaredMethods() method to populate JTree children. But the Javadoc says:

The elements in the returned array are not sorted and are not in any particular order.

So the order of nodes in the JTree sometimes does not match the order in the KSY file.

Here's an example using png.ksy (from ide.kaitai.io). The order in the KSY file:

seq:
  - id: magic
  - id: ihdr_len
  - id: ihdr_type
  - id: ihdr
  - id: ihdr_crc
  - id: chunks

Example of the GUI showing the wrong order:

This pull request gets the correct order from the _seqFields field, which is generated from the KSY file.

The _seqFields field in the compiled png.java file:

public static String[] _seqFields = new String[] { "magic", "ihdrLen", "ihdrType", "ihdr", "ihdrCrc", "chunks" };

Now the JTree nodes are in the correct order:

[generalmimon]

I'm afraid that it's not possible to rely on SEQ_FIELDS alone, because the instances won't be found this way. The existing implementation iterated over methods, where instances were available, so showing only seq fields now would be an ugly regression.

Or am I missing something?

[pfroud]

You are not missing something, it doesn't work with instances!!!

KSY file to test it:

meta:
  id: instances_test
seq:
  - id: my_sequential_item
    type: u1
instances:
  my_instance:
    pos: 1
    type: u1

In the compiled Java code, the seqFields line does not have the instance:

public static String[] _seqFields = new String[] { "mySequentialItem" };

But the methods let us access the sequential item and the instance:

public long mySequentialItem() { ... }
public Long myInstance() { ... }

What do you think about this:

• Find sequential items using seq_fields. The order of the sequential items will match the order in the KSY file.
• Find instances by calling getDeclaredMethods() and then excluding names that are in seq_fields. The instances will be in arbitrary order. Show the instances in the JTree after all the sequential items.

[generalmimon]

@pfroud:

What do you think about this:

• Find sequential items using seq_fields. The order of the sequential items will match the order in the KSY file.
• Find instances by calling getDeclaredMethods() and then excluding names that are in seq_fields. The instances will be in arbitrary order. Show the instances in the JTree after all the sequential items.

Yes, seems reasonable to me. Order of instances in the .ksy spec isn't guaranteed anyway, because in the YAML tree they're defined in a mapping, where the key order is unspecified (each key is the identifier of a particular instance, equivalent of the id key in a seq field) - see the YAML 1.2 spec for reference. So not even the KS compiler knows what the "correct" order of instances should be - it doesn't matter.

[pfroud]

OK, I implemented that change, let me know how it looks

Screenshot using the minimal testing KSY file: