Add keyval_to/is_upper/lower functions to Key struct

[Amjad50]

added:

• keyval_is_upper
• keyval_is_lower
• keyval_to_upper
• keyval_to_lower

As I could not use them in my project in the recent versions, here, As u32 cannot be converted back into Key

what do you think? @GuillaumeGomez

[sdroege]

Looks good to me, but maybe we should also add From<u32> for Key and From<Key> for u32 impls? That's basically there already anyway via the DerefMut / Deref impls

Is there any reason why this could cause problems?

[Amjad50]

oops, actually it appears I can convert without this PR:

let mut val = event.get_keyval();
*val = keyval_to_upper(*val);
match val {
...

I don't know why I struggled a lot for converting it to uppercase, that's why I suggested this PR.
Do you think this would be good anyway? I think its better for code clarity.

we should also add From<u32> for Key and From<Key> for u32 impls?

Yes, though I think From<Key> for u32 is not needed as it is identical to Deref

[sdroege]

Do you think this would be good anyway? I think its better for code clarity.

I agree, yes

[Amjad50]

I guess keyval_name, keyval_to_unicode are needed in lib.rs, they are being exported to outside

[Amjad50]

since now u32 can be converted to Key, are keyval_name(u32), keyval_to_unicode(u32) necessary?

[GuillaumeGomez]

I don't think we should keep them.

[Amjad50]

problems with check_init_asserts?

[GuillaumeGomez]

You might need to add some skip_assert_initialized where it's missing.