Reusable QtModelIndex instance

Why?

Cause - i.e why is it needed?

• Developers wants best performance, if number of the items is hundreds to be viewed there is a performance impact
• There are many cases that the user deals only with an invalid QModelIndex and represents the root index. Extra jni calls can be avoided by adding reusable Q(t)ModelIndex instance.

Customer -  i.e. who needs it?

• TODO

Cruft - i.e. why it is not needed (counter arguments)?

• TODO

What?

Definition -  i.e what is it?

• Share a reference to a static invalid QtModelIndex to avoid extra JNI calls between jvm & native. To eliminate an invalid QtModelndex going back and forth between JVM & native, because an invalid QtModelIndex does not deliver any information other than being an invalid index (mostly when an item does not have parent aka. invalid parent).

Demarcation -  i.e. it is not?

Dependencies -  i.e. it needs?

How?

Effort - i.e  how easy or hard does it feel?

Estimate - i.e. how big is the amount of work (in calendar time)?

Essential - i.e the add on value it brings? High

When?

Flex i.e. time-bound (like platform or feature freeze) or not is it?

• New API, so bound to FF (in Qt 6.11 early December)

Force i.e. labor (do we have enough people working on it) capacity?

Fit i.e. does it fit in (like Qt release)?

• Qt 6.11?