[Bug]: KryptonNumericUpDown loses selection on mouse enter/leave

[Ahmed-Abdelhameed]

Describe the bug
Whenever the mouse enters or leaves the KryptonNumericUpDown control, the selection is cleared.

To Reproduce
Steps to reproduce the behavior:

1. Add a KryptonNumericUpDown control and type something into it.
2. Select the text.
3. Move the mouse cursor over and outside the control and notice the selection being cleared.

Expected behavior
The selection should remain the same when the mouse moves.

Screenshots

Desktop:

• OS: Windows 10
• Build: 2004.

Additional context
Looking at the source, I found out that both OnMouseEnter and OnMouseLeave methods call a private method called InvalidateChildren. That method triggers a redraw of the control (by invoking PI.RedrawWindow(...)) which causes the selection to be lost. I'm not sure if invoking RedrawWindow() is needed in OnMouseEnter or OnMouseLeave to begin with (I didn't dig deeper). If it is needed, then the selection probably needs to be maintained somehow.

While testing this, you might also notice another bug (i.e., #37) which I just reported. I was initially going to report them as one issue but decided not to because they're two separate problems.

Thank you so much for your great work :)

[Ahmed-Abdelhameed]

Actually, I was wrong about the source of the bug. I'm going to close this issue and open another one with more details.