This removes the conflicts between the different parents and also
indicates that this is to be used internally by widgets and should
not be confused with the normal user visible parent.
It is an internal attribute that should not be used by people
not implementing widgets. Marking it as protected signifies it
as such.
Since focus_clear removed all the focused traces, focus was not reverted well
whenever win lost and got focus repeatedly.
For instance,
1. set focus to button1
2. set focus to button2
3. win focus out and in
4. remove button2
5. focus is on win not on button1
So, focus logic changes to not clear focused states when win loses focus.
@fix
Setting the no-render flag on an elm widget had no effect,
as it was not properly propagated to its children. This should
fix that, but I'm not a fan of the solution.
Fixes T3371
Tom Hacohen
WooHyun Jung
Jean-Philippe Andre
Cedric BAIL