Having a lot of child widgets, what can be best, filterevent or place 'detectors'

[tonnot]

I have a container widget where I place some children w.. My container has not empty borders (the children w. are placed from 0,0 to width, height, that is to say, can occupy the whole parent space).
I'like to control when the mouse is on the 4 borders of the parent widget.
What can be best, place 4 transparent frames or install a filter event for all the child widgets ?
Thanks

[wysota]

Just write appropriate event handlers. If that's not enough then install event filters.

[tonnot]

A last question, Is not possible to send mouse events automatically to the widgets placed behind the front widget ?
Something to 'sendtoback' or 'send to children of'. ?
Thanks.

[wysota]

Something to 'sendtoback' or 'send to children of'. ?
I think you should reconsider what is a child of what.