thank you guruji for your reply..

both the options you suggested are same as the some i was thinking of...
i am thinking that in the mouseEvents handlers of "P" i check wether the pos() of click comes in geometry of "B", then manually postEvent() a new mouseEvent to "B"...
so in all the three cases i have to postEvent() a new mouseEvent to "B"... ... so now as i got the confirmation of the guru.. i will go with it... ...