Mouse control alterante switching by a click of mouse

[giogio]

Hello, in many remote control software there is an important feature that I find missing on real-VNc and maybe on ultra-VNC also, for what I could observe.
The feature allows the mouse control input to be switched between local and remote user by a click of the mouse. In other words instead of having both of the mice controlling the presenter screen, the presenter or the remote gain control by first left clicking once on the screen (server side) or on the vnc window (viewer side).
Is the feature implemented already and I missed.
If not I would request it to be implemented.
Regards
G