This method is only allowed to be called by a sub-frame according to
XFrame::activate() or XFramesSupplier::setActiveFrame() .
After this call XFramesSupplier::getActiveFrame() will return the
frame specified by Frame .
In general this method first calls the method XFramesSupplier::setActiveFrame()
at the creator frame with this as the current argument. Then it broadcasts
the FrameActionEvent FrameAction::FRAME_ACTIVATED .
Note: Given parameter Frame must already exist inside the container
(e.g., inserted by using XFrames::append() )