Question on gnuradio.wxgui and the agc block

Does anyone have info on gnuradio.wxgui? Like a list of blocks available
through it, etc?

Also, I have “A dictionary of the GNU Radio blocks” by Dawei Shen, but I
couldn’t find anything about the gr.agc_cc block in it. Any help on
that? I’ll go a step further and ask if there is are more help files on
available GNU radio blocks, and about writing your own block?