How to identify the emacs keybinding for something in the GUI?
The answer to the major question:
- Type
C-h kand then click the toolbar button. It won't actually perform the action, but pop up a help buffer that tells you the name of the function. - Then type
C-h w(for "where is") and type the name of that function. That will tell you what keys, if any, are bound to that function.
Also try C-h m. This shows you the current modes (including the major mode) and its keymaps. The keymap for the major mode is the most important thing. There you see which function is bound to which key.