gtk-text-buffer-paste-clipboard (buffer clipboard &key override editable)

buffer -- a gtk-text-buffer object
clipboard -- a gtk-clipboard object to paste from
override -- a gtk-text-iter location to insert pasted text, or nil to insert at the cursor
editable -- a boolean whether the text buffer is editable by default

Pastes the contents of a clipboard at the insertion point, or at override. Pasting is asynchronous, that is, we will ask for the paste data and return, and at some point later after the main loop runs, the paste data will be inserted.