git clone 'git://github.com/rpav/buffer-buttons.git'


Working in CL, particularly with slime, I often wish I could simply click and evaluate a block of code:

  (some-other-function)) [<- Eval]

That is exactly what buffer-buttons is for. This will let you easily define, save, and load button definitions in files. For instance, if the above buffer were saved to a file, it would look like this:

  (some-other-function)) ;;#button:slime-eval

On load this would be restored to the emacs “button” that lets you eval the block.


Using this is easy; copy or link buffer-buttons.el somewhere emacs can find them, and put this in your .emacs:

(load "buffer-buttons")
(buffer-button-global-mode 1)

Inserting a button

Inserting a button is as simple as M-x buffer-button-insert followed by the button type. The following are predefined:

This will insert the “button” at the point, which you may then click on to activate.

Defining buttons

Defining buttons is fairly simple as well. Here is the definition for the slime-eval button:

(define-buffer-button (slime-eval b
                       :label "<- Eval"
                       :prefix ";;")
    (goto-char (button-start b))

This defines the slime-eval button type, the function buffer-button-fn-slime-eval, and sets the button label to <- Eval. The variable b is the emacs button object. The body is the function is the body executed when the button is clicked.

When a button is inserted via buffer-button-insert, the following text is generated in the buffer: ;;#button:slime-eval. Overlay properties are then used to convert this into a functional and visually-appealing button (or link, depending on your device).

You may also specify :prefix and :suffix, which get prepended and appended respectively to the generated text. This is useful for inserting buttons into source, such that any compilation or evaluation does not error.