A utility to zoom-in and zoom-out while editing text
Save the file eagle-eye.el to disk and add the directory containing it to load-path using a command in your .emacs file like:
(add-to-list 'load-path "~/.emacs.d/")
The above line assumes that you've placed the file into the Emacs directory '.emacs.d'.
Start the package with:
(require 'eagle-eye)
If you have Marmalade added as a repository to your Emacs, you can just install eagle-eye with
M-x package-install eagle-eye RET
Enable eagle-eye-mode in any buffer to scale down the text in that buffer by set scale. Disabling the minor-mode will bring the text size back to normal.
(eagle-eye-mode)
You can also set key-bindings to functions eagle-eye-zoom-in' and eagle-eye-zoom-out', so that you can change text size across Emacs at once.
(global-set-key (kbd "C->") 'eagle-eye-zoom-in)
(global-set-key (kbd "C-<") 'eagle-eye-zoom-out)
The eagle-eye text scaling can be set as
(eagle-eye-set-text-scaling 5)
Also, you can set the step by which zooming in and zooming out happens by
(eagle-eye-set-zoom-step 10)
By default, the eagle-eye text scaling is 5 and zoom step is 10.