Introduction

This is a emcas plugin to convert px unit to vw or vh in css or other files.

How to use

Download the px2vw.el file to your emcas elisp configuration directory, generally it is ~/.emcas.d/lisp/ in MacOS. Or copy the content of px-2vw.el to a .el file in emcas el config path, and i suggest to also named px2vw.el.
Add blow code to your emcas config file, ~/.emcas.d/init.el or ~/.emcas.d/custom.el are ok.

(require 'px2vw)
(global-set-key (kbd "C-c w") 'region-px->vw)

Now，you added a shortcut key to emacs, if it is inconvenient, you can set F9 to do this.

(global-set-key [f9] 'region-px->vw)

Move point to width number with "px" unit, and press shortcut key C-c w, px unit will convert to vw. For example:

.div {
    width: 200px;
}

use C-c w shortcur key in "200px" chars, it will auto convert to

.div {
    width: 13.8889vw;
}

The vw value is convert by expression (/ (* px 100) viewport-width) and maintain four float points.

I gived default width of viewport is 1440, and not support to change by param, so if you want to change, please modify value of the first line constant viewpoint-width in px2vw.el.