wmctrl-pad/lib/getDisplays.js

WindowPad functionality for Linux

// Load in dependencies
var exec = require('./utils').exec;

// Helper to determine displays
function getDisplays() {
  // Grab display sizings/offsets
  // DISPLAYS_STR=$(xrandr | grep ' connected ' | cut --fields=3 --delimiter ' ')
  /*
  $ xrandr | grep ' connected '
  VGA-0 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 597mm x 336mm
  LVDS-0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 344mm x 193mm
  $ xrandr | grep ' connected ' | sed -E 's/^[^ ]+ [^0-9]+([0-9]+x[^ ]+).*$/\1/'
  1920x1080+1920+0
  1920x1080+0+0
  */
  var displaysStr = exec("xrandr | grep ' connected ' | sed -E 's/^[^ ]+ [^0-9]+([0-9]+x[^ ]+).*$/\\1/'"),
      displaysArr = displaysStr.split(/\n/g),
      displays = displaysArr.map(function interpretdisplay (displayStr) {
        // DEV: This is a bash-like implementation -- normally, we would use .match(/.../g), or `extract-values` module
        var displayDimensions = displayStr.replace(/x/g, ' ').replace(/\+/g, ' ').split(' ');
        return {
          width: +displayDimensions[0],
          height: +displayDimensions[1],
          left: +displayDimensions[2],
          top: +displayDimensions[3]
        };
      });

  // Sort the displays in bookshelf order
  displays.sort(function (a, b) {
    if (a.top !== b.top) {
      return a.top - b.top;
    } else {
      return a.left - b.left;
    }
  });

  // Return the displays
  return displays;
}

// Export our helper
module.exports = getDisplays;