jxa-list-fullscreen-windows.js

#!/usr/bin/env osascript -l JavaScript

/**
 * A JXA script to list all the fullscreen windows.
 * Note: In macOS Mojave this method lists all the maximized windows as well.
 * So we don't know which ones are fullscreen.
 */

ObjC.import('CoreGraphics');

const unwrap = ObjC.deepUnwrap.bind(ObjC);
const getBounds = x => ['X', 'Y', 'Width', 'Height'].map(k => x.kCGWindowBounds[k]);

const windowInfo = unwrap($.CGWindowListCopyWindowInfo($.kCGWindowListOptionAll, $.kCGNullWindowID))
const applicationWindows = windowInfo.filter(x => x.kCGWindowLayer === 0 && x.kCGWindowName)
const menubar = windowInfo.filter(x => x.kCGWindowName === 'Menubar')[0]
const desktop = windowInfo.filter(x => x.kCGWindowName === 'Desktop')[0]

const fullFrameSize = getBounds(desktop);
const results = applicationWindows.filter(x => {
  const windowSize = getBounds(x)
  if (JSON.stringify(windowSize) === JSON.stringify(fullFrameSize)) {
    return true
  }
  return false
}).map(x => ({
  app: x.kCGWindowOwnerName,
  pid: x.kCGWindowOwnerPID,
  winTitle: x.kCGWindowName,
  winInfo: x,
}))

console.log("[DEBUG] results =", JSON.stringify(results, null, 2))