stable-diffusion-webui-ux/javascript/hires_fix.js

function onCalcResolutionHires(
  enable,
  width,
  height,
  hr_scale,
  hr_resize_x,
  hr_resize_y
) {
  function setInactive(elem, inactive) {
    elem.classList.toggle("inactive", !!inactive);
  }

  var hrUpscaleBy = gradioApp().getElementById("txt2img_hr_scale");
  var hrResizeX = gradioApp().getElementById("txt2img_hr_resize_x");
  var hrResizeY = gradioApp().getElementById("txt2img_hr_resize_y");

  gradioApp().getElementById("txt2img_hires_fix_row2").style.display =
    opts.use_old_hires_fix_width_height ? "none" : "block";

  setInactive(
    hrUpscaleBy,
    opts.use_old_hires_fix_width_height || hr_resize_x > 0 || hr_resize_y > 0
  );
  setInactive(
    hrResizeX,
    opts.use_old_hires_fix_width_height || hr_resize_x == 0
  );
  setInactive(
    hrResizeY,
    opts.use_old_hires_fix_width_height || hr_resize_y == 0
  );

  setTimeout(function () {
    return [enable, width, height, hr_scale, hr_resize_x, hr_resize_y];
  }, 100);
}