Part 3 - Setting scale for the preview node

Post.js

getPreviewStyleAndPosition = () => {
  const { top, width, height } = this.preview.getBoundingClientRect();

  const transformMatrix = window.getComputedStyle(this.preview).transform;
  // transformMatrix is either 'none', or a string in the form of
  // matrix(0.965, 0, 0, 0.965, 0, 0)

  const scale =
    transformMatrix.indexOf('matrix') === 0
      ? parseFloat(transformMatrix.split(', ')[3])
      : 1;
  // scale above will actually be scaleY

  // since our post node will also be scaled we need to 
  // compensate width, height, and top with the scale
  // attribute
  return {
    top: top - height * (1 - scale) / 2,
    width: width / scale, 
    height: height / scale,
    borderRadius: 16,
    scale // we add the scale attribute
  };
};