src/view/com/lightbox/ImageViewing/utils.ts


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/**
 * Copyright (c) JOB TODAY S.A. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 */

import {Dimensions, Position} from './@types'

export const getImageTransform = (
  image: Dimensions | null,
  screen: Dimensions,
) => {
  if (!image?.width || !image?.height) {
    return [] as const
  }

  const wScale = screen.width / image.width
  const hScale = screen.height / image.height
  const scale = Math.min(wScale, hScale)
  const {x, y} = getImageTranslate(image, screen)

  return [{x, y}, scale] as const
}

export const getImageTranslate = (
  image: Dimensions,
  screen: Dimensions,
): Position => {
  const getTranslateForAxis = (axis: 'x' | 'y'): number => {
    const imageSize = axis === 'x' ? image.width : image.height
    const screenSize = axis === 'x' ? screen.width : screen.height

    return (screenSize - imageSize) / 2
  }

  return {
    x: getTranslateForAxis('x'),
    y: getTranslateForAxis('y'),
  }
}