vm-gallery

VmGallery.vue

<template lang="pug">
  .vm-gallery
    div(
      :style="{ transitionDuration: transitionDuration, transform: translate3DPosition }"
      ref="galleryItems"
    ).vm-gallery-items
      div(v-for="imageItem in imageNodes").vm-gallery-item
        img(
          :src="imageItem.src"
          :key="imageItem.src"
        ).vm-gallery-item-image

    .vm-gallery-controls
      button(@click="sliderStepController('PREV')").vm-gallery-controls-button.vm-gallery-controls-button_left
        // Your left button icon
        span.vm-gallery-controls-button-arrow-icon.vm-gallery-controls-button-arrow-icon_left

      button(@click="sliderStepController('NEXT')").vm-gallery-controls-button.vm-gallery-controls-button_right
        // Your right button icon
        span.vm-gallery-controls-button-arrow-icon.vm-gallery-controls-button-arrow-icon_right

</template>


<script>
  export default {
    name: 'VmGallery',

    props: {
      /**
      * Array of image links
      */
      images: {
        type: Array,
        required: true,
        validate: value => value?.length >= 3
      }
    },

    data() {
      return {
        // View
        transitionDuration: '300ms',
        translate3DPosition: 0,
        imageNodes: [],

        // System
        currentSliderPosition: null,
        sliderReadyToSwitch: true
      }
    },

    methods: {
      calculateCurrentSliderPosition(CURRENT_VIEW_POSITION_INDEX) {
        const IMAGE_WIDTH = 820
        const IMAGE_PADDING = 25
        const TOTAL_POSITION = -((IMAGE_WIDTH + IMAGE_PADDING) * (CURRENT_VIEW_POSITION_INDEX - 1)) + 197.5

        return `translate3d(${TOTAL_POSITION}px, 0, 0)`
      },

      sliderStepController(DIRECTION) {
        if (!this.sliderReadyToSwitch) {
          return
        }

        if (DIRECTION === 'PREV') {
          this.currentSliderPosition -= 1
        }

        if (DIRECTION === 'NEXT') {
          this.currentSliderPosition += 1
        }

        if (this.imageNodes[this.currentSliderPosition - 1].endImageNode) {
          // Bad code (if you find a better solution, write me)
          setTimeout(() => {
            this.resetSlider()
            this.transitionDuration = '0ms'
            setTimeout(() => {
              this.transitionDuration = '300ms'
              this.sliderReadyToSwitch = true
            }, 20)
          }, 300)
        }

        this.translate3DPosition = this.calculateCurrentSliderPosition(this.currentSliderPosition)
      },

      // System
      generateImageNodes() {
        this.imageNodes = this.generateImagesNodeMetaInformation(
          [
            this.images[this.images.length - 1],
            ...this.images,
            ...this.images,
            this.images[0],
            this.images[1]
          ]
        )
      },

      generateImagesNodeMetaInformation(imagesNode) {
        return imagesNode.map((src, imageNodeIndex, imagesNode) => {
          const IS_END_IMAGE_NODE = !!(imageNodeIndex === 1 || imagesNode.length - 2 === imageNodeIndex)
          return {
            src,
            endImageNode: IS_END_IMAGE_NODE
          }
        })
      },

      getCenterPositionImageNumber() {
        return Math.round((this.imageNodes.length - 1) / 2) + 1
      },

      resetSlider() {
        this.currentSliderPosition = this.getCenterPositionImageNumber()
        this.translate3DPosition = this.calculateCurrentSliderPosition(this.currentSliderPosition)
      },

      onEventListeners() {
        this.$refs.galleryItems.addEventListener('transitionend', () => {
          this.sliderReadyToSwitch = true
        })

        this.$refs.galleryItems.addEventListener('transitionstart', () => {
          this.sliderReadyToSwitch = false
        })
      }
    },

    created() {
      this.generateImageNodes()
      this.resetSlider()
    },

    mounted() {
      this.onEventListeners()
    },

    activated() {
      this.onEventListeners()
    }
  }
</script>


<style lang="sass">
  .vm-gallery
    position: relative
    width: 1240px
    min-height: 440px
    overflow: hidden


  .vm-gallery-items
    position: absolute
    display: flex
    min-height: 440px
    transition-timing-function: cubic-bezier(0.22, 1, 0.36, 1)


  .vm-gallery-item
    width: 820px
    height: 440px
    margin-right: 12.5px
    margin-left: 12.5px
    border-radius: 15px

    > img
      display: block
      width: 100%
      height: 100%
      border-radius: 25px


  .vm-gallery-controls
    position: absolute
    top: 0
    z-index: 3
    display: flex
    width: 100%
    height: 100%


  .vm-gallery-controls-button
    position: relative
    display: block
    width: 50%
    height: 100%
    padding: 0
    margin: 0
    cursor: pointer
    border: none
    outline: none
    box-shadow: none
    opacity: 0
    transition: opacity .3s cubic-bezier(0.22, 1, 0.36, 1)

    &_right
      background: linear-gradient(90deg, rgb(0 0 255 / 0%) 72%, rgb(0 0 0 / 20%))

      &:hover
        opacity: 1

    &_left
      background: linear-gradient(-90deg, rgb(0 0 255 / 0%) 72%, rgb(0 0 0 / 20%))

      &:hover
        opacity: 1


  .vm-gallery-controls-button-arrow-icon
    position: absolute
    color: #fff

    &_right
      right: 70px

    &_left
      left: 70px

</style>