budibase/packages/builder/src/components/userInterface/OptionSelect.svelte

<script>
  import { onMount, beforeUpdate, afterUpdate } from "svelte"
  import Portal from "svelte-portal"
  import { buildStyle } from "../../helpers.js"
  export let options = []
  export let value = ""
  export let styleBindingProperty
  export let onChange = value => {}

  let open = null
  let rotate = ""
  let select
  let selectMenu
  let icon

  let selectAnchor = null;
  let dimensions = {top: 0, bottom: 0, left: 0}

  let positionSide = "top"
  let maxHeight = 0
  let scrollTop = 0;
  let containerEl = null;

  const handleStyleBind = value =>
    !!styleBindingProperty ? { style: `${styleBindingProperty}: ${value}` } : {}

  onMount(() => {
    if (select) {
      select.addEventListener("keydown", handleEnter)
    }

    return () => {
      select.removeEventListener("keydown", handleEnter)
    }

  })

  function handleEscape(e) {
    if(open && e.key === "Escape") {
        toggleSelect(false)
    }
  }

  function getDimensions() {
    const { bottom, top: spaceAbove, left } = selectAnchor.getBoundingClientRect()
    const spaceBelow = window.innerHeight - bottom

    let y;

    if (spaceAbove > spaceBelow) {
      positionSide = "bottom"
      maxHeight = spaceAbove - 20  
      y = (window.innerHeight - spaceAbove)
    } else {
      positionSide = "top"
      y = bottom
      maxHeight = spaceBelow - 20
    }

    dimensions = {[positionSide]: y, left}
  }

  function handleEnter(e) {
    if (!open && e.key === "Enter") {
        toggleSelect(true)
    } 
  }

  function toggleSelect(isOpen) {
    getDimensions()
    if (isOpen) {
      icon.style.transform = "rotate(180deg)"      
    } else {
      icon.style.transform = "rotate(0deg)"
    }
    open = isOpen
  }


  function handleClick(val) {
    value = val
    onChange(value)
  }

  $: menuStyle = buildStyle({
    "max-height": `${maxHeight.toFixed(0)}px`,
    "transform-origin": `center ${positionSide}`,
    [positionSide]: `${dimensions[positionSide]}px`,
    "left": `${dimensions.left.toFixed(0)}px`,
  })

  $: isOptionsObject = options.every(o => typeof o === "object")

  $: selectedOption = isOptionsObject
    ? options.find(o => o.value === value)
    : {}

  $: if(open && selectMenu) {
    selectMenu.focus()
  }

  $: displayLabel =
    selectedOption && selectedOption.label ? selectedOption.label : value || ""
</script>

<div
  tabindex="0"
  bind:this={select}
  class="bb-select-container"
  on:click={() => toggleSelect(!open)}>
  <div bind:this={selectAnchor} class="bb-select-anchor selected">
    <span>{displayLabel}</span>
    <i bind:this={icon} class="ri-arrow-down-s-fill" />
  </div>
  {#if open}
  <Portal>
    <div
      tabindex="0"
      class:open
      bind:this={selectMenu}
      style={menuStyle}
      on:keydown={handleEscape}
      class="bb-select-menu">
      <ul>
        {#if isOptionsObject}
          {#each options as { value: v, label }}
            <li
              {...handleStyleBind(v)}
              on:click|self={handleClick(v)}
              class:selected={value === v}>
              {label}
            </li>
          {/each}
        {:else}
          {#each options as v}
            <li
              {...handleStyleBind(v)}
              on:click|self={handleClick(v)}
              class:selected={value === v}>
              {v}
            </li>
          {/each}
        {/if}
      </ul>
    </div>
   <div on:click|self={() => toggleSelect(false)} class="overlay" />
  </Portal>
  {/if}
</div>

<style>
  .overlay {
    position: fixed;
    top: 0;
    bottom: 0;
    right: 0;
    left: 0;
    z-index: 1;
  }

  .bb-select-container {
    outline: none;
    width: 160px;
    height: 36px;
    cursor: pointer;
    font-size: 14px;
  }

  .bb-select-anchor {
    cursor: pointer;
    display: flex;
    padding: 0px 12px;
    height: 36px;
    background-color: var(--grey-2);
    border-radius: 5px;
    align-items: center;
  }

  .bb-select-anchor > span {
    color: var(--ink);
    font-weight: 400;
    width: 140px;
    overflow-x: hidden;
  }

  .bb-select-anchor > i {
    transition: transform 0.13s ease;
    transform-origin: center;
    width: 20px;
    height: 20px;
    text-align: center;
  }

  .selected {
    color: var(--ink);
    font-weight: 400;
  }

  .bb-select-menu {
    position: absolute;
    display: flex;
    outline: none;
    box-sizing: border-box;
    flex-direction: column;
    opacity: 0;
    width: 160px;
    z-index: 2;
    color: var(--ink);
    font-weight: 400;
    height: fit-content !important;
    border-bottom-left-radius: 2px;
    border-bottom-right-radius: 2px;
    background-color: var(--grey-2);
    transform: scale(0);
    transition: opacity 0.13s linear, transform 0.12s cubic-bezier(0, 0, 0.2, 1);
    overflow-y: auto;
  }

  .open {
    transform: scale(1);
    opacity: 1;
  }

  ul {
    list-style-type: none;
    margin: 0;
    padding: 5px 0px;
  }

  li {
    height: auto;
    padding: 5px 0px;
    cursor: pointer;
    padding-left: 10px;
  }

  li:hover {
    background-color: #e6e6e6;
  }
</style>