amis/scss/components/form/_tree.scss

.#{$ns}TreeControl {
  border: 1px solid $Form-input-borderColor;
  padding: 6px 12px;
  border-radius: 2px;
  max-height: 300px;
  overflow: auto;

  &.h-full {
    max-height: none;
    overflow: visible;
  }

  &.no-border {
    border: 0;
  }
}

.#{$ns}Tree {
  &-list,
  &-sublist {
    list-style: none;
    padding: 0;
    margin: 0;
  }

  &-sublist.is-folded {
    display: none;
  }

  &-item {
    line-height: $Tree-itemHeight;
    position: relative;

    > div {
      &:hover {
        text-decoration: none;

        > .#{$ns}Tree-item-icons {
          visibility: visible;
        }
      }

      > span > svg {
        display: inline-block;
        cursor: pointer;
        position: relative;
        top: 2px;
        width: px2rem(16px);
        height: px2rem(16px);
        margin-left: px2rem(5px);
      }
    }
  }

  &-rootItem {
    line-height: $Tree-itemHeight;
  }

  &-item > div:hover > .#{$ns}Tree-item-icons,
  &-rootItem > div:hover > .#{$ns}Tree-item-icons {
    visibility: visible;
  }

  &-itemLabel {
    display: flex;
    &:hover {
      background: $Tree-item-onHover-bg;
    }
  }

  &-item-icons {
    visibility: hidden;
    transition: visibility 0.1s ease;
    display: inline-block;
    vertical-align: top;
    height: $Tree-itemHeight;
    line-height: $Tree-itemHeight;

    > a {
      display: inline-block;
      vertical-align: middle;
      margin-left: $gap-xs;
      cursor: pointer;

      > svg {
        $svgSize: px2rem(16px);
        width: $svgSize;
        height: $svgSize;
        top: 0.125 * $svgSize;
      }
    }
  }

  &-itemInput {
    padding-left: $Tree-itemArrowWidth;

    > a {
      display: inline-block;
      cursor: pointer;
      margin-left: $gap-sm;
      color: $icon-color;

      &:hover {
        color: $icon-onHover-color;
        text-decoration: none;
      }
    }

    > input {
      outline: none;
      background-color: $Form-input-bg;
      border: $Form-input-borderWidth solid $Form-input-borderColor;
      border-radius: $Form-input-borderRadius;
      line-height: $Form-input-lineHeight;
      padding: (
          $Tree-inputHeight - $Form-input-lineHeight * $Form-input-fontSize -
            px2rem(2px)
        )/2 $Form-input-paddingX;
      font-size: $Form-input-fontSize;

      &::placeholder {
        color: $Form-input-placeholderColor;
        user-select: none;
      }

      &:focus {
        border-color: $Form-input-onFocused-borderColor;
        box-shadow: $Form-input-boxShadow;

        @if $Form-input-onFocused-bg !=$Form-input-bg {
          background-color: $Form-input-onFocused-bg;
        }
      }
    }
  }

  &-addTopBtn {
    cursor: pointer;
    height: $Tree-itemHeight;
    line-height: $Tree-itemHeight;
    display: block;

    &:hover {
      text-decoration: none;
    }

    &.is-disabled {
      pointer-events: none;
      color: $text--muted-color;
    }

    > svg {
      $svgSize: px2rem(14px);
      width: $svgSize;
      height: $svgSize;
      top: $svgSize * 0.125;
      margin-right: $Tree-itemArrowWidth - px2rem(14px); // icon 的宽度是14px
    }
  }

  &-itemArrow {
    cursor: pointer;
    width: $Tree-itemArrowWidth;
    text-align: center;
    display: inline-block;

    &:before {
      font-style: normal;
      font-family: $Tree-arrowVendor;
      content: $Tree-unfoldedArrowContent;
    }

    &.is-folded:before {
      content: $Tree-foldedArrowContent;
    }
  }

  &-itemArrowPlaceholder {
    display: inline-block;
    width: $Tree-itemArrowWidth;
  }

  &-itemIcon {
    display: inline-block;
    margin-right: px2rem(3px);
  }

  &-rootIcon {
    &:before {
      font-style: normal;
      font-family: $Tree-rootIconVendor;
      content: $Tree-rootIconContent;
    }
  }

  &-leafIcon {
    &:before {
      font-style: normal;
      font-family: $Tree-leafIconVendor;
      content: $Tree-leafIconContent;
    }
  }

  &-folderIcon {
    &:before {
      font-style: normal;
      font-family: $Tree-folderIconVendor;
      content: $Tree-folderIconContent;
    }
  }

  &-itemLabel {
    user-select: none;

    &.is-checked,
    &.is-children-checked {
      color: $Tree-itemLabel--onChecked-color;
    }

    &.is-disabled {
      color: $text--muted-color;
    }
  }

  &-itemText {
    cursor: pointer;
    flex: 1 auto;
  }

  &-placeholder {
    color: $text--muted-color;
  }

  &-item &-item > &-itemLabel,
  &-item &-item > &-placeholder {
    padding-left: $Tree-indent;
  }

  &-item &-item &-item > &-itemLabel,
  &-item &-item &-item > &-placeholder {
    padding-left: $Tree-indent * 2;
  }

  &-item &-item &-item &-item > &-itemLabel {
    padding-left: $Tree-indent * 3;
  }

  &-item &-item &-item &-item &-item > &-itemLabel {
    padding-left: $Tree-indent * 4;
  }

  &-item &-item &-item &-item &-item &-item > &-itemLabel {
    padding-left: $Tree-indent * 5;
  }

  &-item &-item &-item &-item &-item &-item &-item > &-itemLabel {
    padding-left: $Tree-indent * 6;
  }

  &-item &-item &-item &-item &-item &-item &-item &-item > &-itemLabel {
    padding-left: $Tree-indent * 7;
  }

  &-item &-item &-item &-item &-item &-item &-item &-item &-item > &-itemLabel {
    padding-left: $Tree-indent * 8;
  }

  &-item
    &-item
    &-item
    &-item
    &-item
    &-item
    &-item
    &-item
    &-item
    &-item
    > &-itemLabel {
    padding-left: $Tree-indent * 9;
  }

  &-item
    &-item
    &-item
    &-item
    &-item
    &-item
    &-item
    &-item
    &-item
    &-item
    &-item
    > &-itemLabel {
    padding-left: $Tree-indent * 10;
  }
}