How do I swap the chevron icon when the dropdown opens?

Both renderLeftIcon and renderRightIcon receive the current visibility as their argument.

import Icon from '@expo/vector-icons/Feather';

<Dropdown
  data={data}
  labelField="label"
  valueField="value"
  renderRightIcon={(visible) => (
    <Icon
      name={visible ? 'chevron-up' : 'chevron-down'}
      size={20}
      color="gray"
    />
  )}
  onChange={(item) => setValue(item.value)}
/>;

Same pattern on renderLeftIcon. Both arguments are typed as visible?: boolean — the optional ? just reflects that the render function is called before the first open with undefined; treat undefined the same as false.

Works on Dropdown, MultiSelect, and SelectCountry.