Checkbox

1import * as RadixCheckbox from "@radix-ui/react-checkbox";
2import { useId, useState } from "react";
3import { getClassName } from "@behivetech/get-class-name";
4import styles from "./checkbox.module.scss";
5
6import type { CheckedState } from "@radix-ui/react-checkbox";
7
8export type { CheckedState };
9
10export interface CheckboxProps extends Omit<
11  RadixCheckbox.CheckboxProps,
12  "className"
13> {
14  /** Additional class names to merge with the component root element */
15  className?: string;
16  /** Marks the field as invalid: adds the `--invalid` modifier and sets `aria-invalid="true"` */
17  invalid?: boolean;
18}
19
20/**
21 * Bare checkbox control — the Radix checkbox button is this component's own
22 * root element, no built-in label/hint/error. Wrap it in `FormField` for
23 * that chrome: `<FormField label="..." htmlFor="x"><Checkbox id="x" /></FormField>`.
24 */
25export const Checkbox = ({
26  className,
27  id,
28  checked,
29  defaultChecked = false,
30  onCheckedChange,
31  invalid = false,
32  "aria-invalid": ariaInvalid,
33  ...rest
34}: CheckboxProps) => {
35  const generatedId = useId();
36  const checkboxId = id ?? generatedId;
37
38  const isInvalid = invalid || ariaInvalid === true || ariaInvalid === "true";
39
40  // The controlled `checked` wins; otherwise the component tracks its own
41  // state so `--checked` / `--indeterminate` work uncontrolled too.
42  const [internalChecked, setInternalChecked] =
43    useState<CheckedState>(defaultChecked);
44  const currentChecked = checked ?? internalChecked;
45
46  const handleCheckedChange = (next: CheckedState) => {
47    if (checked === undefined) {
48      setInternalChecked(next);
49    }
50    onCheckedChange?.(next);
51  };
52
53  const [rootClass, getChildClass] = getClassName({
54    className,
55    modifiers: {
56      checked: currentChecked === true,
57      indeterminate: currentChecked === "indeterminate",
58      invalid: isInvalid,
59    },
60    rootClass: "BHT__Checkbox",
61    styles,
62  });
63
64  return (
65    <RadixCheckbox.Root
66      {...rest}
67      id={checkboxId}
68      checked={currentChecked}
69      onCheckedChange={handleCheckedChange}
70      className={rootClass}
71      aria-invalid={isInvalid ? true : ariaInvalid}
72    >
73      <RadixCheckbox.Indicator className={getChildClass("indicator")}>
74        {currentChecked === "indeterminate" ? (
75          <svg
76            viewBox="0 0 12 4"
77            fill="none"
78            stroke="currentColor"
79            strokeWidth="2.5"
80            strokeLinecap="round"
81            aria-hidden="true"
82          >
83            <path d="M1 2H11" />
84          </svg>
85        ) : (
86          <svg
87            viewBox="0 0 12 10"
88            fill="none"
89            stroke="currentColor"
90            strokeWidth="2.5"
91            strokeLinecap="round"
92            strokeLinejoin="round"
93            aria-hidden="true"
94          >
95            <path d="M1 5L4.5 8.5L11 1" />
96          </svg>
97        )}
98      </RadixCheckbox.Indicator>
99    </RadixCheckbox.Root>
100  );
101};

1// Material Design 3 checkbox.
2//
3// `color` on the root is not used for text — it is the state layer's tint
4// (`currentColor` in ::after), so it tracks the box: on-surface-variant when
5// unchecked, primary when checked, error when invalid.
6
7.BHT__Checkbox {
8  // Radix renders as <button role="checkbox">
9  position: relative;
10  width: 1rem;
11  height: 1rem;
12  flex-shrink: 0;
13  border: 2px solid
14    var(--md-sys-color-on-surface-variant, var(--color-border-strong));
15  border-radius: 2px;
16  background: transparent;
17  color: var(--md-sys-color-on-surface-variant, var(--color-text-muted));
18  display: inline-flex;
19  align-items: center;
20  justify-content: center;
21  padding: 0;
22  cursor: pointer;
23  transition:
24    background var(--md-sys-motion-duration-short-3, 150ms)
25      var(--md-sys-motion-easing-standard, ease),
26    border-color var(--md-sys-motion-duration-short-3, 150ms)
27      var(--md-sys-motion-easing-standard, ease);
28
29  // Touch target: a 48px square hit area around the 16px box, without
30  // changing its drawn size. px on purpose — a finger doesn't scale with type.
31  &::before {
32    content: "";
33    position: absolute;
34    top: 50%;
35    left: 50%;
36    translate: -50% -50%;
37    width: 48px;
38    height: 48px;
39  }
40
41  // State layer: MD3 draws it as a circle around the box, not on the box.
42  &::after {
43    content: "";
44    position: absolute;
45    top: 50%;
46    left: 50%;
47    translate: -50% -50%;
48    width: 2.5rem;
49    height: 2.5rem;
50    border-radius: var(--md-sys-shape-corner-full, 9999px);
51    background: currentColor;
52    opacity: 0;
53    pointer-events: none;
54    transition: opacity var(--md-sys-motion-duration-short-2, 100ms)
55      var(--md-sys-motion-easing-standard, ease);
56  }
57
58  &:hover:not(:disabled)::after {
59    opacity: var(--md-sys-state-hover-opacity, 0.08);
60  }
61
62  &:focus-visible::after {
63    opacity: var(--md-sys-state-focus-opacity, 0.1);
64  }
65
66  &:active:not(:disabled)::after {
67    opacity: var(--md-sys-state-pressed-opacity, 0.1);
68  }
69
70  &--checked,
71  &--indeterminate {
72    &.BHT__Checkbox {
73      background: var(--md-sys-color-primary, var(--color-primary));
74      border-color: var(--md-sys-color-primary, var(--color-primary));
75      color: var(--md-sys-color-primary, var(--color-primary));
76    }
77  }
78
79  &:focus-visible {
80    outline: 3px solid var(--md-sys-color-secondary, var(--color-border-focus));
81    outline-offset: 2px;
82  }
83
84  &:disabled {
85    opacity: 0.5;
86    cursor: not-allowed;
87  }
88
89  &--invalid {
90    &.BHT__Checkbox {
91      border-color: var(--md-sys-color-error, var(--color-error));
92      color: var(--md-sys-color-error, var(--color-error));
93
94      &.BHT__Checkbox--checked,
95      &.BHT__Checkbox--indeterminate {
96        background: var(--md-sys-color-error, var(--color-error));
97        border-color: var(--md-sys-color-error, var(--color-error));
98
99        .BHT__Checkbox {
100          &__indicator {
101            color: var(--md-sys-color-on-error, var(--color-on-primary));
102          }
103        }
104      }
105    }
106  }
107
108  &__indicator {
109    color: var(--md-sys-color-on-primary, var(--color-on-primary));
110    display: flex;
111    align-items: center;
112    justify-content: center;
113    width: 0.625rem;
114    height: 0.625rem;
115
116    svg {
117      width: 100%;
118      height: 100%;
119    }
120  }
121}

1export { Checkbox } from "./checkbox.js";
2export type { CheckboxProps, CheckedState } from "./checkbox.js";

1import { useState } from "react";
2import { FormField } from "@behivetech/forms.form-field";
3import { Checkbox } from "./checkbox.js";
4
5export const BasicCheckbox = () => {
6  const [checked, setChecked] = useState(false);
7  return (
8    <Checkbox
9      checked={checked}
10      onCheckedChange={(val) => setChecked(val === true)}
11    />
12  );
13};
14
15export const CheckboxWithFormField = () => {
16  const [checked, setChecked] = useState(false);
17  return (
18    <FormField
19      label="Accept terms and conditions"
20      htmlFor="accept-terms"
21      hint="You can withdraw consent at any time."
22    >
23      <Checkbox
24        id="accept-terms"
25        checked={checked}
26        onCheckedChange={(val) => setChecked(val === true)}
27      />
28    </FormField>
29  );
30};
31
32export const CheckboxWithError = () => (
33  <FormField
34    label="Agree to terms"
35    htmlFor="agree"
36    error="You must agree to continue"
37  >
38    <Checkbox id="agree" invalid checked={false} onCheckedChange={() => {}} />
39  </FormField>
40);
41
42export const IndeterminateCheckbox = () => (
43  <Checkbox checked="indeterminate" onCheckedChange={() => {}} />
44);
45
46export const DisabledCheckbox = () => (
47  <Checkbox disabled checked={false} onCheckedChange={() => {}} />
48);
49
50export const RequiredCheckbox = () => {
51  const [checked, setChecked] = useState(false);
52  return (
53    <FormField
54      label="I have read the privacy policy"
55      htmlFor="privacy"
56      required
57    >
58      <Checkbox
59        id="privacy"
60        required
61        checked={checked}
62        onCheckedChange={(val) => setChecked(val === true)}
63      />
64    </FormField>
65  );
66};