feat: add useFocusWithin

config/hooks.ts

@@ -94,6 +94,7 @@ export const menus = [
       'useResponsive',
       'useScroll',
       'useSize',
+      'useFocusWithin',
     ],
   },
   {

packages/hooks/src/index.ts

@@ -20,6 +20,7 @@ import useEventListener from './useEventListener';
 import useEventTarget from './useEventTarget';
 import useExternal from './useExternal';
 import useFavicon from './useFavicon';
+import useFocusWithin from './useFocusWithin';
 import useFullscreen from './useFullscreen';
 import useFusionTable from './useFusionTable';
 import useGetState from './useGetState';
@@ -142,4 +143,5 @@ export {
   useInfiniteScroll,
   useGetState,
   clearCache,
+  useFocusWithin,
 };

packages/hooks/src/useFocusWithin/demo/demo1.tsx

@@ -0,0 +1,43 @@
+/**
+ * title: Basic usage
+ * desc: Use ref to set area that needs monitoring. The focus can be switched by click the outside with the mouse, or using keys such as `tab` on the keyboard.
+ *
+ * title.zh-CN: 基础用法
+ * desc.zh-CN: 使用 ref 设置需要监听的区域。可以通过鼠标点击外部区域，或者使用键盘的 `tab` 等按键来切换焦点。
+ */
+
+import React, { useRef } from 'react';
+import { useFocusWithin } from 'ahooks';
+import { message } from 'antd';
+
+export default () => {
+  const ref = useRef();
+  const isFocusWithin = useFocusWithin(ref, {
+    onFocus: () => {
+      message.info('focus');
+    },
+    onBlur: () => {
+      message.info('blur');
+    },
+  });
+  return (
+    <div>
+      <div
+        ref={ref}
+        style={{
+          padding: 16,
+          backgroundColor: isFocusWithin ? 'red' : '',
+          border: '1px solid gray',
+        }}
+      >
+        <label style={{ display: 'block' }}>
+          First Name: <input />
+        </label>
+        <label style={{ display: 'block', marginTop: 16 }}>
+          Last Name: <input />
+        </label>
+      </div>
+      <p>isFocusWithin: {JSON.stringify(isFocusWithin)}</p>
+    </div>
+  );
+};

packages/hooks/src/useFocusWithin/demo/demo2.tsx

@@ -0,0 +1,35 @@
+/**
+ * title: Pass in DOM element
+ * desc: Pass in a function that returns the DOM element.
+ *
+ * title.zh-CN: 传入 DOM 元素
+ * desc.zh-CN: 传入 function 并返回一个 dom 元素。
+ */
+
+import { useFocusWithin } from 'ahooks';
+import React from 'react';
+
+export default () => {
+  const isFocusWithin = useFocusWithin(() => document.getElementById('focus-area'));
+
+  return (
+    <div>
+      <div
+        id="focus-area"
+        style={{
+          padding: 16,
+          backgroundColor: isFocusWithin ? 'red' : '',
+          border: '1px solid gray',
+        }}
+      >
+        <label style={{ display: 'block' }}>
+          First Name: <input />
+        </label>
+        <label style={{ display: 'block', marginTop: 16 }}>
+          Last Name: <input />
+        </label>
+      </div>
+      <p>isFocusWithin: {JSON.stringify(isFocusWithin)}</p>
+    </div>
+  );
+};

packages/hooks/src/useFocusWithin/index.en-US.md

@@ -0,0 +1,52 @@
+---
+nav:
+  path: /hooks
+---
+
+# useFocusWithin
+
+Monitor whether the current focus is within a certain area, Same as css attribute [:focus-within](https://developer.mozilla.org/en-US/docs/Web/CSS/:focus-within).
+
+## Examples
+
+### Default usage
+
+<code src="./demo/demo1.tsx" />
+
+### Pass in DOM element
+
+<code src="./demo/demo2.tsx" />
+
+## API
+
+```typescript
+const isFocusWithin = useFocusWithin(
+  target, 
+  {
+   onFocus,
+   onBlur,
+   onChange
+  }
+);
+```
+
+### Params
+
+| Property | Description        | Type                                                        | Default |
+|----------|--------------------|-------------------------------------------------------------|---------|
+| target   | DOM element or ref | `() => Element` \| `Element` \| `MutableRefObject<Element>` | -       |
+| options  | More config        | `Options`                                                   | -       |
+
+### Options
+
+| Property | Description                             | Type                         | Default |
+|----------|-----------------------------------------|------------------------------|---------|
+| onFocus  | Callback to be executed on focus        | `(e: FocusEvent) => void`    | -       |
+| onBlur   | Callback to be executed on blur         | `(e: FocusEvent) => void`    | -       |
+| onChange | Callback to be executed on focus change | `(isFocusWithin: boolean) => void` | -       |
+
+### Result
+
+| Property      | Description                              | Type      |
+|---------------|------------------------------------------|-----------|
+| isFocusWithin | Whether the focus is in the current area | `boolean` |

packages/hooks/src/useFocusWithin/index.tsx

@@ -0,0 +1,45 @@
+import { useState } from 'react';
+import useEventListener from '../useEventListener';
+import type { BasicTarget } from '../utils/domTarget';
+
+export interface Options {
+  onFocus?: (e: FocusEvent) => void;
+  onBlur?: (e: FocusEvent) => void;
+  onChange?: (isFocusWithin: boolean) => void;
+}
+
+export default function useFocusWithin(target: BasicTarget, options?: Options) {
+  const [isFocusWithin, setIsFocusWithin] = useState(false);
+  const { onFocus, onBlur, onChange } = options || {};
+
+  useEventListener(
+    'focusin',
+    (e: FocusEvent) => {
+      if (!isFocusWithin) {
+        onFocus?.(e);
+        onChange?.(true);
+        setIsFocusWithin(true);
+      }
+    },
+    {
+      target,
+    },
+  );
+
+  useEventListener(
+    'focusout',
+    (e: FocusEvent) => {
+      // @ts-ignore
+      if (isFocusWithin && !e.currentTarget?.contains?.(e.relatedTarget)) {
+        onBlur?.(e);
+        onChange?.(false);
+        setIsFocusWithin(false);
+      }
+    },
+    {
+      target,
+    },
+  );
+
+  return isFocusWithin;
+}

packages/hooks/src/useFocusWithin/index.zh-CN.md

@@ -0,0 +1,52 @@
+---
+nav:
+  path: /hooks
+---
+
+# useFocusWithin
+
+监听当前焦点是否在某个区域之内，同 css 属性 [:focus-within](https://developer.mozilla.org/en-US/docs/Web/CSS/:focus-within)。
+
+## 代码演示
+
+### 基础用法
+
+<code src="./demo/demo1.tsx" />
+
+### 传入 DOM 元素
+
+<code src="./demo/demo2.tsx" />
+
+## API
+
+```typescript
+const isFocusWithin = useFocusWithin(
+  target, 
+  {
+   onFocus,
+   onBlur,
+   onChange
+  }
+);
+```
+
+### Params
+
+| 参数    | 说明                  | 类型                                                        | 默认值 |
+|---------|-----------------------|-------------------------------------------------------------|--------|
+| target  | DOM 节点或者 Ref 对象 | `() => Element` \| `Element` \| `MutableRefObject<Element>` | -      |
+| options | 额外的配置项          | `Options`                                                   | -      |
+
+### Options
+
+| 参数     | 说明           | 类型                         | 默认值 |
+|----------|----------------|------------------------------|--------|
+| onFocus  | 获取焦点时触发 | `(e: FocusEvent) => void`    | -      |
+| onBlur   | 失去焦点时触发 | `(e: FocusEvent) => void`    | -      |
+| onChange | 焦点变化时触发 | `(isFocusWithin: boolean) => void` | -      |
+
+### Result
+
+| 参数          | 说明               | 类型      |
+|---------------|--------------------|-----------|
+| isFocusWithin | 焦点是否在当前区域 | `boolean` |