From bb55fc2e322bdc48427bf4e00d7f4ff3c8f8f6a2 Mon Sep 17 00:00:00 2001
From: Alf Eaton <alf.eaton@overleaf.com>
Date: Wed, 23 Jun 2021 09:09:46 +0100
Subject: [PATCH] Add useDropdown hook (#4228)

GitOrigin-RevId: a16762139049aed1e309b1330602c3b291d41f81
---
 .../shared/components/controlled-dropdown.js  | 24 +++------
 .../frontend/js/shared/hooks/use-dropdown.js  | 54 +++++++++++++++++++
 2 files changed, 60 insertions(+), 18 deletions(-)
 create mode 100644 services/web/frontend/js/shared/hooks/use-dropdown.js

diff --git a/services/web/frontend/js/shared/components/controlled-dropdown.js b/services/web/frontend/js/shared/components/controlled-dropdown.js
index f94d70fb84..9e577537dd 100644
--- a/services/web/frontend/js/shared/components/controlled-dropdown.js
+++ b/services/web/frontend/js/shared/components/controlled-dropdown.js
@@ -1,25 +1,13 @@
-import React, { useCallback, useState } from 'react'
+import React from 'react'
 import { Dropdown } from 'react-bootstrap'
 import PropTypes from 'prop-types'
+import useDropdown from '../hooks/use-dropdown'
 
 export default function ControlledDropdown(props) {
-  const [open, setOpen] = useState(Boolean(props.defaultOpen))
-
-  const handleClick = useCallback(event => {
-    event.stopPropagation()
-  }, [])
-
-  const handleToggle = useCallback(value => {
-    setOpen(value)
-  }, [])
+  const dropdownProps = useDropdown(Boolean(props.defaultOpen))
 
   return (
-    <Dropdown
-      {...props}
-      open={open}
-      onToggle={handleToggle}
-      onClick={handleClick}
-    >
+    <Dropdown {...props} {...dropdownProps}>
       {React.Children.map(props.children, child => {
         if (!React.isValidElement(child)) {
           return child
@@ -27,12 +15,12 @@ export default function ControlledDropdown(props) {
 
         // Dropdown.Menu
         if ('open' in child.props) {
-          return React.cloneElement(child, { open })
+          return React.cloneElement(child, { open: dropdownProps.open })
         }
 
         // Overlay
         if ('show' in child.props) {
-          return React.cloneElement(child, { show: open })
+          return React.cloneElement(child, { show: dropdownProps.open })
         }
 
         // anything else
diff --git a/services/web/frontend/js/shared/hooks/use-dropdown.js b/services/web/frontend/js/shared/hooks/use-dropdown.js
new file mode 100644
index 0000000000..b58013e2b4
--- /dev/null
+++ b/services/web/frontend/js/shared/hooks/use-dropdown.js
@@ -0,0 +1,54 @@
+import { useCallback, useEffect, useRef, useState } from 'react'
+import { findDOMNode } from 'react-dom'
+
+export default function useDropdown(defaultOpen = false) {
+  const [open, setOpen] = useState(defaultOpen)
+
+  // store the dropdown node for use in the "click outside" event listener
+  const ref = useRef(null)
+
+  // react-bootstrap v0.x passes `component` instead of `node` to the ref callback
+  const handleRef = useCallback(
+    component => {
+      if (component) {
+        // eslint-disable-next-line react/no-find-dom-node
+        ref.current = findDOMNode(component)
+      }
+    },
+    [ref]
+  )
+
+  // prevent a click on the dropdown toggle propagating to the original handler
+  const handleClick = useCallback(event => {
+    event.stopPropagation()
+  }, [])
+
+  // handle dropdown toggle
+  const handleToggle = useCallback(value => {
+    setOpen(value)
+  }, [])
+
+  // close the dropdown on click outside the dropdown
+  const handleDocumentClick = useCallback(
+    event => {
+      if (ref.current && !ref.current.contains(event.target)) {
+        setOpen(false)
+      }
+    },
+    [ref]
+  )
+
+  // add/remove listener for click anywhere in document
+  useEffect(() => {
+    if (open) {
+      document.addEventListener('mousedown', handleDocumentClick)
+    }
+
+    return () => {
+      document.removeEventListener('mousedown', handleDocumentClick)
+    }
+  }, [open, handleDocumentClick])
+
+  // return props for the Dropdown component
+  return { ref: handleRef, onClick: handleClick, onToggle: handleToggle, open }
+}