feat: add useComposing hook (#5695)

.changeset/ten-queens-walk.md

@@ -0,0 +1,5 @@
+---
+'slate-react': minor
+---
+
+feat: Add useComposing hook"

docs/libraries/slate-react/hooks.md

@@ -8,6 +8,10 @@
 
 React hooks for Slate editors
 
+#### `useComposing(): boolean`
+
+Get the current `composing` state of the editor. It deals with `compositionstart`, `compositionupdate`, `compositionend` events.
+
 #### `useFocused(): boolean`
 
 Get the current `focused` state of the editor.

packages/slate-react/src/hooks/use-composing.ts

@@ -0,0 +1,15 @@
+import { createContext, useContext } from 'react'
+
+/**
+ * A React context for sharing the `composing` state of the editor.
+ */
+
+export const ComposingContext = createContext(false)
+
+/**
+ * Get the current `composing` state of the editor.
+ */
+
+export const useComposing = (): boolean => {
+  return useContext(ComposingContext)
+}