feat(editor): support contextual copy in diff view (#507)

- Extracted contextual copy setup logic into `useContextualCopySetup` hook.
- Replaced direct `setupContextualCopy` usage in `MonacoEditor` with the new hook.
- Added `useContextualCopySetup` to `DiffViewer` to enable contextual copy in diffs.
- Bound copy handlers to both original and modified diff editors.
- Updated `EditorContent` to pass `filePath` and `relativePath` down to `DiffViewer`.
- Made `onSave` optional in `propsRef` since it's not strictly required in diff views.

src/renderer/src/components/editor/DiffViewer.tsx

@@ -3,11 +3,14 @@ import { DiffEditor, type DiffOnMount } from '@monaco-editor/react'
 import { useAppStore } from '@/store'
 import '@/lib/monaco-setup'
 import { computeEditorFontSize } from '@/lib/editor-font-zoom'
+import { useContextualCopySetup } from './useContextualCopySetup'
 
 type DiffViewerProps = {
   originalContent: string
   modifiedContent: string
   language: string
+  filePath: string
+  relativePath: string
   sideBySide: boolean
   editable?: boolean
   onContentChange?: (content: string) => void
@@ -18,6 +21,8 @@ export default function DiffViewer({
   originalContent,
   modifiedContent,
   language,
+  filePath,
+  relativePath,
   sideBySide,
   editable,
   onContentChange,
@@ -39,11 +44,20 @@ export default function DiffViewer({
   const onContentChangeRef = useRef(onContentChange)
   onContentChangeRef.current = onContentChange
 
+  const { setupCopy, toastNode } = useContextualCopySetup()
+
+  const propsRef = useRef({ relativePath, language, onSave })
+  propsRef.current = { relativePath, language, onSave }
+
   const handleMount: DiffOnMount = useCallback(
     (editor, monaco) => {
-      if (editable) {
-        const modifiedEditor = editor.getModifiedEditor()
+      const originalEditor = editor.getOriginalEditor()
+      const modifiedEditor = editor.getModifiedEditor()
 
+      setupCopy(originalEditor, monaco, filePath, propsRef)
+      setupCopy(modifiedEditor, monaco, filePath, propsRef)
+
+      if (editable) {
         // Cmd/Ctrl+S to save
         modifiedEditor.addCommand(monaco.KeyMod.CtrlCmd | monaco.KeyCode.KeyS, () => {
           onSaveRef.current?.(modifiedEditor.getValue())
@@ -59,7 +73,7 @@ export default function DiffViewer({
         editor.focus()
       }
     },
-    [editable]
+    [editable, setupCopy, filePath]
   )
 
   return (
@@ -92,6 +106,7 @@ export default function DiffViewer({
           }}
         />
       </div>
+      {toastNode}
     </div>
   )
 }

src/renderer/src/components/editor/EditorContent.tsx

@@ -287,6 +287,8 @@ export function EditorContent({
       originalContent={dc.originalContent}
       modifiedContent={editBuffers[activeFile.id] ?? dc.modifiedContent}
       language={resolvedLanguage}
+      filePath={activeFile.filePath}
+      relativePath={activeFile.relativePath}
       sideBySide={sideBySide}
       editable={isEditable}
       onContentChange={isEditable ? handleContentChange : undefined}

src/renderer/src/components/editor/MonacoEditor.tsx

@@ -11,9 +11,10 @@ import {
 import { useAppStore } from '@/store'
 import { scrollTopCache, setWithLRU } from '@/lib/scroll-cache'
 import '@/lib/monaco-setup'
-import { setupContextualCopy } from './setup-contextual-copy'
 import { computeEditorFontSize } from '@/lib/editor-font-zoom'
 
+import { useContextualCopySetup } from './useContextualCopySetup'
+
 type MonacoEditorProps = {
   filePath: string
   relativePath: string
@@ -38,8 +39,7 @@ export default function MonacoEditor({
   revealMatchLength
 }: MonacoEditorProps): React.JSX.Element {
   const editorRef = useRef<editor.IStandaloneCodeEditor | null>(null)
-  const copyToastTimeoutRef = useRef<number | null>(null)
-  const copyHintIntervalRef = useRef<number | null>(null)
+  const { setupCopy, toastNode } = useContextualCopySetup()
   // Why: The scroll throttle timer must be accessible from useLayoutEffect cleanup
   // so we can cancel any pending write before synchronously snapshotting the final
   // scroll position on unmount. Without this, a pending timer could fire after
@@ -64,9 +64,6 @@ export default function MonacoEditor({
   const [gutterMenuOpen, setGutterMenuOpen] = useState(false)
   const [gutterMenuPoint, setGutterMenuPoint] = useState({ x: 0, y: 0 })
   const [gutterMenuLine, setGutterMenuLine] = useState(1)
-  const [copyToast, setCopyToast] = useState<{ left: number; top: number } | null>(null)
-  const isMac = navigator.userAgent.includes('Mac')
-  const copyShortcutLabel = isMac ? '⌥⌘C' : 'Ctrl+Alt+C'
   const isDark =
     settings?.theme === 'dark' ||
     (settings?.theme === 'system' && window.matchMedia('(prefers-color-scheme: dark)').matches)
@@ -75,17 +72,7 @@ export default function MonacoEditor({
     (editorInstance, monaco) => {
       editorRef.current = editorInstance
 
-      setupContextualCopy({
-        editorInstance,
-        // eslint-disable-next-line @typescript-eslint/no-explicit-any
-        monaco: monaco as any,
-        filePath,
-        copyShortcutLabel,
-        setCopyToast,
-        propsRef,
-        copyToastTimeoutRef,
-        copyHintIntervalRef
-      })
+      setupCopy(editorInstance, monaco, filePath, propsRef)
 
       // Add Cmd+S save keybinding
       editorInstance.addCommand(monaco.KeyMod.CtrlCmd | monaco.KeyCode.KeyS, () => {
@@ -158,7 +145,7 @@ export default function MonacoEditor({
         }
       }
     },
-    [copyShortcutLabel, filePath, setEditorCursorLine]
+    [setupCopy, filePath, setEditorCursorLine]
   )
 
   const handleChange = useCallback(
@@ -201,19 +188,6 @@ export default function MonacoEditor({
     })
   }, [editorFontSize, settings])
 
-  useEffect(() => {
-    const toastRef = copyToastTimeoutRef
-    const hintRef = copyHintIntervalRef
-    return () => {
-      if (toastRef.current !== null) {
-        window.clearTimeout(toastRef.current)
-      }
-      if (hintRef.current !== null) {
-        window.clearInterval(hintRef.current)
-      }
-    }
-  }, [])
-
   useEffect(() => {
     const handler = (event: Event): void => {
       const detail = (event as CustomEvent).detail as
@@ -278,14 +252,7 @@ export default function MonacoEditor({
         path={filePath}
       />
 
-      {copyToast ? (
-        <div
-          className="pointer-events-none fixed z-50 rounded-md bg-foreground px-2 py-1 text-xs text-background shadow-sm"
-          style={{ left: copyToast.left, top: copyToast.top }}
-        >
-          Context copied
-        </div>
-      ) : null}
+      {toastNode}
       {/* Radix context menu for line number gutter right-click */}
       <DropdownMenu open={gutterMenuOpen} onOpenChange={setGutterMenuOpen} modal={false}>
         <DropdownMenuTrigger asChild>

src/renderer/src/components/editor/setup-contextual-copy.ts

@@ -8,8 +8,7 @@ export function setupContextualCopy({
   copyShortcutLabel,
   setCopyToast,
   propsRef,
-  copyToastTimeoutRef,
-  copyHintIntervalRef
+  copyToastTimeoutRef
 }: {
   editorInstance: editor.IStandaloneCodeEditor
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
@@ -20,11 +19,11 @@ export function setupContextualCopy({
   propsRef: React.MutableRefObject<{
     relativePath: string
     language: string
-    onSave: (content: string) => void
+    onSave?: (content: string) => void
   }>
   copyToastTimeoutRef: React.MutableRefObject<number | null>
-  copyHintIntervalRef: React.MutableRefObject<number | null>
 }): void {
+  let copyHintInterval: number | null = null
   let copyHintWidgetPosition: editor.IContentWidgetPosition | null = null
   let lastCopiedSelectionKey: string | null = null
   const copyHintNode = document.createElement('div')
@@ -151,18 +150,18 @@ export function setupContextualCopy({
 
   const startCopyHintPolling = (): void => {
     updateCopyHint()
-    if (copyHintIntervalRef.current !== null) {
+    if (copyHintInterval !== null) {
       return
     }
-    copyHintIntervalRef.current = window.setInterval(() => {
+    copyHintInterval = window.setInterval(() => {
       updateCopyHint()
     }, 150)
   }
 
   const stopCopyHintPolling = (): void => {
-    if (copyHintIntervalRef.current !== null) {
-      window.clearInterval(copyHintIntervalRef.current)
-      copyHintIntervalRef.current = null
+    if (copyHintInterval !== null) {
+      window.clearInterval(copyHintInterval)
+      copyHintInterval = null
     }
   }
 

src/renderer/src/components/editor/useContextualCopySetup.tsx

@@ -0,0 +1,56 @@
+import React, { useRef, useState, useEffect, useCallback } from 'react'
+import type { editor } from 'monaco-editor'
+import { setupContextualCopy } from './setup-contextual-copy'
+
+export function useContextualCopySetup() {
+  const [copyToast, setCopyToast] = useState<{ left: number; top: number } | null>(null)
+  const copyToastTimeoutRef = useRef<number | null>(null)
+
+  const isMac = navigator.userAgent.includes('Mac')
+  const copyShortcutLabel = isMac ? '⌥⌘C' : 'Ctrl+Alt+C'
+
+  useEffect(() => {
+    const toastRef = copyToastTimeoutRef
+    return () => {
+      if (toastRef.current !== null) {
+        window.clearTimeout(toastRef.current)
+      }
+    }
+  }, [])
+
+  const setupCopy = useCallback(
+    (
+      editorInstance: editor.IStandaloneCodeEditor,
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      monaco: any,
+      filePath: string,
+      propsRef: React.MutableRefObject<{
+        relativePath: string
+        language: string
+        onSave?: (content: string) => void
+      }>
+    ) => {
+      setupContextualCopy({
+        editorInstance,
+        monaco,
+        filePath,
+        copyShortcutLabel,
+        setCopyToast,
+        propsRef,
+        copyToastTimeoutRef
+      })
+    },
+    [copyShortcutLabel]
+  )
+
+  const toastNode = copyToast ? (
+    <div
+      className="pointer-events-none fixed z-50 rounded-md bg-foreground px-2 py-1 text-xs text-background shadow-sm"
+      style={{ left: copyToast.left, top: copyToast.top }}
+    >
+      Context copied
+    </div>
+  ) : null
+
+  return { setupCopy, toastNode }
+}