#268

frontend/src/components/DraggableDroppableTagRow.test.tsx

@@ -0,0 +1,75 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import DraggableDroppableTagRow from '@/components/DraggableDroppableTagRow'
+import { buildTag } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+const dndKit = vi.hoisted (() => ({
+  useDraggable: vi.fn (),
+  useDroppable: vi.fn (),
+}))
+
+vi.mock ('@dnd-kit/core', () => dndKit)
+
+const tag = buildTag ({ id: 7, name: 'ドラッグ元', postCount: 3 })
+
+const renderRow = (activeDndId?: string) => {
+  renderWithProviders (
+      <DraggableDroppableTagRow
+          activeDndId={activeDndId}
+          tag={tag}
+          nestLevel={2}
+          pathKey="cat-general-7"
+          suppressClickRef={{ current: false }}/>,
+  )
+}
+
+const tagBody = (): HTMLElement => {
+  const link = document.querySelector<HTMLElement> ('a[title="ドラッグ元"]')
+
+  if (link == null)
+    throw new Error ('tag link not found')
+
+  const body = link.closest ('div')
+
+  if (body == null)
+    throw new Error ('tag body not found')
+
+  return body
+}
+
+describe ('DraggableDroppableTagRow', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    dndKit.useDraggable.mockReturnValue ({
+        attributes: { 'aria-describedby': 'drag-source' },
+        listeners:  { onPointerDown: vi.fn () },
+        setNodeRef: vi.fn (),
+        transform:  null })
+    dndKit.useDroppable.mockReturnValue ({
+        isOver:     false,
+        setNodeRef: vi.fn () })
+  })
+
+  it ('passes dndId through draggable data for active-row tracking', () => {
+    renderRow ()
+
+    expect (dndKit.useDraggable).toHaveBeenCalledWith (
+        expect.objectContaining ({
+            id:   'tag-node:cat-general-7',
+            data: expect.objectContaining ({
+                dndId:     'tag-node:cat-general-7',
+                nestLevel: 2,
+                tagId:     7 }) }))
+  })
+
+  it ('hides only the active drag source from the explicit active dnd id', () => {
+    renderRow ('tag-node:cat-general-7')
+    expect (tagBody ()).toHaveStyle ({ visibility: 'hidden' })
+  })
+
+  it ('keeps inactive tag rows visible while another tag is dragged', () => {
+    renderRow ('tag-node:other')
+    expect (tagBody ()).toHaveStyle ({ visibility: 'visible' })
+  })
+})

frontend/src/components/DraggableDroppableTagRow.tsx

@@ -13,6 +13,7 @@ import type { CSSProperties, FC, MutableRefObject } from 'react'
 import type { Tag } from '@/types'
 
 type Props = {
+    activeDndId?:      string
     tag:              Tag
     nestLevel:        number
     pathKey:          string
@@ -21,7 +22,15 @@ type Props = {
     sp?:              boolean }
 
 
-const DraggableDroppableTagRow: FC<Props> = ({ tag, nestLevel, pathKey, parentTagId, suppressClickRef, sp }) => {
+const DraggableDroppableTagRow: FC<Props> = ({
+    activeDndId,
+    tag,
+    nestLevel,
+    pathKey,
+    parentTagId,
+    suppressClickRef,
+    sp,
+}) => {
   const behaviourSettings = useClientBehaviourSettings ()
   const animationMode = behaviourSettings.animation ?? 'normal'
   const layoutTransition = clientAnimationTransition (
@@ -53,9 +62,9 @@ const DraggableDroppableTagRow: FC<Props> = ({ tag, nestLevel, pathKey, parentTa
   const { attributes,
 	  listeners,
 	  setNodeRef: setDragRef,
-	  transform,
+	  transform } = useDraggable ({ id:    dndId,
-	  isDragging: dragging } = useDraggable ({ id:    dndId,
 					data:  { kind:   'tag',
+						 dndId,
 						 tagId:  tag.id,
 						 parentTagId,
 						 nestLevel } })
@@ -64,8 +73,12 @@ const DraggableDroppableTagRow: FC<Props> = ({ tag, nestLevel, pathKey, parentTa
       id:   dndId,
       data: { kind: 'tag', tagId: tag.id } })
 
+  const activeDragging = activeDndId === dndId
   const style: CSSProperties = { transform:   CSS.Translate.toString (transform),
-				 visibility:  dragging ? 'hidden' : 'visible' }
+				 visibility:  activeDragging ? 'hidden' : 'visible' }
+  const innerClassName = cn (
+      'inline-flex min-w-0 max-w-full items-baseline overflow-hidden',
+      sp && 'touch-pan-y')
 
   return (
       <div
@@ -101,12 +114,21 @@ const DraggableDroppableTagRow: FC<Props> = ({ tag, nestLevel, pathKey, parentTa
 	      sp && 'touch-pan-y',
 	      over && 'ring-2 ring-offset-2')}
 	  >
+	{activeDragging
+	 ? (
+	    <div
+		ref={setDragRef}
+		style={style}
+		className={innerClassName}
+		{...attributes}
+		{...listeners}>
+	      <TagLink tag={tag} nestLevel={nestLevel}/>
+	    </div>)
+	 : (
 	    <motion.div
 		ref={setDragRef}
 		style={style}
-	    className={cn (
+		className={innerClassName}
-		'inline-flex min-w-0 max-w-full items-baseline overflow-hidden',
-		sp && 'touch-pan-y')}
 		{...attributes}
 		{...listeners}
 		transition={{ layout: layoutTransition }}
@@ -114,7 +136,7 @@ const DraggableDroppableTagRow: FC<Props> = ({ tag, nestLevel, pathKey, parentTa
 		    ? undefined
 		    : `tag-${ sp ? 'sp-' : '' }${ tag.id }`}>
 	      <TagLink tag={tag} nestLevel={nestLevel}/>
-	</motion.div>
+	    </motion.div>)}
       </div>)
 }
 

frontend/src/components/TagDetailSidebar.tsx

@@ -7,7 +7,7 @@ import { DndContext,
 	 useDroppable,
 	 useSensor,
 	 useSensors } from '@dnd-kit/core'
-import { restrictToWindowEdges } from '@dnd-kit/modifiers'
+import { restrictToWindowEdges, snapCenterToCursor } from '@dnd-kit/modifiers'
 import { useQueryClient } from '@tanstack/react-query'
 import { motion } from 'framer-motion'
 import { useEffect, useMemo, useRef, useState } from 'react'
@@ -43,6 +43,7 @@ const alwaysMeasureDroppables = {
 
 
 const renderTagTree = (
+    activeDndId:       string | undefined,
     tag:              TagWithSections,
     nestLevel:        number,
     path:             string,
@@ -54,6 +55,7 @@ const renderTagTree = (
   const self = (
       <li key={key} className="mb-1">
 	<DraggableDroppableTagRow
+	    activeDndId={activeDndId}
 	    tag={tag}
 	    nestLevel={nestLevel}
 	    pathKey={key}
@@ -67,7 +69,14 @@ const renderTagTree = (
       ...((tag.children
 	   ?.sort ((a, b) => a.name < b.name ? -1 : 1)
 	   .flatMap (child =>
-	      renderTagTree (child, nestLevel + 1, key, suppressClickRef, tag.id, sp)))
+	      renderTagTree (
+		  activeDndId,
+		  child,
+		  nestLevel + 1,
+		  key,
+		  suppressClickRef,
+		  tag.id,
+		  sp)))
 	  ?? [])]
 }
 
@@ -211,6 +220,7 @@ type Props = {
     sp?:        boolean }
 
 type ActiveTagDrag = {
+    dndId:       string
     tagId:      number
     nestLevel:  number }
 
@@ -251,6 +261,7 @@ const TagDetailSidebar: FC<Props> = ({ className, post, sp }) => {
       () => buildFlatTagByCategory (tags),
       [tags],
   )
+  const activeDndId = activeTagDrag?.dndId
 
   const suppressClickRef = useRef (false)
 
@@ -359,17 +370,18 @@ const TagDetailSidebar: FC<Props> = ({ className, post, sp }) => {
 	<TagSearch/>
 	<DndContext
 	    sensors={sensors}
-	    collisionDetection={sp ? tagCollisionDetection : undefined}
+	    collisionDetection={tagCollisionDetection}
-	    measuring={sp ? alwaysMeasureDroppables : undefined}
+	    measuring={alwaysMeasureDroppables}
 	    onDragStart={e => {
 	      if (e.active.data.current?.kind === 'tag')
 		{
 		  const tagId = e.active.data.current?.tagId
 		  const nestLevel = e.active.data.current?.nestLevel
+		  const dndId = e.active.data.current?.dndId
 		  setActiveTagDrag (
-		      tagId == null || nestLevel == null
+		      tagId == null || nestLevel == null || dndId == null
 		      ? null
-		      : { tagId, nestLevel })
+		      : { dndId, tagId, nestLevel })
 		}
 	      setDragging (true)
 	      suppressClickRef.current = true
@@ -426,6 +438,7 @@ const TagDetailSidebar: FC<Props> = ({ className, post, sp }) => {
 		    {(tagRelationDisplay === 'grouped'
 		      ? (tags[cat] ?? []).flatMap (tag =>
 			    renderTagTree (
+				activeDndId,
 				tag,
 				0,
 				`cat-${ cat }`,
@@ -437,6 +450,7 @@ const TagDetailSidebar: FC<Props> = ({ className, post, sp }) => {
 		      : (flatTagsByCategory[cat] ?? []).map (tag => (
 			  <li key={`flat-${ cat }-${ tag.id }`} className="mb-1">
 			    <DraggableDroppableTagRow
+				activeDndId={activeDndId}
 				tag={tag}
 				nestLevel={0}
 				pathKey={`flat-${ cat }-${ tag.id }`}
@@ -489,7 +503,10 @@ const TagDetailSidebar: FC<Props> = ({ className, post, sp }) => {
 		</ul>
 	      </motion.div>)}
 
-	  <DragOverlay adjustScale={false}>
+	  <DragOverlay
+	      adjustScale={false}
+	      modifiers={[snapCenterToCursor]}
+	      dropAnimation={animationMode === 'off' ? null : undefined}>
 	    <div className="pointer-events-none">
 	      {activeTagDrag != null && (() => {
 		const tag = findTag (tags, activeTagDrag.tagId)