| 1 | import { type DragItemNode, type DropDirection } from "@platejs/dnd"; |
| 2 | import { |
| 3 | NodeApi, |
| 4 | PathApi, |
| 5 | type NodeEntry, |
| 6 | type Path, |
| 7 | type TElement, |
| 8 | } from "platejs"; |
| 9 | import { type PlateEditor } from "platejs/react"; |
| 10 | import { type DropTargetMonitor } from "react-dnd"; |
| 11 | |
| 12 | import { |
| 13 | canLayoutChildTypeBePlacedInParent, |
| 14 | CIRCULAR_GRID_GROUP, |
| 15 | CIRCULAR_GRID_ITEM, |
| 16 | CIRCULAR_GRID_MAX_ITEMS, |
| 17 | COLUMN_GROUP, |
| 18 | COLUMN_ITEM, |
| 19 | getLayoutParentTypes, |
| 20 | isLayoutChildType, |
| 21 | isLayoutParentType, |
| 22 | } from "../../lib"; |
| 23 | import { type UseDropNodeOptions } from "../hooks"; |
| 24 | import { getHoverDirection } from "./getHoverDirection"; |
| 25 | |
| 26 | type ResolvedDropDirection = Exclude<DropDirection, undefined>; |
| 27 | |
| 28 | export type DropPathResult = { |
| 29 | createColumns: boolean; |
| 30 | direction: ResolvedDropDirection; |
| 31 | dragPath: Path | undefined; |
| 32 | hoveredPath: Path; |
| 33 | isExternalNode: boolean; |
| 34 | isNoop?: boolean; |
| 35 | to: Path; |
| 36 | }; |
| 37 | |
| 38 | /** |
| 39 | * Get the drop path for a drag and drop operation. |
| 40 | * |
| 41 | * @param canCreateColumns - If true, left/right returns path for column creation. |
| 42 | * If false, left/right is treated as reorder (like top/bottom). |
| 43 | */ |
| 44 | export const getDropPath = ( |
| 45 | editor: PlateEditor, |
| 46 | { |
| 47 | canDropNode, |
| 48 | canCreateColumns = false, |
| 49 | dragItem, |
| 50 | element, |
| 51 | monitor, |
| 52 | nodeRef, |
| 53 | }: { |
| 54 | dragItem: DragItemNode; |
| 55 | monitor: DropTargetMonitor; |
| 56 | canCreateColumns?: boolean; |
| 57 | } & Pick<UseDropNodeOptions, "canDropNode" | "element" | "nodeRef">, |
| 58 | ) => { |
| 59 | const direction = getHoverDirection({ |
| 60 | dragItem, |
| 61 | element, |
| 62 | monitor, |
| 63 | nodeRef, |
| 64 | }); |
| 65 | |
| 66 | if (!direction) return; |
| 67 | |
| 68 | return getDropPathFromDirection(editor, { |
| 69 | canDropNode, |
| 70 | canCreateColumns, |
| 71 | direction, |
| 72 | dragItem, |
| 73 | element, |
| 74 | }); |
| 75 | }; |
| 76 | |
| 77 | export const getDropPathFromDirection = ( |
| 78 | editor: PlateEditor, |
| 79 | { |
| 80 | canDropNode, |
| 81 | canCreateColumns = false, |
| 82 | direction, |
| 83 | dragItem, |
| 84 | element, |
| 85 | }: { |
| 86 | direction: ResolvedDropDirection; |
| 87 | dragItem: DragItemNode; |
| 88 | canCreateColumns?: boolean; |
| 89 | } & Pick<UseDropNodeOptions, "canDropNode" | "element">, |
| 90 | ): DropPathResult | undefined => { |
| 91 | let dragEntry: NodeEntry<TElement> | undefined; |
| 92 | let dropEntry: NodeEntry<TElement> | undefined; |
| 93 | |
| 94 | if ("element" in dragItem) { |
| 95 | const dragPath = editor.api.findPath(dragItem.element); |
| 96 | const hoveredPath = editor.api.findPath(element); |
| 97 | |
| 98 | if (!hoveredPath) return; |
| 99 | |
| 100 | // If dragPath is found, we're moving an existing node |
| 101 | // If not, we're inserting a new node (e.g., from external source) |
| 102 | if (dragPath) { |
| 103 | dragEntry = [dragItem.element, dragPath]; |
| 104 | } |
| 105 | |
| 106 | dropEntry = [element, hoveredPath]; |
| 107 | } else { |
| 108 | dropEntry = editor.api.node({ |
| 109 | id: element.id as string, |
| 110 | at: [], |
| 111 | }) as NodeEntry<TElement> | undefined; |
| 112 | } |
| 113 | |
| 114 | if (!dropEntry) return; |
| 115 | |
| 116 | // Only check canDropNode if we have a dragEntry (for existing nodes) |
| 117 | if ( |
| 118 | canDropNode && |
| 119 | dragEntry && |
| 120 | !canDropNode({ dragEntry, dragItem, dropEntry, editor }) |
| 121 | ) { |
| 122 | return; |
| 123 | } |
| 124 | |
| 125 | const dragPath = dragEntry?.[1]; |
| 126 | const hoveredPath = dropEntry[1]; |
| 127 | |
| 128 | if (dragPath && PathApi.equals(dragPath, hoveredPath)) { |
| 129 | return { |
| 130 | createColumns: false, |
| 131 | direction, |
| 132 | dragPath, |
| 133 | hoveredPath, |
| 134 | isExternalNode: false, |
| 135 | isNoop: true, |
| 136 | to: dragPath, |
| 137 | }; |
| 138 | } |
| 139 | |
| 140 | const insideContainerPath = getInsideContainerPath({ |
| 141 | dragPath, |
| 142 | dragType: getDraggedElementTypes(editor, dragItem)[0], |
| 143 | dropElement: dropEntry[0], |
| 144 | hoveredPath, |
| 145 | }); |
| 146 | |
| 147 | if (insideContainerPath) { |
| 148 | const insideResult = { |
| 149 | createColumns: false, |
| 150 | direction, |
| 151 | dragPath, |
| 152 | hoveredPath, |
| 153 | isExternalNode: !dragPath, |
| 154 | to: insideContainerPath, |
| 155 | }; |
| 156 | |
| 157 | if (!canDropAtPath(editor, dragItem, insideResult)) return; |
| 158 | |
| 159 | return insideResult; |
| 160 | } |
| 161 | |
| 162 | // Relationship-backed layout parents only accept their configured child |
| 163 | // element types. This blocks drops onto an existing child from sneaking |
| 164 | // unrelated blocks into the parent as siblings. |
| 165 | const returnIfValid = (result: DropPathResult): DropPathResult | undefined => |
| 166 | canDropAtPath(editor, dragItem, result) ? result : undefined; |
| 167 | |
| 168 | // Handle left/right directions |
| 169 | if (direction === "left" || direction === "right") { |
| 170 | const draggedTypes = getDraggedElementTypes(editor, dragItem); |
| 171 | const canCreateColumnSibling = |
| 172 | draggedTypes.length > 0 && |
| 173 | draggedTypes.every( |
| 174 | (dragType) => |
| 175 | !isLayoutChildType(dragType) && !isLayoutParentType(dragType), |
| 176 | ); |
| 177 | const containingColumnItemPath = getContainingColumnItemPath( |
| 178 | editor, |
| 179 | hoveredPath, |
| 180 | ); |
| 181 | |
| 182 | if (containingColumnItemPath && canCreateColumnSibling) { |
| 183 | return returnIfValid({ |
| 184 | direction, |
| 185 | dragPath, |
| 186 | hoveredPath, |
| 187 | to: containingColumnItemPath, |
| 188 | isExternalNode: !dragPath, |
| 189 | createColumns: true, |
| 190 | }); |
| 191 | } |
| 192 | |
| 193 | // If canCreateColumns is true, return for column creation (handled by onDropNode) |
| 194 | if (canCreateColumns) { |
| 195 | return returnIfValid({ |
| 196 | direction, |
| 197 | dragPath, |
| 198 | hoveredPath, |
| 199 | to: hoveredPath, |
| 200 | isExternalNode: !dragPath, |
| 201 | createColumns: true, |
| 202 | }); |
| 203 | } |
| 204 | |
| 205 | // Otherwise, treat left/right like top/bottom (reorder) |
| 206 | // Left = before (like top), Right = after (like bottom) |
| 207 | let dropPath: Path | undefined; |
| 208 | |
| 209 | if (direction === "right") { |
| 210 | // Insert after hovered node (like bottom) |
| 211 | dropPath = hoveredPath; |
| 212 | if (dragPath && PathApi.equals(dragPath, PathApi.next(dropPath))) { |
| 213 | return { |
| 214 | createColumns: false, |
| 215 | direction, |
| 216 | dragPath, |
| 217 | hoveredPath, |
| 218 | isExternalNode: false, |
| 219 | isNoop: true, |
| 220 | to: dragPath, |
| 221 | }; |
| 222 | } |
| 223 | } |
| 224 | |
| 225 | if (direction === "left") { |
| 226 | // Insert before hovered node (like top) |
| 227 | dropPath = [...hoveredPath.slice(0, -1), hoveredPath.at(-1)! - 1]; |
| 228 | if (dragPath && PathApi.equals(dragPath, dropPath)) { |
| 229 | return { |
| 230 | createColumns: false, |
| 231 | direction, |
| 232 | dragPath, |
| 233 | hoveredPath, |
| 234 | isExternalNode: false, |
| 235 | isNoop: true, |
| 236 | to: dragPath, |
| 237 | }; |
| 238 | } |
| 239 | } |
| 240 | |
| 241 | if (!dropPath) return; |
| 242 | |
| 243 | const before = |
| 244 | dragPath && |
| 245 | PathApi.isBefore(dragPath, dropPath) && |
| 246 | PathApi.isSibling(dragPath, dropPath); |
| 247 | const to = before ? dropPath : PathApi.next(dropPath); |
| 248 | |
| 249 | return returnIfValid({ |
| 250 | createColumns: false, |
| 251 | direction, |
| 252 | dragPath, |
| 253 | hoveredPath, |
| 254 | isExternalNode: !dragPath, |
| 255 | to, |
| 256 | }); |
| 257 | } |
| 258 | |
| 259 | // Handle top/bottom drops for vertical reordering |
| 260 | let dropPath: Path | undefined; |
| 261 | |
| 262 | if (direction === "bottom") { |
| 263 | // Insert after hovered node |
| 264 | dropPath = hoveredPath; |
| 265 | |
| 266 | // If the dragged node is already right after hovered node, no change |
| 267 | if (dragPath && PathApi.equals(dragPath, PathApi.next(dropPath))) { |
| 268 | return { |
| 269 | createColumns: false, |
| 270 | direction, |
| 271 | dragPath, |
| 272 | hoveredPath, |
| 273 | isExternalNode: false, |
| 274 | isNoop: true, |
| 275 | to: dragPath, |
| 276 | }; |
| 277 | } |
| 278 | } |
| 279 | |
| 280 | if (direction === "top") { |
| 281 | // Insert before hovered node |
| 282 | dropPath = [...hoveredPath.slice(0, -1), hoveredPath.at(-1)! - 1]; |
| 283 | |
| 284 | // If the dragged node is already right before hovered node, no change |
| 285 | if (dragPath && PathApi.equals(dragPath, dropPath)) { |
| 286 | return { |
| 287 | createColumns: false, |
| 288 | direction, |
| 289 | dragPath, |
| 290 | hoveredPath, |
| 291 | isExternalNode: false, |
| 292 | isNoop: true, |
| 293 | to: dragPath, |
| 294 | }; |
| 295 | } |
| 296 | } |
| 297 | |
| 298 | if (!dropPath) return; |
| 299 | |
| 300 | const before = |
| 301 | dragPath && |
| 302 | PathApi.isBefore(dragPath, dropPath) && |
| 303 | PathApi.isSibling(dragPath, dropPath); |
| 304 | const to = before ? dropPath : PathApi.next(dropPath); |
| 305 | |
| 306 | return returnIfValid({ |
| 307 | createColumns: false, |
| 308 | direction, |
| 309 | dragPath, |
| 310 | hoveredPath, |
| 311 | isExternalNode: !dragPath, |
| 312 | to, |
| 313 | }); |
| 314 | }; |
| 315 | |
| 316 | export function canDropAtPath( |
| 317 | editor: PlateEditor, |
| 318 | dragItem: DragItemNode, |
| 319 | result: Pick<DropPathResult, "createColumns" | "dragPath" | "to">, |
| 320 | ): boolean { |
| 321 | if (!("element" in dragItem)) return true; |
| 322 | |
| 323 | const draggedTypes = getDraggedElementTypes(editor, dragItem); |
| 324 | |
| 325 | if (draggedTypes.length === 0) return false; |
| 326 | |
| 327 | if (result.createColumns) { |
| 328 | return draggedTypes.every((dragType) => !isLayoutChildType(dragType)); |
| 329 | } |
| 330 | |
| 331 | const parentType = getParentTypeAtPath(editor, result.to); |
| 332 | |
| 333 | if ( |
| 334 | parentType === CIRCULAR_GRID_GROUP && |
| 335 | !canDropIntoCircularGrid(editor, dragItem, result.to) |
| 336 | ) { |
| 337 | return false; |
| 338 | } |
| 339 | |
| 340 | if (parentType && isLayoutParentType(parentType)) { |
| 341 | return draggedTypes.every((dragType) => |
| 342 | canLayoutChildTypeBePlacedInParent(dragType, parentType), |
| 343 | ); |
| 344 | } |
| 345 | |
| 346 | return draggedTypes.every((dragType) => { |
| 347 | if (!isLayoutChildType(dragType)) return true; |
| 348 | |
| 349 | return Boolean( |
| 350 | parentType && getLayoutParentTypes(dragType).includes(parentType), |
| 351 | ); |
| 352 | }); |
| 353 | } |
| 354 | |
| 355 | function canDropIntoCircularGrid( |
| 356 | editor: PlateEditor, |
| 357 | dragItem: DragItemNode, |
| 358 | dropPath: Path, |
| 359 | ): boolean { |
| 360 | const parentPath = PathApi.parent(dropPath); |
| 361 | const parent = NodeApi.get(editor, parentPath); |
| 362 | |
| 363 | if (!isElementNode(parent) || parent.type !== CIRCULAR_GRID_GROUP) { |
| 364 | return true; |
| 365 | } |
| 366 | |
| 367 | const draggedEntries = getDraggedElementEntries(editor, dragItem); |
| 368 | const circularGridItemsToAdd = draggedEntries.filter( |
| 369 | ([node]) => node.type === CIRCULAR_GRID_ITEM, |
| 370 | ); |
| 371 | |
| 372 | if (circularGridItemsToAdd.length === 0) return true; |
| 373 | |
| 374 | const isSameParentReorder = circularGridItemsToAdd.every(([, path]) => |
| 375 | path ? PathApi.equals(PathApi.parent(path), parentPath) : false, |
| 376 | ); |
| 377 | |
| 378 | if (isSameParentReorder) return true; |
| 379 | |
| 380 | const currentCircularGridItems = parent.children.filter( |
| 381 | (child): child is TElement => |
| 382 | isElementNode(child) && child.type === CIRCULAR_GRID_ITEM, |
| 383 | ).length; |
| 384 | |
| 385 | return ( |
| 386 | currentCircularGridItems + circularGridItemsToAdd.length <= |
| 387 | CIRCULAR_GRID_MAX_ITEMS |
| 388 | ); |
| 389 | } |
| 390 | |
| 391 | function getDraggedElementEntries( |
| 392 | editor: PlateEditor, |
| 393 | dragItem: DragItemNode, |
| 394 | ): Array<[TElement, Path | undefined]> { |
| 395 | if (!("element" in dragItem)) return []; |
| 396 | |
| 397 | const draggedIds = getDraggedIds(dragItem); |
| 398 | const entriesFromIds = draggedIds |
| 399 | .map( |
| 400 | (id) => |
| 401 | editor.api.node({ id, at: [] }) as NodeEntry<TElement> | undefined, |
| 402 | ) |
| 403 | .filter((entry): entry is NodeEntry<TElement> => |
| 404 | Boolean(entry && isElementNode(entry[0])), |
| 405 | ) |
| 406 | .map(([node, path]) => [node, path] as [TElement, Path | undefined]); |
| 407 | |
| 408 | if (entriesFromIds.length > 0) return entriesFromIds; |
| 409 | |
| 410 | return getElementEntries(dragItem.element); |
| 411 | } |
| 412 | |
| 413 | function getElementEntries(value: unknown): Array<[TElement, undefined]> { |
| 414 | if (Array.isArray(value)) { |
| 415 | return value.flatMap(getElementEntries); |
| 416 | } |
| 417 | |
| 418 | if (!isElementNode(value)) return []; |
| 419 | |
| 420 | return [[value, undefined]]; |
| 421 | } |
| 422 | |
| 423 | function getDraggedElementTypes( |
| 424 | editor: PlateEditor, |
| 425 | dragItem: DragItemNode, |
| 426 | ): string[] { |
| 427 | if (!("element" in dragItem)) return []; |
| 428 | |
| 429 | const draggedIds = getDraggedIds(dragItem); |
| 430 | const typesFromIds = draggedIds |
| 431 | .map((id) => editor.api.node({ id, at: [] })?.[0]) |
| 432 | .filter(isElementNode) |
| 433 | .map((node) => node.type) |
| 434 | .filter((type): type is string => typeof type === "string"); |
| 435 | |
| 436 | if (typesFromIds.length > 0) return typesFromIds; |
| 437 | |
| 438 | return getElementTypes(dragItem.element); |
| 439 | } |
| 440 | |
| 441 | function getDraggedIds(dragItem: DragItemNode): string[] { |
| 442 | if (!("id" in dragItem)) return []; |
| 443 | |
| 444 | return Array.isArray(dragItem.id) ? dragItem.id : [dragItem.id]; |
| 445 | } |
| 446 | |
| 447 | function getElementTypes(value: unknown): string[] { |
| 448 | if (Array.isArray(value)) { |
| 449 | return value.flatMap(getElementTypes); |
| 450 | } |
| 451 | |
| 452 | if (!isElementNode(value) || typeof value.type !== "string") return []; |
| 453 | |
| 454 | return [value.type]; |
| 455 | } |
| 456 | |
| 457 | function getParentTypeAtPath( |
| 458 | editor: PlateEditor, |
| 459 | path: Path, |
| 460 | ): string | undefined { |
| 461 | if (path.length < 2) return undefined; |
| 462 | |
| 463 | const parent = NodeApi.get(editor, PathApi.parent(path)); |
| 464 | |
| 465 | return isElementNode(parent) && typeof parent.type === "string" |
| 466 | ? parent.type |
| 467 | : undefined; |
| 468 | } |
| 469 | |
| 470 | function getContainingColumnItemPath( |
| 471 | editor: PlateEditor, |
| 472 | path: Path, |
| 473 | ): Path | undefined { |
| 474 | let currentPath = path; |
| 475 | |
| 476 | while (currentPath.length > 0) { |
| 477 | const node = NodeApi.get(editor, currentPath); |
| 478 | |
| 479 | if (isElementNode(node) && node.type === COLUMN_ITEM) { |
| 480 | const parentPath = PathApi.parent(currentPath); |
| 481 | const parent = NodeApi.get(editor, parentPath); |
| 482 | |
| 483 | if (isElementNode(parent) && parent.type === COLUMN_GROUP) { |
| 484 | return currentPath; |
| 485 | } |
| 486 | } |
| 487 | |
| 488 | currentPath = PathApi.parent(currentPath); |
| 489 | } |
| 490 | |
| 491 | return undefined; |
| 492 | } |
| 493 | |
| 494 | function getInsideContainerPath({ |
| 495 | dragPath, |
| 496 | dragType, |
| 497 | dropElement, |
| 498 | hoveredPath, |
| 499 | }: { |
| 500 | dragPath: Path | undefined; |
| 501 | dragType: string | undefined; |
| 502 | dropElement: TElement; |
| 503 | hoveredPath: Path; |
| 504 | }): Path | undefined { |
| 505 | if (!dragType) return undefined; |
| 506 | |
| 507 | const requiredParentTypes = getRequiredParentTypes(dragType); |
| 508 | |
| 509 | if ( |
| 510 | requiredParentTypes.length === 0 || |
| 511 | !requiredParentTypes.includes(dropElement.type) |
| 512 | ) { |
| 513 | return undefined; |
| 514 | } |
| 515 | |
| 516 | const childCount = Array.isArray(dropElement.children) |
| 517 | ? dropElement.children.length |
| 518 | : 0; |
| 519 | |
| 520 | if (dragPath && PathApi.equals(PathApi.parent(dragPath), hoveredPath)) { |
| 521 | return undefined; |
| 522 | } |
| 523 | |
| 524 | return [...hoveredPath, childCount]; |
| 525 | } |
| 526 | |
| 527 | function getRequiredParentTypes(childType: string): string[] { |
| 528 | return [...getLayoutParentTypes(childType)]; |
| 529 | } |
| 530 | |
| 531 | function isElementNode(node: unknown): node is TElement { |
| 532 | return ( |
| 533 | typeof node === "object" && |
| 534 | node !== null && |
| 535 | "type" in node && |
| 536 | "children" in node |
| 537 | ); |
| 538 | } |
| 539 |