Collections: allow to drag and drop to change book position

front/src/api.js

@@ -130,7 +130,7 @@ export function postCollection(collection) {
   return genericPayloadCall('/ws/collection', collection, 'POST')
 }
 
-export function postCollectionAddBook(collectionId, bookId) {
+export function postCollectionAddBook(collectionId, position) {
   return genericPayloadCall(
     '/ws/collection/' + collectionId + '/addbook',
     { bookId: bookId },
@@ -138,6 +138,14 @@ export function postCollectionAddBook(collectionId, bookId) {
   )
 }
 
+export function postCollectionChangePosition(collectionId, itemId, position) {
+  return genericPayloadCall(
+    '/ws/collection/' + collectionId + '/changeposition',
+    { itemId: itemId, position: position },
+    'POST',
+  )
+}
+
 export function putBook(id, book) {
   return genericPayloadCall('/ws/book/edit/' + id, book.value, 'PUT')
 }