feat(ui): improve IAIDndImage performance

`dnd-kit` has a problem where, when drag events start and stop, every item that uses the library rerenders. This occurs due to its use of context.

The dnd library needs to listen for pointer events to handle dragging. Because our images are both clickable (selectable) and draggable, every time you click an image, the dnd necessarily sees this event, its context updates and all other dnd-enabled components rerender.

With a lot of images in gallery and/or batch manager, this leads to some jank.

There is an open PR to address this: clauderic/dnd-kit#1096

But unfortunately, the maintainer hasn't accepted any changes for a few months, and its not clear if this will be merged any time soon :/

This change simply extracts the draggable and droppable logic out of IAIDndImage into their own minimal components. Now only these need to rerender when the dnd context is changed. The rerenders are far less impactful now.

Hopefully the linked PR is accepted and we get even more efficient dnd functionality in the future.

invokeai/frontend/web/src/common/components/IAIDndImage.tsx

@@ -1,35 +1,34 @@
 import {
+  Box,
   ChakraProps,
   Flex,
   Icon,
   Image,
   useColorMode,
   useColorModeValue,
 } from '@chakra-ui/react';
-import { useCombinedRefs } from '@dnd-kit/utilities';
+import {
+  TypesafeDraggableData,
+  TypesafeDroppableData,
+  isValidDrop,
+  useDraggable,
+  useDroppable,
+} from 'app/components/ImageDnd/typesafeDnd';
 import IAIIconButton from 'common/components/IAIIconButton';
 import {
   IAILoadingImageFallback,
   IAINoContentFallback,
 } from 'common/components/IAIImageFallback';
 import ImageMetadataOverlay from 'common/components/ImageMetadataOverlay';
+import { useImageUploadButton } from 'common/hooks/useImageUploadButton';
 import { AnimatePresence } from 'framer-motion';
-import { MouseEvent, ReactElement, SyntheticEvent } from 'react';
-import { memo, useRef } from 'react';
+import { MouseEvent, ReactElement, SyntheticEvent, memo, useRef } from 'react';
 import { FaImage, FaUndo, FaUpload } from 'react-icons/fa';
+import { PostUploadAction } from 'services/api/thunks/image';
 import { ImageDTO } from 'services/api/types';
+import { mode } from 'theme/util/mode';
 import { v4 as uuidv4 } from 'uuid';
 import IAIDropOverlay from './IAIDropOverlay';
-import { PostUploadAction } from 'services/api/thunks/image';
-import { useImageUploadButton } from 'common/hooks/useImageUploadButton';
-import { mode } from 'theme/util/mode';
-import {
-  TypesafeDraggableData,
-  TypesafeDroppableData,
-  isValidDrop,
-  useDraggable,
-  useDroppable,
-} from 'app/components/ImageDnd/typesafeDnd';
 
 type IAIDndImageProps = {
   imageDTO: ImageDTO | undefined;
@@ -83,28 +82,6 @@ const IAIDndImage = (props: IAIDndImageProps) => {
 
   const { colorMode } = useColorMode();
 
-  const dndId = useRef(uuidv4());
-
-  const {
-    attributes,
-    listeners,
-    setNodeRef: setDraggableRef,
-    isDragging,
-    active,
-  } = useDraggable({
-    id: dndId.current,
-    disabled: isDragDisabled || !imageDTO,
-    data: draggableData,
-  });
-
-  const { isOver, setNodeRef: setDroppableRef } = useDroppable({
-    id: dndId.current,
-    disabled: isDropDisabled,
-    data: droppableData,
-  });
-
-  const setDndRef = useCombinedRefs(setDroppableRef, setDraggableRef);
-
   const { getUploadButtonProps, getUploadInputProps } = useImageUploadButton({
     postUploadAction,
     isDisabled: isUploadDisabled,
@@ -139,9 +116,6 @@ const IAIDndImage = (props: IAIDndImageProps) => {
         userSelect: 'none',
         cursor: isDragDisabled || !imageDTO ? 'default' : 'pointer',
       }}
-      {...attributes}
-      {...listeners}
-      ref={setDndRef}
     >
       {imageDTO && (
         <Flex
@@ -154,7 +128,6 @@ const IAIDndImage = (props: IAIDndImageProps) => {
           }}
         >
           <Image
-            onClick={onClick}
             src={thumbnail ? imageDTO.thumbnail_url : imageDTO.image_url}
             fallbackStrategy="beforeLoadOrError"
             fallback={<IAILoadingImageFallback image={imageDTO} />}
@@ -225,13 +198,84 @@ const IAIDndImage = (props: IAIDndImageProps) => {
         </>
       )}
       {!imageDTO && isUploadDisabled && noContentFallback}
+      <Droppable
+        data={droppableData}
+        disabled={isDropDisabled}
+        dropLabel={dropLabel}
+      />
+      <Draggable
+        data={draggableData}
+        disabled={isDragDisabled || !imageDTO}
+        onClick={onClick}
+      />
+    </Flex>
+  );
+};
+
+export default memo(IAIDndImage);
+
+type DroppableProps = {
+  dropLabel?: string;
+  disabled?: boolean;
+  data?: TypesafeDroppableData;
+};
+
+const Droppable = memo((props: DroppableProps) => {
+  const { dropLabel, data, disabled } = props;
+  const dndId = useRef(uuidv4());
+
+  const { isOver, setNodeRef, active } = useDroppable({
+    id: dndId.current,
+    disabled,
+    data,
+  });
+
+  return (
+    <Box
+      ref={setNodeRef}
+      position="absolute"
+      w="full"
+      h="full"
+      pointerEvents="none"
+    >
       <AnimatePresence>
-        {isValidDrop(droppableData, active) && !isDragging && (
+        {isValidDrop(data, active) && (
           <IAIDropOverlay isOver={isOver} label={dropLabel} />
         )}
       </AnimatePresence>
-    </Flex>
+    </Box>
   );
+});
+
+Droppable.displayName = 'Droppable';
+
+type DraggableProps = {
+  disabled?: boolean;
+  data?: TypesafeDraggableData;
+  onClick?: (event: MouseEvent<HTMLDivElement>) => void;
 };
 
-export default memo(IAIDndImage);
+const Draggable = memo((props: DraggableProps) => {
+  const { data, disabled, onClick } = props;
+  const dndId = useRef(uuidv4());
+
+  const { attributes, listeners, setNodeRef } = useDraggable({
+    id: dndId.current,
+    disabled,
+    data,
+  });
+
+  return (
+    <Box
+      onClick={onClick}
+      ref={setNodeRef}
+      position="absolute"
+      w="full"
+      h="full"
+      {...attributes}
+      {...listeners}
+    />
+  );
+});
+
+Draggable.displayName = 'Draggable';