Function onDragEnter

packages/react-aria/src/dnd/useDrop.ts:235–278

(e: DragEvent)

  };

  let onDragEnter = (e: DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
    state.dragOverElements.add(getEventTarget(e));
    if (state.dragOverElements.size > 1) {
      return;
    }

    let allowedOperationsBits = getAllowedOperations(e);
    let allowedOperations = allowedOperationsToArray(allowedOperationsBits);
    let dropOperation = allowedOperations[0];

    if (typeof options.getDropOperation === 'function') {
      let types = new DragTypes(e.dataTransfer);
      dropOperation = getDropOperation(
        allowedOperationsBits,
        options.getDropOperation(types, allowedOperations)
      );
    }

    if (typeof options.getDropOperationForPoint === 'function') {
      let types = new DragTypes(e.dataTransfer);
      let rect = (e.currentTarget as HTMLElement).getBoundingClientRect();
      dropOperation = getDropOperation(
        allowedOperationsBits,
        options.getDropOperationForPoint(
          types,
          allowedOperations,
          e.clientX - rect.x,
          e.clientY - rect.y
        )
      );
    }

    state.x = e.clientX;
    state.y = e.clientY;
    state.allowedOperations = allowedOperationsBits;
    state.dropEffect = DROP_OPERATION_TO_DROP_EFFECT[dropOperation] || 'none';
    e.dataTransfer.dropEffect = state.dropEffect;

    if (dropOperation !== 'cancel') {
      fireDropEnter(e);
    }
  };

  let onDragLeave = (e: DragEvent) => {
    e.preventDefault();