fix: Arrow z-index whenunder bound element

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

packages/element/src/binding.ts

@@ -67,6 +67,7 @@ import {
   deconstructRectanguloidElement,
   projectFixedPointOntoDiagonal,
 } from "./utils";
+import { moveArrowAboveBindable } from "./zindex";
 
 import type { Scene } from "./Scene";
 
@@ -1084,6 +1085,7 @@ export const updateBoundElements = (
     simultaneouslyUpdated?: readonly ExcalidrawElement[];
     changedElements?: Map<string, ExcalidrawElement>;
     indirectArrowUpdate?: boolean;
+    skipArrowZindexUpdate?: boolean;
   },
 ) => {
   if (!isBindableElement(changedElement)) {
@@ -1152,6 +1154,21 @@ export const updateBoundElements = (
           );
 
           if (point) {
+            if (!options?.skipArrowZindexUpdate) {
+              moveArrowAboveBindable(
+                LinearElementEditor.getPointGlobalCoordinates(
+                  element,
+                  point,
+                  elementsMap,
+                ),
+                element,
+                scene.getNonDeletedElements(),
+                scene.getNonDeletedElementsMap(),
+                scene,
+                changedElement,
+              );
+            }
+
             return [
               bindingProp === "startBinding" ? 0 : element.points.length - 1,
               { point },

packages/element/src/delta.ts

@@ -1970,6 +1970,7 @@ export class ElementsDelta implements DeltaContainer<SceneElementsMap> {
         // TODO: with precise bindings this is quite expensive, so consider optimisation so it's only triggered when the arrow does not intersect (imprecise) element bounds
         updateBoundElements(element, scene, {
           changedElements: changed,
+          skipArrowZindexUpdate: true,
         });
       }
     }

packages/element/src/zindex.ts

@@ -18,7 +18,6 @@ import type {
   NonDeletedExcalidrawElement,
   NonDeletedSceneElementsMap,
   Ordered,
-  OrderedExcalidrawElement,
 } from "./types";
 
 const isOfTargetFrame = (element: ExcalidrawElement, frameId: string) => {
@@ -157,7 +156,7 @@ export const moveArrowAboveBindable = (
   elementsMap: NonDeletedSceneElementsMap,
   scene: Scene,
   hit?: NonDeletedExcalidrawElement,
-): readonly OrderedExcalidrawElement[] => {
+) => {
   const hoveredElement = hit
     ? hit
     : getHoveredElementForBinding(point, elements, elementsMap);