fix(core): use center position of handle as snapping point for connection lines (#1625)

* fix(core): calculate handle positions correctly

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

* fix(core): remove handleId check

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

* chore(core): cleanup

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

* chore(core): cleanup click connect handlers

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

* fix(core): add flow id to handle ids

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

* tests: correct updateEdge test

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

* fix(core): use center position of handle

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

* chore(examples): cleanup easy connect example

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

* refactor(tests): run actions on chrome

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

* chore(workflows): correctly hash lock file

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

---------

Signed-off-by: braks <78412429+bcakmakoglu@users.noreply.github.com>

.github/actions/install-dependencies/action.yaml

@@ -26,7 +26,7 @@ runs:
       uses: actions/cache@v4
       with:
         path: ${{ steps.pnpm-cache.outputs.STORE_PATH }}
-        key: ${{ runner.os }}-pnpm-store-${{ hashFiles('**/pnpm-lock.yaml') }}
+        key: ${{ runner.os }}-pnpm-store-${{ hashFiles('pnpm-lock.yaml') }}
         restore-keys: |
           ${{ runner.os }}-pnpm-store-
 

.github/workflows/build-and-test.yml

@@ -54,5 +54,3 @@ jobs:
         with:
           install-command: pnpm cypress install
           command: pnpm run test --cache-dir=.turbo
-          browser: chrome
-          component: true

examples/vite/src/EasyConnect/EasyConnect.vue

@@ -1,12 +1,10 @@
 <script lang="ts" setup>
 import { ref } from 'vue'
 import { Background } from '@vue-flow/background'
-import { Controls } from '@vue-flow/controls'
+import type { Node } from '@vue-flow/core'
-import { MiniMap } from '@vue-flow/minimap'
-import type { Elements } from '@vue-flow/core'
 import { MarkerType, VueFlow, useVueFlow } from '@vue-flow/core'
 import CustomNode from './CustomNode.vue'
-import CustomConnectionLine from './CustomConnectionLine.vue'
+import FloatingConnectionLine from './FloatingConnectionLine.vue'
 import FloatingEdge from './FloatingEdge.vue'
 
 const { onConnect, addEdges } = useVueFlow()
@@ -20,7 +18,7 @@ const defaultEdgeOptions = {
   },
 }
 
-const elements = ref<Elements>([
+const nodes = ref<Node[]>([
   {
     id: '1',
     type: 'custom',
@@ -43,26 +41,21 @@ const elements = ref<Elements>([
   },
 ])
 
+const edges = ref([])
+
 onConnect(addEdges)
 </script>
 
 <template>
-  <div style="height: 100vh">
   <VueFlow
-      v-model="elements"
+    v-model:nodes="nodes"
+    v-model:edges="edges"
     :elevate-nodes-on-select="false"
-      class="vue-flow-basic-example"
-      :default-zoom="1.5"
     :default-edge-options="defaultEdgeOptions"
-      :min-zoom="0.2"
+    fit-view-on-init
-      :max-zoom="4"
   >
     <Background pattern-color="#aaa" :gap="8" />
 
-      <MiniMap />
-
-      <Controls />
-
     <template #node-custom="props">
       <CustomNode :id="props.id" />
     </template>
@@ -72,8 +65,7 @@ onConnect(addEdges)
     </template>
 
     <template #connection-line="cProps">
-        <CustomConnectionLine v-bind="cProps" />
+      <FloatingConnectionLine v-bind="cProps" />
     </template>
   </VueFlow>
-  </div>
 </template>

examples/vite/src/EasyConnect/FloatingConnectionLine.vue

@@ -1,9 +1,9 @@
 <script lang="ts" setup>
-import type { GraphNode } from '@vue-flow/core'
+import type { ConnectionLineProps } from '@vue-flow/core'
-import { getStraightPath } from '@vue-flow/core'
+import { BaseEdge, getStraightPath } from '@vue-flow/core'
 import { computed } from 'vue'
 
-const props = defineProps<{ sourceNode: GraphNode; sourceX: number; sourceY: number; targetX: number; targetY: number }>()
+const props = defineProps<ConnectionLineProps>()
 
 const edgePath = computed(() =>
   getStraightPath({
@@ -15,13 +15,12 @@ const edgePath = computed(() =>
 
 <template>
   <g>
-    <path
+    <BaseEdge
       :style="{
         strokeWidth: 3,
         stroke: 'black',
       }"
-      fill="none"
+      :path="edgePath[0]"
-      :d="edgePath[0]"
     />
     <circle :cx="targetX" :cy="targetY" fill="black" :r="3" stroke="black" :stroke-width="1.5" />
   </g>

examples/vite/src/EasyConnect/FloatingEdge.vue

@@ -1,11 +1,11 @@
 <script lang="ts" setup>
-import type { GraphNode } from '@vue-flow/core'
+import type { EdgeProps } from '@vue-flow/core'
-import { getStraightPath } from '@vue-flow/core'
+import { BaseEdge, getStraightPath } from '@vue-flow/core'
 import { computed } from 'vue'
 
 import { getEdgeParams } from './utils'
 
-const props = defineProps<{ id: string; sourceNode: GraphNode; targetNode: GraphNode; markerEnd: string; style: any }>()
+const props = defineProps<EdgeProps>()
 
 const edgeParams = computed(() => getEdgeParams(props.sourceNode, props.targetNode))
 
@@ -20,5 +20,5 @@ const edgePath = computed(() =>
 </script>
 
 <template>
-  <path :id="id" class="vue-flow__edge-path" :d="edgePath[0]" :marker-end="markerEnd" :style="style" />
+  <BaseEdge :id="id" :path="edgePath[0]" :marker-end="markerEnd" :style="style" />
 </template>

packages/core/src/components/ConnectionLine/index.ts

@@ -1,18 +1,11 @@
 import { computed, defineComponent, h, inject } from 'vue'
 import type { HandleElement } from '../../types'
 import { ConnectionLineType, ConnectionMode, Position } from '../../types'
-import { getHandlePosition, getMarkerId } from '../../utils'
+import { getHandlePosition, getMarkerId, oppositePosition } from '../../utils'
 import { useVueFlow } from '../../composables'
 import { Slots } from '../../context'
 import { getBezierPath, getSimpleBezierPath, getSmoothStepPath } from '../Edges/utils'
 
-const oppositePosition = {
-  [Position.Left]: Position.Right,
-  [Position.Right]: Position.Left,
-  [Position.Top]: Position.Bottom,
-  [Position.Bottom]: Position.Top,
-}
-
 const ConnectionLine = defineComponent({
   name: 'ConnectionLine',
   compatConfig: { MODE: 3 },
@@ -57,7 +50,7 @@ const ConnectionLine = defineComponent({
         return null
       }
 
-      const startHandleId = connectionStartHandle.value.handleId
+      const startHandleId = connectionStartHandle.value.id
 
       const handleType = connectionStartHandle.value.type
 
@@ -78,18 +71,18 @@ const ConnectionLine = defineComponent({
       const { x: fromX, y: fromY } = getHandlePosition(fromNode.value, fromHandle, fromPosition)
 
       let toHandle: HandleElement | null = null
-      if (toNode.value && connectionEndHandle.value?.handleId) {
+      if (toNode.value) {
         // if connection mode is strict, we only look for handles of the opposite type
         if (connectionMode.value === ConnectionMode.Strict) {
           toHandle =
             toNode.value.handleBounds[handleType === 'source' ? 'target' : 'source']?.find(
-              (d) => d.id === connectionEndHandle.value?.handleId,
+              (d) => d.id === connectionEndHandle.value?.id,
             ) || null
         } else {
           // if connection mode is loose, look for the handle in both source and target bounds
           toHandle =
             [...(toNode.value.handleBounds.source || []), ...(toNode.value.handleBounds.target || [])]?.find(
-              (d) => d.id === connectionEndHandle.value?.handleId,
+              (d) => d.id === connectionEndHandle.value?.id,
             ) || null
         }
       }

packages/core/src/components/Edges/EdgeWrapper.ts

@@ -8,7 +8,7 @@ import {
   ErrorCode,
   VueFlowError,
   elementSelectionKeys,
-  getHandle,
+  getEdgeHandle,
   getHandlePosition,
   getMarkerId,
 } from '../../utils'
@@ -150,7 +150,7 @@ const EdgeWrapper = defineComponent({
         sourceNodeHandles = [...(sourceNode.handleBounds.source || []), ...(sourceNode.handleBounds.target || [])]
       }
 
-      const sourceHandle = getHandle(sourceNodeHandles, edge.value.sourceHandle)
+      const sourceHandle = getEdgeHandle(sourceNodeHandles, edge.value.sourceHandle)
 
       let targetNodeHandles
       if (connectionMode.value === ConnectionMode.Strict) {
@@ -159,7 +159,7 @@ const EdgeWrapper = defineComponent({
         targetNodeHandles = [...(targetNode.handleBounds.target || []), ...(targetNode.handleBounds.source || [])]
       }
 
-      const targetHandle = getHandle(targetNodeHandles, edge.value.targetHandle)
+      const targetHandle = getEdgeHandle(targetNodeHandles, edge.value.targetHandle)
 
       const sourcePosition = sourceHandle?.position || Position.Bottom
 

packages/core/src/components/Handle/Handle.vue

@@ -19,6 +19,7 @@ const type = toRef(() => props.type ?? 'source')
 const isValidConnection = toRef(() => props.isValidConnection ?? null)
 
 const {
+  id: flowId,
   connectionStartHandle,
   connectionClickStartHandle,
   connectionEndHandle,
@@ -39,17 +40,17 @@ const isConnectableEnd = toRef(() => (typeof connectableEnd !== 'undefined' ? co
 const isConnecting = toRef(
   () =>
     (connectionStartHandle.value?.nodeId === nodeId &&
-      connectionStartHandle.value?.handleId === handleId &&
+      connectionStartHandle.value?.id === handleId &&
       connectionStartHandle.value?.type === type.value) ||
     (connectionEndHandle.value?.nodeId === nodeId &&
-      connectionEndHandle.value?.handleId === handleId &&
+      connectionEndHandle.value?.id === handleId &&
       connectionEndHandle.value?.type === type.value),
 )
 
 const isClickConnecting = toRef(
   () =>
     connectionClickStartHandle.value?.nodeId === nodeId &&
-    connectionClickStartHandle.value?.handleId === handleId &&
+    connectionClickStartHandle.value?.id === handleId &&
     connectionClickStartHandle.value?.type === type.value,
 )
 
@@ -127,6 +128,8 @@ onMounted(() => {
     position,
     x: (handleBounds.left - nodeBounds.left) / zoom,
     y: (handleBounds.top - nodeBounds.top) / zoom,
+    type: type.value,
+    nodeId,
     ...getDimensions(handle.value),
   }
 
@@ -177,7 +180,7 @@ export default {
 <template>
   <div
     ref="handle"
-    :data-id="`${nodeId}-${handleId}-${type}`"
+    :data-id="`${flowId}-${nodeId}-${handleId}-${type}`"
     :data-handleid="handleId"
     :data-nodeid="nodeId"
     :data-handlepos="position"

packages/core/src/composables/useHandle.ts

@@ -1,16 +1,19 @@
 import type { MaybeRefOrGetter } from 'vue'
 import { toValue } from 'vue'
-import type { Connection, ConnectionHandle, HandleType, MouseTouchEvent, ValidConnectionFunc, ValidHandleResult } from '../types'
+import type { Connection, ConnectionInProgress, HandleElement, HandleType, MouseTouchEvent, ValidConnectionFunc } from '../types'
 import {
   calcAutoPan,
   getClosestHandle,
   getConnectionStatus,
   getEventPosition,
-  getHandleLookup,
+  getHandle,
+  getHandlePosition,
   getHandleType,
   getHostForElement,
+  isConnectionValid,
   isMouseEvent,
   isValidHandle,
+  oppositePosition,
   pointToRendererPoint,
   rendererPointToPoint,
   resetRecentHandle,
@@ -49,6 +52,7 @@ export function useHandle({
   onEdgeUpdateEnd,
 }: UseHandleProps) {
   const {
+    id: flowId,
     vueFlowRef,
     connectionMode,
     connectionRadius,
@@ -67,12 +71,12 @@ export function useHandle({
     edges,
     nodes,
     isValidConnection: isValidConnectionProp,
+    nodeLookup,
   } = useVueFlow()
 
   let connection: Connection | null = null
-  let isValid = false
+  let isValid: boolean | null = false
   let handleDomNode: Element | null = null
-  let previousConnection: ValidHandleResult | null = null
 
   function handlePointerDown(event: MouseTouchEvent) {
     const isTarget = toValue(type) === 'target'
@@ -91,7 +95,7 @@ export function useHandle({
         isValidConnectionHandler = (!isTarget ? node.isValidTargetPos : node.isValidSourcePos) || alwaysValid
       }
 
-      let closestHandle: ConnectionHandle | null
+      let closestHandle: HandleElement | null
 
       let autoPanId = 0
 
@@ -104,17 +108,16 @@ export function useHandle({
         return
       }
 
+      const fromHandleInternal = getHandle(toValue(nodeId), handleType, toValue(handleId), nodeLookup.value, connectionMode.value)
+
+      if (!fromHandleInternal) {
+        return
+      }
+
       let prevActiveHandle: Element
       let connectionPosition = getEventPosition(event, containerBounds)
       let autoPanStarted = false
 
-      const handleLookup = getHandleLookup({
-        nodes: nodes.value,
-        nodeId: toValue(nodeId),
-        handleId: toValue(handleId),
-        handleType,
-      })
-
       // when the user is moving the mouse close to the edge of the canvas while connecting we move the canvas
       const autoPan = () => {
         if (!autoPanOnConnect.value) {
@@ -127,10 +130,37 @@ export function useHandle({
         autoPanId = requestAnimationFrame(autoPan)
       }
 
+      // Stays the same for all consecutive pointermove events
+      const fromHandle: HandleElement = {
+        ...fromHandleInternal,
+        nodeId: toValue(nodeId),
+        type: handleType,
+        position: fromHandleInternal.position,
+      }
+
+      const fromNodeInternal = nodeLookup.value.get(toValue(nodeId))!
+
+      const from = getHandlePosition(fromNodeInternal, fromHandle, Position.Left, true)
+
+      const newConnection: ConnectionInProgress = {
+        inProgress: true,
+        isValid: null,
+
+        from,
+        fromHandle,
+        fromPosition: fromHandle.position,
+        fromNode: fromNodeInternal,
+
+        to: connectionPosition,
+        toHandle: null,
+        toPosition: oppositePosition[fromHandle.position],
+        toNode: null,
+      }
+
       startConnection(
         {
           nodeId: toValue(nodeId),
-          handleId: toValue(handleId),
+          id: toValue(handleId),
           type: handleType,
           position: (clickedHandle?.getAttribute('data-handlepos') as Position) || Position.Top,
         },
@@ -142,52 +172,71 @@ export function useHandle({
 
       emits.connectStart({ event, nodeId: toValue(nodeId), handleId: toValue(handleId), handleType })
 
+      let previousConnection: ConnectionInProgress = newConnection
+
       function onPointerMove(event: MouseTouchEvent) {
         connectionPosition = getEventPosition(event, containerBounds)
 
-        const { handle, validHandleResult } = getClosestHandle(
+        closestHandle = getClosestHandle(
-          event,
-          doc,
           pointToRendererPoint(connectionPosition, viewport.value, false, [1, 1]),
           connectionRadius.value,
-          handleLookup,
+          nodeLookup.value,
-          (handle) =>
+          fromHandle,
-            isValidHandle(
-              event,
-              handle,
-              connectionMode.value,
-              toValue(nodeId),
-              toValue(handleId),
-              isTarget ? 'target' : 'source',
-              isValidConnectionHandler,
-              doc,
-              edges.value,
-              nodes.value,
-              findNode,
-            ),
         )
 
-        closestHandle = handle
-
         if (!autoPanStarted) {
           autoPan()
           autoPanStarted = true
         }
 
-        connection = validHandleResult.connection
+        const result = isValidHandle(
-        isValid = validHandleResult.isValid
+          event,
-        handleDomNode = validHandleResult.handleDomNode
+          {
+            handle: closestHandle,
+            connectionMode: connectionMode.value,
+            fromNodeId: toValue(nodeId),
+            fromHandleId: toValue(handleId),
+            fromType: isTarget ? 'target' : 'source',
+            isValidConnection: isValidConnectionHandler,
+            doc,
+            lib: 'vue',
+            flowId,
+            nodeLookup: nodeLookup.value,
+          },
+          edges.value,
+          nodes.value,
+          findNode,
+        )
+
+        handleDomNode = result.handleDomNode
+        connection = result.connection
+        isValid = isConnectionValid(!!closestHandle, result.isValid)
+
+        const newConnection: ConnectionInProgress = {
+          // from stays the same
+          ...previousConnection,
+          isValid,
+          to:
+            closestHandle && isValid
+              ? rendererPointToPoint({ x: closestHandle.x, y: closestHandle.y }, viewport.value)
+              : connectionPosition,
+          toHandle: result.toHandle,
+          toPosition: isValid && result.toHandle ? result.toHandle.position : oppositePosition[fromHandle.position],
+          toNode: result.toHandle ? nodeLookup.value.get(result.toHandle.nodeId)! : null,
+        }
 
         // we don't want to trigger an update when the connection
         // is snapped to the same handle as before
         if (
           isValid &&
           closestHandle &&
-          previousConnection?.endHandle &&
+          previousConnection?.toHandle &&
-          validHandleResult.endHandle &&
+          newConnection.toHandle &&
-          previousConnection.endHandle.type === validHandleResult.endHandle.type &&
+          previousConnection.toHandle.type === newConnection.toHandle.type &&
-          previousConnection.endHandle.nodeId === validHandleResult.endHandle.nodeId &&
+          previousConnection.toHandle.nodeId === newConnection.toHandle.nodeId &&
-          previousConnection.endHandle.handleId === validHandleResult.endHandle.handleId
+          previousConnection.toHandle.id === newConnection.toHandle.id &&
+          previousConnection.to.x === newConnection.to.x &&
+          previousConnection.to.y === newConnection.to.y
         ) {
           return
         }
@@ -202,11 +251,11 @@ export function useHandle({
                 viewport.value,
               )
             : connectionPosition,
-          validHandleResult.endHandle,
+          result.toHandle,
           getConnectionStatus(!!closestHandle, isValid),
         )
 
-        previousConnection = validHandleResult
+        previousConnection = newConnection
 
         if (!closestHandle && !isValid && !handleDomNode) {
           return resetRecentHandle(prevActiveHandle)
@@ -219,9 +268,9 @@ export function useHandle({
 
           // todo: remove `vue-flow__handle-connecting` in next major version
           handleDomNode.classList.add('connecting', 'vue-flow__handle-connecting')
-          handleDomNode.classList.toggle('valid', isValid)
+          handleDomNode.classList.toggle('valid', !!isValid)
           // todo: remove this in next major version
-          handleDomNode.classList.toggle('vue-flow__handle-valid', isValid)
+          handleDomNode.classList.toggle('vue-flow__handle-valid', !!isValid)
         }
       }
 
@@ -275,8 +324,15 @@ export function useHandle({
     if (!connectionClickStartHandle.value) {
       emits.clickConnectStart({ event, nodeId: toValue(nodeId), handleId: toValue(handleId) })
 
-      startConnection({ nodeId: toValue(nodeId), type: toValue(type), handleId: toValue(handleId) }, undefined, true)
+      startConnection(
-    } else {
+        { nodeId: toValue(nodeId), type: toValue(type), id: toValue(handleId), position: Position.Top },
+        undefined,
+        true,
+      )
+
+      return
+    }
+
     let isValidConnectionHandler = toValue(isValidConnection) || isValidConnectionProp.value || alwaysValid
 
     const node = findNode(toValue(nodeId))
@@ -291,35 +347,40 @@ export function useHandle({
 
     const doc = getHostForElement(event.target as HTMLElement)
 
-      const { connection, isValid } = isValidHandle(
+    const result = isValidHandle(
       event,
       {
+        handle: {
           nodeId: toValue(nodeId),
           id: toValue(handleId),
           type: toValue(type),
+          position: Position.Top,
         },
-        connectionMode.value,
+        connectionMode: connectionMode.value,
-        connectionClickStartHandle.value.nodeId,
+        fromNodeId: connectionClickStartHandle.value.nodeId,
-        connectionClickStartHandle.value.handleId || null,
+        fromHandleId: connectionClickStartHandle.value.id || null,
-        connectionClickStartHandle.value.type,
+        fromType: connectionClickStartHandle.value.type,
-        isValidConnectionHandler,
+        isValidConnection: isValidConnectionHandler,
         doc,
+        lib: 'vue',
+        flowId,
+        nodeLookup: nodeLookup.value,
+      },
       edges.value,
       nodes.value,
       findNode,
     )
 
-      const isOwnHandle = connection.source === connection.target
+    const isOwnHandle = result.connection?.source === result.connection?.target
 
-      if (isValid && !isOwnHandle) {
+    if (result.isValid && result.connection && !isOwnHandle) {
-        emits.connect(connection)
+      emits.connect(result.connection)
     }
 
     emits.clickConnectEnd(event)
 
     endConnection(event, true)
   }
-  }
 
   return {
     handlePointerDown,

packages/core/src/store/actions.ts

@@ -157,8 +157,8 @@ export function useActions(state: State, nodeLookup: ComputedRef<NodeLookup>, ed
         if (doUpdate) {
           const nodeBounds = update.nodeElement.getBoundingClientRect()
           node.dimensions = dimensions
-          node.handleBounds.source = getHandleBounds('.source', update.nodeElement, nodeBounds, zoom)
+          node.handleBounds.source = getHandleBounds('source', update.nodeElement, nodeBounds, zoom)
-          node.handleBounds.target = getHandleBounds('.target', update.nodeElement, nodeBounds, zoom)
+          node.handleBounds.target = getHandleBounds('target', update.nodeElement, nodeBounds, zoom)
 
           changes.push({
             id: node.id,

packages/core/src/types/handle.ts

@@ -1,13 +1,16 @@
 import type { Dimensions, Position, XYPosition } from './flow'
-import type { Connection } from './connection'
+import type { Connection, ConnectionMode } from './connection'
 import type { GraphEdge } from './edge'
 import type { GraphNode } from './node'
+import type { NodeLookup } from './store'
 
 export type HandleType = 'source' | 'target'
 
 export interface HandleElement extends XYPosition, Dimensions {
   id?: string | null
   position: Position
+  type: HandleType
+  nodeId: string
 }
 
 export interface ConnectionHandle extends XYPosition {
@@ -16,18 +19,11 @@ export interface ConnectionHandle extends XYPosition {
   nodeId: string
 }
 
-export interface ValidHandleResult {
-  endHandle: ConnectingHandle | null
-  handleDomNode: Element | null
-  isValid: boolean
-  connection: Connection
-}
-
 export interface ConnectingHandle {
   nodeId: string
   type: HandleType
-  handleId?: string | null
+  id?: string | null
-  position?: Position | null
+  position: Position
 }
 
 /** A valid connection function can determine if an attempted connection is valid or not, i.e. abort creating a new edge */
@@ -63,3 +59,36 @@ export interface HandleProps {
   /** Can this handle be used to *end* a connection */
   connectableEnd?: boolean
 }
+
+export interface IsValidParams {
+  handle: ConnectingHandle | null
+  connectionMode: ConnectionMode
+  fromNodeId: string
+  fromHandleId: string | null
+  fromType: HandleType
+  isValidConnection?: ValidConnectionFunc
+  doc: Document | ShadowRoot
+  lib: string
+  flowId: string | null
+  nodeLookup: NodeLookup
+}
+
+export interface Result {
+  handleDomNode: Element | null
+  isValid: boolean
+  connection: Connection | null
+  toHandle: ConnectingHandle | null
+}
+
+export interface ConnectionInProgress<NodeType extends GraphNode = GraphNode> {
+  inProgress: true
+  isValid: boolean | null
+  from: XYPosition
+  fromHandle: HandleElement
+  fromPosition: Position
+  fromNode: NodeType
+  to: XYPosition
+  toHandle: ConnectingHandle | null
+  toPosition: Position
+  toNode: NodeType | null
+}

packages/core/src/utils/edge.ts

@@ -6,41 +6,36 @@ export function getHandlePosition(
   node: GraphNode,
   handle: HandleElement | null,
   fallbackPosition: Position = Position.Left,
+  center = false,
 ): XYPosition {
   const x = (handle?.x ?? 0) + node.computedPosition.x
   const y = (handle?.y ?? 0) + node.computedPosition.y
   const { width, height } = handle ?? getNodeDimensions(node)
+
+  if (center) {
+    return { x: x + width / 2, y: y + height / 2 }
+  }
+
   const position = handle?.position ?? fallbackPosition
 
   switch (position) {
     case Position.Top:
-      return {
+      return { x: x + width / 2, y }
-        x: x + width / 2,
-        y,
-      }
     case Position.Right:
-      return {
+      return { x: x + width, y: y + height / 2 }
-        x: x + width,
-        y: y + height / 2,
-      }
     case Position.Bottom:
-      return {
+      return { x: x + width / 2, y: y + height }
-        x: x + width / 2,
-        y: y + height,
-      }
     case Position.Left:
-      return {
+      return { x, y: y + height / 2 }
-        x,
-        y: y + height / 2,
-      }
   }
 }
 
-export function getHandle(bounds: HandleElement[] = [], handleId?: string | null): HandleElement | null {
+export function getEdgeHandle(bounds: HandleElement[] | undefined, handleId?: string | null): HandleElement | null {
-  if (!bounds.length) {
+  if (!bounds) {
     return null
   }
 
+  // if no handleId is given, we use the first handle, otherwise we check for the id
   return (!handleId ? bounds[0] : bounds.find((d) => d.id === handleId)) || null
 }
 

packages/core/src/utils/handle.ts

@@ -1,4 +1,4 @@
-import { ConnectionMode } from '../types'
+import { ConnectionMode, Position } from '../types'
 import type {
   Actions,
   Connection,
@@ -6,23 +6,17 @@ import type {
   ConnectionStatus,
   GraphEdge,
   GraphNode,
+  HandleElement,
   HandleType,
+  IsValidParams,
   NodeHandleBounds,
-  Position,
+  NodeLookup,
-  ValidConnectionFunc,
+  Result,
-  ValidHandleResult,
   XYPosition,
 } from '../types'
-import { getEventPosition, getHandlePosition } from '.'
+import { getEventPosition, getHandlePosition, getOverlappingArea, nodeToRect } from '.'
 
-function defaultValidHandleResult(): ValidHandleResult {
+const alwaysValid = () => true
-  return {
-    handleDomNode: null,
-    isValid: false,
-    connection: { source: '', target: '', sourceHandle: null, targetHandle: null },
-    endHandle: null,
-  }
-}
 
 export function resetRecentHandle(handleDomNode: Element): void {
   handleDomNode?.classList.remove('valid', 'connecting', 'vue-flow__handle-valid', 'vue-flow__handle-connecting')
@@ -55,126 +49,126 @@ export function getHandles(
   return connectionHandles
 }
 
+function getNodesWithinDistance(position: XYPosition, nodeLookup: NodeLookup, distance: number): GraphNode[] {
+  const nodes: GraphNode[] = []
+  const rect = {
+    x: position.x - distance,
+    y: position.y - distance,
+    width: distance * 2,
+    height: distance * 2,
+  }
+
+  for (const node of nodeLookup.values()) {
+    if (getOverlappingArea(rect, nodeToRect(node)) > 0) {
+      nodes.push(node)
+    }
+  }
+
+  return nodes
+}
+
+// this distance is used for the area around the user pointer
+// while doing a connection for finding the closest nodes
+const ADDITIONAL_DISTANCE = 250
+
 export function getClosestHandle(
-  event: MouseEvent | TouchEvent,
+  position: XYPosition,
-  doc: Document | ShadowRoot,
-  pos: XYPosition,
   connectionRadius: number,
-  handles: ConnectionHandle[],
+  nodeLookup: NodeLookup,
-  validator: (handle: Pick<ConnectionHandle, 'nodeId' | 'id' | 'type'>) => ValidHandleResult,
+  fromHandle: { nodeId: string; type: HandleType; id?: string | null },
-) {
+): HandleElement | null {
-  // we always want to prioritize the handle below the mouse cursor over the closest distance handle,
+  let closestHandles: HandleElement[] = []
-  // because it could be that the center of another handle is closer to the mouse pointer than the handle below the cursor
-  const { x, y } = getEventPosition(event)
-  const domNodes = doc.elementsFromPoint(x, y)
-
-  const handleBelow = domNodes.find((el) => el.classList.contains('vue-flow__handle'))
-
-  if (handleBelow) {
-    const handleNodeId = handleBelow.getAttribute('data-nodeid')
-
-    if (handleNodeId) {
-      const handleType = getHandleType(undefined, handleBelow)
-      const handleId = handleBelow.getAttribute('data-handleid')
-      const validHandleResult = validator({ nodeId: handleNodeId, id: handleId, type: handleType })
-
-      if (validHandleResult) {
-        const handle = handles.find((h) => h.nodeId === handleNodeId && h.type === handleType && h.id === handleId)
-
-        return {
-          handle: {
-            id: handleId,
-            type: handleType,
-            nodeId: handleNodeId,
-            x: handle?.x || pos.x,
-            y: handle?.y || pos.y,
-          },
-          validHandleResult,
-        }
-      }
-    }
-  }
-
-  // if we couldn't find a handle below the mouse cursor we look for the closest distance based on the connectionRadius
-  let closestHandles: { handle: ConnectionHandle; validHandleResult: ValidHandleResult }[] = []
   let minDistance = Number.POSITIVE_INFINITY
 
-  for (const handle of handles) {
+  const closeNodes = getNodesWithinDistance(position, nodeLookup, connectionRadius + ADDITIONAL_DISTANCE)
-    const distance = Math.sqrt((handle.x - pos.x) ** 2 + (handle.y - pos.y) ** 2)
 
-    if (distance <= connectionRadius) {
+  for (const node of closeNodes) {
-      const validHandleResult = validator(handle)
+    const allHandles = [...(node.handleBounds?.source ?? []), ...(node.handleBounds?.target ?? [])]
 
-      if (distance <= minDistance) {
+    for (const handle of allHandles) {
-        if (distance < minDistance) {
+      // if the handle is the same as the fromHandle we skip it
-          closestHandles = [{ handle, validHandleResult }]
+      if (fromHandle.nodeId === handle.nodeId && fromHandle.type === handle.type && fromHandle.id === handle.id) {
-        } else if (distance === minDistance) {
+        continue
-          // when multiple handles are on the same distance we collect all of them
-          closestHandles.push({
-            handle,
-            validHandleResult,
-          })
       }
 
+      // determine absolute position of the handle
+      const { x, y } = getHandlePosition(node, handle, handle.position, true)
+
+      const distance = Math.sqrt((x - position.x) ** 2 + (y - position.y) ** 2)
+      if (distance > connectionRadius) {
+        continue
+      }
+
+      if (distance < minDistance) {
+        closestHandles = [{ ...handle, x, y }]
         minDistance = distance
+      } else if (distance === minDistance) {
+        // when multiple handles are on the same distance we collect all of them
+        closestHandles.push({ ...handle, x, y })
       }
     }
   }
 
   if (!closestHandles.length) {
-    return { handle: null, validHandleResult: defaultValidHandleResult() }
+    return null
+  }
+
+  // when multiple handles overlay each other we prefer the opposite handle
+  if (closestHandles.length > 1) {
+    const oppositeHandleType = fromHandle.type === 'source' ? 'target' : 'source'
+    return closestHandles.find((handle) => handle.type === oppositeHandleType) ?? closestHandles[0]
   }
 
-  if (closestHandles.length === 1) {
   return closestHandles[0]
-  }
-
-  const hasValidHandle = closestHandles.some(({ validHandleResult }) => validHandleResult.isValid)
-  const hasTargetHandle = closestHandles.some(({ handle }) => handle.type === 'target')
-
-  // if multiple handles are layout on top of each other we prefer the one with type = target and the one that is valid
-  return (
-    closestHandles.find(({ handle, validHandleResult }) =>
-      hasTargetHandle ? handle.type === 'target' : hasValidHandle ? validHandleResult.isValid : true,
-    ) || closestHandles[0]
-  )
 }
 
-// checks if  and returns connection in fom of an object { source: 123, target: 312 }
+// checks if  and returns connection in form of an object { source: 123, target: 312 }
 export function isValidHandle(
   event: MouseEvent | TouchEvent,
-  handle: Pick<ConnectionHandle, 'nodeId' | 'id' | 'type'> | null,
+  {
-  connectionMode: ConnectionMode,
+    handle,
-  fromNodeId: string,
+    connectionMode,
-  fromHandleId: string | null,
+    fromNodeId,
-  fromType: HandleType,
+    fromHandleId,
-  isValidConnection: ValidConnectionFunc,
+    fromType,
-  doc: Document | ShadowRoot,
+    doc,
+    lib,
+    flowId,
+    isValidConnection = alwaysValid,
+  }: IsValidParams,
   edges: GraphEdge[],
   nodes: GraphNode[],
   findNode: Actions['findNode'],
 ) {
   const isTarget = fromType === 'target'
+  const handleDomNode = handle
+    ? doc.querySelector(`.${lib}-flow__handle[data-id="${flowId}-${handle?.nodeId}-${handle?.id}-${handle?.type}"]`)
+    : null
 
-  const handleDomNode = doc.querySelector(`.vue-flow__handle[data-id="${handle?.nodeId}-${handle?.id}-${handle?.type}"]`)
   const { x, y } = getEventPosition(event)
-  const elementBelow = doc.elementFromPoint(x, y)
+  const handleBelow = doc.elementFromPoint(x, y)
-
   // we always want to prioritize the handle below the mouse cursor over the closest distance handle,
   // because it could be that the center of another handle is closer to the mouse pointer than the handle below the cursor
-  const handleToCheck = elementBelow?.classList.contains('vue-flow__handle') ? elementBelow : handleDomNode
+  const handleToCheck = handleBelow?.classList.contains(`${lib}-flow__handle`) ? handleBelow : handleDomNode
 
-  const result = defaultValidHandleResult()
+  const result: Result = {
+    handleDomNode: handleToCheck,
+    isValid: false,
+    connection: null,
+    toHandle: null,
+  }
 
   if (handleToCheck) {
-    result.handleDomNode = handleToCheck
-
     const handleType = getHandleType(undefined, handleToCheck)
-    const handleNodeId = handleToCheck.getAttribute('data-nodeid')!
+    const handleNodeId = handleToCheck.getAttribute('data-nodeid')
     const handleId = handleToCheck.getAttribute('data-handleid')
     const connectable = handleToCheck.classList.contains('connectable')
     const connectableEnd = handleToCheck.classList.contains('connectableend')
 
+    if (!handleNodeId || !handleType) {
+      return result
+    }
+
     const connection: Connection = {
       source: isTarget ? handleNodeId : fromNodeId,
       sourceHandle: isTarget ? handleId : fromHandleId,
@@ -185,7 +179,6 @@ export function isValidHandle(
     result.connection = connection
 
     const isConnectable = connectable && connectableEnd
-
     // in strict mode we don't allow target to target or source to source connections
     const isValid =
       isConnectable &&
@@ -193,54 +186,21 @@ export function isValidHandle(
         ? (isTarget && handleType === 'source') || (!isTarget && handleType === 'target')
         : handleNodeId !== fromNodeId || handleId !== fromHandleId)
 
-    if (isValid) {
+    result.isValid =
-      result.isValid = isValidConnection(connection, {
+      isValid &&
-        edges,
+      isValidConnection(connection, {
         nodes,
-        sourceNode: findNode(connection.source)!,
+        edges,
-        targetNode: findNode(connection.target)!,
+        sourceNode: findNode(fromNodeId)!,
+        targetNode: findNode(handleNodeId)!,
       })
 
-      result.endHandle = {
+    result.toHandle = handle
-        nodeId: handleNodeId,
-        handleId,
-        type: handleType as HandleType,
-        position: result.isValid ? (handleToCheck.getAttribute('data-handlepos') as Position) : null,
-      }
-    }
   }
 
   return result
 }
 
-interface GetHandleLookupParams {
-  nodes: GraphNode[]
-  nodeId: string
-  handleId: string | null
-  handleType: string
-}
-
-export function getHandleLookup({ nodes, nodeId, handleId, handleType }: GetHandleLookupParams) {
-  const handleLookup: ConnectionHandle[] = []
-  for (let i = 0; i < nodes.length; i++) {
-    const node = nodes[i]
-
-    const { handleBounds } = node
-
-    let sourceHandles: ConnectionHandle[] = []
-    let targetHandles: ConnectionHandle[] = []
-
-    if (handleBounds) {
-      sourceHandles = getHandles(node, handleBounds, 'source', `${nodeId}-${handleId}-${handleType}`)
-      targetHandles = getHandles(node, handleBounds, 'target', `${nodeId}-${handleId}-${handleType}`)
-    }
-
-    handleLookup.push(...sourceHandles, ...targetHandles)
-  }
-
-  return handleLookup
-}
-
 export function getHandleType(edgeUpdaterType: HandleType | undefined, handleDomNode: Element | null): HandleType | null {
   if (edgeUpdaterType) {
     return edgeUpdaterType
@@ -253,7 +213,7 @@ export function getHandleType(edgeUpdaterType: HandleType | undefined, handleDom
   return null
 }
 
-export function getConnectionStatus(isInsideConnectionRadius: boolean, isHandleValid: boolean) {
+export function getConnectionStatus(isInsideConnectionRadius: boolean, isHandleValid: boolean | null) {
   let connectionStatus: ConnectionStatus | null = null
 
   if (isHandleValid) {
@@ -264,3 +224,44 @@ export function getConnectionStatus(isInsideConnectionRadius: boolean, isHandleV
 
   return connectionStatus
 }
+
+export function isConnectionValid(isInsideConnectionRadius: boolean, isHandleValid: boolean) {
+  let isValid: boolean | null = null
+
+  if (isHandleValid) {
+    isValid = true
+  } else if (isInsideConnectionRadius && !isHandleValid) {
+    isValid = false
+  }
+
+  return isValid
+}
+
+export function getHandle(
+  nodeId: string,
+  handleType: HandleType,
+  handleId: string | null,
+  nodeLookup: NodeLookup,
+  connectionMode: ConnectionMode,
+  withAbsolutePosition = false,
+): HandleElement | null {
+  const node = nodeLookup.get(nodeId)
+  if (!node) {
+    return null
+  }
+
+  const handles =
+    connectionMode === ConnectionMode.Strict
+      ? node.handleBounds?.[handleType]
+      : [...(node.handleBounds?.source ?? []), ...(node.handleBounds?.target ?? [])]
+  const handle = (handleId ? handles?.find((h) => h.id === handleId) : handles?.[0]) ?? null
+
+  return handle && withAbsolutePosition ? { ...handle, ...getHandlePosition(node, handle, handle.position, true) } : handle
+}
+
+export const oppositePosition = {
+  [Position.Left]: Position.Right,
+  [Position.Right]: Position.Left,
+  [Position.Top]: Position.Bottom,
+  [Position.Bottom]: Position.Top,
+}

packages/core/src/utils/node.ts

@@ -1,15 +1,15 @@
 import type { Ref } from 'vue'
 import { nextTick } from 'vue'
-import type { Actions, GraphNode, HandleElement, Position } from '../types'
+import type { Actions, GraphNode, HandleElement, HandleType, Position } from '../types'
 import { getDimensions } from '.'
 
 export function getHandleBounds(
-  selector: string,
+  type: HandleType,
   nodeElement: HTMLDivElement,
   nodeBounds: DOMRect,
   zoom: number,
 ): HandleElement[] {
-  const handles = nodeElement.querySelectorAll(`.vue-flow__handle${selector}`)
+  const handles = nodeElement.querySelectorAll(`.vue-flow__handle.${type}`)
 
   const handlesArray = Array.from(handles) as HTMLDivElement[]
 
@@ -19,6 +19,8 @@ export function getHandleBounds(
     return {
       id: handle.getAttribute('data-handleid'),
       position: handle.getAttribute('data-handlepos') as unknown as Position,
+      nodeId: handle.getAttribute('data-nodeid') as string,
+      type,
       x: (handleBounds.left - nodeBounds.left) / zoom,
       y: (handleBounds.top - nodeBounds.top) / zoom,
       ...getDimensions(handle),

tests/cypress/component/2-vue-flow/updateEdge.cy.ts

@@ -50,13 +50,13 @@ describe('Check if edges are updatable', () => {
             view: win,
           })
           .trigger('mousemove', {
-            clientX: x + 5,
+            clientX: x,
-            clientY: y + 5,
+            clientY: y,
             force: true,
           })
           .trigger('mouseup', {
-            clientX: x + 5,
+            clientX: x,
-            clientY: y + 5,
+            clientY: y,
             force: true,
             view: win,
           })

tests/package.json

@@ -3,7 +3,7 @@
   "version": "0.0.0",
   "private": true,
   "scripts": {
-    "test": "cypress run --component",
+    "test": "cypress run --component --browser chrome",
     "open": "cypress open",
     "lint": "eslint --ext .js,.ts ./"
   },