From 348f311fc79eca5514bf561a46469902671cbfd9 Mon Sep 17 00:00:00 2001
From: moklick <info@moritzklack.com>
Date: Tue, 26 Sep 2023 13:08:27 +0200
Subject: [PATCH] feat(react,svelte): add nodeDragThreshold

---
 examples/react/src/examples/Switch/index.tsx  |  10 +-
 examples/svelte/src/routes/edges/+page.svelte |   2 +-
 .../src/components/StoreUpdater/index.tsx     |   3 +
 .../react/src/container/ReactFlow/index.tsx   |   2 +
 packages/react/src/store/initialState.ts      |   1 +
 packages/react/src/types/component-props.ts   |   1 +
 packages/react/src/types/store.ts             |   1 +
 packages/svelte/CHANGELOG.md                  |   5 +-
 packages/svelte/src/lib/actions/drag/index.ts |   1 +
 .../container/SvelteFlow/SvelteFlow.svelte    |   4 +-
 .../src/lib/container/SvelteFlow/types.ts     |   1 +
 .../src/lib/container/SvelteFlow/utils.ts     |   1 +
 .../svelte/src/lib/store/initial-store.ts     |   1 +
 packages/system/package.json                  |   2 +-
 packages/system/src/xydrag/XYDrag.ts          | 106 +++++++++++-------
 15 files changed, 94 insertions(+), 47 deletions(-)

diff --git a/examples/react/src/examples/Switch/index.tsx b/examples/react/src/examples/Switch/index.tsx
index d2b237c8..517cbf8f 100644
--- a/examples/react/src/examples/Switch/index.tsx
+++ b/examples/react/src/examples/Switch/index.tsx
@@ -1,9 +1,6 @@
 import { MouseEvent, useCallback } from 'react';
 import { ReactFlow, addEdge, Node, Connection, Edge, useNodesState, useEdgesState } from '@xyflow/react';
 
-const onNodeDragStop = (_: MouseEvent, node: Node) => console.log('drag stop', node);
-const onNodeClick = (_: MouseEvent, node: Node) => console.log('click', node);
-
 const nodesA: Node[] = [
   {
     id: '1a',
@@ -83,7 +80,10 @@ const edgesB: Edge[] = [
   { id: 'e4b', source: 'inputb', target: '4b' },
 ];
 
+const onNodeDragStart = (_: MouseEvent, node: Node) => console.log('drag start', node);
 const onNodeDrag = (_: MouseEvent, node: Node) => console.log('drag', node.position);
+const onNodeDragStop = (_: MouseEvent, node: Node) => console.log('drag stop', node);
+const onNodeClick = (_: MouseEvent, node: Node) => console.log('click', node);
 
 const BasicFlow = () => {
   const [nodes, setNodes, onNodesChange] = useNodesState(nodesA);
@@ -99,8 +99,10 @@ const BasicFlow = () => {
       onEdgesChange={onEdgesChange}
       onNodeClick={onNodeClick}
       onConnect={onConnect}
-      onNodeDragStop={onNodeDragStop}
+      onNodeDragStart={onNodeDragStart}
       onNodeDrag={onNodeDrag}
+      onNodeDragStop={onNodeDragStop}
+      nodeDragThreshold={10}
     >
       <div style={{ position: 'absolute', right: 10, top: 10, zIndex: 4 }}>
         <button
diff --git a/examples/svelte/src/routes/edges/+page.svelte b/examples/svelte/src/routes/edges/+page.svelte
index f8d2be0e..403b0ef6 100644
--- a/examples/svelte/src/routes/edges/+page.svelte
+++ b/examples/svelte/src/routes/edges/+page.svelte
@@ -145,7 +145,7 @@
 	]);
 </script>
 
-<SvelteFlow {nodes} {edges} fitView>
+<SvelteFlow {nodes} {edges} fitView nodeDragThreshold={2}>
 	<Controls />
 	<Background variant={BackgroundVariant.Dots} />
 	<MiniMap />
diff --git a/packages/react/src/components/StoreUpdater/index.tsx b/packages/react/src/components/StoreUpdater/index.tsx
index bd6e7e07..7b714503 100644
--- a/packages/react/src/components/StoreUpdater/index.tsx
+++ b/packages/react/src/components/StoreUpdater/index.tsx
@@ -56,6 +56,7 @@ type StoreUpdaterProps = Pick<
   | 'connectionRadius'
   | 'isValidConnection'
   | 'selectNodesOnDrag'
+  | 'nodeDragThreshold'
 > & { rfId: string };
 
 const selector = (s: ReactFlowState) => ({
@@ -140,6 +141,7 @@ const StoreUpdater = ({
   connectionRadius,
   isValidConnection,
   selectNodesOnDrag,
+  nodeDragThreshold,
 }: StoreUpdaterProps) => {
   const {
     setNodes,
@@ -203,6 +205,7 @@ const StoreUpdater = ({
   useDirectStoreUpdater('connectionRadius', connectionRadius, store.setState);
   useDirectStoreUpdater('isValidConnection', isValidConnection, store.setState);
   useDirectStoreUpdater('selectNodesOnDrag', selectNodesOnDrag, store.setState);
+  useDirectStoreUpdater('nodeDragThreshold', nodeDragThreshold, store.setState);
 
   useStoreUpdater<Node[]>(nodes, setNodes);
   useStoreUpdater<Edge[]>(edges, setEdges);
diff --git a/packages/react/src/container/ReactFlow/index.tsx b/packages/react/src/container/ReactFlow/index.tsx
index 5bc47f04..f4565099 100644
--- a/packages/react/src/container/ReactFlow/index.tsx
+++ b/packages/react/src/container/ReactFlow/index.tsx
@@ -163,6 +163,7 @@ const ReactFlow = forwardRef<ReactFlowRefType, ReactFlowProps>(
       onError,
       style,
       id,
+      nodeDragThreshold,
       ...rest
     },
     ref
@@ -292,6 +293,7 @@ const ReactFlow = forwardRef<ReactFlowRefType, ReactFlowProps>(
             connectionRadius={connectionRadius}
             isValidConnection={isValidConnection}
             selectNodesOnDrag={selectNodesOnDrag}
+            nodeDragThreshold={nodeDragThreshold}
           />
           <SelectionListener onSelectionChange={onSelectionChange} />
           {children}
diff --git a/packages/react/src/store/initialState.ts b/packages/react/src/store/initialState.ts
index db673ef2..52a5545c 100644
--- a/packages/react/src/store/initialState.ts
+++ b/packages/react/src/store/initialState.ts
@@ -28,6 +28,7 @@ const initialState: ReactFlowStore = {
   paneDragging: false,
   noPanClassName: 'nopan',
   nodeOrigin: [0, 0],
+  nodeDragThreshold: 0,
 
   snapGrid: [15, 15],
   snapToGrid: false,
diff --git a/packages/react/src/types/component-props.ts b/packages/react/src/types/component-props.ts
index 65e47b6a..b1078e7b 100644
--- a/packages/react/src/types/component-props.ts
+++ b/packages/react/src/types/component-props.ts
@@ -148,6 +148,7 @@ export type ReactFlowProps = HTMLAttributes<HTMLDivElement> & {
   connectionRadius?: number;
   onError?: OnError;
   isValidConnection?: IsValidConnection;
+  nodeDragThreshold?: number;
 };
 
 export type ReactFlowRefType = HTMLDivElement;
diff --git a/packages/react/src/types/store.ts b/packages/react/src/types/store.ts
index 36e79220..f79cb874 100644
--- a/packages/react/src/types/store.ts
+++ b/packages/react/src/types/store.ts
@@ -61,6 +61,7 @@ export type ReactFlowStore = {
   translateExtent: CoordinateExtent;
   nodeExtent: CoordinateExtent;
   nodeOrigin: NodeOrigin;
+  nodeDragThreshold: number;
 
   nodesSelectionActive: boolean;
   userSelectionActive: boolean;
diff --git a/packages/svelte/CHANGELOG.md b/packages/svelte/CHANGELOG.md
index 369d0d29..439de951 100644
--- a/packages/svelte/CHANGELOG.md
+++ b/packages/svelte/CHANGELOG.md
@@ -1,5 +1,8 @@
-## WIP
+## 0.0.22
 
+- add `nodeDragThreshold` prop
+- add `fitViewOptions` prop
+- add `defaultEdgeOptions` prop
 - add `on:edgecontextmenu` event handler prop
 - add `connectionMode` prop
 - add `attributionPosition` prop
diff --git a/packages/svelte/src/lib/actions/drag/index.ts b/packages/svelte/src/lib/actions/drag/index.ts
index 276e319c..65f7a1e7 100644
--- a/packages/svelte/src/lib/actions/drag/index.ts
+++ b/packages/svelte/src/lib/actions/drag/index.ts
@@ -38,6 +38,7 @@ export default function drag(domNode: Element, params: UseDragParams) {
         autoPanOnNodeDrag: get(store.autoPanOnNodeDrag),
         nodesDraggable: get(store.nodesDraggable),
         selectNodesOnDrag: get(store.selectNodesOnDrag),
+        nodeDragThreshold: get(store.nodeDragThreshold),
         unselectNodesAndEdges: store.unselectNodesAndEdges,
         updateNodePositions: store.updateNodePositions,
         panBy: store.panBy
diff --git a/packages/svelte/src/lib/container/SvelteFlow/SvelteFlow.svelte b/packages/svelte/src/lib/container/SvelteFlow/SvelteFlow.svelte
index 6c47f37e..e48b3dfd 100644
--- a/packages/svelte/src/lib/container/SvelteFlow/SvelteFlow.svelte
+++ b/packages/svelte/src/lib/container/SvelteFlow/SvelteFlow.svelte
@@ -34,6 +34,7 @@
   export let panActivationKey: $$Props['panActivationKey'] = undefined;
   export let nodesDraggable: $$Props['nodesDraggable'] = undefined;
   export let nodesConnectable: $$Props['nodesConnectable'] = undefined;
+  export let nodeDragThreshold: $$Props['nodeDragThreshold'] = undefined;
   export let elementsSelectable: $$Props['elementsSelectable'] = undefined;
   export let snapGrid: $$Props['snapGrid'] = undefined;
   export let deleteKey: $$Props['deleteKey'] = undefined;
@@ -118,7 +119,8 @@
       autoPanOnConnect,
       autoPanOnNodeDrag,
       onError,
-      connectionMode
+      connectionMode,
+      nodeDragThreshold
     };
 
     updateStoreByKeys(store, updatableProps);
diff --git a/packages/svelte/src/lib/container/SvelteFlow/types.ts b/packages/svelte/src/lib/container/SvelteFlow/types.ts
index b7667a92..0b6eb87c 100644
--- a/packages/svelte/src/lib/container/SvelteFlow/types.ts
+++ b/packages/svelte/src/lib/container/SvelteFlow/types.ts
@@ -43,6 +43,7 @@ export type SvelteFlowProps = DOMAttributes<HTMLDivElement> & {
   fitView?: boolean;
   fitViewOptions?: FitViewOptions;
   nodeOrigin?: NodeOrigin;
+  nodeDragThreshold?: number;
   minZoom?: number;
   maxZoom?: number;
   initialViewport?: Viewport;
diff --git a/packages/svelte/src/lib/container/SvelteFlow/utils.ts b/packages/svelte/src/lib/container/SvelteFlow/utils.ts
index 93092bea..0579eaa9 100644
--- a/packages/svelte/src/lib/container/SvelteFlow/utils.ts
+++ b/packages/svelte/src/lib/container/SvelteFlow/utils.ts
@@ -63,6 +63,7 @@ export type UpdatableStoreProps = {
   autoPanOnNodeDrag?: UnwrapWritable<SvelteFlowStore['autoPanOnNodeDrag']>;
   connectionMode?: UnwrapWritable<SvelteFlowStore['connectionMode']>;
   onError?: UnwrapWritable<SvelteFlowStore['onError']>;
+  nodeDragThreshold?: UnwrapWritable<SvelteFlowStore['nodeDragThreshold']>;
 };
 
 export function updateStoreByKeys(store: SvelteFlowStore, keys: UpdatableStoreProps) {
diff --git a/packages/svelte/src/lib/store/initial-store.ts b/packages/svelte/src/lib/store/initial-store.ts
index 1c82f301..021bb6e8 100644
--- a/packages/svelte/src/lib/store/initial-store.ts
+++ b/packages/svelte/src/lib/store/initial-store.ts
@@ -65,6 +65,7 @@ export const getInitialStore = () => ({
   minZoom: writable<number>(0.5),
   maxZoom: writable<number>(2),
   nodeOrigin: writable<NodeOrigin>([0, 0]),
+  nodeDragThreshold: writable<number>(0),
   nodeExtent: writable<CoordinateExtent>(infiniteExtent),
   translateExtent: writable<CoordinateExtent>(infiniteExtent),
   autoPanOnNodeDrag: writable<boolean>(true),
diff --git a/packages/system/package.json b/packages/system/package.json
index e1f6f65a..da20c3c6 100644
--- a/packages/system/package.json
+++ b/packages/system/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@xyflow/system",
-  "version": "0.0.6",
+  "version": "0.0.7",
   "description": "xyflow core system that powers React Flow and Svelte Flow.",
   "keywords": [
     "node-based UI",
diff --git a/packages/system/src/xydrag/XYDrag.ts b/packages/system/src/xydrag/XYDrag.ts
index f56a40f4..5381d0ef 100644
--- a/packages/system/src/xydrag/XYDrag.ts
+++ b/packages/system/src/xydrag/XYDrag.ts
@@ -44,6 +44,7 @@ type StoreItems = {
   autoPanOnNodeDrag: boolean;
   nodesDraggable: boolean;
   selectNodesOnDrag: boolean;
+  nodeDragThreshold: number;
   panBy: PanBy;
   unselectNodesAndEdges: () => void;
   onError?: OnError;
@@ -93,6 +94,7 @@ export function XYDrag({
   let mousePosition: XYPosition = { x: 0, y: 0 };
   let dragEvent: MouseEvent | null = null;
   let containerBounds: DOMRect | null = null;
+  let dragStarted = false;
 
   const d3Selection = select(domNode);
 
@@ -192,63 +194,84 @@ export function XYDrag({
       autoPanId = requestAnimationFrame(autoPan);
     }
 
+    function startDrag(event: UseDragEvent) {
+      const {
+        nodes,
+        multiSelectionActive,
+        nodesDraggable,
+        transform,
+        snapGrid,
+        snapToGrid,
+        selectNodesOnDrag,
+        onNodeDragStart,
+        onSelectionDragStart,
+        unselectNodesAndEdges,
+      } = getStoreItems();
+
+      dragStarted = true;
+
+      if ((!selectNodesOnDrag || !isSelectable) && !multiSelectionActive && nodeId) {
+        if (!nodes.find((n) => n.id === nodeId)?.selected) {
+          // we need to reset selected nodes when selectNodesOnDrag=false
+          unselectNodesAndEdges();
+        }
+      }
+
+      if (isSelectable && selectNodesOnDrag) {
+        onNodeClick?.();
+      }
+
+      const pointerPos = getPointerPosition(event.sourceEvent, { transform, snapGrid, snapToGrid });
+      lastPos = pointerPos;
+      dragItems = getDragItems(nodes, nodesDraggable, pointerPos, nodeId);
+
+      const onNodeOrSelectionDragStart = nodeId ? onNodeDragStart : wrapSelectionDragFunc(onSelectionDragStart);
+
+      if (dragItems) {
+        const [currentNode, currentNodes] = getEventHandlerParams({
+          nodeId,
+          dragItems,
+          nodes,
+        });
+        onDragStart?.(event.sourceEvent as MouseEvent, dragItems, currentNode, currentNodes);
+        onNodeOrSelectionDragStart?.(event.sourceEvent as MouseEvent, currentNode, currentNodes);
+      }
+    }
+
     const d3DragInstance = drag()
       .on('start', (event: UseDragEvent) => {
-        const {
-          nodes,
-          multiSelectionActive,
-          domNode,
-          nodesDraggable,
-          transform,
-          snapGrid,
-          snapToGrid,
-          selectNodesOnDrag,
-          onNodeDragStart,
-          onSelectionDragStart,
-          unselectNodesAndEdges,
-        } = getStoreItems();
+        const { domNode, nodeDragThreshold, transform, snapGrid, snapToGrid } = getStoreItems();
 
-        if ((!selectNodesOnDrag || !isSelectable) && !multiSelectionActive && nodeId) {
-          if (!nodes.find((n) => n.id === nodeId)?.selected) {
-            // we need to reset selected nodes when selectNodesOnDrag=false
-            unselectNodesAndEdges();
-          }
-        }
-
-        if (isSelectable && selectNodesOnDrag) {
-          onNodeClick?.();
+        if (nodeDragThreshold === 0) {
+          startDrag(event);
         }
 
         const pointerPos = getPointerPosition(event.sourceEvent, { transform, snapGrid, snapToGrid });
         lastPos = pointerPos;
-        dragItems = getDragItems(nodes, nodesDraggable, pointerPos, nodeId);
-
-        const onNodeOrSelectionDragStart = nodeId ? onNodeDragStart : wrapSelectionDragFunc(onSelectionDragStart);
-
-        if (dragItems) {
-          const [currentNode, currentNodes] = getEventHandlerParams({
-            nodeId,
-            dragItems,
-            nodes,
-          });
-          onDragStart?.(event.sourceEvent as MouseEvent, dragItems, currentNode, currentNodes);
-          onNodeOrSelectionDragStart?.(event.sourceEvent as MouseEvent, currentNode, currentNodes);
-        }
-
         containerBounds = domNode?.getBoundingClientRect() || null;
         mousePosition = getEventPosition(event.sourceEvent, containerBounds!);
       })
       .on('drag', (event: UseDragEvent) => {
-        const { autoPanOnNodeDrag, transform, snapGrid, snapToGrid } = getStoreItems();
+        const { autoPanOnNodeDrag, transform, snapGrid, snapToGrid, nodeDragThreshold } = getStoreItems();
         const pointerPos = getPointerPosition(event.sourceEvent, { transform, snapGrid, snapToGrid });
 
-        if (!autoPanStarted && autoPanOnNodeDrag) {
+        if (!autoPanStarted && autoPanOnNodeDrag && dragStarted) {
           autoPanStarted = true;
           autoPan();
         }
 
+        if (!dragStarted) {
+          const x = pointerPos.xSnapped - (lastPos.x ?? 0);
+          const y = pointerPos.ySnapped - (lastPos.y ?? 0);
+          const distance = Math.sqrt(x * x + y * y);
+
+          if (distance > nodeDragThreshold) {
+            startDrag(event);
+          }
+        }
+
         // skip events without movement
-        if ((lastPos.x !== pointerPos.xSnapped || lastPos.y !== pointerPos.ySnapped) && dragItems) {
+        if ((lastPos.x !== pointerPos.xSnapped || lastPos.y !== pointerPos.ySnapped) && dragItems && dragStarted) {
           dragEvent = event.sourceEvent as MouseEvent;
           mousePosition = getEventPosition(event.sourceEvent, containerBounds!);
 
@@ -256,7 +279,12 @@ export function XYDrag({
         }
       })
       .on('end', (event: UseDragEvent) => {
+        if (!dragStarted) {
+          return;
+        }
+
         autoPanStarted = false;
+        dragStarted = false;
         cancelAnimationFrame(autoPanId);
 
         if (dragItems) {