fix(drag): use correct coordinates closes #72

src/components/NodesSelection/index.tsx

@@ -1,19 +1,24 @@
+/**
+ * The nodes selection rectangle gets displayed when a user
+ * made a selectio  with on or several nodes
+ */
+
 import React, { useState, memo } from 'react';
 import ReactDraggable from 'react-draggable';
 
 import { useStoreState, useStoreActions } from '../../store/hooks';
 import { isNode } from '../../utils/graph';
-import { Node, Elements, XYPosition } from '../../types';
+import { Node, XYPosition } from '../../types';
 
 type StartPositions = { [key: string]: XYPosition };
 
-function getStartPositions(elements: Elements): StartPositions {
+function getStartPositions(nodes: Node[]): StartPositions {
   const startPositions: StartPositions = {};
 
-  return (elements.filter(isNode) as Node[]).reduce((res, node) => {
+  return nodes.reduce((res, node) => {
     const startPosition = {
       x: node.__rg.position.x || node.position.x,
-      y: node.__rg.position.y || node.position.x,
+      y: node.__rg.position.y || node.position.y,
     };
 
     res[node.id] = startPosition;
@@ -30,21 +35,26 @@ export default memo(() => {
     selectedNodesBbox: s.selectedNodesBbox,
     selectedElements: s.selectedElements,
     snapToGrid: s.snapToGrid,
-    snapGrid: s.snapGrid
+    snapGrid: s.snapGrid,
+    nodes: s.nodes,
   }));
   const updateNodePos = useStoreActions(a => a.updateNodePos);
-  const [x, y, k] = state.transform;
+  const [tx, ty, tScale] = state.transform;
   const position = state.selectedNodesBbox;
   const grid = (state.snapToGrid ? state.snapGrid : [1, 1])! as [number, number];
 
   const onStart = (evt: MouseEvent) => {
     const scaledClient: XYPosition = {
-      x: evt.clientX * (1 / k),
+      x: evt.clientX / tScale,
-      y: evt.clientY * (1 / k),
+      y: evt.clientY / tScale,
     };
-    const offsetX: number = scaledClient.x - position.x - x;
+    const offsetX: number = scaledClient.x - position.x - tx;
-    const offsetY: number = scaledClient.y - position.y - y;
+    const offsetY: number = scaledClient.y - position.y - ty;
-    const nextStartPositions = getStartPositions(state.selectedElements);
+    const selectedNodes = (state.selectedElements.filter(isNode) as Node[]).map(
+      selectedNode => state.nodes.find(node => node.id === selectedNode.id)! as Node
+    );
+
+    const nextStartPositions = getStartPositions(selectedNodes);
 
     if (nextStartPositions) {
       setOffset({ x: offsetX, y: offsetY });
@@ -54,24 +64,14 @@ export default memo(() => {
 
   const onDrag = (evt: MouseEvent) => {
     const scaledClient: XYPosition = {
-      x: evt.clientX * (1 / k),
+      x: evt.clientX / tScale,
-      y: evt.clientY * (1 / k),
+      y: evt.clientY / tScale,
     };
 
     (state.selectedElements.filter(isNode) as Node[]).forEach(node => {
       const pos: XYPosition = {
-        x:
+        x: startPositions[node.id].x + scaledClient.x - position.x - offset.x - tx,
-          startPositions[node.id].x +
+        y: startPositions[node.id].y + scaledClient.y - position.y - offset.y - ty,
-          scaledClient.x -
-          position.x -
-          offset.x -
-          x,
-        y:
-          startPositions[node.id].y +
-          scaledClient.y -
-          position.y -
-          offset.y -
-          y,
       };
 
       updateNodePos({ id: node.id, pos });
@@ -82,11 +82,11 @@ export default memo(() => {
     <div
       className="react-flow__nodesselection"
       style={{
-        transform: `translate(${x}px,${y}px) scale(${k})`,
+        transform: `translate(${tx}px,${ty}px) scale(${tScale})`,
       }}
     >
       <ReactDraggable
-        scale={k}
+        scale={tScale}
         grid={grid}
         onStart={evt => onStart(evt as MouseEvent)}
         onDrag={evt => onDrag(evt as MouseEvent)}

src/components/UserSelection/index.tsx

@@ -1,3 +1,7 @@
+/**
+ * The user selection rectangle gets displayed when a user drags the mouse while pressing shift
+ */
+
 import React, { useEffect, useRef, useState, memo } from 'react';
 
 import { useStoreActions } from '../../store/hooks';

src/store/index.ts

@@ -226,7 +226,6 @@ const storeModel: StoreModel = {
     state.selection = selection;
     state.nodesSelectionActive = true;
     state.selectedNodesBbox = selectedNodesBbox;
-    state.nodesSelectionActive = true;
   }),
 
   setSelectedElements: action((state, elements) => {