From d4507855a47c7d8a7fb7600829ad4a77fb2dcf77 Mon Sep 17 00:00:00 2001
From: moklick <info@moritzklack.com>
Date: Wed, 24 Jul 2019 10:57:31 +0200
Subject: [PATCH] feat(selection): add container bounds

---
 src/Selection/index.js | 33 +++++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/src/Selection/index.js b/src/Selection/index.js
index 10dd8945..d31e58f1 100644
--- a/src/Selection/index.js
+++ b/src/Selection/index.js
@@ -14,6 +14,15 @@ const initialRect = {
   fixed: false
 };
 
+function getMousePosition(evt) {
+  const containerBounds = document.querySelector('.react-graph').getBoundingClientRect();
+
+  return {
+    x: evt.clientX - containerBounds.left,
+    y: evt.clientY - containerBounds.top,
+  }
+}
+
 export default () => {
   const selectionPane = useRef(null);
   const [rect, setRect] = useState(initialRect);
@@ -21,12 +30,14 @@ export default () => {
 
   useEffect(() => {
     function onMouseDown(evt) {
+      const mousePos = getMousePosition(evt);
+
       setRect((r) => ({
         ...r,
-        startX: evt.clientX,
-        startY: evt.clientY,
-        x: evt.clientX,
-        y: evt.clientY,
+        startX: mousePos.x,
+        startY: mousePos.y,
+        x: mousePos.x,
+        y: mousePos.y,
         draw: true
       }));
 
@@ -35,8 +46,10 @@ export default () => {
 
     function onMouseMove(evt) {
       setRect((r) => {
-        const negativeX = evt.clientX < r.startX;
-        const negativeY = evt.clientY < r.startY;
+        const mousePos = getMousePosition(evt);
+
+        const negativeX = mousePos.x < r.startX;
+        const negativeY = mousePos.y < r.startY;
 
         if (!r.draw) {
           return r;
@@ -44,10 +57,10 @@ export default () => {
 
         const nextRect = {
           ...r,
-          x: negativeX ? evt.clientX : r.x,
-          y: negativeY ? evt.clientY : r.y,
-          width: negativeX ? r.startX - evt.clientX : evt.clientX - r.startX,
-          height: negativeY ? r.startY - evt.clientY : evt.clientY - r.startY,
+          x: negativeX ? mousePos.x : r.x,
+          y: negativeY ? mousePos.y : r.y,
+          width: negativeX ? r.startX - mousePos.x : mousePos.x - r.startX,
+          height: negativeY ? r.startY - mousePos.y : mousePos.y - r.startY,
         };
 
         dispatch(updateSelection(nextRect));