From 2f2848bbff4f29cc6b7a35a5e8494ba2f5191d96 Mon Sep 17 00:00:00 2001
From: Christopher Chedeau <vjeuxx@gmail.com>
Date: Thu, 2 Jan 2020 13:36:59 -0800
Subject: [PATCH] Hit test

---
 src/index.tsx | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/src/index.tsx b/src/index.tsx
index d1383f3ca..152c5a986 100644
--- a/src/index.tsx
+++ b/src/index.tsx
@@ -24,14 +24,14 @@ function distanceBetweenPointAndSegment(
   x2: number,
   y2: number
 ) {
-  var A = x - x1;
-  var B = y - y1;
-  var C = x2 - x1;
-  var D = y2 - y1;
+  const A = x - x1;
+  const B = y - y1;
+  const C = x2 - x1;
+  const D = y2 - y1;
 
-  var dot = A * C + B * D;
-  var lenSquare = C * C + D * D;
-  var param = -1;
+  const dot = A * C + B * D;
+  const lenSquare = C * C + D * D;
+  let param = -1;
   if (lenSquare !== 0) {
     // in case of 0 length line
     param = dot / lenSquare;
@@ -534,6 +534,12 @@ class App extends React.Component<{}, AppState> {
                   return isSelected;
                 });
 
+                // deselect everything except target element to-be-selected
+                elements.forEach(element => {
+                  if (element === selectedElement) return;
+                  element.isSelected = false;
+                });
+
                 if (selectedElement) {
                   this.setState({ draggingElement: selectedElement });
                 } else {