From dd9c30beb1b5cea8dbf2ab3c73f2605b40a4e414 Mon Sep 17 00:00:00 2001
From: Quincy Morgan <quincy.morgan@icloud.com>
Date: Fri, 13 Mar 2020 13:23:06 -0700
Subject: [PATCH] Use pointer events instead of mouse events for lasso
 selection (re: #5505)

---
 modules/behavior/lasso.js | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/modules/behavior/lasso.js b/modules/behavior/lasso.js
index a1bdbf7ce9..46e5ff4e4f 100644
--- a/modules/behavior/lasso.js
+++ b/modules/behavior/lasso.js
@@ -7,6 +7,9 @@ import { uiLasso } from '../ui/lasso';
 
 export function behaviorLasso(context) {
 
+    // use pointer events on supported platforms; fallback to mouse events
+    var _pointerPrefix = 'PointerEvent' in window ? 'pointer' : 'mouse';
+
     var behavior = function(selection) {
         var lasso;
 
@@ -17,8 +20,8 @@ export function behaviorLasso(context) {
                 lasso = null;
 
                 d3_select(window)
-                    .on('mousemove.lasso', mousemove)
-                    .on('mouseup.lasso', mouseup);
+                    .on(_pointerPrefix + 'move.lasso', mousemove)
+                    .on(_pointerPrefix + 'up.lasso', mouseup);
 
                 d3_event.stopPropagation();
             }
@@ -62,8 +65,8 @@ export function behaviorLasso(context) {
 
         function mouseup() {
             d3_select(window)
-                .on('mousemove.lasso', null)
-                .on('mouseup.lasso', null);
+                .on(_pointerPrefix + 'move.lasso', null)
+                .on(_pointerPrefix + 'up.lasso', null);
 
             if (!lasso) return;
 
@@ -76,12 +79,12 @@ export function behaviorLasso(context) {
         }
 
         selection
-            .on('mousedown.lasso', mousedown);
+            .on(_pointerPrefix + 'down.lasso', mousedown);
     };
 
 
     behavior.off = function(selection) {
-        selection.on('mousedown.lasso', null);
+        selection.on(_pointerPrefix + 'down.lasso', null);
     };