Only accept primary button for activating drag.

Fix an issue on some platforms where the contextmenu shows on
right-click and intercepts the pointerup events that would cancel the
drag, leading to a sticky unintended drag.

For #30

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Changelog
 
+## [Unreleased]
+
+### Fixed
+
+- Only accept primary button (left-click) for activating drag with default
+  pointer sensor. Fix an issue on some platforms where the contextmenu shows on
+  right-click and intercepts the pointerup events that would cancel the drag,
+  leading to a sticky unintended drag.
+
 ## [0.7.2] - 2022-10-07
 
 ### Fixed

src/create-pointer-sensor.ts

@@ -40,6 +40,8 @@ const createPointerSensor = (id: Id = "pointer-sensor"): void => {
   let activationDraggableId: Id | null = null;
 
   const attach: SensorActivator<"pointerdown"> = (event, draggableId) => {
+    if (event.button !== 0) return;
+
     document.addEventListener("pointermove", onPointerMove);
     document.addEventListener("pointerup", onPointerUp);