When using `pointers.touch = true`, conditionally calling `preventDefault` has flaky behavior in iOS

[stephen]

Describe the bug

I want to conditionally call event.preventDefault to cancel scrolling (use case: implementing pull to refresh where my custom behavior only happens at the top of scrollTop). On iOS, I noticed that sometimes (half?), the event passed would have event.cancelable === false and would still scroll while my drag ran.

I noticed that useDrag() only attaches touchstart event at rest. I found this stackoverflow answer that matches my symptoms.

The following patch corrects the issue for me, confirming the diagnosis:

diff --git a/node_modules/@use-gesture/core/dist/actions-76b8683e.esm.js b/node_modules/@use-gesture/core/dist/actions-76b8683e.esm.js
index 9322a47..e5492e2 100644
--- a/node_modules/@use-gesture/core/dist/actions-76b8683e.esm.js
+++ b/node_modules/@use-gesture/core/dist/actions-76b8683e.esm.js
@@ -826,10 +826,12 @@ class DragEngine extends CoordinatesEngine {
   bind(bindFunction) {
     const device = this.config.device;
     bindFunction(device, 'start', this.pointerDown.bind(this));
-    if (this.config.pointerCapture) {
+    if (this.config.pointerCapture || this.config.device === 'touch') {
       bindFunction(device, 'change', this.pointerMove.bind(this));
       bindFunction(device, 'end', this.pointerUp.bind(this));
       bindFunction(device, 'cancel', this.pointerUp.bind(this));
+    }
+    if (this.config.pointerCapture) {
       bindFunction('lostPointerCapture', '', this.pointerUp.bind(this));
     }
     if (this.config.keys) {

I am not recommending this patch, but this is the workaround I'm using to fix this for now.

Information:

• Use Gesture version: ^10.2.27
• Device: iPhone 15
• OS: iOS 18.2
• Browser: stock safari

Checklist:

• I've read the documentation.
• If this is an issue with drag, I've tried setting touch-action: none to the draggable element. I did not do this because I want to be able to conditionally choose if the browser's default drag is activated or not.