Interoperable pointerrawupdate events exposed only in secure contexts

concepts

1. Secure-context Only

   Drag inside the pad: count pointermove against pointerrawupdate events live, and see the isSecureContext probe that gates the latter.

2. Signature Pad

   The motivating use case in the explainer: drawing apps. Side-by-side signature pads — left uses coalesced pointermove, right uses raw samples — with a live samples-per-second readout per pad.

3. Precision Tracker

   Trace a diagonal line on both pads. Measure RMS pixel error from the ideal path under coalesced pointermove versus raw samples. See whether your input device benefits — and the raw hardware sample rate in Hz.

4. Raw vs Coalesced Comparator

   A split canvas: left side listens to pointerrawupdate, right to pointermove + getCoalescedEvents(). Draw a freehand curve on both and see the live point count, ratio, and smoothing factor. A "Show points" toggle overlays dots at every sample so density differences are visible.

why it shipped

The PointerEvents spec restricted pointerrawupdate to secure contexts in 2020, hiding both the event firing and the global event listeners from insecure contexts. Through this feature, Chrome will match the updated spec and become interoperable with other major browsers.

references

• ChromeStatus entry
• Spec