MSPointer

MSPointer refers to Microsoft’s vendor-prefixed set of pointer events used to unify handling of input from mouse, touch, and stylus devices. Introduced with Internet Explorer 10 and Windows 8, MSPointer events were designed to provide a single API for multiple input modalities across Microsoft's platforms.

The MSPointer event family includes MSPointerDown, MSPointerMove, MSPointerUp, MSPointerCancel, MSPointerEnter, MSPointerLeave, MSPointerOver, and MSPointerOut. Like the later standard pointer events, they expose common properties such as pointerId, pointerType (mouse, touch, pen), width, height, pressure, and, for stylus input, tiltX and tiltY. They also support pointer capture through mechanisms similar to setPointerCapture, enabling precise control of event delivery to a specific element.

MSPointer events were intended to replace separate mouse and touch events by providing a unified flow of events for all input types. In practice, they coexisted with traditional mouse and touch events, and developers could listen for MSPointer events or for the standard events depending on browser support and compatibility needs.

Over time, the W3C standardized the Pointer Events API, introducing unprefixed event names such as pointerdown, pointermove, pointerup, and related properties. Modern browsers predominantly support the standard pointer events, and MSPointer events are considered legacy and deprecated. For new development, the recommended approach is to use standard pointer events and provide backward compatibility as needed by detecting support for the unprefixed API. Some older Microsoft environments may still expose MSPointer events for compatibility.