UxK — Kinetic UX: A Long-Press Directional Gesture System for Handwriting Annotation and Editing on Touch Devices

Prior art disclosure for UxK (Kinetic UX), a four-gesture interaction system embedded in the Miroir IME (Android InputMethodService). A long-press followed by directional drag triggers distinct editing operations on a selected ink group — right (write-on-selection), left (temporal point-by-point erasure), down (spatial displacement), up (label correction) — without leaving the writing surface. Key contributions: (1) unified long-press + four-directional vocabulary on handwritten ink groups; (2) asymmetric termination protocol — three gestures exit on pen-up, label correction exits on tap-in-void; (3) temporal erasure by reverse-order point removal driven by drag distance; (4) symbiotic annotation loop — label correction produces validated HTR training pairs as a side effect of normal use; (5) blob as spatial inclusion mechanism for ink group membership, computed by ray casting over per-point absorption ellipses. Reference implementation: MiroirIME.kt, CaptureView.kt, GroupManager.kt (Kotlin, Apache 2.0, Boox Note Air 5C). Related: Conduit VStar binary protocol (Zenodo CC0, 2026). Dataset: ODbL open HTR dataset (planned). CC0 — public domain dedication for prior art purposes only.