find.keyboardPopup() (finders.js VERSION 3) replaces the same
g_PopupManager lookup in the swipe, extra keys and touch typing patches
(VERSIONs 29, 24, 4). hub.js keeps its own: it gets no finder library.
Steam's UpdateTouchState counts the event's `touches` per key: that count
is the pressed highlight (rgLayoutTouchCount -> Touched) and where the long
press (Backspace repeat, accents) starts. The touch-start event left the
new touch out of `touches`, like a touchend; now it is in, as in a DOM
touchstart (tracker.js touchEvent, with a test against a model of Steam's
handlers).
keyboard.vr.touchTyping (off by default): a key is pressed when a
controller's tip, where SteamVR's laser starts (/pose/tip: the device pose
times the render model's "tip" component), passes through it from the
front; released when pulled back 1 cm, re-armed 5 mm in front. Both hands,
also at once. Keys go through the keyboard's own HandleTouchStart /
HandleTouchEnd, like a laser press (Backspace repeats while held). Options
depth (cm) and haptics.
The geometry lives in a reusable controller bridge (vr-keyboard-controllers,
internal option): a systemui patch reads the keyboard's pose with SteamVR's
SGQueryService (an empty transform of ours in the keyboard's mount) and both
controllers' poses, and streams per hand the tip, the laser's hit on the
keyboard and the trigger (~90 Hz while relevant) through the
vr-keyboard-controllers-relay service to __sfuiControllers in Steam's
SharedJSContext. Tests: flake checks vr-keyboard-controllers and
vr-keyboard-touch.