GlassToKey

Intention

An attempt to use the Apple Magic Trackpad as a keyboard (and mouse!) like the TouchStream LP~ Since it is built on the same technology, I thought it would be fun to try and create an open source version!

It's just Codex and I vibe coding~ You can submit an issue but this is really just a repo for me, you might have to fork and extend!

Usage

Build the GlassToKey project and you are good to go! A status bar indicator shows the active mode:

• Green: Mixed mode (typing + mouse intent)
• Purple: Keyboard mode (full keyboard, no mouse intent)
• Red: Mouse-only mode (typing disabled)

Clicking the indicator light will allow you to view the Config or Quit the program.

Clicking Visualize will draw the touches - it is toggleable for performance reasons.

Clicking Edit will allow you to click any Column/Button and set the Action/Hold Action and set the positioning and size. (It's really laggy idk what to do, so it's in a toggle)

Typing Tuning

• Tap/Hold (ms): Time in miliseconds until a tap becomes a hold
• Tap/Drag (mm): How far you need to move before tap becomes a drag
• Force Cap (g): Pressure (in grams) beyond the initial touch that disqualifies the touch before it can type, preventing accidental strong presses.
• Typing Grace (ms): Time after a key dispatch to keep typing intent active.
• Intent Move (mm): Movement threshold before a touch is treated as mouse intent.
• Intent Velocity (mm/s): Speed threshold before a touch is treated as mouse intent.
• Snap Radius: On release during typing intent, off-key taps will snap to the nearest key center if the release point is within this percent of the key’s smaller dimension.
• Autocorrect: Enables the built-in autocorrect engine for post-key dispatch word replacement.
• Tap Click: two-finger tap = left click, three-finger tap = right click
• Mouse Takeover: Allow mouse intent to interrupt typing before all fingers are lifted.
• Keyboard Mode: When enabled, the typing toggle (and 5‑finger swipe) switches between full keyboard and mouse‑only. In keyboard mode, mouse down/up events are blocked globally (except inside the GlassToKey config window) and tap‑click gestures are disabled. Blocking clicks requires Input Monitoring/Accessibility permission.

Intent State Machine

GlassToKey runs a simple intent state machine to decide when touches should be interpreted as typing vs mouse input. The UI intent badges use these labels: idle, cand, typing, mouse, gest.

           on-key + stable                 buffer elapsed
      ┌──────────────────────┐         ┌───────────────────┐
      ▼                      │         ▼                   │
[idle] → [cand] → [typing] ← [mouse] ← [mouseActive] ← [mouseCandidate]
  │        │          │           ▲
  │        │          └─ grace ────┘
  │        └─ mouse-like motion → [mouseCandidate]
  └─ 2+ touches in buffer (or 3+ simultaneous) → [gest] ──> [idle]

• Idle (idle): No active contacts. Any touch that begins on a key enters keyCandidate; otherwise it enters mouseCandidate.
• KeyCandidate (cand): A short buffer window (fixed at 40ms) watches for mouse-like motion. If the touch stays within thresholds, it becomes typingCommitted.
• TypingCommitted (typing): Key dispatches are allowed. Typing Grace keeps this state alive for a short window after a key is released.
• MouseCandidate (mouse): Short buffer window (fixed at 40ms) watching for mouse-like motion. If motion exceeds thresholds or the buffer elapses, it becomes mouseActive.
• MouseActive (mouse): Typing is suppressed while mouse intent is active.
• GestureCandidate (gest): Multi-finger gesture guard. If 2+ touches begin within the 40ms buffer (or 3+ touches arrive together), typing is suppressed and intent displays as gesture until the contact count drops.

Transitions and notes:

• Typing Grace extends typingCommitted after a key dispatch, even if all fingers lift.
• Tap/Drag immediately disqualifies the touch and forces mouseActive.
• GestureCandidate enters when 2+ touches start within the key buffer window (or 3+ simultaneous touches) and exits back to idle once fewer than two contacts remain.

Diagnostics (Debug Builds)

• Performance profiling uses OSSignposter intervals around touch processing.
• The debug build also emits InputFrame / SnapshotUpdate events and per-side ProcessTouches intervals so you can trace how a raw frame becomes a dispatched keystroke.

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References

This is a fork of Kyome22/OpenMultitouchSupport with some added features.

This library refers the following frameworks very much. Special Thanks!

• mhuusko5/M5MultitouchSupport
• calftrail/Touch
• KrishKrosh/OpenMultitouchSupport

Requirements

• Development with Xcode 16.0+
• swift-tools-version: 6.0
• Compatible with macOS 13.0+

Permissions

Keyboard Mode’s global click blocking requires system permission:

1. Open System Settings → Privacy & Security → Input Monitoring and enable GlassToKey.
2. Also enable System Settings → Privacy & Security → Accessibility for GlassToKey.
3. Restart GlassToKey after granting permissions.

FUTURE

• Add windows support based on https://github.com/vitoplantamura/MagicTrackpad2ForWindows (They should have USB drivers for USB-C support soon?)

RECOMMENDED

• BetterTouchTool: https://folivora.ai Not affiliated but I personally use it for all of my trackpad gestures and def. think it is worth the $24 lifetime license!