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Fixes for Issue #167 — System-wide input degradation

Problem

SwiftShift's mouse-click shortcuts (Command+click for Move, Command+right-click for Resize) use a CGEventTap to intercept mouse events. macOS silently disables event taps on sleep/wake, display changes, session lock, and slow callbacks — but SwiftShift had no recovery mechanism. A dead tap causes system-wide input lag because CGEventTaps are synchronous (WindowServer pauses all input until the callback returns).

Fixes applied

1. CGEventSupervisor: Proper teardown (run loop source leak)

Files: CGEventSupervisor.swift, CGEventSupervisor+Setup.swift

  • Added eventTapRunLoopSource stored property to track the run loop source
  • teardown() now removes the source from the run loop and invalidates the CFMachPort, not just disables the tap

2. CGEventSupervisor: Handle disabled-tap events

File: CGEventSupervisor+Callback.swift

  • The callback now checks for .tapDisabledByTimeout and .tapDisabledByUserInput
  • When detected, re-enables the tap via CGEvent.tapEnable(tap:enable: true)
  • Prevents silent tap death from slow callbacks

3. ShortcutsManager: System event recovery

File: Swift Shift/src/Manager/ShortcutsManager.swift

Added observers for three system events that kill taps:

  • NSWorkspace.didWakeNotification — sleep/wake
  • NSWorkspace.sessionDidBecomeActiveNotification — screen lock/unlock, fast user switch
  • NSApplication.didChangeScreenParametersNotification — display connect/disconnect, resolution change

rebuildAllInputHooks() now:

  1. Stops any active tracking and clears activeShortcuts state
  2. Tears down the current tap via CGEventSupervisor.shared.cancelAll()
  3. Rebuilds keyboard monitors via updateGlobalShortcuts()
  4. Force-rebuilds mouse chord subscriptions via MouseChordActionManager.shared.forceRebuild()

4. MouseChordActionManager: forceRebuild()

File: Swift Shift/src/Manager/ShortcutsManager.swift

Added forceRebuild() which properly resets the internal isSubscribed flag before re-subscribing. This fixes a state corruption issue where cancelAll() could leave the isSubscribed flag true, causing subscribeIfNeeded() to return early without actually re-creating the CGEventSupervisor subscriber.

ShortcutsManager.rebuildAllInputHooks() (not forceRebuild()) clears activeShortcuts and stops any in-progress tracking before rebuild, preventing stale modifier-key state from blocking future shortcut activations.

5. MouseChordActionManager: Periodic tap health check

File: Swift Shift/src/Manager/ShortcutsManager.swift

Added a 60-second repeating timer that calls forceRebuild() when subscribed. This catches tap death from Secure Input (password prompts, sudo) and any other no-notification tap-killing scenarios by fully tearing down and rebuilding the subscription.

6. CGEventSupervisor vendored into project

Files: Swift Shift/packages/CGEventSupervisor/

The CGEventSupervisor dependency (previously stephancasas/CGEventSupervisor) is now a local package. This allows us to ship the teardown and callback fixes without waiting for upstream. The package is unchanged except for the fixes documented in items 1 and 2 above. The reporter uses Command+click for Move and Command+right-click for Resize. Each shortcut press creates CGEventSupervisor subscriptions which create a CGEventTap. The tap dies silently on system events, and without recovery the tap stays dead — causing the system-wide input delay described in the bug. Restarting the app works because it creates a fresh tap.