* feat(macos): add privacy mode support for macOS
## Summary
Add privacy mode functionality for macOS platform, allowing remote
desktop sessions to hide the screen content from local users.
## Changes
### Core Implementation (src/platform/macos.mm)
- Implement screen blackout using CGDisplayGammaTable API
- Implement input blocking using CGEventTap to intercept keyboard/mouse
- Store and restore original gamma values for proper cleanup
### Privacy Mode Integration (src/privacy_mode.rs, src/privacy_mode/macos.rs)
- Add macOS privacy mode implementation with PrivacyMode trait
- Register macOS privacy mode in PRIVACY_MODE_CREATOR
- Set DEFAULT_PRIVACY_MODE_IMPL for macOS platform
- Implement get_supported_privacy_mode_impl() for macOS
### Connection Handling (src/server/connection.rs)
- Add supported_privacy_mode_impl to platform_additions for macOS
- Enable privacy mode toggle in client UI when connecting via LAN IP
### Localization (src/lang/*.rs)
- Add "privacy_mode_impl_macos_tip" translation for en/cn/tw
## Safety & Security
- Implements Drop trait to ensure cleanup on normal exit
- macOS system automatically restores gamma table on process termination
- CGEventTap is automatically released when process terminates
- Tested with SIGKILL to verify crash recovery
## Testing
- Verified privacy mode toggle works via both ID and LAN IP connection
- Verified screen recovery after process crash (kill -9)
- Verified input restoration after process termination
* refactor: use existing 'Privacy mode' translation key
* refactor: rename gamma channel variables for better readability - rename r/g/b to red/green/blue to avoid variable shadowing confusion
* fix: add error handling for gamma table restoration with fallback to system reset
* fix: add error handling for CGEventTapCreate failure in privacy mode
* fix: only set display to black if original gamma was saved successfully
* fix: add error handling for CGSetDisplayTransferByTable when setting display to black
* fix: improve event tap callback to properly distinguish remote input from local input
* fix: missing macos.rs
* Fix: Add display validation before restoring gamma values
* Fix: Add mutex lock for thread safety in MacSetPrivacyMode
* Fix: Handle return values and add missing mouse events in macos privacy mode
* fix: only set conn_id after privacy mode is successfully turned on
* fix: reimplement privacy mode with stable display identification
Address code review concern: original gamma values stored with DisplayID
as key could become stale if display list changes between privacy mode
activations (e.g., display reconnected with different ID).
Solution:
- Use UUID instead of DisplayID as storage key (stable across reconnections)
- Clear g_originalGammas when privacy mode is turned off
- Register CGDisplayReconfigurationCallback to handle hot-plug events
- Validate display state via FindDisplayIdByUUID() before restoration
Key features:
- UUID-based display identification (stable across reconnections)
- Hot-plug support via CGDisplayReconfigurationCallback
- EventTap auto re-enable on system timeout
- Fallback to CGDisplayRestoreColorSyncSettings() for recovery
- Detailed error logging with display name/ID/UUID
* fix: ensure EventTap runs on main thread and improve gamma restore error handling
- Add SetupEventTapOnMainThread() to create EventTap on main thread using dispatch_sync, avoiding potential issues when called from background threads
- Add TeardownEventTapOnMainThread() for consistent cleanup on main thread
- Check [NSThread isMainThread] to avoid deadlock when already on main thread
- Add error tracking for gamma restoration during cleanup
- Use CGDisplayRestoreColorSyncSettings() as fallback when individual gamma restoration fails
* fix: remove invalid eventMask bits that caused undefined behavior in input blocking
* fix: address code review comments for macos privacy mode implementation
Changes to src/privacy_mode/macos.rs:
- Add check_on_conn_id() in turn_on_privacy() to prevent duplicate activation
- Add check_off_conn_id() in turn_off_privacy() to validate connection ID
- Add self.conn_id = 0 in clear() to reset connection state
Changes to src/platform/macos.mm:
- Add link comment for ENIGO_INPUT_EXTRA_VALUE referencing libs/enigo/src/macos/macos_impl.rs
- Fix NSLog format string mismatch (5 placeholders vs 4 values)
- Make ApplyBlackoutToDisplay() return bool for proper error handling
- Return false when UUID is empty since privacy mode requires ALL displays
- Add else branches with logging for:
- CGGetDisplayTransferByTable failures
- Zero gamma table capacity (not supported)
- Zero blackout capacity
- Remove unused g_uuidToDisplayId variable (was only written, never read)
* fix(macos): add early return with privacy mode exit on display hotplug failures
Why large-scale changes are needed:
The code review suggested adding early return when errors occur in
DisplayReconfigurationCallback. However, simply returning early is not
enough - when a newly connected display cannot be blacked out, we must
exit privacy mode entirely to maintain security guarantees.
The challenge is that DisplayReconfigurationCallback already holds
g_privacyModeMutex, so calling MacSetPrivacyMode(false) directly would
cause a deadlock. This necessitated:
1. Extract TurnOffPrivacyModeInternal() - a lock-free internal function
that can be safely called from within the callback
2. Refactor MacSetPrivacyMode(false) branch to use this internal function
3. Add early returns with TurnOffPrivacyModeInternal() calls at each
failure point in DisplayReconfigurationCallback
Changes in DisplayReconfigurationCallback:
- UUID empty: log + exit privacy mode + early return
- Gamma table capacity zero: log + exit privacy mode + early return
- CGGetDisplayTransferByTable fails: log + exit privacy mode + early return
- ApplyBlackoutToDisplay fails: log + exit privacy mode + early return
* fix(macos): address code review feedback and improve privacy mode stability
Code Review Fixes:
- Add detailed comments for potential deadlock scenarios in dispatch_sync
with g_privacyModeMutex (SetupEventTapOnMainThread/TeardownEventTapOnMainThread)
- Use async dispatch for privacy mode shutdown from DisplayReconfigurationCallback
to avoid unregistering callback from within itself
- Extract RestoreAllGammas() helper function to reduce code duplication
- Fix Drop implementation in macos.rs to call self.clear() for consistency
- Add comment explaining why _state parameter is ignored on macOS
- Define DISPLAY_RECONFIG_MONITOR_DURATION_MS and GAMMA_CHECK_INTERVAL_MS constants
- Add gamma restoration when UUID retrieval fails during privacy mode activation
Privacy Mode Stability Improvements (Continuous Resolution Changes):
- Implement continuous gamma value monitoring with timer polling after display
reconfiguration to handle rapid successive resolution changes
- Monitor gamma values every 200ms for 5 seconds after each resolution change
- Automatically reapply blackout if system (ColorSync) restores gamma
- Add IsDisplayBlackedOut() to detect if display gamma has been restored
- Use timestamp-based debouncing: monitoring period automatically extends
when new reconfig events occur during active monitoring
- Ensure blackout remains effective even under continuous resolution changes
where macOS may asynchronously restore gamma values multiple times
This ensures privacy mode remains stable and effective when users rapidly
change display resolution multiple times in succession.
---------
Co-authored-by: libin <libin.chat@outlook.com>
Restore display settings.
Only restore by the display registry settings.
Do not change display settings twice when turning off privacy mode.
Only restore the registry values.
Signed-off-by: fufesou <linlong1266@gmail.com>
1. Windows, multi-display, as the controlled side.
2. Connect
3. Turn on privacy mode, with mode 2.
4. Turn off privacy mode.
Then the display settings are continues changed when connect &
disconnect.
Signed-off-by: fufesou <linlong1266@gmail.com>
