Validate trackpad gestures against system settings

[aaronkollasch]

This is a tracking issue for adding warning icons to gestures that are incompatible with system settings like tap-to-click and three-finger drag.

Bad combinations:

• two-fix one-double-tap also triggers two three-finger clicks when system tap-to-click is enabled #42
• three-finger drag perpetually triggers three-finger click and can trigger three-finger swipe gestures #37
• system three-finger and four-finger swipe gestures interfere with Jitouch's #37

System settings to consider:

• tap-to-click

  defaults read "com.apple.AppleMultitouchTrackpad" "Clicking" == '1'
  

• three-finger drag

  defaults read "com.apple.driver.AppleBluetoothMultitouch.trackpad" "TrackpadThreeFingerDrag" == '1'
  

• three-finger drag vertical

  any(
  defaults read "com.apple.dock" "showMissionControlGestureEnabled" == '1'
  defaults read "com.apple.dock" "showAppExposeGestureEnabled" == '1'
  defaults read "com.apple.dock" "showDesktopGestureEnabled" == '1'
  )
  defaults read "com.apple.driver.AppleBluetoothMultitouch.trackpad" "TrackpadThreeFingerVertSwipeGesture" == '2'
  defaults read "com.apple.AppleMultitouchTrackpad" "TrackpadThreeFingerVertSwipeGesture" == '2'
  

• four-finger drag

  defaults read "com.apple.driver.AppleBluetoothMultitouch.trackpad" "TrackpadThreeFingerVertSwipeGesture" == '0'
  defaults read "com.apple.AppleMultitouchTrackpad" "TrackpadThreeFingerVertSwipeGesture" == '0'
  

• three-finger drag horizontal

  defaults read "com.apple.AppleMultitouchTrackpad" "TrackpadThreeFingerHorizSwipeGesture" '2'
  defaults read "com.apple.driver.AppleBluetoothMultitouch.trackpad" "TrackpadThreeFingerHorizSwipeGesture" '2'
  

• four-finger drag horizontal

  defaults read "com.apple.AppleMultitouchTrackpad" "TrackpadThreeFingerHorizSwipeGesture" == '0'
  defaults read "com.apple.driver.AppleBluetoothMultitouch.trackpad" "TrackpadThreeFingerHorizSwipeGesture" == '0'
  defaults read "com.apple.AppleMultitouchTrackpad" "TrackpadFourFingerHorizSwipeGesture" == '2'
  

• three-finger swipe between pages

  defaults read "com.apple.AppleMultitouchTrackpad" "TrackpadThreeFingerVertSwipeGesture" == '1'
  defaults read "com.apple.AppleMultitouchTrackpad" "TrackpadThreeFingerHorizSwipeGesture" == '1'
  defaults read "com.apple.driver.AppleBluetoothMultitouch.trackpad" "TrackpadThreeFingerVertSwipeGesture" == '1'
  defaults read "com.apple.driver.AppleBluetoothMultitouch.trackpad" "TrackpadThreeFingerHorizSwipeGesture" == '1'