Figure 5- 17 A complaint email to Shoghian
I was stuck on this problem for nearly half a month. During that period, I was always
thinking, what could iOS do inside the setter? Since preferences specifier plist used
PostNotification to notify changes of configuration files to other processes, and the
configuration of AccessibilitySettings was associated with MobilePhone, which happened to be
the mode of inter-process communication. Would accessibilitySetPreference:specifier: change
the configuration file and post a notification? To verify my guesses, I made use of
LibNotifyWatch by limneos to observe if there were any related notifications through manually
changing the configuration of “Incoming Calls”. Unexpectedly, it really made me a lucky hit.
FunMaker-4s:~ root# grep LibNotifyWatch: /var/log/syslog
Nov 26 00:09:20 FunMaker-4s Preferences[6488]: LibNotifyWatch: <CFNotificationCenter
0x1e875600 [0x39b4b100]> postNotificationName:UIViewAnimationDidCommitNotification
object:UIViewAnimationState userInfo:{
Nov 26 00:09:20 FunMaker-4s Preferences[6488]: LibNotifyWatch: <CFNotificationCenter
0x1e875600 [0x39b4b100]> postNotificationName:UIViewAnimationDidStopNotification
object:<UIViewAnimationState: 0x1ea74f20> userInfo:{
......
Nov 26 00:09:21 FunMaker-4s Preferences[6488]: LibNotifyWatch:
CFNotificationCenterPostNotification center=<CFNotificationCenter 0x1dd86bd0
[0x39b4b100]> name=com.apple.accessibility.defaultrouteforcall userInfo=(null)
deliverImmediately=1
Nov 26 00:09:21 FunMaker-4s Preferences[6488]: LibNotifyWatch: notify_post
com.apple.accessibility.defaultrouteforcall
......I’ve found two notifications named “com.apple.accessibility.defaultrouteforcall”.
Combining them with previous mentioned deductions, there was no need to further explain.