ios - Wait with execution of viewWillDisappear until custom animation has completed? -

i'd perform animation when user taps on button segue root view controller. animation highlight changes user made in detail view controller.

i tried this. animation works (and not essential question, left in illustrate i'm doing.) problem segueing happens fast , can't see animation.

how can wait execution of viewwilldisappear until animation has completed?

override func viewwilldisappear(animated: bool) {         // ...          // animate if text changes. reminderafterrulesrun custom data structure. remindernametextinput outlet label         if remindernametextinput.text != reminderafterrulesrun.title {              let originalremindernametextinputcolor = self.remindernametextinput.textcolor              // animate removing of "all" , replacing commonly used list.             uiview.animatewithduration(0.3, delay: 0, options: .autoreverse, animations: {                  // fade out                 self.remindernametextinput.textcolor = uicolor.redcolor()                 self.remindernametextinput.text = reminderafterrulesrun.title                 self.remindernametextinput.alpha = 0.0                  }, completion: {                     (finished: bool) -> void in                      // once label invisible, set text , fade in                     uiview.animatewithduration(0.3, delay: 0, options: .autoreverse, animations: {                         //                        self.remindernametextinput.selectedsegmentindex = self.tosegmentedcontrolvalue(reminderafterrulesrun.remindernametextinput)!                         self.remindernametextinput.text = reminderafterrulesrun.title                         self.remindernametextinput.textcolor = originalremindernametextinputcolor                         self.remindernametextinput.alpha = 1.0                         }, completion: nil)                      })         } } 

looks you'll want use view controller transition api. @ high level need implement uinavigationcontrollerdelegate protocol methods in view controller. when set view controller delegate of nav controller , transition happen, method called. here can check , see view controllers involved in interaction , direction transition going (push or pop). info can provide appropriate animator.

- (id<uiviewcontrolleranimatedtransitioning>)                navigationcontroller:(uinavigationcontroller *)navigationcontroller     animationcontrollerforoperation:(uinavigationcontrolleroperation)operation                  fromviewcontroller:(uiviewcontroller*)fromvc                    toviewcontroller:(uiviewcontroller*)tovc { if (operation == uinavigationcontrolleroperationpush) {     return self.animator; }     return nil; } 

the "animator" nsobject subclass implements uiviewcontrolleranimatedtransitioning protocol. protocol has methods ask time of transition

- (nstimeinterval)transitionduration:(id <uiviewcontrollercontexttransitioning>)transitioncontext {     return 0.25; } 

and call implementing transition:

- (void)animatetransition:    (id<uiviewcontrollercontexttransitioning>)transitioncontext { uiviewcontroller* toviewcontroller = [transitioncontext viewcontrollerforkey:uitransitioncontexttoviewcontrollerkey]; uiviewcontroller* fromviewcontroller = [transitioncontext viewcontrollerforkey:uitransitioncontextfromviewcontrollerkey]; [[transitioncontext containerview] addsubview:toviewcontroller.view]; toviewcontroller.view.alpha = 0;  [uiview animatewithduration:[self transitionduration:transitioncontext] animations:^{     fromviewcontroller.view.transform = cgaffinetransformmakescale(0.1, 0.1);     toviewcontroller.view.alpha = 1; } completion:^(bool finished) {     fromviewcontroller.view.transform = cgaffinetransformidentity;     [transitioncontext completetransition:![transitioncontext transitionwascancelled]];  }];  }