Multiple CAAnimations On Different Views Simultaneously - iphone

Question

I'm trying execute a couple of animations at the same time. One is transitioning from one uimageview to another and the other is animating translation.x of a label. The label resides on top of uiimageview.
But what I get is either translation working fine and transition happens immediately, or the transitioning -based on hidden property - also applies to my label which should only be shifted (it also goes from hidden to visible). I can't use caanimationgroup because they apply to different views.
//CAKeyFrameAnimation for sliding the label
...
CAKeyframeAnimation *anim = [CAKeyframeAnimation animationWithKeyPath:#"transform.translation.x"];
NSArray *xValues = #[[NSNumber numberWithFloat:myLabel.bounds.origin.x],
[NSNumber numberWithFloat:myLabel.bounds.origin.x + screenHalf],
[NSNumber numberWithFloat:myLabel.bounds.origin.x + screenHalf * 4]];
[anim setValues:xValues];
NSMutableArray *timeFrames = [NSMutableArray array];
CGFloat timeStep = 1.0 / ([xValues count] - 1);
for (NSInteger i = 0; i < [xValues count]; i++)
{
[timeFrames addObject:[NSNumber numberWithFloat:timeStep * i]];
}
[anim setKeyTimes:timeFrames];
[anim setDuration:duration];
[anim setFillMode:kCAFillModeForwards];
[anim setRemovedOnCompletion:FALSE];
[myLabel.layer addAnimation:anim forKey:nil];
...
//Transitioning from uiimageview to another one
...
CATransition *transition = [CATransition animation];
[transition setDuration:duration];
[transition setType:kCATransitionFade];
//These two are uiimageviews i'm switching from and to
initial.hidden = TRUE;
next.hidden = FALSE;
//Initial and next are subviews of container which itself is a subview of viewcontroller's main view
[container.layer addAnimation:transition forKey:#""];
If I call the animations like above the transition occurs immediately and label slides across screen correctly. If I change the last line to:
[self.view.layer addAnimation:transition forKey:#""];
Then hidden animation also applies to myLabel. What is the fix for combining animations like above, and also more elaborately what is the cause?

Answer 1

I would wrap the entire code in a CATransaction to group the different CAAnimations into a single group.
Psuedo-code for using this with CAKeyFrameAnimation would look like:
[CATransaction begin];
// set completion block if you want
[CATransaction setCompletionBlock:^{ NSLog(#"I'm done"); }];
// start a keyframe animation
CAKeyframeAnimation *key1 = .....
// start another keyframe animation block
CAKeyframeAnimation *key2 = ......
// Maybe do a basic animation
CABasicAnimation *anim1 = .....
// close out all the animations and have them start
[CATransaction commit];