Question

This is my first question her so please be gentle:
I have followig animation code running smoothly on the simulator as well as on the real device (I am testng on iPhone 3GS 3.1.2).
Animation is a simple transition between the 2 views, something like book page flipping.

One diffrence betwen simulator an real device (The problem I cannot investigate – solve) is that on real device when animation finishes – after rotation has been done animated view blink (show for a split of second) for a moment before it goes hidden. On the simulator this ‘unexpected’ blink does not happen.

Here is the animation code:

-(void)flip{
    UIView *animatedView;

    // create an animation to hold the page turning
    CABasicAnimation *transformAnimation = [CABasicAnimation animationWithKeyPath:@"transform"];
    transformAnimation.removedOnCompletion = NO;
    transformAnimation.delegate = self;
    transformAnimation.duration = ANIMATION_TIME;
    transformAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

    // this is the basic rotation by 90 degree along the y-axis
    CATransform3D endTransform = CATransform3DMakeRotation(3.141f/2.0f,
                                                           0.0f,
                                                           -1.0f,
                                                           0.0f);
    // these values control the 3D projection outlook
    endTransform.m34 = 0.001f;
    endTransform.m14 = -0.0015f;


    // start the animation from the current state
    transformAnimation.fromValue = [NSValue valueWithCATransform3D:CATransform3DIdentity];
    transformAnimation.toValue = [NSValue valueWithCATransform3D:endTransform];
    animatedView = screenShot;

    // Create an animation group to hold the rotation and possibly more complex animation in the future
    CAAnimationGroup *theGroup = [CAAnimationGroup animation];

    // Set self as the delegate to receive notification when the animation finishes
    theGroup.delegate = self;
    theGroup.duration = ANIMATION_TIME;
    // CAAnimation-objects support arbitrary Key-Value pairs, we add the UIView tag
    // to identify the animation later when it finishes
    [theGroup setValue:[NSNumber numberWithInt:animatedView.tag] forKey:@"animated"];
    // Here you could add other animations to the array
    theGroup.animations = [NSArray arrayWithObjects:transformAnimation,nil];
    theGroup.removedOnCompletion = NO;
    // Add the animation group to the layer
    if (animatedView.layer.anchorPoint.x != 0.0f) 
    {
        animatedView.layer.anchorPoint = CGPointMake(0.0f, 0.5f);
        float yy = animatedView.center.x - (animatedView.bounds.size.width / 2.0f);
        animatedView.center = CGPointMake(yy, animatedView.center.y);
    }

    if(![animatedView isDescendantOfView:self.view])[self.view addSubview:animatedView];
    screenShot.hidden = NO;
    animatedView.hidden = NO;


    [animatedView.layer addAnimation:theGroup forKey:@"flip"];

}

- (void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag {

    screenShot.hidden = YES;

}

Answer 1

Try setting theGroup’s and / or transformAnimation’s fillMode to kCAFillModeForwards:

theGroup.fillMode = kCAFillModeForwards;

This should cause your animation to persist once its active duration has completed. I’ve used this to remove an end-of-animation flicker before.