i have modified this code to the code as shown below. I am using touch events to trigger the function below to run the animation. The results I am trying to achieve is: every time I touch 1 time, the image layer remove just processes 1 time. The problem I am facing is when I set removedOnCompletion to YES, whatever the layer just feels like it has removed 1 time but it is never removed, so the program is stuck on same layer. If I keep removedOnCompletion as NO, then image layer will auto remove all the layers.
So, how I can make sure that every time the process removes just 1 Image layer? Any help is appreciated.
-(void)animate:(id)sender {
//Dont implicitly animate the delay change
[CATransaction setDisableActions:YES];
//Reset the replicator delays to their origonal values
imageLayer.instanceDelay = X_TIME_DELAY;
//Re-enable the implicit animations
[CATransaction setDisableActions:NO];
//Create the transform matrix for the animation
//Move forward 1000 units along z-axis
CATransform3D t = CATransform3DMakeTranslation( -500, -500, 1000);
//Rotate Pi radians about the axis (0.7, 0.3, 0.0)
t = CATransform3DRotate(t, M_PI, 0.7, 0.3, 0.0);
//Scale the X and Y dimmensions by a factor of 3
t = CATransform3DScale(t, 0.5, 0.5, 1);
//Transform Animation
CABasicAnimation *animation = [CABasicAnimation animation];
animation.fromValue = [NSValue valueWithCATransform3D: CATransform3DIdentity];
animation.toValue = [NSValue valueWithCATransform3D: t];
animation.duration = 1.0;
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeBoth;
[subLayer addAnimation:animation forKey:#"transform"];
//Opacity Animation
animation = [CABasicAnimation animation];
animation.fromValue = [NSNumber numberWithFloat:1.0];
animation.toValue = [NSNumber numberWithFloat:0.0];
animation.duration = 1.0;
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeBoth;
[subLayer addAnimation:animation forKey:#"opacity"];
stuckfile = NO;
}
Related
I have a CAShapeLayer where I animate a circle. The animation is to first "undraw" the circle clockwise and then redraw the circle clockwise. Sort of a "rotating circle". Another way to put it: Move path stroke end point to start, then move the start point to the end.
The animation itself works, but it produces glitches now and then. It manifests in a short glimpse of the entire circle when it is supposed to be "undrawn".
Why does this occur and how can you fix it?
Thanks,
// Shape creation
layer.path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, self.width - 2 * OUTER_BORDER_WIDTH, self.width - 2* OUTER_BORDER_WIDTH)].CGPath;
// Animation queuing
-(void) applyNextAnimation
{
CABasicAnimation* animation;
if (self.animatingOpening)
{
animation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
animation.fromValue = [NSNumber numberWithFloat:0.0f];
animation.toValue = [NSNumber numberWithFloat:1.0f];
self.animatingOpening = NO;
}
else
{
animation = [CABasicAnimation animationWithKeyPath:#"strokeStart"];
animation.fromValue = [NSNumber numberWithFloat:0.0f];
animation.toValue = [NSNumber numberWithFloat:1.0f];
self.animatingOpening = YES;
}
animation.duration = 1.0f;
animation.autoreverses = NO;
animation.delegate = self;
animation.removedOnCompletion = YES;
[self.outerCircleLayer addAnimation:animation forKey:#"stroke"];
}
// Animation stop callback
-(void) animationDidStop:(CAAnimation *)anim finished:(BOOL)flag
{
if (self.isAnimating)
{
[self applyNextAnimation];
}
}
It blinks becuase you are not setting the corresponding property on the layer. So when the animation completes, the layer's model is still in the pre-animated state and that is what you see momentarily between the two animations.
This will get you towards what you want...
if (self.animatingOpening)
{
self.outerCircleLayer.strokeStart = 0.0;
animation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
animation.fromValue = [NSNumber numberWithFloat:0.0f];
animation.toValue = [NSNumber numberWithFloat:1.0f];
self.animatingOpening = NO;
}
else
{
self.outerCircleLayer.strokeStart = 1.0;
animation = [CABasicAnimation animationWithKeyPath:#"strokeStart"];
animation.fromValue = [NSNumber numberWithFloat:0.0f];
animation.toValue = [NSNumber numberWithFloat:1.0f];
self.animatingOpening = YES;
}
animation.duration = 1.0f;
animation.autoreverses = NO;
that almost works, but you will notice a more subtle glitch as you transition from the undrawn state to start animating the drawing state. The beginning of the circle has a small reverse animation as it starts. This is an implicit animation triggered by setting strokeStart from 1.0 to 0.0: which you need to get rid of so that all of the animations effects are under your control. You can achieve that most simply by setting disableActions to YES on CATransaction:
[CATransaction setDisableActions:YES];
( add it just above if (self.animatingOpening))
I've got simple animation which moves my view's layer and remains in it's final state.
CGPoint originalPosition = self.redSquare.layer.position;
self.redSquare.layer.position = CGPointMake(100, 100);
CABasicAnimation *animation = [[CABasicAnimation alloc]init];
animation.keyPath = #"position.x";
animation.fromValue = #(originalPosition.x);
animation.toValue = #250;
animation.duration = 2;
[self.redSquare.layer addAnimation:animation forKey:#"basic"];
self.redSquare.layer.position = CGPointMake(250, originalPosition.y);
But when I change a label's text the layer jumps to it's original position.
CGPoint originalPosition = self.redSquare.layer.position;
self.redSquare.layer.position = CGPointMake(100, 100);
CABasicAnimation *animation = [[CABasicAnimation alloc]init];
animation.keyPath = #"position.x";
animation.fromValue = #(originalPosition.x);
animation.toValue = #250;
animation.duration = 2;
animation.delegate = self;
[self.redSquare.layer addAnimation:animation forKey:#"basic"];
self.redSquare.layer.position = CGPointMake(250, originalPosition.y);
self.label.text = #"Started";
Why does it happen?
Because,when you change your text,the view need to redraw,
If you enable autoLayout of this view(default is enabled), it will adjust frame to autolayout.
So there are to solutions
Option 1:
Disable auto layout of your view
Option 2
When it comes to frame changed animation, try to animate autolayout
I've got a CABasicAnimation that is operating on the transform property of a CALayer.
The animation looks fairly cool and it all works fine, but now I want to know through which values the transform of the layer is going to go through for a perfect 30/60 FPS animation.
I don't want to run the aniamtion and measure the values, I want to know beforehand.
The timingFunction has to be taken into account for this calculation.
How can I find out these transform values?
That's the animation code:
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath: #"transform"];
animation.fromValue = [NSValue valueWithCATransform3D: _myLayer.transform];
animation.toValue = valueTransform;
animation.duration = 0.7;
animation.timingFunction = [CAMediaTimingFunction functionWithName: kCAMediaTimingFunctionEaseInEaseOut];
[_myLayer addAnimation: animation forKey:#"transformAnimation"];
Consider the following animation:
CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
pathAnimation.duration = 1.0;
pathAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
pathAnimation.fromValue = [NSNumber numberWithFloat:0.0f];
pathAnimation.toValue = [NSNumber numberWithFloat:1.0f];
pathAnimation.removedOnCompletion = NO;
pathAnimation.delegate = self;
This will essentially animate the drawing of the layer from one end to the next. The problem is that once the animation completes, the strokeEnd property resets back to 0 (where it was initially set). How do I make the final value "stick"?
I have attempted to change this in the animationDidStop delegate method. This mostly works, but can cause a flash of strokeEnd at 0 briefly, even when put inside a CATransaction to disable animations. I have also played with the additive and cumulative properties to no avail. Any suggestions?
You simply set the strokeEnd property to its final value yourself! Like this:
// your current code (stripped of unnecessary stuff)
CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
pathAnimation.duration = 1.0;
pathAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
pathAnimation.fromValue = [NSNumber numberWithFloat:0.0f];
pathAnimation.toValue = [NSNumber numberWithFloat:1.0f];
// just add this to it:
theLayer.strokeEnd = 1;
// and now add the animation to theLayer
If strokeEnd were implicitly animatable (so that that line would itself cause animation) we would turn off implicit animation first:
[CATransaction setDisableActions:YES];
theLayer.strokeEnd = 1;
Note that your pathAnimation.removedOnCompletion = NO; is wrong, and so is the other answer's kCAFillModeForwards. Both are based on misunderstandings of how Core Animation works.
I have two rotation animations in my CAAnimationGroup, one that starts from zero and another that repeats and autoreverses from that state:
- (void)addWobbleAnimationToView:(UIView *)view amount:(float)amount speed:(float)speed
{
NSMutableArray *anims = [NSMutableArray array];
// initial wobble
CABasicAnimation *startWobble = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
startWobble.toValue = [NSNumber numberWithFloat:-amount];
startWobble.duration = speed/2.0;
startWobble.beginTime = 0;
startWobble.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
[anims addObject:startWobble];
// rest of wobble
CABasicAnimation *wobbleAnim = [CABasicAnimation animationWithKeyPath:#"transform.rotation.z"];
wobbleAnim.fromValue = [NSNumber numberWithFloat:-amount];
wobbleAnim.toValue = [NSNumber numberWithFloat:amount];
wobbleAnim.duration = speed;
wobbleAnim.beginTime = speed/2.0;
wobbleAnim.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
wobbleAnim.autoreverses = YES;
wobbleAnim.repeatCount = INFINITY;
[anims addObject:wobbleAnim];
CAAnimationGroup *wobbleGroup = [CAAnimationGroup animation];
wobbleGroup.duration = DBL_MAX; // this stops it from working
wobbleGroup.animations = anims;
[view.layer addAnimation:wobbleGroup forKey:#"wobble"];
}
Since CFTimeInterval is defined as a double, I try setting the duration of the animation group to DBL_MAX, but that stops the animation group from running. However, If I set it to a large number, such as 10000, it runs fine. What is the largest number I can use for a duration of a CAAnimationGroup, to ensure it runs for as near to infinity as possible?
UPDATE: It appears that if I put in a very large value such as DBL_MAX / 4.0 then it freezes for a second, then starts animating. If I put in the value DBL_MAX / 20.0 then the freeze at the beginning is a lot smaller. It seems that having such a large value for the duration is causing it to freeze up. Is there a better way of doing this other than using a very large value for the duration?
I am faced with the exact same issue right now... I hope someone proves me wrong, but the only reasonable way I see to handle this situation is by moving the first animation to a CATransaction, and chaining that with the autoreverse animation using:
[CATransaction setCompletionBlock:block];
It's not ideal, but gets the job done.
Regarding your question about the animations being paused when coming back from background, that's a classic limitation of the CoreAnimation framework, many solutions have been proposed for it. The way I solve it is by simply reseting the animations at a random point of the animation, by randomizing the timeOffset property. The user can't tell exactly what the animation state should be, since the app was in the background. Here is some code that could help (look for the //RANDOMIZE!! comment):
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(startAnimating)
name:UIApplicationWillEnterForegroundNotification
object:[UIApplication sharedApplication]];
...
for (CALayer* layer in _layers)
{
// RANDOMIZE!!!
int index = arc4random()%[levels count];
int level = ...;
CGFloat xOffset = ...;
layer.position = CGPointMake(xOffset, self.bounds.size.height/5.0f + yOffset * level);
CGFloat speed = (1.5f + (arc4random() % 40)/10.f);
CGFloat duration = (int)((self.bounds.size.width - xOffset)/speed);
NSString* keyPath = #"position.x";
CABasicAnimation* anim = [CABasicAnimation animationWithKeyPath:keyPath];
anim.fromValue = #(xOffset);
anim.toValue = #(self.bounds.size.width);
anim.duration = duration;
anim.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
// RANDOMIZE!!
anim.timeOffset = arc4random() % (int) duration;
anim.repeatCount = INFINITY;
[layer removeAnimationForKey:keyPath];
[layer addAnimation:anim forKey:keyPath];
[_animatingLayers addObject:layer];
}
It is much simpler to use a single keyframe animation instead of a group of two separate animations.
- (void)addWobbleAnimationToView:(UIView *)view amount:(CGFloat)amount speed:(NSTimeInterval)speed {
CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:#"transform.rotation.z"];
animation.duration = 2 * speed;
animation.values = #[ #0.0f, #(-amount), #0.0f, #(amount), #0.0f ];
animation.keyTimes = #[ #0.0, #0.25, #0.5, #0.75, #1.0 ];
CAMediaTimingFunction *easeOut =[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
CAMediaTimingFunction *easeIn =[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
animation.timingFunctions = #[ easeOut, easeIn, easeOut, easeIn ];
animation.repeatCount = HUGE_VALF;
[view.layer addAnimation:animation forKey:animation.keyPath];
}