Animation resets to begin state after ending or firing second animation - ios

I'm trying to make a breathing circle animation. Only breathInAnimation (grow circle) seems to animate. breathOutAnimation (shrink circle) gets called but doesn't seem to do anything. I'm guessing it immediately reverts back to the starting state but I don't understand why.
- (void)viewDidLoad
animationView = [[UIView alloc] initWithFrame:CGRectMake(self.view.frame.size.width / 2.0, self.view.frame.size.height / 2.0, 200, 200)];
animationView.backgroundColor = [UIColor blueColor];
animationView.layer.cornerRadius = 100;
animationView.center = self.view.center;
[self.view addSubview: animationView];
[self drawCircleEdge];
[self breathInAnimation];
[NSTimer timerWithTimeInterval:7.0 target:self selector:#selector(breathOutAnimation) userInfo:nil repeats:YES];
- (void)breathInAnimation
CABasicAnimation *scaleAnimation = [CABasicAnimation animationWithKeyPath:#"transform.scale"];
[scaleAnimation setValue:#"breathIn" forKey:#"id"];
scaleAnimation.duration = 4;
scaleAnimation.fromValue = [NSNumber numberWithFloat:0.1];
scaleAnimation.toValue = [NSNumber numberWithFloat:1];
[animationView.layer addAnimation:scaleAnimation forKey:#"scale"];
- (void)breathOutAnimation
CABasicAnimation *breathOut = [CABasicAnimation animationWithKeyPath:#"transform.scale"];
breathOut.duration = 8;
breathOut.fromValue = [NSNumber numberWithFloat:1];
breathOut.toValue = [NSNumber numberWithFloat:0.1];
[animationView.layer removeAllAnimations];
[animationView.layer addAnimation: breathOut forKey:#"scale"];
I also tried using the delegate of scaleAnimation.
- (void)animationDidStop:(CABasicAnimation *)theAnimation2 finished:(BOOL)flag
This works but after the animation finished the circle goes back to the state it was after ending the first animation. Shrinking -> animation ends -> fullsize again.
I'm not sure what I'm missing here.

CAAnimations doesn't apply the transformation to your layer, it's animating on a presentation layer and then switch back to your layer when animation is finished.
You should apply your transform when you are playing the animation.
-(void)breathOutAnimation
{
CABasicAnimation *breathOut = [CABasicAnimation animationWithKeyPath:#"transform.scale"];
breathOut.duration = 8;
breathOut.fromValue = [NSNumber numberWithFloat:1];
breathOut.toValue = [NSNumber numberWithFloat:0.1];
[animationView.layer removeAllAnimations];
[animationView.layer addAnimation: breathOut forKey:#"scale"];
animationView.layer.transform = CATransform3DMakeScale(0.1, 0.1, 0.1);
}

Related

Glitches when queuing CAAnimations

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))

Animation is not working as expected

I implemented corePlot in xcode and I'm using the pie chart. I'm trying to create a 3d flip animation while the chart reloads. Here is the code:
CABasicAnimation *scaleAnimation = [CABasicAnimation animationWithKeyPath:#"transform.scale.x"];
scaleAnimation.fromValue = [NSNumber numberWithFloat:1.0];
scaleAnimation.toValue = [NSNumber numberWithFloat:0.5];
scaleAnimation.duration = 1.0f;
scaleAnimation.removedOnCompletion = NO;
[self.pieChart addAnimation:scaleAnimation forKey:#"scale"];
[self.pieChart reloadData];
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"transform.scale.x"];
animation.fromValue = [NSNumber numberWithFloat:0.5];
animation.toValue = [NSNumber numberWithFloat:1.0];
animation.duration = 1.0f;
[self.pieChart addAnimation:animation forKey:#"scale"];
I didn't get desirable effects. I think what's happening is, both animations are happening at once. (Though I'm not sure that is what's happening.)
Also, is it possible to add z-depth? If so, how?
Update
I tried the follwoing:
CABasicAnimation *currentAnition = (CABasicAnimation *)anim;
if (currentAnition == self.scaleAnimation {...}
And it didn't work.
CAAnimation is KVC compliant, so we can store whether you're starting or finishing for lookup in the delegate methods:
{
CABasicAnimation *scaleAnimation = [CABasicAnimation animationWithKeyPath:#"transform.scale.x"];
[scaleAnimation setValue:#(YES) forKey:#"scaleAnimation"];
// set the delegate
scaleAnimation.delegate = self;
scaleAnimation.fromValue = [NSNumber numberWithFloat:1.0];
scaleAnimation.toValue = [NSNumber numberWithFloat:0.5];
scaleAnimation.duration = 1.0f;
scaleAnimation.removedOnCompletion = NO;
[self.pieChart addAnimation:scaleAnimation forKey:#"scale"];
[self.pieChart reloadData];
}
- (void)runSecondAnimation
{
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"transform.scale.x"];
[animation setValue:#(YES) forKey:#"secondAnimation"];
animation.delegate = self;
animation.fromValue = [NSNumber numberWithFloat:0.5];
animation.toValue = [NSNumber numberWithFloat:1.0];
animation.duration = 1.0f;
[self.pieChart addAnimation:animation forKey:#"scale"];
}
/* Called when the animation either completes its active duration or
* is removed from the object it is attached to (i.e. the layer). 'flag'
* is true if the animation reached the end of its active duration
* without being removed. */
- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag {
BOOL scaleAnimation = [[anim valueForKey:#"scaleAnimation"] boolValue];
if (scaleAnimation) {
[self runSecondAnimation];
}
BOOL secondAnimation = [[anim valueForKey:#"secondAnimation"] boolValue];
if (secondAnimation) {
[self runThirdAnimation];
}
}
And remember you have also:
/* Called when the animation begins its active duration. */
- (void)animationDidStart:(CAAnimation *)anim;

How do I smoothly update the toValue/end point of an animation in Core Animation?

I'm trying to emulate the effect Apple has as a progress indicator when downloading an app in iOS 7, somewhat of a pie chart:
My code's coming along pretty well. I can give it a value to go to and it will update to that.
- (void)drawRect:(CGRect)rect
{
[super drawRect:rect];
CGFloat radius = CGRectGetWidth(self.frame) / 2;
CGFloat inset = 1;
CAShapeLayer *ring = [CAShapeLayer layer];
ring.path = [UIBezierPath bezierPathWithRoundedRect:CGRectInset(self.bounds, inset, inset)cornerRadius:radius-inset].CGPath;
ring.fillColor = [UIColor clearColor].CGColor;
ring.strokeColor = [UIColor whiteColor].CGColor;
ring.lineWidth = 2;
self.innerPie = [CAShapeLayer layer];
inset = radius/2;
self.innerPie.path = [UIBezierPath bezierPathWithRoundedRect:CGRectInset(self.bounds, inset, inset)
cornerRadius:radius-inset].CGPath;
self.innerPie.fillColor = [UIColor clearColor].CGColor;
self.innerPie.strokeColor = [UIColor whiteColor].CGColor;
self.innerPie.lineWidth = (radius-inset)*2;
[self.layer addSublayer:ring];
[self.layer addSublayer:self.innerPie];
self.progress = 0.0;
self.innerPie.hidden = YES;
}
- (void)setProgress:(CGFloat)progress animated:(BOOL)animated {
if (animated) {
self.innerPie.hidden = NO;
self.innerPie.strokeEnd = progress;
CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
pathAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
pathAnimation.duration = 0.5;
pathAnimation.fromValue = [NSNumber numberWithFloat:self.progress];
pathAnimation.toValue = [NSNumber numberWithFloat:progress];
[self.innerPie addAnimation:pathAnimation forKey:#"strokeEnd"];
}
else {
[CATransaction setDisableActions:YES];
[CATransaction begin];
self.innerPie.hidden = NO;
self.innerPie.strokeEnd = progress;
[CATransaction commit];
}
self.progress = progress;
}
My issue lies in updating the progress while in the middle of an animation. For example, if I'm downloading a file and the progress jumps from 0.1 to 0.2 (10% to 20%), I want to animate that. Say I give it a 0.5 second animation. What if, 0.2 seconds into the 0.5 second animation it jumps to 0.4 (40%)?
With my current code, it jumps to where it should have ended (when it should have animated) in the first animation (20%) and then starts animating again toward 40%.
What I'd like is for it to almost update the toValue to 0.4. At least that's what I think I want. Conceptually I'd like it to continue the animation toward the new value without interrupting the previous value. Smoothness, to put it simply.
How would I accomplish this?
I know there's libraries to do this. I want to do it myself for learning purposes.
You should replace
pathAnimation.fromValue = [NSNumber numberWithFloat:self.progress];
with :
pathAnimation.fromValue = [NSNumber numberWithFloat:[self.innerPie.presentationLayer strokeEnd]];
Initially, [self.innerPie.presentationLayer strokeEnd]]will be 1, so you will need to set the initial value to 0. Add these 2 lines to place where you create your 'innerPie' :
self.innerPie.strokeStart = 0;
self.innerPie.strokeEnd = 0;
I've tested and it works.

Cannot control animation timing of a UITableViewCell's sublayer

The CAMediaTiming protocol defines property timeOffset which is supposed to set additional time offset of an animation or animated layer. By setting layer.speed = 0 it's possible to manually control animation timing by setting layer.timeOffset to a given value.
And I managed to do it in a regular view, however when I try to do it (set time offset of a layer) when the layer is a descendant of UITableViewCell's layer it has no effect.
Here's a quick snippet so you can see what I am trying to achieve and what doesn't work.
-(void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
[tableView deselectRowAtIndexPath:indexPath animated:NO];
CALayer *layer = [CALayer layer];
layer.frame = CGRectMake(0, 0, 80, 80);
layer.backgroundColor = [UIColor redColor].CGColor;
layer.opacity = .1f;
[cell.contentView.layer addSublayer:layer];
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"opacity"];
animation.toValue = (id) [NSNumber numberWithFloat:1.f];
animation.duration = 1.f;
[layer addAnimation:animation forKey:nil];
layer.timeOffset = 0.7f;
layer.speed = 0.f;
}
You must allow the animation to start before you can control its timeOffset. Use a block with very small delay to do so:
CABasicAnimation* ba = [CABasicAnimation animationWithKeyPath:#"opacity"];
ba.removedOnCompletion = NO;
ba.duration = kAnimationDuration;
ba.autoreverses = YES;
ba.repeatCount = HUGE_VALF;
ba.fromValue = [NSNumber numberWithDouble:kInitialAlpha];
ba.toValue = [NSNumber numberWithDouble:kFinalAlpha];
[self.layer addAnimation:ba forKey:#"opacity"];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(.1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
double offset = self.alphaOffset * ( kAnimationDuration / kNumAlphaOffsets );
self.layer.timeOffset = offset;
});

Loop animation - doesn't go

I'm trying to repeat a sequence of animations, inside a LOOP, changing at each loop some parameters randomly. Here is the code. Anyone please knows why it doesn't work?
If I call it once with a button action, it works, but with a loop it doesn't.
Thanks a lot! Giuseppe
-(IBAction)startLoop:(id)sender {
for (int i=1;i<10; i++) {
[self animation2];
}
}
-(id) animation2 {
int max=500;
UIImage *myImage = [UIImage imageNamed:#"coccinella2.png"];
CALayer *myLayer = [CALayer layer];
myLayer.contents = (id)myImage.CGImage;
myLayer.bounds = CGRectMake(0, 0, 50, 60);
[myLayer setPosition:CGPointMake(arc4random()%(max), arc4random()%(max))];
[myLayer setBounds:CGRectMake(0.0, 0.0, 50.0, 60.0)];
[self.view.layer addSublayer:myLayer];
//translation1
CGPoint startPt = CGPointMake(arc4random()%(max),arc4random()%(max));
CGPoint endPt = CGPointMake(arc4random()%(max),arc4random()%(max));
CABasicAnimation *transl1 = [CABasicAnimation animationWithKeyPath:#"position"];
transl1.removedOnCompletion = FALSE;
transl1.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
transl1.fromValue = [NSValue valueWithCGPoint:startPt];
transl1.toValue = [NSValue valueWithCGPoint:endPt];
transl1.duration = 2.0;
transl1.fillMode = kCAFillModeForwards;
transl1.beginTime = 0;
//scale 1
CABasicAnimation *scale1 = [CABasicAnimation
animationWithKeyPath:#"transform.scale"];
scale1.removedOnCompletion = FALSE;
[scale1 setToValue:[NSNumber numberWithInt:3]];
[scale1 setDuration:2.0f];
scale1.fillMode = kCAFillModeForwards;
scale1.beginTime = 0;
//rotation1
CABasicAnimation *rotation1 = [CABasicAnimation
animationWithKeyPath:#"transform.rotation.z"];
rotation1.removedOnCompletion = FALSE;
[rotation1 setFromValue:DegreesToNumber(0)];
[rotation1 setToValue:DegreesToNumber(90)];
//rotation1.repeatCount = HUGE_VALF;
[rotation1 setDuration:2.0f];
rotation1.fillMode = kCAFillModeForwards;
rotation1.beginTime = 0;
//group
CAAnimationGroup* group = [CAAnimationGroup animation];
[group setDuration: 6.0];
group.removedOnCompletion = FALSE;
group.fillMode = kCAFillModeForwards;
[group setAnimations: [NSArray arrayWithObjects:scale1, transl1, rotation1, nil]];
[myLayer addAnimation: group forKey: nil];
}
Your code doesn't repeat the annotation 10 times but starts 10 animations right away. If your goal is to start the animations after the previous one ended you should try using an NSTimer.
You can use an NSTimer to trigger each group of animations at a different time, or you can set the beginTime on each group, with code like this:
group.beginTime = CACurrentMediaTime() + delay;
For animations, using the beginTime gives more accurate timing, since CA is run on a separate thread and doesn't stall like NSTimers if your app gets busy.

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