When animating a CAShapeLayer, is it necessary to constantly keep updating the path of the layer, or is there a way to rely on CABasicAnimation alone?
In the example below, I set up four circles paths and draw them.
Then I want to animate them down to disappear. After the animation has completed however, they spring back to their original paths.
int radius = halfWidth-30; //the radius is the distance out from the centre
trackActive.path = [UIBezierPath bezierPathWithArcCenter:cicleCenter radius:radius startAngle:degreesToRadians(circleStart) endAngle:degreesToRadians(circleEnd) clockwise:true].CGPath;
circleActive.path = [UIBezierPath bezierPathWithArcCenter:cicleCenter radius:radius startAngle:degreesToRadians(circleStart) endAngle:degreesToRadians(circleEnd) clockwise:true].CGPath;
radius = halfWidth - 10;
trackNew.path = [UIBezierPath bezierPathWithArcCenter:cicleCenter radius:radius startAngle:degreesToRadians(circleStart) endAngle:degreesToRadians(circleEnd) clockwise:true].CGPath;
circleNew.path = [UIBezierPath bezierPathWithArcCenter:cicleCenter radius:radius startAngle:degreesToRadians(circleStart) endAngle:degreesToRadians(circleEnd) clockwise:true].CGPath;
NSArray * layers = #[trackActive, circleActive, trackNew, circleNew];
for (CAShapeLayer * layer in layers){
[CATransaction begin];
CABasicAnimation * animation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
animation.duration = 1.0f;
animation.removedOnCompletion = false;
animation.fromValue = #(1.0);
animation.toValue = #(0.0);
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
[layer addAnimation:animation forKey:#"circleAnimation"];
[CATransaction commit];
}
I understand that I can add this to set the new path:
[CATransaction setCompletionBlock:^{
//set the new path
layer.path = [UIBezierPath bezierPathWithArcCenter:cicleCenter radius:radius startAngle:degreesToRadians(circleStart) endAngle:degreesToRadians(arcEnd) clockwise:true].CGPath;
}];
But would prefer avoid keep having to update the path, and instead rely on the animation layer exclusively. Is this possible?
Something like: layer.path = animation.path or animation.updatesOriginalPath=true; could be wishful thinking, not sure.
You can simplify your code and omit the spring effect:
[CATransaction begin];
[CATransaction setAnimationDuration:1.0];
[CATransaction setAnimationTimingFunction: kCAMediaTimingFunctionEaseInEaseOut];
layer.strokeEnd = 0.0;
[CATransaction commit];
The transaction will create and add an implicit animation object for you.
You can set a flag in a an animation so it stays where it was in the end and starts where it should start like this:
[animation setRemovedOnCompletion:NO];
[animation setFillMode:kCAFillModeBoth];
check also this answer:
What exactly does removedOnCompletion = NO do?
Related
This code creating a complete circle but I want to create a circle based on value either 360 or percentage 100%. IF percentage is 56% I want 56% circle. Like this based on percentage/value, I want circle.
CAShapeLayer *circle = [CAShapeLayer layer];
circle.path = [UIBezierPath bezierPathWithArcCenter:CGPointMake(29, 29) radius:27 startAngle:-M_PI_2 endAngle:2 * M_PI - M_PI_2 clockwise:YES].CGPath;
circle.fillColor = [UIColor clearColor].CGColor;
circle.strokeColor = [UIColor greenColor].CGColor;
circle.lineWidth = 4;
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
animation.duration = 10;
animation.removedOnCompletion = NO;
animation.fromValue = #(0);
animation.toValue = #(1);
animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
[circle addAnimation:animation forKey:#"drawCircleAnimation"];
[_colouredCircle.layer.sublayers makeObjectsPerformSelector:#selector(removeFromSuperlayer)];
[_colouredCircle.layer addSublayer:circle];
That means that your toValue should match your percentage.
In your case, animation.toValue = #(0.56); would end the stroke at 56% of the circle (0...1 range).
See this answer for information about keeping the final animated value after completion.
TLDR: You have to also update the model layer.
circle.strokeStart = 0;
circle.strokeEnd = 0.56; // Your target value
...
// Your animation
Check out this circular progress bar and set colour as you want to set at particular position.
I am trying to animate the the appearance and then the disappearance of a UIBezierPath in a CAShapeLayer.
How I would like to do it is that at start, the path would be invisible by setting strokeStart and strokeEnd to 0. Then, in my animate method I would do a CABasicAnimation with setting the strokeEnd to 1, and after this is done, another animation where I set the strokeStart to 1, so the path would disappear again. Here is what I've tried:
- (void)animate
{
CAShapeLayer *layer = (CAShapeLayer *)self.layer;
CABasicAnimation *appearingAnimation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
appearingAnimation.duration = _duration / 2.0;
appearingAnimation.fromValue = #0;
appearingAnimation.toValue = #1;
CABasicAnimation *disappearingAnimation = [CABasicAnimation animationWithKeyPath:#"strokeStart"];
disappearingAnimation.beginTime = _duration / 2.0;
disappearingAnimation.duration = _duration / 2.0;
disappearingAnimation.fromValue = #0;
disappearingAnimation.toValue = #1;
CAAnimationGroup *animationGroup = [CAAnimationGroup animation];
animationGroup.duration = _duration;
animationGroup.animations = #[appearingAnimation, disappearingAnimation];
animationGroup.repeatCount = MAXFLOAT;
[layer addAnimation:animationGroup forKey:#"test"];
}
But the effect I am seeing is that the appearingAnimation is working properly, but as soon as it is done, the path instantly disappears without any animation. After this (_duration/2.0 time later) the whole thing starts over, so it would appear that the disappearingAnimation has no effect.
I tried another approach, but that only worked if the path was on my view.layer. As soon as I added it to a sublayer and tried to animate that one, the second (disappearing) animation had a glitch in it. Here is my second approach:
- (void)animate
{
CAShapeLayer *layer = (CAShapeLayer *)self.layer;
layer.strokeStart = 0;
layer.strokeEnd = 1;
[CATransaction begin];
[CATransaction setCompletionBlock:^{
layer.strokeStart = 1;
layer.strokeEnd = 1;
[CATransaction begin];
[CATransaction setCompletionBlock:^{
[self animate];
}];
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"strokeStart"];
animation.duration = _duration / 2.0;
animation.fromValue = [NSNumber numberWithDouble:0];
animation.toValue = [NSNumber numberWithDouble:1];
[layer addAnimation:animation forKey:#"animation1"];
[CATransaction commit];
}];
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
animation.duration = _duration / 2.0;
animation.fromValue = [NSNumber numberWithDouble:0];
animation.toValue = [NSNumber numberWithDouble:1];
[layer addAnimation:animation forKey:#"animation"];
[CATransaction commit];
}
Any idea why the first solution doesn't work at all, or why the second is only working properly on the view.layer and not on a sublayer?
When animating a layer property, you will want to set the layer property to the end value before adding the animation, as the animation changes are only applied to the presentation, not the model layer. Once the animation is completed it will be removed, leaving the layer in the state it was before.
Both the first and second methods you have outlined worked for me once a layer had been created (missing from your snippet):
- (void)animate
{
CAShapeLayer *layer = [CAShapeLayer layer];
CGFloat _duration = 2.0;
CGFloat radius = self.view.frame.size.width/2.0;
CGFloat startAngle = -(M_PI_2);
CGFloat endAngle = (3*M_PI_2);
CGPoint center = CGPointMake(self.view.frame.size.width/2.0, self.view.frame.size.height/2.0);
layer.path = [[UIBezierPath bezierPathWithArcCenter:center
radius:radius
startAngle:startAngle
endAngle:endAngle
clockwise:YES] CGPath];
layer.fillColor = [[UIColor clearColor] CGColor];
layer.strokeColor = [[UIColor blackColor] CGColor];
[self.view.layer addSublayer:layer];
... {animation code}
}
I think it is the problem of the value of _duration / 2.0. It may be the problem of floating number calculation.
Try not to halve the total duration but to make the durations of appearingAnimation and disappearingAnimation as the base duration:
#define DURATION_BASE 1
// You can choose the DURATION_BASE value whaterver you like
- (void)animate
{
CAShapeLayer *layer = (CAShapeLayer *)self.layer;
CABasicAnimation *appearingAnimation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
appearingAnimation.duration = DURATION_BASE;
appearingAnimation.fromValue = #0;
appearingAnimation.toValue = #1;
CABasicAnimation *disappearingAnimation = [CABasicAnimation animationWithKeyPath:#"strokeStart"];
disappearingAnimation.beginTime = appearingAnimation.duration;
disappearingAnimation.duration = DURATION_BASE;
disappearingAnimation.fromValue = #0;
disappearingAnimation.toValue = #1;
CAAnimationGroup *animationGroup = [CAAnimationGroup animation];
animationGroup.duration = appearingAnimation.duration+disappearingAnimation.duration;
animationGroup.animations = #[appearingAnimation, disappearingAnimation];
animationGroup.repeatCount = MAXFLOAT;
[layer addAnimation:animationGroup forKey:#"test"];
}
When you want to change durations of appearingAnimation and disappearingAnimation, you just need modify the code like
appearingAnimation.duration = DURATION_BASE*1.2;
disappearingAnimation.duration = DURATION_BASE*1.2;
with Xcode for iOS, I have animated a drawn line.
I wish to delete it (or fade away) almost immediately.
I have tried to repeat the code with the colour set to clear (red for the tests) as my background is a grid pattern. But I only get the last colour line drawn.
Any ideas on drawing the lines in sequence one after each other?
{
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(0.0,100.0)];
[path addLineToPoint:CGPointMake(150.0, 100.0)];
[path addLineToPoint:CGPointMake(155.0, 50.0)];
[path addLineToPoint:CGPointMake(160.0, 150.0)];
[path addLineToPoint:CGPointMake(165.0, 100.0)];
[path addLineToPoint:CGPointMake(350.0, 100.0)];
CAShapeLayer *pathLayer = [CAShapeLayer layer];
pathLayer.frame = self.view.bounds;
pathLayer.path = path.CGPath;
pathLayer.strokeColor = [[UIColor greenColor] CGColor];
pathLayer.fillColor = nil;
pathLayer.lineWidth = 2.0f;
pathLayer.lineJoin = kCALineJoinBevel;
[self.view.layer addSublayer:pathLayer];
CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
pathAnimation.duration = 1.0;
pathAnimation.fromValue = [NSNumber numberWithFloat:0.0f];
pathAnimation.toValue = [NSNumber numberWithFloat:1.0f];
[pathLayer addAnimation:pathAnimation forKey:#"strokeEnd"];
}
Thanks
Add:
pathAnimation.autoreverses = true;
pathAnimation.removedOnCompletion = false;
pathAnimation.fillMode = kCAFillModeForwards;
You'll also probably want to use the animation delegate functions to remove the layer on completion.
Alternatively, if you want a delay (even slight) before the animation reverses, or want to fade it out in a different manner than reversing the animation, you can use a CAAnimationGroup to execute a series of animations on the same timeline.
Thanks for all the help.
I managed to find and successfully use code from the "Core Animation" Apple documentation. This is the first time I've managed that. Sorry for being slow, learning all the time. I had to replace "titleLayer" with "pathLayer". I'm sure that would have helped some of the suggestions.
Thanks again.
Here's my working code. Added after the code I posted above, before the last curly bracket.
CABasicAnimation* fadeAnim = [CABasicAnimation animationWithKeyPath:#"opacity"];
fadeAnim.fromValue = [NSNumber numberWithFloat:1.0];
fadeAnim.toValue = [NSNumber numberWithFloat:0.0];
fadeAnim.duration = 1.5;
[pathLayer addAnimation:fadeAnim forKey:#"opacity"];
// Change the actual data value in the layer to the final value.
pathLayer.opacity = 0.0;
there are a lot of examples how to animate along a UIBezierPath. But i can't figure it out, how to animate only the appendPath of an UIBezierPath.
In my case i have the following example:
// Create path from view controller
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:
CGRectMake(0, 0, tutorialController.bounds.size.width,
tutorialController.bounds.size.height) cornerRadius:0];
// Create circle path
UIBezierPath *circlePath = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(x, y, 2.0*radius, 2.0*radius) cornerRadius:radius];
[path appendPath:circlePath];
[path setUsesEvenOddFillRule:YES];
// Create spot layer
spotLayer = [CAShapeLayer layer];
spotLayer.path = path.CGPath;
spotLayer.fillRule = kCAFillRuleEvenOdd;
spotLayer.fillColor = [UIColor blackColor].CGColor;
spotLayer.opacity = 0.90;
So basically its a circle inside a rect and i now want to animate only the circle. In all attempts the rect was also moved.
Here is my example, how i can animate "along" a path
CGPoint pathStart = CGPointMake(96.000000, 226.000000);
CGPoint pathEnd = CGPointMake(120.000000, 300.000000);
[circlePath moveToPoint:pathStart];
[circlePath addLineToPoint:pathEnd];
CAKeyframeAnimation *anim = [CAKeyframeAnimation animationWithKeyPath:#"position"];
anim.path = circlePath.CGPath;
anim.duration = 5.0;
anim.calculationMode = kCAAnimationPaced;
[spotLayer addAnimation:anim forKey:#"bezierPathAnim"];
But that is not what i want...
What i want to do is, to move my circle path (which is an appended path of a rectangle path) via animation
Does anybody has some ideas?
Regards
I solved my Problem :-)
Here is the solution...
// If there is an old path animate to the new path
if(oldPath != nil){
CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:#"path"];
[anim setFromValue:(__bridge id)oldPath];
[anim setToValue:(__bridge id)[path CGPath]];
[anim setDuration:0.3];
[anim setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut]];
[spotLayer addAnimation:anim forKey:#"path"];
}
First of all i kept the oldPath (starting point) and then animate to the new setted path.
I have a CircleView : UIView class that animates (shrinks and grows) when you touch it (via the pop function). I would also like for a stroked circle to appear and grow out (like a basic water ripple) when you touch it too. (The effect I am talking about is shown here in CSS)
How do I go about doing this?
Some more information:
Ideally both animations would be controllable from the single CircleView class
CircleView inherits off UIView
Update
Based on answers I have added a new object to via a subLayer. This displays ok BUT it doesn't animate during the pop. Can anyone help me understand why?
Here is my current code (the pertinent bits anyway)
- (void)layoutSubviews
{
[self setLayerProperties];
}
- (void)setLayerProperties {
//The view’s Core Animation layer used for rendering.
CAShapeLayer *layer = (CAShapeLayer *)self.layer;
UIBezierPath *bezierPath = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)
byRoundingCorners:UIRectCornerAllCorners
cornerRadii:self.frame.size];
layer.path = bezierPath.CGPath;
layer.fillColor = _Color.CGColor;
rippleLayer = [[CALayer alloc] init];
layer.path = bezierPath.CGPath;
layer.strokeColor = [UIColor blueColor].CGColor;
[layer addSublayer:rippleLayer];
}
// Does the animated "pop"
- (void)pop{
CABasicAnimation *animation = [self animationWithKeyPath:#"transform.scale"];
[animation setFromValue:[NSNumber numberWithFloat:1.0f]];
[animation setToValue:[NSNumber numberWithFloat:0.8f]];
[animation setRemovedOnCompletion:YES];
[animation setDuration:0.15];
[animation setAutoreverses:YES];
[self.layer addAnimation:animation forKey:animation.keyPath];
rippleLayer.anchorPoint = CGPointMake(1, 1);
CABasicAnimation *scale = [CABasicAnimation animationWithKeyPath:#"transform.scale"];
[scale setFromValue:[NSNumber numberWithFloat:1.0f]];
[scale setToValue:[NSNumber numberWithFloat:2.0f]];
[scale setRepeatCount:1];
[scale setDuration:1.0f];
//r[scale setRemovedOnCompletion:YES];
[scale setFillMode:kCAFillModeForwards];
[rippleLayer addAnimation:scale forKey:scale.keyPath];
}
Just add the other objects you want to animate to your layer and set their alpha to 0.0. You can then play with that value in or immediately before your animation.
I noticed that you did not follow the convention of naming variables with small initial. _color would be preferable to _Color.
Also, if you want to put the layer into its original state you usually use the identify transform matrix:
self.transform = CGAffineTransformIdentity;