I need help with core animation on iOS
I have the following view
I need to animate curve appearance from left to right. This step was achieved by animationWithKeyPath:#"strokeEnd", it works and all is fine.
Also I need to animate the gradient appearance under the curve, which goes from left to right along with the curve appearance
Here is the cut from reference video about the appearance I need to achieve
How can I achieve this?
Layers and paths I have:
(1) gradient curve line - uishapelayer
colored gradient - cagradient layer having (1) as mask
(2) closed path layer - path along the (1) curve, but with [path closePath];
gray gradient - cagradient having (2) as mask
(3) animationLayer - layer, added as [self.layer addSublayer:animationLayer]
(3) has colored gradien and gray gradient as sublayers
initWithFrame:
_animationLayer = [CALayer new];
_animationLayer.frame = frame;
_animationLayer.masksToBounds = YES;
[self.layer addSublayer:_animationLayer];
_path = [self characteristicsGraph:frame];
_pathLayer = [CAShapeLayer new];
_pathLayer.frame = frame;
_pathLayer.path = _path.CGPath;
_pathLayer.strokeColor = [color CGColor];
_pathLayer.fillColor = nil;
_pathLayer.lineWidth = lineW;
_fillPathLayer = [CAShapeLayer new];
_fillPathLayer.frame = frame;
_fillPathLayer.path = [self closePath:_path].CGPath;
_fillPathLayer.strokeColor = [color CGColor];
_fillPathLayer.fillColor = [color CGColor];
_fillPathLayer.masksToBounds = YES;
_fillGradient = [self gradient:frame];
_fillGradient.frame = frame;
_fillGradient.mask = _fillPathLayer;
_lineGradient = [self lineGradient:frame];
_lineGradient.frame = frame;
_lineGradient.mask = _pathLayer;
[_animationLayer addSublayer:_fillGradient];
[_animationLayer addSublayer:_lineGradient];
pathLayer animation (animates colored gradient appearance):
self.currentAnimation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
self.currentAnimation.fromValue = #(0);
self.currentAnimation.toValue = #(1);
self.currentAnimation.duration = .5;
[self.pathLayer addAnimation:self.currentAnimation forKey:animationKey];
Gray gradient is static, can't animate it.
Will be grateful for help
You could make a mask layer for the gradient layer - just make it a rectangle that expands as the line animates.
The other problem I noticed if you want to be 100% true to the video is that your gradient will need to be angled along the trend of the chart - notice their chart trends up, and the gradient angle matches.
Related
I am using this code to create the slide to unlock like animation but I am unable to make it animate from right to left.
How can I make it start from right and animate to left?
-(void)slideToCancel {
CALayer *maskLayer = [CALayer layer];
// Mask image ends with 0.15 opacity on both sides. Set the background color of the layer
// to the same value so the layer can extend the mask image.
maskLayer.backgroundColor = [[UIColor colorWithRed:0.0f green:0.0f blue:0.0f alpha:0.50f] CGColor];
maskLayer.contents = (id)[[UIImage imageNamed:#"slidetocancel.png"] CGImage];
// Center the mask image on twice the width of the text layer, so it starts to the left
// of the text layer and moves to its right when we translate it by width.
maskLayer.contentsGravity = kCAGravityCenter;
maskLayer.frame = CGRectMake(_slideToCancelLbl.frame.size.width * -1, 0.0f, _slideToCancelLbl.frame.size.width * 2, _slideToCancelLbl.frame.size.height);
// Animate the mask layer's horizontal position
CABasicAnimation *maskAnim = [CABasicAnimation animationWithKeyPath:#"position.x"];
maskAnim.byValue = [NSNumber numberWithFloat:_slideToCancelLbl.frame.size.width];
maskAnim.repeatCount = 1e100f;
maskAnim.duration = 1.5f;
[maskLayer addAnimation:maskAnim forKey:#"slideAnim"];
_slideToCancelLbl.layer.mask = maskLayer;
}
You should be able to simply use a negative byValue. However, the code you've posted is a canned animation, not one that responds to a slide gesture.
I'm trying to create circle animation by adding CAShapeLayers with different stroke colors:
UIView *view = [[UIButton alloc] initWithFrame:CGRectMake(100, 100, 200, 200)];
[self.view addSubview:view];
view.backgroundColor = [UIColor redColor];
[self addCircleAnimationTo:view direction:YES];
- (void)addCircleAnimationTo:(UIView *)view direction:(BOOL)direction {
CGFloat animationTime = 3;
// Set up the shape of the circle
int radius = view.frame.size.width/2;
CAShapeLayer *circle = [CAShapeLayer layer];
// Make a circular shape
circle.path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, 2.0*radius, 2.0*radius)
cornerRadius:radius].CGPath;
// Center the shape in view
circle.position = CGPointMake(radius,
radius);
circle.bounds = view.bounds;
// Configure the apperence of the circle
circle.fillColor = [UIColor clearColor].CGColor;
// switch color
circle.strokeColor = (direction) ? [UIColor blueColor].CGColor : [UIColor whiteColor].CGColor;
circle.lineWidth = 5;
circle.lineJoin = kCALineJoinBevel;
circle.strokeStart = .0;
circle.strokeEnd = 1.;
// Configure animation
CABasicAnimation *drawAnimation = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
drawAnimation.duration = animationTime;
drawAnimation.repeatCount = 1;
// Animate from no part of the stroke being drawn to the entire stroke being drawn
drawAnimation.fromValue = [NSNumber numberWithFloat:0.0f];
drawAnimation.toValue = [NSNumber numberWithFloat:1.];
// Experiment with timing to get the appearence to look the way you want
drawAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
// Add to parent layer
[view.layer addSublayer:circle];
// Add the animation to the circle
[circle addAnimation:drawAnimation forKey:#"drawCircleAnimation"];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)((animationTime-0.1) * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[self addCircleAnimationTo:view direction:!direction];
});
}
I'm wondering why I can see blue when white layer animates and how to get rid of this weird blue color border:
You know that you are adding more and more shape layers after each call to addCircleAnimationTo ?
While you animate the new layer the old shape layer reminds below the new one. That is why you see it.
[EDIT 2] SHORT EXPLANATION
We create two layers first with blue path colour, second with white path colour.
To first layer we add fill animation - change of layer.strokeEnd property, we animate it from 0 to 1 and from 1 to 1. Half of duration from 0 to 1 and half of duration from 1 to 1 (visually nothing happens, but is needed).
We add clear animation - change of layer.strokeStart, we animate it from 0 to 1. Duration of this animation is half of duration of fill animation. Begin time is also half of fill animation because we want to move beginning of stroke when end stroke is still.
We add the same animations to second, white layer but with appropriate begin time offset, thanks to that white path unwinds and blue path winds.
[EDIT] ADDED REAL ANSWER
Here is my suggestion to solve your animation problem. Hope it helps ... :)
- (void)viewDidLoad {
[super viewDidLoad];
UIView *view = [[UIButton alloc] initWithFrame:CGRectMake(100, 100, 200, 200)];
[self.view addSubview:view];
view.backgroundColor = [UIColor redColor];
self.circle1 = [self circle:view.bounds];
self.circle1.strokeColor = [UIColor blueColor].CGColor;
self.circle2 = [self circle:view.bounds];
self.circle2.strokeColor = [UIColor whiteColor].CGColor;
[view.layer addSublayer:self.circle1];
[view.layer addSublayer:self.circle2];
[self.circle1 addAnimation:[self fillClearAnimation:0] forKey:#"fillclear"];
[self.circle2 addAnimation:[self fillClearAnimation:3] forKey:#"fillclear"];
}
- (CAAnimationGroup *)fillClearAnimation:(CFTimeInterval)offset
{
CGFloat animationTime = 3;
CAAnimationGroup *group = [CAAnimationGroup animation];
CAKeyframeAnimation *fill = [CAKeyframeAnimation animationWithKeyPath:#"strokeEnd"];
fill.values = #[ #0,#1,#1];
fill.duration = 2*animationTime;
fill.beginTime = 0.f;
CAKeyframeAnimation *clear = [CAKeyframeAnimation animationWithKeyPath:#"strokeStart"];
clear.values = #[ #0, #1];
clear.beginTime = animationTime;
clear.duration = animationTime;
group.animations = #[ fill, clear ];
group.duration = 2*animationTime;
group.beginTime = CACurrentMediaTime() + offset;
group.repeatCount = FLT_MAX;
return group;
}
- (CAShapeLayer *)circle:(CGRect)frame
{
CAShapeLayer *circle = [CAShapeLayer layer];
CGFloat radius = ceil(frame.size.width/2);
// Make a circular shape
circle.path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, 2.0*radius, 2.0*radius)
cornerRadius:radius].CGPath;
// Center the shape in view
circle.position = CGPointMake(radius,
radius);
circle.frame = frame;
// Configure the apperence of the circle
circle.fillColor = [UIColor clearColor].CGColor;
circle.lineWidth = 5;
circle.lineJoin = kCALineJoinBevel;
circle.strokeStart = 0.f;
circle.strokeEnd = 0.f;
return circle;
}
The antialiasing is what's causing the problem
When the white CAShapeLayer gets drawn over the blue, the edge gets blended with the previous edge blending that the antialiasing created.
The only real solution is to clear the blue from underneath the white as you animate. You can do this by animating the strokeStart property of the previous layer from 0.0 to 1.0. You should be able to re-use your drawAnimation for this, by just changing the keyPath. For example, change your dispatch_after to:
- (void)addCircleAnimationTo:(UIView *)view direction:(BOOL)direction {
// Insert your previous animation code, where drawAnimation is defined and added to the circle layer.
drawAnimation.keyPath = #"strokeStart"; // Re-use the draw animation object, setting it to animate strokeStart now.
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)((animationTime-0.1) * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[self addCircleAnimationTo:view direction:!direction];
[circle addAnimation:drawAnimation forKey:#"(un)drawCircleAnimation"]; // Sets the previous layer to animate out
});
}
That way the antialiasing edge blending gets cleared from the blue layer, allowing the white layer to get a nice & clean antialiasing. Just don't forget to remove the layer once you've animated it out!
Another potential solution is to increase the stroke width of the white layer, so it strokes over the blue layer's edge blending, however I would imagine it would create an undesired effect. You could also disable antialiasing, but that would look horrible on the circle.
I am trying to create a circle which is filled depending upon a certain percentage. Here is pic of the effect I am going for:
I have a UIView and to this I add a CAShapeLayer which draws the circle. I am then creating another UIShapeLayer as a square to match the UIView containing the circle. Then setting the height of this depending on the figure. So if the square is 100px high and the value is 10% then I set the square to 10px so that it fills 10% of circle.
The image below shows 50% of the circle being filled. As you can see it covers the UIView as well as the circle. However when I try to set the CAShapeLayer to mask to bounds ( circle.maskToBounds) the circle complete disappears along with the square that I am adding as it's subview.
Here is my code:
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 200, 200)];
[self drawCircleInView:view];
[self.view addSubview:view];
}
- (void)drawCircleInView:(UIView *)v
{
// Set up the shape of the circle
int radius = v.frame.size.height / 2;
CAShapeLayer *circle = [CAShapeLayer layer];
// Make a circular shape
circle.path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, 2*radius, 2*radius)
cornerRadius:radius].CGPath;
// Center the shape in self.view
circle.position = CGPointMake(CGRectGetMidX(v.bounds)-radius,
CGRectGetMidY(v.bounds)-radius);
// Configure the apperence of the circle
circle.fillColor = [UIColor blueColor].CGColor;
circle.strokeColor = [UIColor clearColor].CGColor;
circle.lineWidth = 5;
circle.masksToBounds = YES; // HERE IS THE LINE OF CODE THAT MAKES THE CIRCLE DISAPPEAR
CAShapeLayer *sublayer = [CAShapeLayer layer];
sublayer.backgroundColor = [UIColor orangeColor].CGColor;
sublayer.opacity = .5f;
sublayer.frame = CGRectMake(0, 100, 200, 100);
[circle addSublayer:sublayer];
// Add to parent layer
[v.layer addSublayer:circle];
}
I am wondering why setting circle.masksToBounds = YES is making the circle and the sublayer disappear completely. My understanding is that by setting this it should only show the sublayer over the circle.
Many thanks in advance.
Try this:
- (void)drawCircleInView:(UIView *)v {
// Set up the shape of the circle
CGSize size = v.bounds.size;
CALayer *layer = [CALayer layer];
layer.frame = v.bounds;
layer.backgroundColor = [UIColor blueColor].CGColor;
CALayer *sublayer = [CALayer layer];
sublayer.frame = CGRectMake(0, size.height/2, size.width, size.height/2);
sublayer.backgroundColor = [UIColor orangeColor].CGColor;
sublayer.opacity = .5f;
CAShapeLayer *mask = [CAShapeLayer layer];
mask.frame = v.bounds;
mask.path = [UIBezierPath bezierPathWithOvalInRect:v.bounds].CGPath;
mask.fillColor = [UIColor blackColor].CGColor;
mask.strokeColor = [UIColor clearColor].CGColor;
[layer addSublayer:sublayer];
[layer setMask:mask];
// Add to parent layer
[v.layer addSublayer:layer];
}
maskToBounds is "to bounds" you are not setting bounds nor frame.
It's not necessary, but you'd better to set frame of CAShapeLayer, to prevent unnecessary confusion.
bounds is rectangle, not CAShapeLayer's shape. Use mask layer to mask by shape instead.
circle and sublayer is not need to be CAShapeLayer because it will be masked by shaped mask layer.
To achieve this use a square image with its center circle as transparent. like this image
How to use this image for this effect -
Add a square layer (with lighter color/ or non fill color) first. above that add a layer with the fill color with sane rect. and above all place this image. and change the frame of middle layer that has the fill color to achieve desired effect
I have a CABasicAnimation that creates an iris wipe effect on an image. In short, the animation works fine on the simulator but there is no joy on device. The timers still fire correctly and the animationCompleted block gets called however there is no visible animation.
Here is the code to get the iris wipe working:
- (void)irisWipe
{
animationCompletionBlock theBlock;
_resultsImage.hidden = FALSE;//Show the image view
[_resultsImage setImage:[UIImage imageNamed:#"logoNoBoarder"]];
[_resultsImage setBackgroundColor:[UIColor clearColor]];
[_resultsImage setFrame:_imageView.bounds];
//Create a shape layer that we will use as a mask for the waretoLogoLarge image view
CAShapeLayer *maskLayer = [CAShapeLayer layer];
CGFloat maskHeight = _resultsImage.layer.bounds.size.height;
CGFloat maskWidth = _resultsImage.layer.bounds.size.width;
CGPoint centerPoint;
centerPoint = CGPointMake( maskWidth/2, maskHeight/2);
//Make the radius of our arc large enough to reach into the corners of the image view.
CGFloat radius = sqrtf(maskWidth * maskWidth + maskHeight * maskHeight)/2;
// CGFloat radius = MIN(maskWidth, maskHeight)/2;
//Don't fill the path, but stroke it in black.
maskLayer.fillColor = [[UIColor clearColor] CGColor];
maskLayer.strokeColor = [[UIColor blackColor] CGColor];
maskLayer.lineWidth = radius; //Make the line thick enough to completely fill the circle we're drawing
// maskLayer.lineWidth = 10; //Make the line thick enough to completely fill the circle we're drawing
CGMutablePathRef arcPath = CGPathCreateMutable();
//Move to the starting point of the arc so there is no initial line connecting to the arc
CGPathMoveToPoint(arcPath, nil, centerPoint.x, centerPoint.y-radius/2);
//Create an arc at 1/2 our circle radius, with a line thickess of the full circle radius
CGPathAddArc(arcPath,
nil,
centerPoint.x,
centerPoint.y,
radius/2,
3*M_PI/2,
-M_PI/2,
NO);
maskLayer.path = arcPath;
//Start with an empty mask path (draw 0% of the arc)
maskLayer.strokeEnd = 1.0;
CFRelease(arcPath);
//Install the mask layer into out image view's layer.
_resultsImage.layer.mask = maskLayer;
//Set our mask layer's frame to the parent layer's bounds.
_resultsImage.layer.mask.frame = _resultsImage.layer.bounds;
//Create an animation that increases the stroke length to 1, then reverses it back to zero.
CABasicAnimation *swipe = [CABasicAnimation animationWithKeyPath:#"strokeEnd"];
swipe.duration = 1;
swipe.delegate = self;
[swipe setValue: theBlock forKey: kAnimationCompletionBlock];
swipe.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
swipe.fillMode = kCAFillModeForwards;
swipe.removedOnCompletion = NO;
swipe.autoreverses = NO;
swipe.toValue = [NSNumber numberWithFloat: 0];
//Set up a completion block that will be called once the animation is completed.
theBlock = ^void(void)
{
NSLog(#"completed");
};
[swipe setValue: theBlock forKey: kAnimationCompletionBlock];
// doingMaskAnimation = TRUE;
[maskLayer addAnimation: swipe forKey: #"strokeEnd"];
}
Is there something in iOS7 I should be aware of when working with CAAnimations etc? OR is there a error in the code?
Note this code was sourced from: How do you achieve a "clock wipe"/ radial wipe effect in iOS?
I think the problem (or at least part of it) may be this line:
[_resultsImage setFrame:_imageView.bounds];
That should read
[_resultsImage setBounds:_imageView.bounds];
Instead. If you set the FRAME to the bounds of the image view, you're going to move the image view to 0.0 in its superview.
I'm also not clear what _imageView is, as opposed to _resultsImage.
I would step through your code in the debugger, looking at the frame rectangles that are being set for the image view and mask layer, and all the other values that are calculated.
Goal:
I am drawing a custom shape that has a gradient. I also want to animate the drawing of this shape by having it draw in from left to right.
Problem:
The code below works on an iPad simulator, but it doesn't work on my iPad 4 running iOS 7. Does anyone know how to make this work on the device? Is there a different way to achieve this same result?
Explanation of my Code:
My code works (only on simulator) using 3 CALayers.
gradientLayer holds my gradient.
shapeMaskLayer holds my custom shape.
animationMaskLayer animates it's path to simulate drawing from left to right
animationMaskLayer --masks--> shapeMaskLayer --masks--> gradientLayer
I then animate the frame of animationMaskLayer to animate the whole shape.
Code:
// Animation Mask Rects
CGPathRef leftStartingRectPath = CGPathCreateWithRect(CGRectMake(0, 0, 0, self.frame.size.height), 0);
CGPathRef fullViewRectPath = CGPathCreateWithRect(CGRectMake(0, 0, self.frame.size.width, self.frame.size.height), 0);
// Animation Mask Layer
CAShapeLayer *animationMaskLayer = [CAShapeLayer layer];
animationMaskLayer.path = fullViewRectPath;
animationMaskLayer.fillColor = UIColor.blackColor.CGColor;
// Shape Mask Layer
CAShapeLayer *shapeMaskLayer = [CAShapeLayer layer];
shapeMaskLayer.path = CGPathCreateWithEllipseInRect(self.bounds, 0);
shapeMaskLayer.fillColor = [UIColor blueColor].CGColor;
shapeMaskLayer.mask = animationMaskLayer;
// Gradient Layer
CAGradientLayer *gradientLayer = [CAGradientLayer layer];
gradientLayer.frame = self.bounds;
gradientLayer.colors = self.colors;
gradientLayer.mask = shapeMaskLayer;
mountainLayer.anchorPoint = pt(0, 0);
mountainLayer.position = pt(0, 0);
[self.layer addSublayer:gradientLayer];
// Left To Right Animation
CABasicAnimation *leftToRightAnimation = [CABasicAnimation animationWithKeyPath:#"path"];
leftToRightAnimation.duration = 0.5;
leftToRightAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
leftToRightAnimation.fromValue = (__bridge id)leftStartingRectPath;
leftToRightAnimation.toValue = (__bridge id)fullViewRectPath;
leftToRightAnimation.fillMode = kCAFillModeForwards;
leftToRightAnimation.removedOnCompletion = NO;
[animationMaskLayer addAnimation:leftToRightAnimation forKey:#"animatePath"];
// Memory Management
CGPathRelease(leftStartingRectPath);
CGPathRelease(fullViewRectPath);
Animating the mask of a mask? I'm surprised that even works in the simulator.
Have you tried nesting two layers, with the parent layer with masksToBounds on? You can then set an independent mask on both layers, and the outer layer will effectively mask your inner layer with its own mask (due to masksToBounds). It probably doesn't matter which layer gets which mask (because you want the intersection of both masks).
With the code you listed in your question, you would just need to add one line, and comment out one line to get the correct functionality:
self.layer.mask = animationMaskLayer;
// shapeMaskLayer.mask = animationMaskLayer;