I have a collection of CALayers. Each layer is a sublayer of the same parent CALayer, and each has a shadow applied to it. The layers are positioned dynamically, and there are many of them, so I can't predict how they'll be arranged ahead of time.
If the layers are adjacent to each other (close enough that they are almost touching) the shadow of one of the CALayers is rendered on top of the other CALayer. That's probably the desired effect in most cases, but I want my layers to exist in the same z-plane. (An example of this is the way CSS3 shadows are applied to block elements in web design.)
Is this possible? How can I achieve this?
(I had this idea: Adding a 'shadow' sublayer to each CALayer with my own shadow image, and setting the z-position to a lower value. But doesn't the layer-tree make this impossible? Z-positions in one layer's coordinate system are independent from z-positions in another layer's coordinate system, right?)
If all of the shadowed layers have the same shadow settings, put them into a container layer and set the shadow on the container layer. Example:
- (void)viewDidLoad
{
[super viewDidLoad];
CALayer *containerLayer = [CALayer layer];
containerLayer.frame = self.view.bounds;
containerLayer.shadowRadius = 10;
containerLayer.shadowOpacity = 1;
[self.view.layer addSublayer:containerLayer];
CAShapeLayer *layer1 = [CAShapeLayer layer];
layer1.bounds = CGRectMake(0, 0, 200, 200);
layer1.position = CGPointMake(130, 130);
layer1.path = [UIBezierPath bezierPathWithOvalInRect:layer1.bounds].CGPath;
layer1.fillColor = [UIColor redColor].CGColor;
[containerLayer addSublayer:layer1];
CAShapeLayer *layer2 = [CAShapeLayer layer];
layer2.bounds = CGRectMake(0, 0, 200, 200);
layer2.position = CGPointMake(170, 200);
layer2.path = [UIBezierPath bezierPathWithOvalInRect:layer2.bounds].CGPath;
layer2.fillColor = [UIColor blueColor].CGColor;
[containerLayer addSublayer:layer2];
}
Output:
Related
I'm using this code to add a layer to a custom UIView and it works like a charm:
CGRect newrect = CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.height);
CALayer* heartBackground = [CALayer layer];
heartBackground.contents = (__bridge id)([UIImage imageNamed:#"5HeartsGray"].CGImage);
heartBackground.frame = newrect;
[self.layer addSublayer:heartBackground];
But when I tried to use it in draw method using Quartz using a new Rect(like this)
CGContextSaveGState(context);
CGRect ratingRect = CGRectMake(250, 100, 150, 20);
CALayer* heartBackground = [CALayer layer];
heartBackground.contents = (__bridge id)([UIImage imageNamed:#"5HeartsGray"].CGImage);
heartBackground.frame = ratingRect;
[heartBackground renderInContext:context];
CGContextRestoreGState(context);
It renders in the beginning of the frame and not inside of ratingRect.
If I call [heartBackground setNeedsDisplay] it disappear. The same thing with heartBackground.masksToBounds = YES
What I'm doing wrong. Do I need To switch to CGLayer because I'm using CoreGraphics?
This is the output when working with CoreGraphics (as you see the hearts starts at coordinates x=0, y=0 and normally it starts at x=250, y=100):
It doesn't make sense to create and draw a CALayer inside draw function of a UIView. CALayer is an independently drawable unit and it draws itself on its parentLayer's context by default. Which means if you really want to use separate CALayers try adding as many subLayers to self.layer (inside a UIView) as you want, set their frames and they'll get drawn when their container view shows up. Regarding your problem, here's what you can try.
Option 1: Take this code
CGRect ratingRect = CGRectMake(250, 100, 150, 20);
CALayer* heartBackground = [CALayer layer];
heartBackground.contents = (__bridge id)([UIImage imageNamed:#"5HeartsGray"].CGImage);
heartBackground.frame = ratingRect;
[self.layer addSubLayer:heartBackground];
Out of the drawRect: method and write it in initWithFrame: and in drawRect simply do [heartBackground renderInContext:UIGraphicsGetCurrentContext];
Option 2: Draw your hearts without a CALayer.
CGRect ratingRect = CGRectMake(250, 100, 150, 20);
[[UIImage imageNamed:#"5HeartsGray"] drawInRect:ratingRect];
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
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;
I would like the move a layer by setting its frame, but without the layer clip being moved as well.
I have created a layer which is created as follows:
layer = [CustomLayer layer];
layer.frame = CGRectMake(50, 50, 100, 30);
[layer setNeedsDisplay];
[self.view.layer addSublayer:layer];
And a clip layer like so:
clipLayer = [CAShapeLayer layer];
UIBezierPath *clipPath = [UIBezierPath bezierPathWithRoundedRect:layer.bounds
cornerRadius:10.0f];
clipLayer.path = clipPath.CGPath;
layer.mask = clipLayer;
However, at some later point in my code, if I set the layer frame:
layer.frame = CGRectOffset(layer.frame, -20.0, 0.0);
Both the layer and its clip mask are offset. The effect I am trying to achieve is to 'scroll' a layer beneath a rounded rectangular clipping area. Any ideas?
I would clip the clip layer to a third layer.This third layer needs to:
be of the same size of the layer you want to mask
be at the same position of the layer you want to mask
have clearColor background color
then just move the underlying layer and third layer with its clipped layer will stay put.
NOTE: This worked for me - although, you also have to ensure that the layer being moved is a subview of the clipping layer.
I am trying to round the bottom two corners of a UIView, and have the layer’s border show up rounded as well. I am currently doing:
UIRectCorners corners = UIRectCornerBottomLeft | UIRectCornerBottomRight;
CGSize radii = CGSizeMake(kThisViewCornerRadius, kThisViewCornerRadius);
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:myView.bounds
byRoundingCorners:corners
cornerRadii:radii];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
[maskLayer setPath:path.CGPath];
myView.layer.mask = maskLayer;
This works fine for normal views. However, myView’s layer has its borderColor and borderWidth set, and as you can see from the screenshot, the layer’s border is not getting rounded:
I also tried subclassing UIView and returning [CAShapeLayer layer] from +[Class layerClass], and setting up the view’s layer as a shape layer, but the border ended up beneath the view’s subviews.
Is it possible to round some of a view’s corners, round the view’s layer’s border, and clip the subviews underneath the layer’s border?
Note that this is not about how to round some corners and not others, but rather how to get the stroke to behave correctly.
I figured out a new way of thinking about it, thanks to David Rönnqvist’s comment.
I was trying to do the corner rounding and the stroke all in one layer. Instead, I broke it up into two layers: one to mask the view’s layer to round the corners, and the other in a view to add the stroke.
UIView *containerView = [[UIView alloc] initWithFrame:someFrame];
UIRectCorners corners = UIRectCornerBottomLeft | UIRectCornerBottomRight;
CGSize radii = CGSizeMake(kThisViewCornerRadius, kThisViewCornerRadius);
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:myView.bounds
byRoundingCorners:corners
cornerRadii:radii];
// Mask the container view’s layer to round the corners.
CAShapeLayer *cornerMaskLayer = [CAShapeLayer layer];
[cornerMaskLayer setPath:path.CGPath];
containerView.layer.mask = cornerMaskLayer;
// Make a transparent, stroked layer which will dispay the stroke.
CAShapeLayer *strokeLayer = [CAShapeLayer layer];
strokeLayer.path = path.CGPath;
strokeLayer.fillColor = [UIColor clearColor].CGColor;
strokeLayer.strokeColor = [UIColor redColor].CGColor;
strokeLayer.lineWidth = 2; // the stroke splits the width evenly inside and outside,
// but the outside part will be clipped by the containerView’s mask.
// Transparent view that will contain the stroke layer
UIView *strokeView = [[UIView alloc] initWithFrame:containerView.bounds];
strokeView.userInteractionEnabled = NO; // in case your container view contains controls
[strokeView.layer addSublayer:strokeLayer];
// configure and add any subviews to the container view
// stroke view goes in last, above all the subviews
[containerView addSubview:strokeView];
Zev Eisenberg's answer is the right one.
Although I prefer:
[self.layer addSublayer:strokeLayer];
instead of creating and adding a subview:
CGSize radii = CGSizeMake(radius, radius);
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:self.bounds
byRoundingCorners:corners
cornerRadii:radii];
// Mask the container view’s layer to round the corners.
CAShapeLayer *cornerMaskLayer = [CAShapeLayer layer];
[cornerMaskLayer setPath:path.CGPath];
self.layer.mask = cornerMaskLayer;
// Make a transparent, stroked layer which will dispay the stroke.
CAShapeLayer *strokeLayer = [CAShapeLayer layer];
strokeLayer.path = path.CGPath;
strokeLayer.fillColor = [UIColor clearColor].CGColor;
strokeLayer.strokeColor = color.CGColor;
strokeLayer.lineWidth = 2; // the stroke splits the width evenly inside and outside,
// but the outside part will be clipped by the containerView’s mask.
[self.layer addSublayer:strokeLayer];
Here is the small code. Alloc init a view and send to this method to get corners rounded. You can optionally round any of the corners u want. Also give shadow stroke color.
-(void) setMaskTo:(UIView*)view byRoundingCorners:(UIRectCorner)corners withColor: (UIColor*) color
{
UIBezierPath* rounded = [UIBezierPath bezierPathWithRoundedRect:view.bounds byRoundingCorners:corners cornerRadii:CGSizeMake(9.0, 9.0)];
CAShapeLayer* shape = [[[CAShapeLayer alloc] init] autorelease];
[shape setPath:rounded.CGPath];
shape.strokeColor = [[UIColor grayColor] CGColor];
view.backgroundColor=color;
view.layer.mask = shape;
}
Call the method like this.
[self setMaskTo:ABCView byRoundingCorners:UIRectCornerAllCorners withColor:[UIColor greenColor]];