Keeping CAShapeLayer Mask Static During Animation - ios

I'm trying to rotate a UIImageView within a circular mask (which is set with myImageView.layer.mask). The problem is that any time I attempt to rotate said UIImageView, the mask rotates with it. Here is some code.
Setting up the mask:
UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:CGPointMake(0, - 169)
radius:191
startAngle:0.0
endAngle:2*M_PI
clockwise:YES];
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
[shapeLayer setFrame:myImageView.bounds];
[shapeLayer setPath:[path CGPath]];
myImageView.layer.mask = shapeLayer;
Animation:
[UIView animateWithDuration:kRotationTime animations:^(void){
myImageView.transform = CGAffineTransformMakeRotation(angle);
}];
And that's basically all there is to it. A UIImageView rotating about its own center within a fixed-position circular mask--that's the desired effect. Perhaps there is another way to structure the view hierarchy so that myImageView and the mask are siblings, but I haven't had luck going that route.

Put the image view into an additional plain UIView superview. Set the layer mask on the superview. Animate the image view.

Related

How to curve UIVew only top corner and not whole view in Objective C?

I am new in iOS and I am facing problem regarding to curve UIView. I want to curve the radius of the top of UIView like this in the Image
As you can see the screenshot of my work view.
I am using code like this
UIBezierPath *maskPath = [UIBezierPath
bezierPathWithRoundedRect:ViewSwapMyWork.bounds
byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerTopRight)
cornerRadii:CGSizeMake(70, 70)
];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = ViewSwapMyWork.bounds;
maskLayer.path = maskPath.CGPath;
ViewSwapMyWork.layer.mask = maskLayer;
First your view should have the same height and width means it should be square, then you can do like this,
[ViewSwapMyWork.layer setCornerRadius:ViewSwapMyWork.frame.size.width/2];
[ViewSwapMyWork.layer setMasksToBounds:YES];

Rounded Corners only for the bottoms edges of UITableView

I'm using the below code to make rounded corners only for the bottom edges of tableView
CALayer *capa = self.patientTableView.layer;
//Round
CGRect bounds = capa.bounds;
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:bounds
byRoundingCorners:(UIRectCornerBottomLeft | UIRectCornerBottomRight)
cornerRadii:CGSizeMake(10.0, 10.0)];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = bounds;
maskLayer.path = maskPath.CGPath;
[capa addSublayer:maskLayer];
capa.mask = maskLayer;
This code works fine, but the tableview is not showing up the contents below its frame height (but it scrolls to its offset.y).
You can fix this by putting the table view inside a UIView, and then apply the mask to that container view. That way the mask will not move with the contentOffset of the table view.

How to remove black edge on UIImageView with rounded corners and a border width?

I have the following code to make the UIImageView in each of my UITableView's cells have rounded corners:
- (void)awakeFromNib
{
// Rounded corners.
[[cellImage layer] setCornerRadius:([cellImage frame].size.height / 2)];
[[cellImage layer] setMasksToBounds:YES];
[[cellImage layer] setBorderColor:[[UIColor whiteColor] CGColor]];
[[cellImage layer] setBorderWidth:3]; // Trouble!
}
I want the images to have a bit of a gap between them, and figured I could make use of the border width to make that happen. Below is an image of what actually happened:
It's that faint black border that I want to know how to get rid of. I'd like to think there's a way of doing it using border width. If not, the best approach might be just to resize the image itself and just set the border width to be 0.
Rather than using corner radius, you can create bezier path for the mask, create a shape layer for that path, and then specify that shape layer for the image view's layer's mask:
CGFloat margin = 3.0;
CGRect rect = CGRectInset(imageView.bounds, margin, margin);
UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:CGPointMake(imageView.bounds.size.width/2, imageView.bounds.size.height/2) radius:radius startAngle:0 endAngle:M_PI*2 clockwise:NO];
CAShapeLayer *mask = [CAShapeLayer layer];
mask.path = path.CGPath;
imageView.layer.mask = mask;
What you are doing is, you are clipping the profile image and the border together, which is making the cell's profile image extending through the border.
You are missing this line:-
cellImage.clipsToBounds = YES;

Setting mask layer on UITableViewCell's subview overrides Auto Layout constraints

I have a UITableViewCell with multiple subviews. One of the subviews is a UILabel and the cell's height is dynamically sized based on the amount of text in the UILabel. This works perfectly.
I have another subview in the cell that has constraints as well. This subview is always supposed to have the exact same height as the cell. This works perfectly as well.
However, I run into problems when trying to set a mask layer on that subview. The mask layer works correctly, but then the subview's height is wrong and it is not the same height as the cell.
Here is my mask layer code:
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:self.mySubview.bounds
byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerTopRight | UIRectCornerBottomLeft | UIRectCornerBottomRight)
cornerRadii:CGSizeMake(10, 10)];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = self.mySubview.bounds;
maskLayer.path = maskPath.CGPath;
self.mySubview.layer.mask = maskLayer;
I have been doing research and trying to find a way to fix this so I can both set the mask layer and have the subview have it's correct height but I haven't been able to get it to work.
I have seen this solution recommended several times now:
[self setNeedLayout];
[self layoutIfNeeded];
// Customize cell after here
But this doesn't work for me either. Is there a way for me to know when the Auto Layout constraints have been applied so that I can then apply the mask layer afterwards?
The mask layer code is really simple, it uses the bounds of the subview, and the bounds are off because it's using the bounds that exist before the constraints have been applied and the subview has the correct height. At least I think I'm understanding that correctly.
I finally got it. I'm not sure if this is the correct place to put this or if it might cause performance problems, but so far it works perfectly:
- (void)drawRect:(CGRect)rect
{
[super drawRect:rect];
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:self.mySubview.bounds
byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerTopRight | UIRectCornerBottomLeft | UIRectCornerBottomRight)
cornerRadii:CGSizeMake(10, 10)];
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = self.mySubview.bounds;
maskLayer.path = maskPath.CGPath;
self.mySubview.layer.mask = maskLayer;
}
I had to override drawRect: in my UITableViewCell subclass and set the mask layer there.
I have had same problem and doing things in - (void)drawRect:(CGRect)rect does the work but it could be costly in terms of performance.
You can call your clipping or shadow methods in perform selector
[self performSelector:#selector(<your drawing method>) withObject:nil afterDelay:0.0000001 ];//a very low delay

Round some corners of UIView and round the view’s layer’s border too

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]];

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