class AttributedView: UIView {
private let gradient = CAGradientLayer()
var cornerRadius: CGFloat = 3 {
didSet {
layer.cornerRadius = cornerRadius
}
}
}
I simply use it for both: button view (corner radius: 20) and background circle (corner radius: 600).
Why button is smooth, and background is not?
With iOS 13.0 you can simple do, in addition to setting corner radius
yourView.layer.cornerCurve = .continuous
You should use bezzier paths and draw circle. After that you will receive nice, smooth edges.
let context = UIGraphicsGetCurrentContext()!
let gradient = CGGradient(colorsSpace: nil, colors: [UIColor.red.cgColor, UIColor.white.cgColor] as CFArray, locations: [0, 1])!
let ovalPath = UIBezierPath(ovalIn: CGRect(x: 64, y: 9, width: 111, height: 93))
context.saveGState()
ovalPath.addClip()
context.drawLinearGradient(gradient, start: CGPoint(x: 119.5, y: 9), end: CGPoint(x: 119.5, y: 102), options: [])
context.restoreGState()
UIBezierPath is a simple and efficient class for drawing shapes using Swift, which you can then put into CAShapeLayer, SKShapeNode, or other places. It comes with various shapes built in, so you can write code like this to create a rounded rectangle or a circle:
let rect = CGRect(x: 0, y: 0, width: 256, height: 256)
let roundedRect = UIBezierPath(roundedRect: rect, cornerRadius: 50)
let circle = UIBezierPath(ovalIn: rect)
You can also create custom shapes by moving a pen to a starting position then adding lines:
let freeform = UIBezierPath()
freeform.move(to: .zero)
freeform.addLine(to: CGPoint(x: 50, y: 50))
freeform.addLine(to: CGPoint(x: 50, y: 150))
freeform.addLine(to: CGPoint(x: 150, y: 50))
freeform.addLine(to: .zero)
If your end result needs a CGPath, you can get one by accessing the cgPath property of your UIBezierPath.
You probably should clip bounds of this view:
attributedView.clipsToBounds = true
Related
I'm trying to add a custom shape to an imageView. Please check the below images.
This is the required one:
This is what I have done so far:
I'm new to Core Graphics and I have done this so far:
private func customImageClipper(imageV: UIImageView){
let path = UIBezierPath()
let size = imageV.frame.size
print(size)
path.move(to: CGPoint(x: 0.0, y: size.height))
path.addLine(to: CGPoint(x: 0.8, y: size.height/2))
path.close()
let shape = CAShapeLayer()
shape.path = path.cgPath
imageV.layer.sublayers = [shape]
}
I'm creating a function to achieve a shape like this, but whenever I pass the imageView into this function, I can not see any change at all. I know that I have to move from points to another point to achieve this shape, but I have never done this. Any help would be appreciated. This is how I'm calling this function:
imageV.layoutIfNeeded()
customImageClipper(imageV: imageV)
P.S.: I'm not using Storyboard, I have created this programmatically.
There are many ways to create shapes using UIBezierPaths. This post here discusses the use of the draw function to create a shape.
Here is an example using your clip function within the cell.
func clip(imageView: UIView, withOffset offset: CGFloat) {
let path = UIBezierPath()
//Move to Top Left
path.move(to: .init(x: imageView.bounds.size.width * offset, y: 0))
//Draw line from Top Left to Top Right
path.addLine(to: .init(x: imageView.bounds.size.width, y: 0))
//Draw Line from Top Right to Bottom Right
path.addLine(to: .init(x: imageView.bounds.size.width * (1 - offset), y: imageView.bounds.size.height))
//Draw Line from Bottom Right to Bottom Left
path.addLine(to: .init(x: 0, y: imageView.bounds.size.height))
//Close Path
path.close()
//Create the Shape Mask for the ImageView
let shapeLayer = CAShapeLayer()
shapeLayer.path = path.cgPath
shapeLayer.fillColor = UIColor.black.cgColor
imageView.layer.mask = shapeLayer
}
In this function, the offset is the amount of angle you would like on the shape, ranging from 0 to 1. (0.4) seems to work for your requirements.
This shares a lot of similarities with Apseri's answer, except I chose the route of percentages, rather than exact size. Nothing wrong with either approach, I just found it easier to understand with percentages. :)
One last note to point out, I used this function in the layoutSubviews function.
override func layoutSubviews() {
super.layoutSubviews()
imageView.layoutIfNeeded()
clip(imageView: self.imageView, withOffset: 0.4)
}
This output the following image:
Hope this helps.
Here is example of some path clipping. Of course path can be also put via parameters, and this can be applied to any view, as shown.
Before:
After (grey background is below ScrollView background):
func customImageClipper(imageV: UIView){
let path = UIBezierPath()
let size = imageV.frame.size
path.move(to: CGPoint(x: size.width/3.0, y: 0))
path.addLine(to: CGPoint(x: size.width/3.0 + 50, y: 0))
path.addLine(to: CGPoint(x: size.width/3.0, y: size.height))
path.addLine(to: CGPoint(x: size.width/3.0 - 50, y: size.height))
path.addLine(to: CGPoint(x: size.width/3.0, y: 0))
path.close()
let shape = CAShapeLayer()
shape.path = path.cgPath
shape.fillColor = UIColor.black.cgColor
imageV.layer.mask = shape
}
1- Subclassing your UIImageView
2- implement your custom drawings inside setNeedsLayout using UIBezierPath
class MyCustomImageView: UIImageView {
override func setNeedsLayout() {
let path = UIBezierPath()
path.moveToPoint(CGPoint(x: self.frame.size.width/2, y: self.frame.size.height))
path.addLineToPoint(CGPoint(x: self.frame.size.width, y: self.frame.size.height/2))
path.addLineToPoint(CGPoint(x: self.frame.size.width/2, y: 0))
path.addArcWithCenter(CGPoint(x: self.frame.size.width/2, y: self.frame.size.height/2), radius: self.frame.size.width/2, startAngle:-CGFloat(M_PI_2), endAngle: CGFloat(M_PI_2), clockwise: false)
path.moveToPoint(CGPoint(x: self.frame.size.width/2, y: self.frame.size.height))
path.closePath()
UIColor.redColor().setFill()
path.stroke()
path.bezierPathByReversingPath()
let shapeLayer = CAShapeLayer()
shapeLayer.frame = self.bounds
shapeLayer.path = path.CGPath
shapeLayer.fillColor = UIColor.redColor().CGColor
self.layer.mask = shapeLayer;
self.layer.masksToBounds = true;
}
}
I added a subview (with a black border) in a view and centered it.
Then I generate 2 identical triangles with CAShapeLayer and add one to the subview and the other to the main view.
Here is the visual result in Playground where we can see that the green triangle is totally off and should have been centered.
And here is the code:
let view = UIView()
let borderedView = UIView()
var containedFrame = CGRect(x: 0, y: 0, width: 100, height: 100)
func setupUI() {
view.frame = CGRect(x: 0, y: 0, width: 300, height: 600)
view.backgroundColor = .white
borderedView.frame = containedFrame
borderedView.center = view.center
borderedView.backgroundColor = .clear
borderedView.layer.borderColor = UIColor.black.cgColor
borderedView.layer.borderWidth = 1
view.addSubview(borderedView)
setupTriangles()
}
private func setupTriangles() {
view.layer.addSublayer(createTriangle(color: .red)) // RED triangle
borderedView.layer.addSublayer(createTriangle(color: .green)) // GREEN triangle
}
private func createTriangle(color: UIColor) -> CAShapeLayer {
let layer = CAShapeLayer()
let bezierPath = UIBezierPath()
bezierPath.move(to: CGPoint(x: 0, y: 0))
bezierPath.addLine(to: CGPoint(x: -containedFrame.width, y: 0))
bezierPath.addLine(to: CGPoint(x: 0, y: -containedFrame.height))
bezierPath.close()
layer.position = borderedView.center
layer.path = bezierPath.cgPath
layer.fillColor = color.cgColor
return layer
}
Note: All position (of view, the borderedView and both triangles) are the same (150.0, 300.0)
Question: Why is the green layer not in the right position?
#DuncanC is right that each view has its own coordinate system. Your problem is this line:
layer.position = borderedView.center
That sets the layer's position to the center of the frame for the borderedView which is in the coordinate system of view. When you create the green triangle, it needs to use the coordinate system of borderedView.
You can fix this by passing the view to your createTriangle function, and then use the center of the bounds of that view as the layer position:
private func setupTriangles() {
view.layer.addSublayer(createTriangle(color: .red, for: view)) // RED triangle
borderedView.layer.addSublayer(createTriangle(color: .green, for: borderedView)) // GREEN triangle
}
private func createTriangle(color: UIColor, for view: UIView) -> CAShapeLayer {
let layer = CAShapeLayer()
let bezierPath = UIBezierPath()
bezierPath.move(to: CGPoint(x: 0, y: 0))
bezierPath.addLine(to: CGPoint(x: -containedFrame.width, y: 0))
bezierPath.addLine(to: CGPoint(x: 0, y: -containedFrame.height))
bezierPath.close()
layer.position = CGPoint(x: view.bounds.midX, y: view.bounds.midY)
layer.path = bezierPath.cgPath
layer.fillColor = color.cgColor
return layer
}
Note: When you do this, the green triangle appears directly below the red one, so it isn't visible.
Every view/layer uses the coordinate system of it's superview/superlayer. If you add a layer to self.view.layer, it will be positioned in self.view.layer's coordinate system. If you add a layer to borderedView.layer, it will be in borderedView.layer's coordinate system.
Think of the view/layer hierarchy as stacks of pieces of graph paper. You place a new piece of paper on the current piece (the superview/layer) in the current piece's coordinates system, but then if you draw on the new view/layer, or add new views/layer inside that one, you use the new view/layer's coordinate system.
I want to shrink a triangle downward as below:
But the triangle shrink upward as below:
The transform code is below:
layer.setAffineTransform(CGAffineTransformMakeScale(1.0, 0.5))
I tried to use anchorPoint but I can't scceed.
//: Playground - noun: a place where people can play
import UIKit
let view = UIView(frame: CGRectMake(0, 0, 200, 150))
let layer = CAShapeLayer()
let triangle = UIBezierPath()
triangle.moveToPoint (CGPointMake( 50, 150))
triangle.addLineToPoint(CGPointMake(100, 50))
triangle.addLineToPoint(CGPointMake(150, 150))
triangle.closePath()
layer.path = triangle.CGPath
layer.strokeColor = UIColor.blueColor().CGColor
layer.lineWidth = 3.0
view.layer.addSublayer(layer)
view
layer.setAffineTransform(CGAffineTransformMakeScale(1.0, 0.5))
view
Anish gave me a advice but doesn't work well:
layer.setAffineTransform(CGAffineTransformMakeScale(2.0, 0.5))
Transforms operate around the layer's anchorPoint, which by default is at the center of the layer. Thus, you shrink by collapsing inwards, not by collapsing downwards.
If you want to shrink downward, you will need to scale down and change the view's position (or use a translate transform in addition to your scale transform), or change the layer's anchorPoint before performing the transform.
Another serious problem with your code is that your layer has no assigned size. This causes the results of your transform to be very misleading.
I ran this version of your code and got exactly the results you are asking for. I have put a star next to the key lines that I added. (Note that this is Swift 3; you really need to step up to the plate and update here.)
let view = UIView(frame:CGRect(x: 0, y: 0, width: 200, height: 150))
let layer = CAShapeLayer()
layer.frame = view.layer.bounds // *
let triangle = UIBezierPath()
triangle.move(to: CGPoint(x: 50, y: 150))
triangle.addLine(to: CGPoint(x: 100, y: 50))
triangle.addLine(to: CGPoint(x: 150, y: 150))
triangle.close()
layer.path = triangle.cgPath
layer.strokeColor = UIColor.blue.cgColor
layer.lineWidth = 3
view.layer.addSublayer(layer)
view
layer.anchorPoint = CGPoint(x: 0.5, y: 0) // *
layer.setAffineTransform(CGAffineTransform(scaleX: 1, y: 0.5))
view
Before:
After:
I wanna draw a sloping oval with UIBezierPath. There is only a method UIBezierPath.init(ovalInRect: rect) to draw a oval without slop.What can I do to draw this? thanks
Here is an example of a rotated oval:
class MyView: UIView {
override func draw(_ rect: CGRect) {
// create oval centered at (0, 0)
let path = UIBezierPath(ovalIn: CGRect(x: -75, y: -50, width: 150, height: 100))
// rotate it 30 degrees
path.apply(CGAffineTransform(rotationAngle: 30 * .pi / 180))
// translate it to where you want it
path.apply(CGAffineTransform(translationX: self.bounds.width / 2, y: self.bounds.height / 2))
// set stroke color
UIColor.blue.setStroke()
// stroke the path
path.stroke()
}
}
let view = MyView(frame: CGRect(x: 0, y: 0, width: 200, height: 200))
view.backgroundColor = .white
Here it is running in a Playground:
Trying to create this curve in Swift using CG drawing on a view in my storyboard.
I've done the white curve but having trouble with filling it with a gradient as show in the image
There are three parts to this image.
The white curve.
The gradient.
The mask that blocks out the gradient.
Your best approach would be to create these as separate layers.
First create a CAGradientLayer with your desired colours.
Then create a path curve in white and add it above the gradient.
Now create a third layer with a closed path (similar to the curve but closed at the bottom. Use this as a maskLayer on the gradient layer.
Here is working code
class FillCurve: UIView {
override func draw(_ rect: CGRect) {
// Drawing ARC
let center = CGPoint(x: bounds.width / 2 , y: bounds.height / 2)
let curve = UIBezierPath()
curve.move(to:CGPoint(x: 10, y: bounds.height - 20))
curve.addQuadCurve(to: CGPoint(x: bounds.width - 20 , y: bounds.height - 20), controlPoint:center )
UIColor.white.setStroke()
curve.lineWidth = 2.0
curve.stroke()
let fillPath = curve.copy() as! UIBezierPath
fillPath.addLine(to: CGPoint(x: bounds.width , y: bounds.height - 2))
fillPath.addLine(to: CGPoint(x: 0, y: bounds.height - 2))
fillPath.close()
fillPath.fill()
fillPath.addClip()
let colorSpace = CGColorSpaceCreateDeviceRGB()
let colors = [UIColor.cyan.cgColor,UIColor.black.cgColor]
let location:[CGFloat] = [0.0,1.0]
let gradient = CGGradient(colorsSpace: colorSpace, colors: colors as CFArray, locations: location)!
UIGraphicsGetCurrentContext()?.drawLinearGradient(gradient, start: CGPoint(x: 0, y: fillPath.bounds.height), end: CGPoint(x: 0, y: bounds.height), options: [])
}
}
output