I have attached the image. I want create corner radius of UIView. Please look image https://i.stack.imgur.com/AkUuO.png
Hope this helps:
let redBox = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
redBox.backgroundColor = .red
redBox.layer.cornerRadius = 25
redBox.layer.maskedCorners = [.layerMaxXMaxYCorner]
Looks like a similar question asked here: How to set cornerRadius for only top-left and top-right corner of a UIView?
Related
I want to crop out a portion of a view. I followed this article: "How to mask one UIView using another UIView", and this is my code currently:
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
/// show a green border around the image view's original frame
let backgroundView = UIView(frame: CGRect(x: 50, y: 50, width: 200, height: 300))
backgroundView.layer.borderColor = UIColor.green.cgColor
backgroundView.layer.borderWidth = 4
view.addSubview(backgroundView)
let imageView = UIImageView(frame: CGRect(x: 50, y: 50, width: 200, height: 300))
imageView.image = UIImage(named: "TestImage")
imageView.contentMode = .scaleAspectFill
imageView.clipsToBounds = true
view.addSubview(imageView)
// MARK: - Mask code
let maskView = UIView(frame: CGRect(x: 80, y: 100, width: 100, height: 100))
maskView.backgroundColor = .blue /// ensure opaque
view.addSubview(maskView)
imageView.mask = maskView
}
}
The mask is working fine:
Without mask
With mask
However, I want the parts of the image view that are cropped out to still be there, but just have a lower alpha. This is what it should look like:
I've tried changing maskView.alpha to 0.25, but that just makes the part with the mask be less opaque.
How can I make the cropped-out parts still be there, but just a bit more transparent?
Preferably I don't want to make another view, because eventually I'll be using this on a camera preview layer — an extra view might have a cost on performance.
Edit: matt's answer
I tried adding a subview with a background color with less alpha:
let maskView = UIView(frame: CGRect(x: 0, y: 0, width: 200, height: 300))
maskView.backgroundColor = UIColor.blue.withAlphaComponent(0.3)
let maskView2 = UIView(frame: CGRect(x: 80, y: 100, width: 100, height: 100))
maskView2.backgroundColor = UIColor.blue.withAlphaComponent(1)
maskView2.alpha = 0
maskView.addSubview(maskView2)
imageView.mask = maskView
But this is the result:
It’s all in the transparency of the colors you paint the mask with. (The hues — what we usually think of as color — are irrelevant.) The masking depends upon the degree of transparency. Areas of the mask that are partially transparent will make the masked view be partially transparent.
So make the mask the whole size of the target view, and make the whole mask a partially transparent color, except for the central area which is an opaque color.
I am generating a custom header view for my UITableView which has two horizontal lines up & down and a UILabel in between.
let lineWidth = tableView.bounds.width //This is not correct, will never align with UITableViewCell
let offset = (tableView.bounds.width - lineWidth)/2 //This will always yield 0, but my question is to compute line width that aligns with UITableViewCell as shown in the image attached to this question.
let topLine = UIView(frame: CGRect(x: offset, y: 0, width: lineWidth, height: 1))
topLine.backgroundColor = UIColor.white
let bottomLine = UIView(frame: CGRect(x: offset, y: 49.0, width: lineWidth, height: 1))
bottomLine.backgroundColor = UIColor.white
let label = UILabel(frame: CGRect(x: 0, y: 1.0, width: tableView.bounds.width, height: 48.0))
label.textColor = UIColor.white
let headerView = UIView(frame: CGRect(x: 0, y: 0, width: tableView.bounds.width, height: 50))
headerView.addSubview(topLine)
headerView.addSubview(label)
headerView.addSubview(bottomLine)
Problem: I need the top & bottom lines to align with UITableViewCell bounds in the section as shown in the picture below. What I get with the code above is horizontal lines that cover the entire width of UITableView. How do I achieve it?
EDIT: Some answers here describe an arbitrary offset value, but the heart of the problem is how to compute offset that aligns with UITableViewCell bounds in the section? In other words, I need exact width of UITableViewCell's that go into the section.
Your Offset will be practically zero as you are subtracting the same things
let lineWidth = tableView.bounds.width
let offset = (tableView.bounds.width - lineWidth)/2
let topLine = UIView(frame: CGRect(x: offset, y: 0, width: lineWidth, height: 1)) // this line gonna give offset as zero and width of full tableview width
Change this to the below code and try
let lineWidth = tableView.bounds.width - 20
let topLine = UIView(frame: CGRect(x: 10, y: 0, width: lineWidth, height: 1))
It seems the issue with the position of your top & bottom lines. As per the calculation of offset it always set to 0 for top & bottom lines. So it would be better to remove that offset calculation and you can add some desired static value as a x for CGRect of top & bottom lines.
As far as we are going to move the position of x for the top & bottom line don't forget to remove the added value for x position from the width of the top & bottom lines.
let yourLine = UIView(frame: CGRect(x: some_value, y: 0, width: Int(lineWidth - (some_value * 2)), height: 1))
The best practice is you can use some variables to achieve this.
How do I add boarder like in the below image (in Objective-C ) to UIImageView. I tried using UIBezierPath but wasn't successful.
Create a UIView (square in dimensions), add corner radius = 1/2 times its side.
Now add the UIImageView as a subview to this UIView.
As the image is circular in shape, so a simpler appraoch to the solution to your problem is to add corner radius to your UIVIew.
Below is the code I used:
let circleView: UIView = UIView(frame: CGRect(x: 0,
y: 0,
width: 100,
height: 100))
circleView.center = view.center
circleView.backgroundColor = .lightGray
circleView.layer.cornerRadius = 50
view.addSubview(circleView)
let imageView: UIImageView = UIImageView(frame: CGRect(x: 0,
y: 0,
width: 100,
height: 100))
imageView.image = UIImage(named: "F8FIs.png")
circleView.addSubview(imageView)
Please note that I added lightGray color to circle view for clarity.
And here is the screenshot of how it looks:
I'm trying to determine the right scaling factor for my node tree to make it fit exactly in my presentation rectangle, so I'm trying to find the smallest bounding rectangle around all my nodes. Apple's docs say that calculateAccumulatedFrame "Calculates a rectangle in the parent’s coordinate system that contains the content of the node and all of its descendants." That sounds like what I need, but it's not giving me the tight fit that I expect. My complete playground code is:
import SpriteKit
import PlaygroundSupport
let view:SKView = SKView(frame: CGRect(x: 0, y: 0, width: 800, height: 800))
PlaygroundPage.current.liveView = view
let scene:SKScene = SKScene(size: CGSize(width: 1000, height: 800))
scene.scaleMode = SKSceneScaleMode.aspectFill
view.presentScene(scene)
let yellowBox = SKSpriteNode(color: .yellow, size:CGSize(width: 300, height: 300))
yellowBox.position = CGPoint(x: 400, y: 500)
yellowBox.zRotation = CGFloat.pi / 10
scene.addChild(yellowBox)
let greenCircle = SKShapeNode(circleOfRadius: 100)
greenCircle.fillColor = .green
greenCircle.position = CGPoint(x: 300, y: 50)
greenCircle.frame
yellowBox.addChild(greenCircle)
let uberFrame = yellowBox.calculateAccumulatedFrame()
let blueBox = SKShapeNode(rect: uberFrame)
blueBox.strokeColor = .blue
blueBox.lineWidth = 2
scene.addChild(blueBox)
And the results are:
The left and bottom edges of the blue rectangle look good, but why are there gaps between the blue rectangle and the green circle on the top and right?
The notion "frame" does funny things when you add a transform. The bounding box around the box and circle is a rectangle. You have rotated that rectangle. Therefore its corners stick out. The accumulated frame embraces that rotated rectangle, including the sticking-out corners. It does not magically hug the drawn appearance of the nodes (e.g. the circle).
I have been fighting with this all morning and can't seem to find a solution. I have created a UIImageView, filled it with red, then added it to a UIScrollView and set the contentSize to the size of the UIImageView. If I print the contentOffset i see (0, 0) and if I print the contentSize and the UIImageView.frame.size they are the same but the red "image" always appears smaller than what the scrollView thinks the contentSize is.
If I scroll all the way to the top I see a cyan stripe about 100 pixels high above the red image and the scroll bar will not make it all the way to the top of what I believe the top of my scroll view to be. Although the top of the scroll bar does line up with the top of my red window so it would seem as though the scroll view is confused as to where it actually lives. Or more likely, I'm confused
Here is my what seems like very simple code...
imgHorizon = UIImage.init(named:"horizon")!
imgBezel = UIImage.init(named:"bezel_transparent")!
imgWings = UIImage.init(named:"wings_transparent")!
imgViewHorizon = UIImageView.init()
imgViewBezel = UIImageView.init()
imgViewWings = UIImageView.init()
svHorizon = UIScrollView.init()
super.init(coder: aDecoder)
imgViewHorizon = UIImageView(frame: CGRect(x: 0, y: 0, width: imgBezel.size.width, height: imgHorizon.size.height))
imgViewHorizon.backgroundColor = UIColor.red
imgViewBezel = UIImageView(frame: CGRect(x: 0, y: 0, width: imgBezel.size.width, height: imgBezel.size.height))
imgViewBezel.contentMode = UIViewContentMode.center
imgViewBezel.clipsToBounds = true
imgViewBezel.image = imgBezel
imgViewWings = UIImageView(frame: CGRect(x: 0, y: 0, width: imgBezel.size.width, height: imgBezel.size.height))
imgViewWings.contentMode = UIViewContentMode.center
imgViewWings.clipsToBounds = true
imgViewWings.image = imgWings
svHorizon = UIScrollView(frame: CGRect(x: 0, y: 0, width: imgBezel.size.width, height: imgBezel.size.width))
svHorizon.contentSize = CGSize(width: imgBezel.size.width, height: imgHorizon.size.height)
svHorizon.contentMode = UIViewContentMode.scaleToFill
svHorizon.bounces = false
svHorizon.backgroundColor = UIColor.cyan
svHorizon.contentOffset = CGPoint(x: 0, y: 0)
svHorizon.addSubview(imgViewHorizon)
addSubview(svHorizon)
addSubview(imgViewBezel)
addSubview(imgViewWings)
From the discussion in the comments it turns out that the Adjust Scroll View Insets option was checked in the attributes inspector of the ViewController. Unchecking it resolved the problem. Have a look at the image below. You need to uncheck the highlighted option.