https://www.dropbox.com/s/wlizis5zybsvnfz/File%202017-04-04%2C%201%2052%2024%20PM.jpeg?dl=0
Hello all Swifters,
Could anyone tell me how to set this kind of UI? Is there any half rounded image that they have set?
Or there are two images. One with the mountains in the background and anohter image made half rounded in white background and placed in on top?
Please advise
Draw an ellipse shape using UIBezier path.
Draw a rectangle path exactly similar to imageView which holds your image.
Transform the ellipse path with CGAffineTransform so that it will be in the center of the rect path.
Translate rect path with CGAffineTransform by 0.5 to create intersection between ellipse and the rect.
Mask the image using CAShapeLayer.
Additional: As Rob Mayoff stated in comments you'll probably need to calculate the mask size in viewDidLayoutSubviews. Don't forget to play with it, test different cases (different screen sizes, orientations) and adjust the implementation based on your needs.
Try the following code:
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var imageView: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
guard let image = imageView.image else {
return
}
let size = image.size
imageView.clipsToBounds = true
imageView.image = image
let curveRadius = size.width * 0.010 // Adjust curve of the image view here
let invertedRadius = 1.0 / curveRadius
let rect = CGRect(x: 0,
y: -40,
width: imageView.bounds.width + size.width * 2 * invertedRadius,
height: imageView.bounds.height)
let ellipsePath = UIBezierPath(ovalIn: rect)
let transform = CGAffineTransform(translationX: -size.width * invertedRadius, y: 0)
ellipsePath.apply(transform)
let rectanglePath = UIBezierPath(rect: imageView.bounds)
rectanglePath.apply(CGAffineTransform(translationX: 0, y: -size.height * 0.5))
ellipsePath.append(rectanglePath)
let maskShapeLayer = CAShapeLayer()
maskShapeLayer.frame = imageView.bounds
maskShapeLayer.path = ellipsePath.cgPath
imageView.layer.mask = maskShapeLayer
}
}
Result:
You can find an answer here:
https://stackoverflow.com/a/34983655/5479510
But generally, I wouldn't recommend using a white image overlay as it may appear distorted or pixelated on different devices. Using a masking UIView would do just great.
Why you could not just create (draw) rounded transparent image and add UIImageView() with UIImage() at the top of the view with required height and below this view add other views. I this this is the easiest way. I would write comment but I cant.
Related
I would like to create a very simple image editor, same as twitter (for the profile image)
I know how to pinch or move an image.
But i don’t know how to create the "circle layer" and just keep this part of the image, like this :
Make sure to import QuarzCore.
func maskRoundedImage(image: UIImage, radius: CGFloat) -> UIImage {
let imgView: UIImageView = UIImageView(image: image)
let layer = imgView.layer
layer.masksToBounds = true
layer.cornerRadius = radius
UIGraphicsBeginImageContext(imgView.bounds.size)
layer.render(in: UIGraphicsGetCurrentContext()!)
let roundedImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return roundedImage!
}
https://github.com/andreaantonioni/AAPhotoCircleCrop
Each view has an underlying layer onto which you apply a corner radius. Then you must apply clipToBounds on that layer in order to apply that mask to the overlying UIView. The corner radius must be half the width of the view in order to get a circle effect. Otherwise the corners of the view will be rounded.
For example:
let square = UIView()
square.center = view.center
square.bounds.size = CGSize(width: 100, height: 100)
square.backgroundColor = .red
view.addSubview(square)
square.layer.cornerRadius = 50
square.clipsToBounds = true
Above mentioned ways are good, But you can not achieved exact output as in above image E.g You can not get alpha effect.
I suggest simple way to do it.
1) Add new image to project with transparent background with Opocity and circle.
2) Add new imageView above to mainview as below.
let image = UIImageView(frame: view.bounds)
mage.image = UIImage.init(named:"imageName")
view.addSubview(image)
Then output should be as per your requirement.
I'm trying to crop a sub-image of a image view using an overlay UIView that can be positioned anywhere in the UIImageView. I'm borrowing a solution from a similar post on how to solve this when the UIImageView content mode is 'Aspect Fit'. That proposed solution is:
func computeCropRect(for sourceFrame : CGRect) -> CGRect {
let widthScale = bounds.size.width / image!.size.width
let heightScale = bounds.size.height / image!.size.height
var x : CGFloat = 0
var y : CGFloat = 0
var width : CGFloat = 0
var height : CGFloat = 0
var offSet : CGFloat = 0
if widthScale < heightScale {
offSet = (bounds.size.height - (image!.size.height * widthScale))/2
x = sourceFrame.origin.x / widthScale
y = (sourceFrame.origin.y - offSet) / widthScale
width = sourceFrame.size.width / widthScale
height = sourceFrame.size.height / widthScale
} else {
offSet = (bounds.size.width - (image!.size.width * heightScale))/2
x = (sourceFrame.origin.x - offSet) / heightScale
y = sourceFrame.origin.y / heightScale
width = sourceFrame.size.width / heightScale
height = sourceFrame.size.height / heightScale
}
return CGRect(x: x, y: y, width: width, height: height)
}
The problem is that using this solution when the image view is aspect fill causes the cropped segment to not line up exactly with where the overlay UIView was positioned. I'm not quite sure how to adapt this code to accommodate for Aspect Fill or reposition my overlay UIView so that it lines up 1:1 with the segment I'm trying to crop.
UPDATE Solved using Matt's answer below
class ViewController: UIViewController {
#IBOutlet weak var catImageView: UIImageView!
private var cropView : CropView!
override func viewDidLoad() {
super.viewDidLoad()
cropView = CropView(frame: CGRect(x: 0, y: 0, width: 45, height: 45))
catImageView.image = UIImage(named: "cat")
catImageView.clipsToBounds = true
catImageView.layer.borderColor = UIColor.purple.cgColor
catImageView.layer.borderWidth = 2.0
catImageView.backgroundColor = UIColor.yellow
catImageView.addSubview(cropView)
let imageSize = catImageView.image!.size
let imageViewSize = catImageView.bounds.size
var scale : CGFloat = imageViewSize.width / imageSize.width
if imageSize.height * scale < imageViewSize.height {
scale = imageViewSize.height / imageSize.height
}
let croppedImageSize = CGSize(width: imageViewSize.width/scale, height: imageViewSize.height/scale)
let croppedImrect =
CGRect(origin: CGPoint(x: (imageSize.width-croppedImageSize.width)/2.0,
y: (imageSize.height-croppedImageSize.height)/2.0),
size: croppedImageSize)
let renderer = UIGraphicsImageRenderer(size:croppedImageSize)
let _ = renderer.image { _ in
catImageView.image!.draw(at: CGPoint(x:-croppedImrect.origin.x, y:-croppedImrect.origin.y))
}
}
#IBAction func performCrop(_ sender: Any) {
let cropFrame = catImageView.computeCropRect(for: cropView.frame)
if let imageRef = catImageView.image?.cgImage?.cropping(to: cropFrame) {
catImageView.image = UIImage(cgImage: imageRef)
}
}
#IBAction func resetCrop(_ sender: Any) {
catImageView.image = UIImage(named: "cat")
}
}
The Final Result
Let's divide the problem into two parts:
Given the size of a UIImageView and the size of its UIImage, if the UIImageView's content mode is Aspect Fill, what is the part of the UIImage that fits into the UIImageView? We need, in effect, to crop the original image to match what the UIImageView is actually displaying.
Given an arbitrary rect within the UIImageView, what part of the cropped image (derived in part 1) does it correspond to?
The first part is the interesting part, so let's try it. (The second part will then turn out to be trivial.)
Here's the original image I'll use:
https://static1.squarespace.com/static/54e8ba93e4b07c3f655b452e/t/56c2a04520c64707756f4267/1455596221531/
That image is 1000x611. Here's what it looks like scaled down (but keep in mind that I'm going to be using the original image throughout):
My image view, however, will be 139x182, and is set to Aspect Fill. When it displays the image, it looks like this:
The problem we want to solve is: what part of the original image is being displayed in my image view, if my image view is set to Aspect Fill?
Here we go. Assume that iv is the image view:
let imsize = iv.image!.size
let ivsize = iv.bounds.size
var scale : CGFloat = ivsize.width / imsize.width
if imsize.height * scale < ivsize.height {
scale = ivsize.height / imsize.height
}
let croppedImsize = CGSize(width:ivsize.width/scale, height:ivsize.height/scale)
let croppedImrect =
CGRect(origin: CGPoint(x: (imsize.width-croppedImsize.width)/2.0,
y: (imsize.height-croppedImsize.height)/2.0),
size: croppedImsize)
So now we have solved the problem: croppedImrect is the region of the original image that is showing in the image view. Let's proceed to use our knowledge, by actually cropping the image to a new image matching what is shown in the image view:
let r = UIGraphicsImageRenderer(size:croppedImsize)
let croppedIm = r.image { _ in
iv.image!.draw(at: CGPoint(x:-croppedImrect.origin.x, y:-croppedImrect.origin.y))
}
The result is this image (ignore the gray border):
But lo and behold, that is the correct answer! I have extracted from the original image exactly the region portrayed in the interior of the image view.
So now you have all the information you need. croppedIm is the UIImage actually displayed in the clipped area of the image view. scale is the scale between the image view and that image. Therefore, you can easily solve the problem you originally proposed! Given any rectangle imposed upon the image view, in the image view's bounds coordinates, you simply apply the scale (i.e. divide all four of its attributes by scale) — and now you have the same rectangle as a portion of croppedIm.
(Observe that we didn't really need to crop the original image to get croppedIm; it was sufficient, in reality, to know how to perform that crop. The important information is the scale along with the origin of croppedImRect; given that information, you can take the rectangle imposed upon the image view, scale it, and offset it to get the desired rectangle of the original image.)
EDIT I added a little screencast just to show that my approach works as a proof of concept:
EDIT Also created a downloadable example project here:
https://github.com/mattneub/Programming-iOS-Book-Examples/blob/39cc800d18aa484d17c26ffcbab8bbe51c614573/bk2ch02p058cropImageView/Cropper/ViewController.swift
But note that I can't guarantee that URL will last forever, so please read the discussion above to understand the approach used.
Matt answered the question perfectly. I was creating a full-screen camera and had a need to make the final output match the full-screen preview. Offering here a compact extension of Matt's overall answer in Swift 5 for easy use by others. Recommend reading Matt's answer as it explains things very well.
extension UIImage {
func cropToRect(rect: CGRect) -> UIImage? {
var scale = rect.width / self.size.width
scale = self.size.height * scale < rect.height ? rect.height/self.size.height : scale
let croppedImsize = CGSize(width:rect.width/scale, height:rect.height/scale)
let croppedImrect = CGRect(origin: CGPoint(x: (self.size.width-croppedImsize.width)/2.0,
y: (self.size.height-croppedImsize.height)/2.0),
size: croppedImsize)
UIGraphicsBeginImageContextWithOptions(croppedImsize, true, 0)
self.draw(at: CGPoint(x:-croppedImrect.origin.x, y:-croppedImrect.origin.y))
let croppedImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return croppedImage
}
}
I am having three UIView's one after the other horizontally, with each UiView.Layer.BorderColor set to Black and UiView.Layer.BorderWidth set to 0.25f like shown below. So this gives a border look for each of the view.
Now i have a requirement to only display the horizontal borders of the UiViews. Hence i create a mask layer and set path and frame to that mask layer to apply clip. Please refer the code snippet below to give you an idea of what am doing.
foreach (UIView UiView in myViews)
{
UiView.Layer.BorderColor = Color.Black.ToCGColor();
UiView.Layer.BorderWidth = 0.25f;
UIBezierPath maskPath = null;
CAShapeLayer maskLayer = new CAShapeLayer();
maskLayer.Frame = UiView.Bounds;
// Applying Clip to my layer
maskPath = UIBezierPath.FromRect(new CGRect(UiView.Bounds.Left + 0.5, UiView.Bounds.Top, UiView.Bounds.Width - 1, UiView.Bounds.Height));
maskLayer.Path = maskPath.CGPath;
view.Layer.Mask = maskLayer;
}
Yes i am aware that whatever the bounds i set for the maskPath is the Visible region, so given that each UiView is 60 in width , my visible region according to what i have written in code is , from 0.5 pixel upto 59.5 pixel of each UIView . Thus eliminating the borders present in the pixels from 0 to 0.5 and from 59.5 to 60. Hope this part is clear for you. Please refer the below image for a visual representation of my mask area. The Yellow borders denotes the mask bounds.
Now all is fine , but this 0.5 pixels border which is hidden causes a white space in my top and bottom borders of the UiView's put together continuously. Please refer the below image with the circled spots highlighting the void spaces in the top and bottom.
This can be easily reproduced in code too. Please suggest me on how to overcome this problem. What am i doing wrong. I know this is a very small blank space of half a pixel which is barely visible to the naked eye most of the times, but it will not be visually pleasing for my grid view application.
PS : Am developing in Xamarin.iOS , however native iOS solutions will also be helpful.
Thanks in advance
Try this for Swift.
class ViewController: UIViewController {
#IBOutlet weak var view1: UIView!
#IBOutlet weak var view2: UIView!
#IBOutlet weak var view3: UIView!
override func viewDidLoad() {
super.viewDidLoad()
var borderwidth = CGFloat()
borderwidth = 5
let topBorder = CALayer()
topBorder.backgroundColor = UIColor.black.cgColor
topBorder.frame = CGRect(x: self.view1.frame.origin.x, y: self.view1.frame.origin.y, width: self.view3.frame.origin.x + self.view3.frame.size.width - self.view1.frame.origin.x, height: borderwidth)
self.view.layer.addSublayer(topBorder)
let bottomBorder = CALayer()
bottomBorder.backgroundColor = UIColor.black.cgColor
bottomBorder.frame = CGRect(x: self.view1.frame.origin.x, y: self.view1.frame.origin.y + self.view1.frame.size.height - borderwidth, width: self.view3.frame.origin.x + self.view3.frame.size.width - self.view1.frame.origin.x, height: borderwidth)
self.view.layer.addSublayer(bottomBorder)
}
}
See this screenshot : 1
Masking is the problem. Try like this.
view.Layer.MasksToBounds = false;
view.Layer.AllowsEdgeAntialiasing = true;
layer.BorderColor = color.ToCGColor();
layer.BorderWidth = 0.5f;
if (layer.SuperLayer == null && layer.SuperLayer != view.Layer)
view.Layer.AddSublayer(layer);
view.Layer.BorderColor = Color.Transparent.ToCGColor();
layer.Frame = new CGRect(view.Bounds.Left, view.Bounds.Bottom - 0.5f, view.Bounds.Right, view.Bounds.Bottom);
I am trying to get a detection zone in a live preview on my camera preview layer.
Is it possible for this, say there is a live feed and you have face detect on and as you look around it will only put a box around the face in a certain area for example a rectangle in the centre of the screen. all other faces in the preview that are outside of the rectangle don't get detected?
Im using Vision, iOS, Swift.
I figured this out by adding a guard before the CALayer adding
Before View did load
#IBOutlet weak var scanAreaImage: UIImageView!
var regionOfInterest: CGRect!
In View did load
scanAreaImage.frame is a image view that I put in via storyboard and this would represent the area I only wanted detection in,
let someRect: CGRect = scanAreaImage.frame
regionOfInterest = someRect
then in the vision text detection section.
func highlightLetters(box: VNRectangleObservation) {
let xCord = box.topLeft.x * (cameraPreviewlayer?.frame.size.width)!
let yCord = (1 - box.topLeft.y) * (cameraPreviewlayer?.frame.size.height)!
let width = (box.topRight.x - box.bottomLeft.x) * (cameraPreviewlayer?.frame.size.width)!
let height = (box.topLeft.y - box.bottomLeft.y) * (cameraPreviewlayer?.frame.size.height)!
// This is the section I Added for the rec of interest detection zone.
//////////////////////////////////////////////
let wordRect = CGRect(x: xCord, y: yCord, width: width, height: height)
guard regionOfInterest.contains(wordRect.origin) else { return } // only draw a box if the orgin of the word box is within the regionOfInterest
// regionOfInterest being the cgRect you created earlier
//////////////////////////////////////////////
let outline = CALayer()
outline.frame = CGRect(x: xCord, y: yCord, width: width, height: height)
outline.borderWidth = 1.0
if textColour == 1 {
outline.borderColor = UIColor.blue.cgColor
}else {
outline.borderColor = UIColor.clear.cgColor
}
cameraPreviewlayer?.addSublayer(outline)
this will only show outlines of the things inside the rectangle you created in storyboard. (Mine being the scanAreaImage)
I hope this helps someone.
if a I have a path for a polyline saved as string,
From google maps sdk: path.encodedPath()
Or I have a series of latlngs points,
Can I draw a thumbnail for that path ?
I don't want to draw it on mapView, I wonder if I can draw it in any other view like imageView or any thing similar.
I created swift 3 code which you can just copy and paste in playground and see the results immediately
the code is here:
import UIKit
import PlaygroundSupport
var str = "Hello, playground"
//All you need is to create a path with that points and create image or layer with that path
//To perpare for this let make some extensions with helper code
//Extension for UIBeziePath to easily create it from points
extension UIBezierPath
{
convenience init(points:[CGPoint])
{
self.init()
//connect every points by line.
//the first point is start point
for (index,aPoint) in points.enumerated()
{
if index == 0 {
self.move(to: aPoint)
}
else {
self.addLine(to: aPoint)
}
}
}
}
//to create image from path you can use this class function
extension UIImage
{
class func imageFrom(path:UIBezierPath,lineColor:UIColor,fillColor:UIColor)->UIImage
{
//create context to draw in use path bounds as context size. assume that path is inzide of rect with start corener at 0,0 coordinate
UIGraphicsBeginImageContextWithOptions(path.bounds.size, false, 0)
print("path bounds \(path.bounds) lineWidth:\(path.lineWidth)")
let context = UIGraphicsGetCurrentContext()
//set fill color
context?.setFillColor(fillColor.cgColor)
//set line coolor
context?.setStrokeColor(lineColor.cgColor)
context?.setLineWidth(path.lineWidth)
//draw a path
context?.addPath(path.cgPath)
context?.drawPath(using: .fillStroke)
//get image from context
let image = UIGraphicsGetImageFromCurrentImageContext()!
//finish context
UIGraphicsEndImageContext()
return image
}
}
//2. To create layer use this extension
extension CAShapeLayer
{
convenience init(path:UIBezierPath, lineColor:UIColor, fillColor:UIColor)
{
self.init()
self.path = path.cgPath
self.strokeColor = lineColor.cgColor
self.fillColor = fillColor.cgColor
self.lineWidth = path.lineWidth
self.opacity = 1
self.frame = path.bounds
}
}
//how to use:
//1. assume you recieved points
let points:[CGPoint] = [CGPoint(x: 0, y: 0),CGPoint(x: 150, y: 50),CGPoint(x: 75, y:140),CGPoint(x: 0, y: 80)]
//2. create path
let path = UIBezierPath(points: points)
//3. you can specify path line width
path.lineWidth = 2
//4. as a joinstyle too
path.lineJoinStyle = .round
//5. a)now you can create image from path with helper function
let image = UIImage.imageFrom(path: path, lineColor: UIColor.purple, fillColor: UIColor.red)
print(image)
//and set it to imageView
let imageView = UIImageView(image: image)
imageView.frame.origin = CGPoint(x: 200, y: 200)
imageView.backgroundColor = UIColor.green
//5. Maybe you will need to specify content mode for imageView
imageView.contentMode = .scaleAspectFit
//5 b.) Or you can create a Layer. Add add it to someone's layer layter
//if you need, you can apply transform to path - this is special way to
//adjust scale, rotation an lots of other cool stuff on layers, paths.
//Create special struct which descripbes transformation
//Identity is a special case which does not make any transformations at all
var transform = CGAffineTransform.identity
//scale it by 0.5 for x and 0.5 for y. if you need to increse scale by
//100 times, just pass 100 for x and y arguments
transform = transform.scaledBy(x: 0.5, y: 0.5)
//no apply transform to path.
path.apply(transform)
let layer = CAShapeLayer(path: path, lineColor: UIColor.blue, fillColor: UIColor.brown)
//6. let see results
let container = UIView(frame: CGRect(x: 0, y: 0, width: 400, height: 400))
container.backgroundColor = UIColor.white
//for imageView
container.addSubview(imageView)
//for CAShapeLayer
container.layer.addSublayer(layer)
//for playGround you can set this to see result there
//Do not forget to select from menu
//View -> Assistant Editor-> Show Assistance Editor
PlaygroundPage.current.liveView = container
PlaygroundPage.current.needsIndefiniteExecution = true
//Also I have to mention that the CAShapeLayer solution takes less memory which is critical for really big images
//but the UIImage is easier to use
the brown figure is layer with path scaled by 0.5, the red one is imageView
If you have a series of lat longs, you can know the maximum and minimum lat long, say they are : maxLat, maxLong, minLat, minLong. Please not that the both max values need not belong to the same coordinate. Same for both min values.
You can use this to get a rect :
let rect = CGRect(x: minLng , y: minLat, width: (maxLng - minLng), height: (maxLat - minLat))
Now, all other lat longs are points in this rectangle. You can get every coordinate's corresponding CGPoint value by
let point = CGPoint(x: maxLng - coordinate.longitude, y: maxLat - coordinate.latitude)
Using this rect and the series of CGPoints you created, you can draw a path (by starting with the first point and adding all subsequent points to it) on a view (like the image view you mention in your answer) or create a graphics context just to create a thumbnail of your path and save it as an image.
Refer the drawing and printing guide if you are unfamiliar with drawing in CGContexts.
However, if you mean to place this thumbnail equivalent of path on an image the real challenge is, how would you know the position. A simple trick would be to get map-equivalent min max coordinates of the image on which you mean to superimpose the path thumbnail and use these min max values to create the path and the context. Then you can center the thumbnail on the image.
Your project sounds interesting. Enjoy, and good luck.