Swift / cut background image - ios

My background image is set with UIView extension.
extension UIView {
func addBackground() {
// screen width and height:
let width = UIScreen.mainScreen().bounds.size.width
let height = UIScreen.mainScreen().bounds.size.height
let imageViewBackground = UIImageView(frame: CGRectMake(0, 0, width, height))
imageViewBackground.image = UIImage(named: "index_clear")
// you can change the content mode:
imageViewBackground.contentMode = UIViewContentMode.ScaleAspectFill
self.addSubview(imageViewBackground)
self.sendSubviewToBack(imageViewBackground)
}}
For segue animation the view moves from left to right. The background image is way larger than the screen, what is visible while the animation.
How can I cut the background image to perfectly fit into the view?
.ScaleAspectFit does the job, but since it's a picture it looks bad.
Help is very appreciated.

You can use .ScaleAspectFill to crop the image rather than scale it to fit. This won't distort your image, but obviously you won't be able to see the whole thing.
You need to ensure that you set clipsToBounds=true on the UIImageView so that the cropped area isn't visible
extension UIView {
func addBackground() {
// screen width and height:
let width = UIScreen.mainScreen().bounds.size.width
let height = UIScreen.mainScreen().bounds.size.height
let imageViewBackground = UIImageView(frame: CGRectMake(0, 0, width, height))
imageViewBackground.image = UIImage(named: "index_clear")
// you can change the content mode:
imageViewBackground.contentMode = UIViewContentMode.ScaleAspectFill
imageViewBackground.clipsToBounds=true
self.addSubview(imageViewBackground)
self.sendSubviewToBack(imageViewBackground)
}

Related

How to make a UIImageView have a square size based on a given bounds/container

So I am trying to create a simple UIImageView to make it have a square frame/size with CGSize. Based on a given bounds. So for example if the bounds container is the width & height of the screen then. The function should resize the UIImageView to fit like a perfect square base on those bounds on the screen.
Code:
let myImageView = UIImageView()
myImageView.frame.origin.y = (self.view?.frame.height)! * 0.0
myImageView.frame.origin.x = (self.view?.frame.width)! * 0.0
myImageView.backgroundColor = UIColor.blue
self.view?.insertSubview(myImageView, at: 0)
//("self.view" is the ViewController view that is the same size as the devices screen)
MakeSquare(view: myImageView, boundsOf: self.view)
func MakeSquare(view passedview: UIImageView, boundsOf container: UIView) {
let ratio = container.frame.size.width / container.frame.size.height
if container.frame.width > container.frame.height {
let newHeight = container.frame.width / ratio
passedview.frame.size = CGSize(width: container.frame.width, height: newHeight)
} else{
let newWidth = container.frame.height * ratio
passedview.frame.size = CGSize(width: newWidth, height: container.frame.height)
}
}
The problem is its giving me back the same bounds/size of the container & not changed
Note: I really have know idea how to pull this off, but wanted to see if its possible. My function comes from a question here. That takes a UIImage and resizes its parent view to make the picture square.
This should do it (and will centre the image view in the containing view):
func makeSquare(view passedView: UIImageView, boundsOf container: UIView) {
let minSize = min(container.bounds.maxX, container.bounds.maxY)
passedView.bounds = CGRect(x: container.bounds.midX - minSize / 2.0,
y: container.bounds.midY - minSize / 2.0,
width: minSize, height: minSize)
}

Adding UIImage ignores and resizes UIImageView frame

I'm currently trying to add an image into the navigation item for one view. In the view's viewDidLoad(), a function is called with the following code, similar to this post:
let logo = UIImage(named: "Menu_Logo")
let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 122, height: 26))
imageView.contentMode = .scaleAspectFit
imageView.clipsToBounds = true
imageView.image = logo
self.navigationItem.titleView = imageView
Instead of giving me the expected size however, the view ends up looking like this:
Removing the UIImage from the UIImageView makes the view sized correctly like this:
This seems like strange behaviour to me, especially since I did set the content mode to .scaleAspectFit. Is there something I am forgetting regarding adding an UIImageView as the navigationItem.titleView?
On UINavigationBar, title view takes its full size, if content is large.
Resize the image rather than UIImageView as following with passing size (122, 26). This will solve your problem.
func imageResize(sizeChange: CGSize) -> UIImage {
let hasAlpha = true
let scale: CGFloat = 0.0 // Use scale factor of main screen
UIGraphicsBeginImageContextWithOptions(sizeChange, !hasAlpha, scale)
self.draw(in: CGRect(origin: CGPoint.zero, size: sizeChange))
let scaledImage = UIGraphicsGetImageFromCurrentImageContext()
return scaledImage!
}

How to center an image in navigationBar across all UIViewControllers? Swift / Obj-C

Problem visually:
I have tried putting the image in the center of its own frame with no luck. I have also tried to center it with playing the x of the CGRect with no luck either. I presume I can just put an empty icon with the same background as the navigation bar; however, I don't want to do it that way. I might have 2-3 icons on the right; then what?
let image = UIImage(named: "some_logo")!
let imageSize = CGSizeMake(60, 42)
let marginX: CGFloat = (self.navigationController!.navigationBar.frame.size.width / 2) - (imageSize.width / 2)
let imageView = UIImageView(frame: CGRect(x: marginX, y: 0, width: imageSize.width, height: imageSize.height))
imageView.image = image
imageView.contentMode = .ScaleAspectFit
self.navigationItem.titleView = imageView
I prefer swift but obj-c solutions are welcomed as well.
Any pointers appreciated.
This app has nothing to do with KIA, it is just some logo I got off the google search, searching "some logo".
I have faced the same issue. Then i tried one code shown below.
override func viewDidAppear(animated: Bool) {
let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 150, height: 40))
imageView.contentMode = .ScaleAspectFit
let image = UIImage(named: "googlePlus")
imageView.image = image
navigationItem.titleView = imageView
}
This Code working fine when i tested with Left & Right Bar Button.
But in my previous code there is no Right Bar Button.
So the image is moving towards right.
For solving this i created a Right Bar Button & change the Tint color to clear color.
So everything seems to be working fine. This is one Temporary Solution for your problem.
The easiest way of doing this is in Interface Builder.
Simply drag a 'NavigationItem' from the object library and place it into your ViewController, then place a UIView where the title goes (ensure you set the background to 'clear')
Then place a UIImageView into that view and set the image in the Attributes Inspector to your required image. Scale your UIImage accordingly and set your your constraints accordingly.
I created an extension for solving this problem using the hint of #idrougge.
In order to center the title view image no matter what buttons you have, a content view is set as title view, then the image view is added as child of the content view. Finally, using constraints the image view is aligned inside its parent (content view).
import UIKit
extension UIViewController {
func addLogoToNavigationBarItem() {
let imageView = UIImageView()
imageView.translatesAutoresizingMaskIntoConstraints = false
imageView.heightAnchor.constraint(equalToConstant: <your_height>).isActive = true
imageView.contentMode = .scaleAspectFit
imageView.image = <your_image>
//imageView.backgroundColor = .lightGray
// In order to center the title view image no matter what buttons there are, do not set the
// image view as title view, because it doesn't work. If there is only one button, the image
// will not be aligned. Instead, a content view is set as title view, then the image view is
// added as child of the content view. Finally, using constraints the image view is aligned
// inside its parent.
let contentView = UIView()
self.navigationItem.titleView = contentView
self.navigationItem.titleView?.addSubview(imageView)
imageView.centerXAnchor.constraint(equalTo: contentView.centerXAnchor).isActive = true
imageView.centerYAnchor.constraint(equalTo: contentView.centerYAnchor).isActive = true
}
}
I hope this helps someone,
Xavi
As question heading stated "Swift / Obj-C" so I am sharing code of Obj-C :
UIImageView *titleImage = (UIImageView *)self.navigationItem.titleView;
titleImage = [[UIImageView alloc]initWithFrame:CGRectMake((self.navigationController.navigationBar.frame.size.width/2) - (100/2), 0, 100,self.navigationController.navigationBar.frame.size.height)];
//setting the image for UIImageView
titleImage.image = [UIImage imageNamed:#"someLogo"];
titleImage.contentMode = UIViewContentModeCenter;
self.navigationItem.titleView = titleImage;
Had same issue on phones with smaller sizes. Image in title was moving to right. Causing this issue back button -> [back_button][title_view]. Its centered when there is no back button or there is right bar button. Richard Hope's was right, you just need to put UIView first, and then put UIImageView as subview. Programmatically could be done like this.
private var imageView: UIView {
let bannerWidth = navigationBar.frame.size.width * 0.5 // 0.5 its multiplier to get correct image width
let bannerHeight = navigationBar.frame.size.height
let view = UIView()
view.backgroundColor = .clear
view.frame = CGRect(x: 0, y: 0, width: bannerWidth, height: bannerHeight)
let image = UIImage(named: "your_image_name")
let imageView = UIImageView(image: image)
imageView.contentMode = .scaleAspectFit
imageView.frame = CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.height)
view.addSubview(imageView)
return view
}
The just change titleView
navigationItem.titleView = imageView
What about setting the center of your image equals to the navigationBar.center instead of setting a margin?
//assuming we already have our navigationController
let myNicelLogoWidth = 100
let myNiceLogoHeight = 50
//start positioning your logo at 0.0, 0.0
let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: myNicelLogoWidth, height: myNiceLogoHeight))
imageView.contentMode = .scaleAspectFit
imageView.center = navigationBar.center //the put your image at the center
let image = UIImage(named: "myNiceLogoImage")
imageView.image = image
navigationItem.titleView = imageView
I once face with this problem, and finally i found out that the problem is the previous navigation bar title still located next to burger button, but it's invisible.
Fast solution but not sure if it's the best is to change the previous navigation bar title to empty string before show the next view controller.
Hope it's help.

Image in top background of UITableView - iOS

I can set an image to my TableView background, but the image is in the center of the view.
How can I set the image to top ?
I'm using staticTableView
let image = UIImageView(image: UIImage(named: "img.jpg"))
self.settingsTableView.backgroundView = image
self.settingsTableView.backgroundView?.frame = CGRectZero
self.settingsTableView.backgroundView?.contentMode = UIViewContentMode.ScaleAspectFit
If you're using a static table and theres no chance of changing it you might want to take an approach like this:
override func viewDidLoad() {
super.viewDidLoad()
//Create the UIImage
let image = UIImage(named: "testing")
//Create a container view that will take all of the tableView space and contain the imageView on top
let containerView = UIView(frame: CGRect(x: 0.0, y: 0.0, width: self.view.bounds.width, height: self.view.bounds.height))
//Create the UIImageView that will be on top of our table
let imageView = UIImageView(frame: CGRect(x: 0.0, y: 0.0, width: self.view.bounds.width, height: image!.size.height))
//Set the image
imageView.image = image
//Clips to bounds so the image doesnt go over the image size
imageView.clipsToBounds = true
//Scale aspect fill so the image doesn't break the aspect ratio to fill in the header (it will zoom)
imageView.contentMode = UIViewContentMode.ScaleAspectFit
containerView.addSubview(imageView)
self.tableView.backgroundView = containerView
}
Make the cells or the headers transparent as you wish. I don't know how your UI should work. This method WON'T scroll the imageView but you can simply do it in the scrollView delegate method. Let me know if you need it to scroll and I'll help you out

Swift UIImageView Stretched Aspect

UIImageView renders the size of an image incorrectly. Using Scale Aspect Fit, if the UIImageView is a square the image is the correct aspect ratio with transparency in the areas the image does not fill.
//Image is Square & Correct Size
var imageView = UIImageView(frame: CGRectMake(0, 50, 320, 320))
imageView.clipsToBounds = true
imageView.contentMode = UIViewContentMode.ScaleAspectFit
//Image is Rectangle & Incorrect Size
var imageView = UIImageView(frame: CGRectMake(0, 50, 320, 450))
imageView.clipsToBounds = true
imageView.contentMode = UIViewContentMode.ScaleAspectFit
The UIImageView needs to touch the edges and have transparent space at the top and bottom of the screen and the image inside needs to keep its original ratio rather than stretching taller. I have attached two images of how the image inside the UIImageView is rendering.
I added an autoresizing mask to the UIImageView and it now displays the correct ratios.
imageView.autoresizingMask = UIViewAutoresizing.FlexibleBottomMargin | UIViewAutoresizing.FlexibleHeight | UIViewAutoresizing.FlexibleRightMargin | UIViewAutoresizing.FlexibleLeftMargin | UIViewAutoresizing.FlexibleTopMargin | UIViewAutoresizing.FlexibleWidth
imageView.contentMode = UIViewContentMode.ScaleAspectFit
This answer helped me: Captured photo is stretched with AVCaptureSession sessionPreset = AVCaptureSessionPresetPhoto as I was using an image that was taken through the phones camera.
I was having the same issue, and what fixed it for me was making sure to set the imageView image after the content mode was set. ie:
self.imageView.contentMode = UIViewContentMode.ScaleAspectFit
self.imageView.image = imageChosen
Cheers
Swift 3 version of your code:
imageView.autoresizingMask = [.flexibleWidth, .flexibleHeight, .flexibleBottomMargin, .flexibleRightMargin, .flexibleLeftMargin, .flexibleTopMargin]
imageView.contentMode = .scaleAspectFit // OR .scaleAspectFill
imageView.clipsToBounds = true
That's the intended behaviour for UIViewContentMode.ScaleAspectFit. From the docs:
UIViewContentModeScaleAspectFit
The option to scale the content to fit
the size of the view by maintaining the aspect ratio. Any remaining
area of the view’s bounds is transparent.
It seems from what you describe that you need UIViewContentMode.ScaleAspectFill
UIViewContentModeScaleAspectFill
The option to scale the content to
fill the size of the view. Some portion of the content may be clipped
to fill the view’s bounds.
Swift 5
You can apply UIView.ContentMode.scaleAspectFit only for UIImageView
like this:
let logoImage:UIImage = UIImage(named: "my_logo")!
let logoImageView = UIImageView(image: logoImage)
logoImageView.contentMode = UIView.ContentMode.scaleAspectFit
return logoImageView
There is a great solution here: by olearyj234 .
and it helped me a lot. I suggest taking a look. Also, here is his code in swift 4 and Xcode 9.2:
class ScaledHeightImageView: UIImageView {
override var intrinsicContentSize: CGSize {
if let myImage = self.image {
let myImageWidth = myImage.size.width
let myImageHeight = myImage.size.height
let myViewWidth = self.frame.size.width
let ratio = myViewWidth/myImageWidth
let scaledHeight = myImageHeight * ratio
return CGSize(width: myViewWidth, height: scaledHeight)
}
return CGSize(width: -1.0, height: -1.0)
}
}

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