Two identical CGSize's and one appears smaller - ios

I have an ImageView and I have a CustomView that I want to appear the same size on screen.
public override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
progress.frame.size = circle.frame.size
print("Progress frame size w: \(progress.frame.size.width) h: \(progress.frame.size.height)
print("Circle frame size w: \(circle.frame.size.width) h: \(circle.frame.size.height)
//Progress frame size w: 300 h: 300
//Circle frame size w: 300 h: 300
and yet they appear with different size on the Simulator:
I tried setting the bounds instead of frame. I also tried calculating the difference from the view to the circle and setting the progress frame according to that:
let widthDifference = UIScreen.main.bounds.width - circle.frame.size.width
let progressWidth = UIScreen.main.bounds.width - widthDifference
...
but no success.
I don't know what's happening, I am really new to iOS development and many things are weird to me.
The size of the progress bar was fine when the scene was wrapped in a NavigationController. When I removed the NavigationController the dimensions were totally screwed.
FYI: Circle is an image view. Progress is a third-party circular progress bar
Thank you for your time!

Your progress bar is indeed the same size of your circle but that doesn't mean that the bar will take the full size of 300px for diameter.
If you are curious, take a look at this line from the library, and also this line to see how the radius is created.
You can also try to print out the value of arcRadius and it must be smaller than 150px.

Related

Slider - incorrect color at the beginning and in the end

I have a custom slider where i have to increase slider's height (thickness). The code looks like this:
class CustomSlider: UISlider
{
override open func trackRect(forBounds bounds: CGRect) -> CGRect {
var defaultBounds = super.trackRect(forBounds: bounds)
let newHeight: CGFloat = 20
return CGRect(x: defaultBounds.origin.x,
y: defaultBounds.origin.y + defaultBounds.size.height/2 - newHeight/2,
width: defaultBounds.size.width,
height: newHeight)
}
}
The height is increased, but the problem now is that slider is not colored properly at the beginning and in the end. For example, at the beginning it now looks like this:
wrong color at the beginning
After some point the color becomes correct and fills blue: correct color after some point
In the end there is the same problem, at first everything works as expected: normal behavior
But then after some point the color becomes updated to blue too soon: wrong color in the end
Has anyone experienced anything similar before? Is there any solution for this?
I have tried using setMinimumTrackImage and setMaximumTrackImage instead of minimumTrackTintColor and maximumTrackTintColor, it works, but i cannot use it because when i rotate screen - slider stretches and the image which i am using stretches as well, so slider's corner radius looks stretched and not the same as it has to be.
Also an interesting fact is that the more I increase slider height - the later the correct color appears at the beginning.
Since setting track images is working and the only issue is stretched corners, the latter can be solved by using resizableImage(withCapInsets:) on your track images, so only the middle part of the image will be stretched and the rest will remain untouched.
These articles cover the topic in great details:
https://www.natashatherobot.com/ios-stretchable-button-uiedgeinsetsmake/
https://www.hackingwithswift.com/example-code/media/how-to-make-resizable-images-using-resizableimagewithcapinsets

Swift button frame height issue (viewDidLayoutSubviews)

I've got some square buttons that I'd like to add rounded corners to that are proportional to the button's height. In past versions of my app, I had implemented this feature without issues using viewDidLayoutSubviews(). For some reason, after pushing a new version of my app with other features I had tweaked, this section of code no longer functions as expected. Here is the code:
override func viewDidLayoutSubviews() {
for button in buttons {
button!.layer.shadowColor = UIColor.black.cgColor
button!.layer.shadowOffset = CGSize(width: 0, height: 1.0)
button!.layer.shadowOpacity = 0.4
button!.layer.shadowRadius = button!.frame.height / 40
button!.layer.cornerRadius = button!.frame.height / 10
}
Again, this block of code used to work just fine but for some reason it no longer works. What I am experiencing is much larger relative radii on smaller buttons (iPhone SE) compared to bigger buttons (iPads).
To troubleshoot, in viewDidLayoutSubviews(), I'm printing the button!.frame.height and I'm noticing that no matter what device I use the frame height is 395.5, which I believe is the correct size only on the 12.9" iPad. Therefore, the buttons look correct on the 12.9" iPad but the radii end up being too large on all of the smaller devices.
Any idea what's going on here? Why is it that they're all returning the same frame height even though they're visually very different sizes on the different devices?
I copy and pasted the above code into the viewWillAppear() method and
the problem was resolved. I then deleted the code from
viewWillAppear(), leaving me with my original code during posting of
question, and it is continuing to run as expected (working). What
could possibly be the cause of this intermittent behavior
The reason when you initialized the buttons in viewWillAppear and remove them but it still work because your button's frame did not change in the viewDidLayoutSubview method. And the viewDidLayoutSubview is invoked only controller's view is updated, rotated, or changed, which in your case it does not.
If you try to rotate your device you will see your parent view's frame changed.
For more information about view hierarchy. See this article
Try like this:-
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
for button in buttons {
button!.layer.shadowColor = UIColor.black.cgColor
button!.layer.shadowOffset = CGSize(width: 0, height: 1.0)
button!.layer.shadowOpacity = 0.4
button!.layer.shadowRadius = button!.frame.height / 40
button!.layer.cornerRadius = button!.frame.height / 10
}

Full width view does not contain same frame width as parent

I'm having an issue where I have a UIImageView that spans the entire width of the screen using the following constraints.
Align Leading to : Superview (Equals: -20)
Align Trailing to : Superview (Equals: -20)
Top Space to : Top Layout Guide (Equals: 0)
Aspect Ratio : 1:1
The image assumes the width of the screen while gaining aspect ratio (in this case a square). The issue comes with when I started attempting to make a circle out of the image, that I noticed that my UIIMageView's frames do not have proper values.
You'll have to excuse to code below for not being in Objective-C as I'm using Java through RoboVM but with very little effort you can mentally convert the code to Objective-C as it's pretty straightforward.
public class MyViewController extends UIViewController {
#IBOutlet private UIImageView myImageView;
#Override public void viewDidLoad() {
System.out.println("Image view width: " + myImageView.getFrame().getWidth());
System.out.println("Superview width: " + this.getView().getFrame().getWidth());
}
}
The results of running the application with this Controller shows the following:
Image view width: 240.0
Superview width: 320.0
When cutting the frame width of the image in half and applying that to the CALayer#cornerRadius property, the image does not make a complete circle, however when using half of the superviews width (Which is actually the size of the image) the result is a perfect circle.
In viewDidLoad, it has just loaded your view from the XIB or storyboard, not sized it yet. The size should be correct when viewWillAppear is called. So try putting your code in viewWillAppear and see if that helps.
The reason you need the -20 margin is because your superview has a margin of 20, and the constraints are created by default to 'Relative to margin' - if you uncheck that, you can set the 'real' constraint - in this case zero rather than -20
If you select the constraint in the assistant editor, you will see the check box to toggle this value

iPhone - resizing image and two labels to fit the screen

I'm new to iPhone developing. I have a screen with image, title and content:
Image has dynamic size and also all text can have any length. What I want to achievie is to fit the image exactly in screen and make all labels to be only as long as they should be.
Afterk about 5 hours of work I have:
Working labels length, achieved by setting Lines=0 and Preferred Width=content width
Not working image, which lefts blank spaces
I have read a lot, I understand Content Hugging Priority and Content Compression Resistance Priority. I know differences in UIViewContentMode. I know that I can manually set UIImage.frame=CGRectMake(...). Nothing works. My image is more wider than higher (lets assume that width/height = 3). If I have UIViewContentMode=Aspect Fit then I will have blank space above and below the image. If set to Aspect fill then image is too high and also cropped. Changing frame in code doesn't change anything in view. What I want is to have image with size that was made using Aspect fit, but without blank space.
Finally I dit it. First of all, everyone writes that UIImageView.Frame should be modified to shrink the image, but be aware, that if your view is UITableViewCell then you should do that in layoutSubviews method (remember to invoke super.layoutSubviews() at the begging).
Secondly, make in IB a height constraint for your UIImageView for temporary value (for example 100). You will change that constraint in layoutSubviews method.
And finally: fitting image is NOT about its ratio. Set UIViewContentMode=Aspect Fit. Then the case with blank top and bottom areas occurs only when the initial image is wider than screen. Calculating the proper height should also take place in layoutSubviews.
Example implementation:
override func layoutSubviews() {
super.layoutSubviews()
var imageWidth = (imageViewObject.image?.size.width)!
var imageHeight = (imageViewObject.image?.size.height)!
var frameWidth = UIScreen.mainScreen().bounds.width
var properHeight: CGFloat
if imageWidth > frameWidth {
var ratio = frameWidth / imageWidth
properHeight = imageHeight * ratio
}
else {
properHeight = imageHeight
}
imageHeightConstraint.constant = properHeight
imageViewObject.frame = CGRectMake(0, 0, frameWidth, properHeight)
}

issues with UIImageView.layer.cornerRadius to create rounded images on different pixel densities ios

I'm simply trying to create a perfectly round image. Here's my swift code:
myImage.layer.cornerRadius = myImage.frame.size.width/2
myImage.layer.masksToBounds = true
This works on a 4s, but is not quite round on a 5s, and appears as a rounded rectangle on a iphone 6.
I'm assuming this has to do with frame.size.width returning values in pixels not points or something like that, but I've been unable to solve this problem.
If you're putting that code in viewDidLoad, try moving it to viewDidLayoutSubviews.
I'm guessing it's an auto layout issue -- although you've used the corner radius property appropriately and are in fact making the image frame circular, after auto-layout, the corner radius stays the same, but the image stretches so that it's no longer circular.
If your code is in viewDidLoad in ViewController, try moving it to viewDidLayoutSubviews.
If your rounded imageView is in tableViewCell, try moving it to draw.
override func draw(_ rect: CGRect) {
avatarView.layer.cornerRadius = avatarView.frame.size.width / 2
avatarView.layer.masksToBounds = true
avatarView.clipsToBounds = true
avatarView.contentMode = .scaleAspectFill
}
The problem is that if you change the cornerRadius of Any view, and expect it to look like a circle, the view has to be a square.
Now, because of different devices and different device size, the size of your image view might change and it may be a rectangle.
For e.g.
If you view is a 50 * 50
myImage.layer.cornerRadius = myImage.frame.size.width/2
This would add corner radios of 25 on both sides to make it a circle.
But because of auto layout of device change, your view might be a 50 * 80
Corner radius would add a 25, but as the height is 80, it will add 25 on both sides, and the remaining 30 won't be a curve and look straight.
What you can do is try viewing the screen in various orientations in the storyboard and change auto layout Constraints (Or structs and springs) to ensure that the image view is a square in all the devices
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
myImage.layer.cornerRadius = myImage.frame.size.width/2
myImage.layer.masksToBounds = true
}
This should work:
myImage.layer.cornerRadius = myImage.**bounds**.size.width/2
myImage.layer.masksToBounds = true

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