I am trying to make an overlaying view which just makes the screen turn red. However, even if I set the background color to any color, it just shows as gray. I can still maneuver it around the screen, I just can't change the color for some reason.
Here's what I put into my didMove to view function:
let pulseView = SKView(frame: self.view!.frame)
pulseView.backgroundColor = SKColor.red
pulseView.alpha = 1
self.view?.addSubview(pulseView)
I know it may sound a little bit of a drag to ask this question but I am curious if anything like this is available.
I am building a app in which the background image (covers full view with a blur effect) of each view controller changes dynamically. This background image will be in all the view controllers, each one having a different set of UIControls (Labels, Buttons, Table Views, Collection Views, containers, tabs, etc).
Sometimes when the background image is very light, the foreground texts (labels, buttons) with white text colour are not visible at all. Also the vice versa is a problem too.
So I would like to know if there is any way to change the foreground text colour dynamically based on its background.
Recently I faced the same problem, And I think what you looking for is either image is bright or dark so that you can set property accordingly Hope this will help.
Create observer, everytime image change it will check if its a dark image or bright and based on that will call the function UIForDarkImage and UIForBrightImage
//ImageView observer to observe the image change and perform the UI action based on the image colour
//Your imageView you are using to set image
var imageView: UIImageView {
didSet {
if imageView.isDark(image.bounds) { //dont pass the full image bounds pass the rect where your buttons or label places it will save your hell lot of time
setUIForDarkImage() // here you set buttons and labels color to white or whatever changes you want to perform based dark image
}
else {
setUIForBrightImage() // here you set buttons and labels color to black or whatever changes you want to perform based bright image
}
}
}
UIImageViewExtension for checking if Image is a dark image or bright Image.
What happening is, It will go through image pixel-by-pixel and check if the pixel is bright or dark and if we get dark pixels more than the threshold we have set, we will assuming that its a dark image else it's a bright image.
PS: For better efficiency not checking the whole image (for a high-resolution image it will slow down if we will check all pixels) so only checking the part of the image in which we need our button or label, you can set rect based on your requirement. And also scaling by 0.45 to check few pixels in that rect(you can increase or decrease for more/less accuracy).
extension UIImageView {
func isDark(_ rect:CGRect)->Bool {
let s=image?.cgImage?.cropping(to: rect);
let data=s?.dataProvider?.data;
if data == nil {return false;}
guard let ptr = CFDataGetBytePtr(data) else {return false;}
let threshold = Int(Double(rect.width * rect.height) * 0.45);
var dark = 0,len=CFDataGetLength(data);
for i in stride(from: 0, to: len, by: 4) {
let r = ptr[i], g = ptr[i+1], b = ptr[i+2];
if (0.299 * Double(r) + 0.587 * Double(g) + 0.114 * Double(b)) < 100 {dark += 1;}
if dark > threshold {return true;}
}
return false;
}
}
PS: If you also like to know what I am doing in setUIForBrightImage() and setUIForDarkImage do let me know
Here's what I would do: Create a struct that contains the name of the image view and a tint color to use for your labels, buttons, etc.
Add a property to your view controllers using this new struct. Let's call it backgroundImageSettings.
Add a didSet method to the property that calls another method useBackgroundImageSettings() that installs the image into the background of the view controller's content view, sets the tint color for the view controller's content view, and calls setNeedsDisplay() on the content view.. Also call useBackgroundImageSettings() in your viewDidLoad so that setting your backgroundImageSettings still works even if you view controller's view hasn't been loaded yet.
I like Duncan's answer! An additional step you can take is to set a slight overlay onto your background image.
For example, if you have a background image with really dark colors and you can't see your black text very well, then you can add a layer with a background color of white and an opacity less than 1. That way there's a bit of white to make your text more readable, and you can still see the background image.
let overlay = UIView(frame: yourSuperView.bounds)
overlay.backgroundColor = UIColor.white
overlay.layer.opacity = 0.5
yourSuperView.addSubview(overlay)
I am implementing a popover view using UIPopoverPresentationController.
The trouble with this, is that by default, I have a shadow with a large radius for the controller.
I want to disable this - the overlay.
I have tried:
to customise the layout shadow (using a UIPopoverBackgroundView):
layer.shadowColor = UIColor.white.withAlphaComponent(0.01).cgColor
layer.shadowOffset = .zero
layer.shadowRadius = 0
In view debugging - I can see behind the popup 4 image views with gray gradient background:
I am sure this is a default behaviour, of showing an overlay behind a popover.
How do disable this?
I found this and this. But those didn't helped.
If you take a closer look at the views hierarchy you will notice that the shadow layer _UIMirrorNinePatchView is a sublayer of UITransitionView same as UIPopoverView - both are on the same level.
views hierarchy picture
In this case you can try to hide this sublayer like so:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if let shadowLayer = UIApplication.shared.windows.first?.layer.sublayers?[1].sublayers?[1] {
shadowLayer.isHidden = true
}
}
Make sure to hide it in viewDidLayoutSubviews to avoid exceptions related to missing sublayers or sublayer flickering.
I've to make my navigation bar transparent, I tried with this code :
self.navigationController?.navigationBar.setBackgroundImage(UIImage(), for: UIBarMetrics.default)
self.navigationController?.navigationBar.shadowImage = UIImage()
self.navigationController?.navigationBar.isTranslucent = true
self.navigationController?.view.backgroundColor = UIColor.clear
But my navigation bar become white, I don't understand the reason!
Can someone help to solve this problem?
You are doing right way to make transparent UINavigationBar but seem like you have a wrong constraint. Make sure you top constraint of your scrollView is equal to Superview.Top.
If your top constraint of your scrollView is equal to Safe Area.Top, of course your ScrollView won't scroll below UINavigationBar.
When I select a cell on a table view it by default changes it's ContentView background colour to a light grey and I am trying to override this.
And I am using the following code to remove this grey colour from the selection. But it is removing the background colour of everything (UIViews, UIImageViews) inside that cell.
Is there a way to eliminate the background colour of the ContentView only?
let changeselectionColor = UIView()
changeselectionColor.backgroundColor = UIColor.clearColor()
cell.selectedBackgroundView = changeselectionColor
I have the following table view cell.
This is how it should look like when selected
This is how it end up looking with all BGs transparent
You don't need to override anything to achieve the effect, actually UITableViewCell provides the API to remove the highlight gray:
cell.selectionStyle = UITableViewCellSelectionStyle.None