What's the difference between view and superview? - ios

What´s the difference between view and superview?
let fromViewController = self.source
let containerView = fromViewController.view.superview

Suppose that
let v1 = UIView()
parent.addSubview(v1)
here
v1 ----- >>> v1 ( The view itself )
v1.superview ------- >>> parent

Views are the fundamental building blocks of your app's user interface, and the UIView class defines the behaviors that are common to all views. A view object renders content within its bounds rectangle and handles any interactions with that content.
let rect = CGRect(x: 10, y: 10, width: 100, height: 100)
let myView = UIView(frame: rect)
The superview is the immediate ancestor of the current view. The value of this property is nil when the view is not installed in a view hierarchy. To set the value of this property, use the addSubview(_:) method to embed the current view inside another view.
let rect = CGRect(x: 10, y: 10, width: 100, height: 100)
let myView = self.view.addSubview( UIView(frame: rect))

Related

only last added view is visible in UIScrollView iOS

I am facing an issue with scrollView. I have added scrollView in my storyboard as
View
- MainView
- ScrollView
- accountSavingSubView
Now I am trying to add views in accountSavingSubView as below
//MARK:- Create and add wallets on the UI
private func createAndAddWallets()
{
var yPosition : CGFloat = 0.0
//1. Create left hand side wallets with help of keys
for key in dictData.keys
{
let walletView:Wallet = Bundle.main.loadNibNamed("Wallet", owner: self, options: nil)?.first as! Wallet
walletView.translatesAutoresizingMaskIntoConstraints = false
walletView.frame = CGRect(x: 0.0, y: yPosition, width: accountSavingSubView.frame.width, height: accountSavingSubView.frame.height)
walletView.accountNameLabel.text = key
accountSavingSubView.addSubview(walletView)
yPosition += walletView.frame.maxY
walletView.isUserInteractionEnabled = true
print("walletView frame is :\(walletView.frame)")
}
//set continer scroll content size
self.contanerScrollView.contentSize = CGSize(width: self.accountSavingSubView.frame.width, height: CGFloat(80.0/320.0)*UIScreen.main.bounds.width*CGFloat(self.dictData.keys.count))
}
Where dictData is a dictionary of ([String: String]).
But in my view, I can see only last view is added on (x=0, y=0). ScrollView content size is correct & I can scroll without having views except last one at first place(x:0,y:0).
Please let me know what am I doing wrong here in my code while adding views.
You need to comment this
walletView.translatesAutoresizingMaskIntoConstraints = false
as it's used with setting constraints only ,and verify that the supplied frame values here are not 0
walletView.frame = CGRect(x: 0.0, y: yPosition, width: accountSavingSubView.frame.width, height: accountSavingSubView.frame.height)
btw you can also comment it as the frame will be captured as you set it in xib if you make it freedom size

Programmatically adding UILabel is not visible

I'm trying to practice here, I have a SearchBar in my view and i've used
func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String)
Once the user starts writing, I hide on of my views, and make another one programmatically
Here's my concept, Once i start writing, my 2nd view comes in:
But once i get the second view properly added, i'd like to add a UILabel to it. Here's my code:
self.word_of_the_day_view.isHidden = true // main view
self.popularView.frame = CGRect(x: self.searcy_bar_view.frame.minX, y: self.searcy_bar_view.frame.maxY + 15, width: self.searcy_bar_view.frame.width, height: self.searcy_bar_view.frame.height) // don't mind the height and width
self.popularView.backgroundColor = .white
self.popularView.layer.cornerRadius = self.searcy_bar_view.layer.cornerRadius
self.popularView.popIn() // just an animation
is_popular_added = true
self.view.addSubview(popularView)
let label_1 = UILabel()
label_1.frame = CGRect(x: self.popularView.frame.minX + 3, y: self.popularView.frame.minY, width: self.popularView.frame.width, height: 20)
label_1.font = UIFont(name: "avenirnext-regular", size: 13)
label_1.text = "Hello World!"
label_1.layer.borderColor = UIColor.red.cgColor
popularView.addSubview(label_1)
But on runtime, the UILabel isn't even added.
Thank you so much for even reading the question!
You need to understand the difference between Frame and Bounds.
The Frame of the view is the position of the view in it's super view, so his origin can have any value of a CGPoint.
The Bounds are just the view itself, so it always have an origin of (0,0)
I think the problem is
label_1.frame = CGRect(x: self.popularView.frame.minX + 3, y: self.popularView.frame.minY, width: self.popularView.frame.width, height: 20)
try to change in
label_1.frame = CGRect(x: self.popularView.bounds.minX + 3, y: self.popularView.bounds.minY, width: self.popularView.frame.width, height: 20)
or
label_1.frame = CGRect(x: 3, y: 0, width: self.popularView.frame.width, height: 20)
In your code
label_1.frame = CGRect(x: self.popularView.frame.minX + 3, y: self.popularView.frame.minY, width: self.popularView.frame.width, height: 20)
This is because self.popularView.frame.minX and self.popularView.frame.minY have some +value that crosses the boundary of the current view on which you are trying to add label_1.
you should use self.popularView.bounds.origin.x and self.popularView.bounds.origin.y
Difference between bounds and frame
frame = a view's location and size with respect to the parent view's coordinate system
bounds = a view's size using its own coordinate system
This issues is due to confusion between frames and bounds. I also got similar issue in on of my app.
The bounds of an UIView is the rectangle, expressed as a location (x,y) and size (width,height) relative to its own coordinate system (0,0).
The frame of an UIView is the rectangle, expressed as a location (x,y) and size (width,height) relative to the superview it is contained within.
you should use self.popularView.bounds.origin.x and self.popularView.bounds.origin.y in place of self.popularView.frame.minX and self.popularView.frame.minY

Getting details about the pinch gesture in ARKit

In my project I have a pinch to resize option for the object that has been placed in scene view. But when someone pinch the screen to reduce or enlarge the actual size of the object I need to get that scale. I need to display the scale in which the object is being changed in the screen. How do I get the scale when the action is being performed?
Thank you
Within your main ViewController Class for the ARSCNView
declare the label view, and the label itself at the top.
let scaleLabel = UILabel(frame: CGRect(x: 0, y: 0, width: 300, 70))
let labelView = UIView(frame: CGRect(x: 300, y: 300, width: 300, height: 70))
Now within LoadView or ViewDidLoad you can set the attributes for the label such backgroundColor, textColor etc... and also add the view and label to sceneView.
// add your attributes for label,view
labelView.backgroundColor = .clear
scaleLabel.textColor = .white
scaleLabel.adjustsFontSizeToFitWidth
// add you views to sceneView
labelView.addSubview(scaleLabel)
sceneView.addSubview(labelView)
Lastly, with the pinch gesture function for scaling.. which should look something like this.
#objc func pinchGesture(_ gesture: UIPinchGestureRecognizer) {
if nodeYouScale != nil {
let action = SCNAction.scale(by: gesture.scale, duration: 0.1)
nodeYouScale.runAction(action)
gesture.scale = 1
// this part updates the label with the current scale factor
scaleLabel.text = "X: \(nodeYouScale.scale.x) Y: \(nodeYouScale.scale.y) Z:\(nodeYouScale.scale.z)"
} else {
return
}

iOS - Display a progress indicator at the center of the screen rather than the view

I want to display a progress indicator at the center of the screen, NOT the view. It should be the center of the view because the view is scrollable. Most answers only tells how to center it in the view. I have this code:
let screenBound = UIScreen.main.bounds
let progressIndc = UIActivityIndicatorView()
progressIndc.frame = CGRect(x: screenBound.width / 2 - 10,
y: screenBound.height / 2 - 10,
width: 20, height: 20)
progressIndc.hidesWhenStopped = true
progressIndc.color = UIColor.gray
progressIndc.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.gray
// self.view is scroll view
self.view.addSubview(progressIndc)
progressIndc.startAnimating()
But it shown near the top in iPhone 7. What should be the right way? I can also do a blocking pop-up dialog with a progress indicator.
if you want to keep the indicator view at the center of screen while scrolling, you can add a overlay view to the current topmost UIWindow, then add your indicator view to the overlay view:
guard let topWindow = UIApplication.shared.windows.last else {return}
let overlayView = UIView(frame: topWindow.bounds)
overlayView.backgroundColor = UIColor.clear
topWindow.addSubview(overlayView)
let hudView = UIActivityIndicatorView()
hudView.bounds = CGRect(x: 0, y: 0, width: 20, height: 20)
overlayView.addSubview(hudView)
hudView.center = overlayView.center
you should do this after the topmost UIViewController's view was attached on the top UIWindow, for example, in viewDidAppearmethod.
you can use center property of UIView
progressIndc.center = self.view.center
for e.g
let screenBound = UIScreen.main.bounds
let progressIndc = UIActivityIndicatorView()
progressIndc.frame = CGRect(x: screenBound.width / 2 - 10,
y: screenBound.height / 2 - 10,
width: 20, height: 20)
progressIndc.hidesWhenStopped = true
progressIndc.color = UIColor.gray
progressIndc.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.gray
// self.view is scroll view
progressIndc.center = self.view.center
self.view.addSubview(progressIndc)
progressIndc.startAnimating()
output
you can try this one to add you indicator on top of the screen. but it's not pretty solution -
AppDelegate.sharedInstance.window?.addSubview(progressIndc);

Frame on ViewController

I have this class:
extension UIViewController {
func waiting() -> UIView{
let strLabel = UILabel(frame: CGRect(x: 50, y: 0, width: 200, height: 50))
strLabel.text = "Aguarde..."
strLabel.textColor = UIColor.whiteColor()
let messageFrame = UIView(frame: CGRect(x: view.frame.midX - 90, y: view.frame.midY - 25 , width: 180, height: 50))
messageFrame.layer.cornerRadius = 15
messageFrame.backgroundColor = UIColor(white: 0, alpha: 0.40)
let activityIndicator = UIActivityIndicatorView(activityIndicatorStyle: UIActivityIndicatorViewStyle.White)
activityIndicator.frame = CGRect(x: 0, y: 0, width: 50, height: 50)
activityIndicator.startAnimating()
messageFrame.addSubview(activityIndicator)
messageFrame.addSubview(strLabel)
view.addSubview(messageFrame)
return messageFrame
}
}
When I need use this class I use:
class MyController: UIViewController{
....
func x(){
let messageFrame = waiting()
//my code
messageFrame.removeFromSuperview()
}
}
The problem is when the frame is showed if I touch anywhere on my app this frame is hidden. I need that when this frame is showed other options staying disabled, when I finish the frame, the options of app is enabled again. How can I do it?
Change the view that you are returning a bit:
Make a "container" view that has the same frame as the view controller's view. Give this view a "clear" background.
Make a "background" view, same size as the "container" view and add it to the container. Give this view a black background and an alpha of, say, 0.4.
Now put the view that you are currently building in your "waiting" method, and add it to the "container" view (NOT to the background view, this should be a sibling of the background view, otherwise your alert will also be transparent).
Make sure all user interaction is disabled on your views (might only need it disabled on the "container" view).
This gives you a container view that covers the entire screen, and it has 2 children: a transparent background of the same size, and your current "waiting" alert thing.
Now if you add the "container" view to your view controller's view, the user can only touch on the container view which does nothing.
(Keep in mind that this doesn't handle screen rotation...you will have to do that yourself if needed.)

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