I´ve looked around but can´t find a solution...
I have a MPVolumeView in my app to control the unit´s system volume. I changed the MPVolumeView SliderThumbImage to an image of my own and what I´ve noticed is 2 bugs:
Bug 1 :
The thumb image sometimes gets offset horizontally to the right.
this usually happens when I run from Xcode and the phone´s volume is at maximum. see the image where the bug happened and I bring the volume down to a minimum.
if I bring the volume to minimum, close the app and reopen it, it will be put at the correct location. I think it may have something to do with how the units volume translates into a value for the slider and where the image gets positioned according to said value, but I´m unsure how to solve this. Bug 1
Bug 2: Apple´s own volume indicator layer sometimes shows up and sometimes does not.
I would rather it didn´t at all.
I use a view in the storyboard which I classed MPvolumeView and then in the viewdidload I use the following code to put the image
let faderknob : UIImage = UIImage.init(imageLiteralResourceName:"faderknob50.png")
func setVolumeThumbImage(_ image: UIImage?,for state: UIControl.State){
volumeView.setVolumeThumbImage(faderknob, for: .normal)
volumeView.showsRouteButton = false
}
setVolumeThumbImage(faderknob, for: .normal)
any help on how to fix theses 2 bugs would be great!
Thanks
Was also experiencing your first bug: how higher the volume, how greater the offset of the thumbimage to the right on intial appearance of the volumeview. When the app is relaunched from the background the offset is gone.
When overriding volumeSliderRect in a subclass, the problem is solved:
import MediaPlayer
class VolumeView: MPVolumeView {
override func volumeSliderRect(forBounds bounds: CGRect) -> CGRect {
return bounds
}
}
A side effect is that the thumb image now gets animated from the left to the initial position on first appearance. Actually looks not too bad in my opinion.
As you now have your own subclass, you can set your custom thumbimage during init:
import MediaPlayer
class VolumeView: MPVolumeView {
required init?(coder: NSCoder) {
super.init(coder: coder)
commonInit()
}
override init(frame: CGRect) {
super.init(frame: frame)
commonInit()
}
func commonInit() {
setValue(false, forKey: "showsRouteButton") // no deprecated warning
setVolumeThumbImage(UIImage(named: "volume.slider.thumb"), for: .normal)
}
override func volumeSliderRect(forBounds bounds: CGRect) -> CGRect {
return bounds
}
}
Related
I'm writing nib-less views in which I use autolayout for all my layout logic. I find myself having to turn off autoresizing with every view I instantiate. My code is littered with a lot of these:
view.translatesAutoresizingMaskIntoConstraints
Ideally I'd like to just
extension UIView/NSView {
override var translatesAutoresizingMaskIntoConstraints: Bool = false
}
and get it over with once and for all, but extensions can't override stored properties.
Is there some other simple way to switch off autoresizing for good?
Well just a suggestion since its annoying to always set that to false, just setup a function with all the shared setups for the UIView and call it every time,
its saves time and its kinda less annoying than trying and setting the values each time,
extension UIView {
func notTranslated() {
self.translatesAutoresizingMaskIntoConstraints = false
//Add any additional code.
}
}
//Usage
let view = UIView()
view.notTranslated()
You can't override this constraints properties because the UIView maybe declared in the IB
translatesAutoresizingMaskIntoConstraints according to apple.
By default, the property is set to true for any view you programmatically create. If you add views in Interface Builder, the system automatically sets this property to false.
imagine if you could override that from an extension that would lead to some conflicts if there was other UIView's that's have the opposite value True || false, so in my opinion:
Apple did this to prevent any conflicts with the views constrains, therefore if you don't like to write it every time just wrap it up in a function.
Please if anyone have additional information, don't hesitate to contribute.
UPDATE: I found this cool answer that could also work, check out the code below.
class MyNibless: UIView {
//-----------------------------------------------------------------------------------------------------
//Constructors, Initializers, and UIView lifecycle
//-----------------------------------------------------------------------------------------------------
override init(frame: CGRect) {
super.init(frame: frame)
didLoad()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
didLoad()
}
convenience init() {
self.init(frame: CGRect.zero)
}
func didLoad() {
//Place your initialization code here
//I actually create & place constraints in here, instead of in
//updateConstraints
}
override func layoutSubviews() {
super.layoutSubviews()
//Custom manually positioning layout goes here (auto-layout pass has already run first pass)
}
override func updateConstraints() {
super.updateConstraints()
//Disable this if you are adding constraints manually
//or you're going to have a 'bad time'
//self.translatesAutoresizingMaskIntoConstraints = false
translatesAutoresizingMaskIntoConstraints = false
//Add custom constraint code here
}
}
var nibless: UIView = MyNibless()
//Usage
nibless.updateConstraints()
print(nibless.translatesAutoresizingMaskIntoConstraints) //false
So simply just create MyNibless instance as UIView and this also open big door to customizations too
I setup UILabel appearance in my app delegate using:
UILabel.appearance().textColor = UIColor.white
I also have a custom UIView subclass that contains a UILabel along with some other elements (omitted here):
#IBDesignable
class CustomView: UIView {
private let descriptionLabel = HCLabel()
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
}
override func awakeFromNib() {
super.awakeFromNib()
self.setup()
}
private func setup() {
self.descriptionLabel.textColor = UIColor.black
// ... other things not related to descriptionLabel
}
}
If I instantiate CustomView in a storyboard, everything works just fine. If, however, I instantiate it in code, the descriptionLabel is white (appearance color), not black (the color I set). What's going on here? The way I understood it was that if I set a custom color, the appearance color will not be used.
What you're experiencing is simply a matter of the exact timing with which the UIAppearance proxy applies its settings to a new UIView. When are we to suppose it does this? It can't possibly do it before init, because init is the first thing that happens in the life of the UIView. Thus, the order of events is like this:
override init(frame: CGRect) {
super.init(frame: frame)
setup() // black
}
// and some time later, UIAppearance proxy comes along and sets it to white
So your goal is to call setup pretty early in the life of the label — and certainly before the user ever has a chance to see it — but not so early that the UIAppearance proxy acts later. Let's move the call to setup to a bit later in the life of the label:
// some time earlier, UIAppearance proxy sets it to white
override func didMoveToSuperview() {
setup() // black
}
Now we're acting after the appearance proxy has had a chance to act, and so your settings are the last to operate, and they win the day.
We remain in ignorance of how early we could move the call to setup and still come along after the appearance proxy setting has been obeyed. If you have time, you might like to experiment with that. For example, willMoveToSuperview is earlier; if you call setup there (and not in didMoveToSuperview), does that work? Play around and find out!
This all worked yesterday under Xcode 9 and iOS 11; however, after updating to Xcode 10 and iOS 12, the view is no longer showing. I was having a video displayed inside a view. Today I could hear but not see the video. I checked the frame and found it to be zero which explained the issue. However, nothing had changed from the prior version. I have removed the video stuff and have just looked at the view's frame after anchor constraints were applied and they are all zero.
import UIKit
import AVKit
class VideoView: UIView {
private var videoURL:URL!
private var parentView:UIView!
private var avPlayer:AVPlayer!
private var avPlayerLayer:AVPlayerLayer!
init(url:URL, parentView:UIView) {
super.init(frame: .zero)
self.videoURL = url
self.parentView = parentView
setup()
}
private func setup() {
self.translatesAutoresizingMaskIntoConstraints = false
self.parentView.addSubview(self)
self.topAnchor.constraint(equalTo: self.parentView.safeAreaLayoutGuide.topAnchor, constant: 10).isActive = true
self.leadingAnchor.constraint(equalTo: self.parentView.leadingAnchor, constant: 8).isActive = true
self.trailingAnchor.constraint(equalTo: self.parentView.trailingAnchor, constant: -8).isActive = true
self.heightAnchor.constraint(equalToConstant: 200).isActive = true
print(self.parentView.frame)
print(self.frame)
}
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
}
notice the two print statements at the end of setup(). The parentView return 0,0,414,736. The self view returns 0,0,0,0.
If in Init I set the frame size it will respect it; however, it does not apply the anchor constraints so the size of the view will remain whatever it is I put into the init.
It appears that the anchor constraints are not at all being taken into account. There is no error in the debugger about them and as we can see, translatesAutoresizingMaskIntoConstraints is set to false and all constraints have the isActive set to true.
Only the Xcode and iOS version have changed. What am I missing?
Update 1:
If I create a label and add it to self, the label shows fine. If I create a background color for self that also shows fine including the proper height as set with the anchor constraints. However, the frame remains at zero. So when trying to add an AVPlayerLayer by setting its frame to the bounds of self it doesn't work because of course self remains at zero. So the question remains as to why the frame's dimensions are not changing after initialization.
Update 2:
I added a self.layoutIfNeeded() just after applying the anchor constraints and that seems to have solved the issue. Although looking at the frame for self and I get -199,-100,398,200 Cannot say I understand the values for X and Y. Nevertheless the layOutIfNeeded seems to have solved the problem although why this is required in Xcode 10/ iOS 12 is also a mystery.
I posted what seems to be the answer in my second update, but for clarity:
I added a self.layoutIfNeeded() just after applying the anchor constraints and that seems to have solved the issue. Although looking at the frame for self and I get -199,-100,398,200 Cannot say I understand the values for X and Y. Nevertheless the layOutIfNeeded seems to have solved the problem although why this is required in Xcode 10/ iOS 12 is also a mystery.
I am working through the "Start Developing iOS Apps" tutorial provided by Apple, and having a problem in the Implement a Custom Control section. I have tried everything to get the button to print something to the console, but can't get it to work. I am on the section in the tutorial "Add Buttons to the View" about a fifth of the way down the page.
Everything else works fine.
I have set up the RatingControl.swift file as follows:
import UIKit
class RatingControl: UIView {
// MARK: Initialisation
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
// Create a square button
let button = UIButton(frame: CGRect(x: 0, y: 0, width: 44, height: 44))
// Set the background colour of the button
button.backgroundColor = UIColor.darkGray
button.addTarget(self, action: #selector(RatingControl.ratingButtonTapped(_:)), for: .touchDown)
// Add the button to the view
addSubview(button)
}
// MARK: Button Action
func ratingButtonTapped(_: UIButton) {
print("Button pressed")
}
}
A few things there are slightly different to the tutorial, but that is because Xcode says things have changed.
In my Main.storyboard file I have added a View using the RatingControl class. The button displays but nothing happens when I click it.
Any help would be appreciated. If any extra information is needed please let me know.
There is actually a hierarchy of three views in this story:
A stack view (not mentioned in the original question)
The RatingControl
The button
Well, the stack view, a complicated control whose job involves a lot of voodoo with the constraints of its arranged subviews, is reducing the size of the RatingControl to zero. The button is thus outside the RatingControl's bounds (easily proved by giving the RatingControl a background color — the background color doesn't appear). The RatingControl does not clip to its bounds, so the button is still visible — but, being outside its superview, it is not tappable.
As for why the stack view is reducing the size of the RatingControl to zero: it's because the RatingControl has no intrisicContentSize. The reason why we need this is complicated and has to do with how a stack view manipulates its arranged subviews and gives them constraints. But in essence, it makes a lot of its decisions based on an arranged view's intrinsicContentSize.
In the comments you said:
In size inspector it has intrinsic size set to placeholder, width 240, height 44. Or is there something I need to do to stop the stack view making it zero sized?
The key thing to understand here is that that setting in the size inspector is only a placeholder. It is merely to shut the storyboard up so that it won't complain. It doesn't actually give the view any intrinsic size at runtime. To do that, you must actually override the intrinsicContentSize property, in your code, as a computed variable returning an actual size.
Looks like you're stumbling through the "Start Developing iOS Apps (Swift)" tutorial before it's updated for iOS 10 and Swift 3. Amazing you've made it this far! Anyhow, #matt has a great technical explanation below but did not include the actual code to get your tutorial working:
Add the following to your class definition (outside the init function):
override var intrinsicContentSize: CGSize {
return CGSize(width: 240, height: 44)
}
then your code will work : -
class RatingView: UIView {
// MARK: Initialisation
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
// Create a square button
let button = UIButton(frame: CGRect(x: 200, y: 100, width: 44, height: 44))
// Set the background colour of the button
button.backgroundColor = UIColor.darkGray
button.addTarget(self, action: #selector(self.ratingButtonTapped(_:)), for: .touchDown)
// Add the button to the view
addSubview(button)
}
// MARK: Button Action
func ratingButtonTapped(_: UIButton) {
print("Button pressed")
}
}
Problem solved. See end of post.
Sorry if this is a bit long but I'm hoping I've included as much info to get this solved.
Brief overview of problem: Enter value in a textField using my custom keypad. Tap done button(should trigger view.endEditing) and some textFields will cause the app to freeze, most the time Xcode won't even throw an error but instead just restart the app, but i did catch one once(pic below). It works as expected on some textFields.
So I have a view controller with a bunch of textFields for the user to fill out which then performs calculations.
I have made a custom Keypad which essentially is the decimal pad with a "Done" button. I did this by making an keyboard.xib file and a keyboard.swift file.
Heres a snapshot of the error, I've included a whole bunch of my code below incase I'm using a method that isn't the best.
This is how the keyboard.swift file looks:
import UIKit
// The view controller will adopt this protocol (delegate)
// and thus must contain the keyWasTapped method
protocol KeyboardDelegate: class {
func keyWasTapped(character: String)
func keyDone()
func backspace()
}
class keyboard: UIView {
// This variable will be set as the view controller so that
// the keyboard can send messages to the view controller.
weak var delegate: KeyboardDelegate?
// MARK:- keyboard initialization
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
initializeSubviews()
}
override init(frame: CGRect) {
super.init(frame: frame)
initializeSubviews()
}
func initializeSubviews() {
let xibFileName = "Keyboard" // xib extention not included
let view = NSBundle.mainBundle().loadNibNamed(xibFileName, owner: self, options: nil)[0] as! UIView
self.addSubview(view)
view.frame = self.bounds
}
// MARK:- Button actions from .xib file
#IBAction func keyTapped(sender: UIButton) {
// When a button is tapped, send that information to the
// delegate (ie, the view controller)
self.delegate?.keyWasTapped(sender.titleLabel!.text!) // could alternatively send a tag value
}
#IBAction func backspace(sender: UIButton) {
self.delegate?.backspace()
}
#IBAction func Done(sender: UIButton) {
self.delegate?.keyDone()
}
}
In the viewController I'm pretty sure I've included all the necessary things to access the keyboard seeing as it works for some textFields. Such as:
class myViewController: UITableViewController,UITextFieldDelegate, KeyboardDelegate
Then in viewDidLoad set each textField delegate:
self.textField1.delegate = self
self.textField2.delegate = self
self.textField3.delegate = self
// initialize custom keyboard
let keyboardView = keyboard(frame: CGRect(x: 0, y: 0, width: 0, height: numpad.height))
keyboardView.delegate = self // the view controller will be notified by the keyboard whenever a key is tapped
// replace system keyboard with custom keyboard
textField1.inputView = keyboardView
textField2.inputView = keyboardView
textField3.inputView = keyboardView
Then this function (which seems to me to be the problem):
func keyDone() {
view.endEditing(true)
//activeTextField.resignFirstResponder()
print("please dont freeze")
}
I have checked all the connections, they seem to be fine.
Let me know if I can add any more info to help work it out.
Many Thanks.
Solved!!!
I suppose ill just put it down to beating my head over it rather than taking a break from the screen! Still I'm confused why it wasn't given a more specific error.
The problem was that in some cases one of the functions was dividing by zero (this is undefined... not possible) but a good thing to take from this(thank you Olivier) is the Instruments Tools to help find where abouts the code was losing its mind. This tutorial helped me understand how to use instruments! So once I could see where it was going crazy I set up a bunch of print statements to watch the values as they went into the 'problem' calculation, where I found the denominator to be zero. Bit of rearranging the code around to avoid this and problem solved!
This error message is basically saying that there is a memory issue, try running the code with instruments (Allocations in particular) this might reveal is there is something amiss with your keyboard
Edit 2: for anyone finding this error message in future (actual solution in this case)
Double check any code code running after keyDone() to see if there are any infinite loops or situations that would cause the compiler to assume an infinite amount of memory is required. In this case a line of code was dividing by zero, causing a fatal memory error (unable to allocate the N/A value it generated)