Hi so right now I'm making some sort of camera app with some basic button like turn on flash, enable grid, etc.
The cameraViewController manages the view. And it has the UIView for previewing what to capture, and at the bottom, a UIView for the buttons, and shutter button.
Right now, this is how I approach it.
ShutterButtonUIView inside CameraEditorUIView, and CameraEditorUIView inside CameraViewController.
And my editor buttons (flash, grid, filters, etc) is of their own class. And I insert it into my view like so. That way, I promote separation of concern and my class won't be cluttered by all the many buttons.
let editorButtons = ActionButtonFactory.shared.editorButtons
for button in editorButtons {
// Insert to CameraEditorUIView
}
And example of one of my editor button class
class FilterAction: UIButton {
private let filter = ["paintbrush.fill"]
override init(frame: CGRect) {
super.init(frame: frame)
self.setImage(getIcon(), for: .normal)
self.addTarget(self, action: #selector(filterTapped), for: .touchUpInside)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
#objc private func filterTapped() {
TapticHelper.shared.lightTaptic()
NotificationCenter.default.post(name: .presentFilterListVC, object: nil) //Not sure if this is a good approach
}
private func getIcon() -> UIImage {
return IconHelper.shared.getIconImage(iconName: filter[0])
}
}
This makes my line of code very neat and small, good. But is it a good approach? I can't do any view controller functions such as presenting any alert, instantiate another VC, and such from the UIView.
So let's say After pressing the shutter button I want to go to imageDetailVC, My approach is to use NotificationCenter observer pattern.
I'm not sure if this is a good approach or not. Or should I put everything under CameraViewController?
Also, another reason I have doubt on this approach is when I need to disable the rule of third grid for example, I need to make it a static so that my other UIView can access it.
ie: A button from another class
I'm not sure if this is the best approach, But I've figured that instead of using UIView, I used UIViewController. And add them as a child VC. That way, I can still access the parent without coupling with notifications and make it harder.
So if I was to instantiate a new VC, I just used self.parent.
Related
Description
I am trying to use NSSegmentedControls to transition between Child ViewControllers. The ParentViewController is located in Main.storyboard and the ChildViewControllers are located in Assistant.storyboard. Each ChildViewController has a SegmentedControl divided into 2 Segments and their primary use is to navigate between the ChildViewControllers. So they are set up as momentaryPushIn rather than selectOne. Each ChildViewController uses a Delegate to communicate with the ParentViewController.
So in the ParentViewController I added the ChildViewControllers as following:
/// The View of the ParentViewController configured as NSVisualEffectView
#IBOutlet var visualEffectView: NSVisualEffectView!
var assistantChilds: [NSViewController] {
get { return [NSViewController]() }
set(newValue) {
for child in newValue { self.addChild(child) }
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do view setup here.
addAssistantViewControllersToChildrenArray()
}
override func viewWillAppear() {
visualEffectView.addSubview(self.children[0].view)
self.children[0].view.frame = self.view.bounds
}
private func addAssistantViewControllersToChildrenArray() -> Void {
let storyboard = NSStoryboard.init(name: "Assistant", bundle: nil)
let exampleChild = storyboard.instantiateController(withIdentifier: "ExampleChild") as! ExampleChildViewController
let exampleSibling = storyboard.instantiateController(withIdentifier: "ExampleSibling") as! ExampleSiblingViewController
exampleChild.navigationDelegate = self
exampleSibling.navigationDelegate = self
assistantChilds = [exampleChild, exampleSibling]
}
So far so good. The ExampleChildViewController has an NSTextField instance. While I am in the scope of the TextField, I can trigger the action of the SegmentedControls. Its navigating forward and backward as it should. But once I leave the scope of the TextField I can still click the Segments, but they are not triggering any action. They should be able to navigate forward and backward even if the TextField is not the current "First Responder" of the application. I think I am missing something out here, I hope anyone can help me with this. I know the problem is not the NSSegmentedControl because I am seeing the same behavior with an NSButton, which is configured as Switch/Checkbox, in the SiblingViewController. I just don't have any idea anymore what I am doing wrong.
It`s my first time asking a question myself here, so I hope the way I am doing is fine for making progress with the solution. Let me know if I can do something better/different or if I need to provide more information about something.
Thanks in advance!
Additional Information
For the sake of completeness:
The ParentViewController itself is embedded in a ContainerView,
which is owned by the RootViewController. I can't imagine this does
matter in any way, but this way we are not missing something out.
I am actually not showing the navigation action, because I want to
keep it as simple as possible. Furthermore the action is not problem,
it does what I want it to do. Correct me if I am wrong with this.
Possible solutions I found while researching, which did not work for me:
Setting window.delegate of the ChildViewControllers to NSApp.windows.first?.delegate
Setting the ChildViewController to becomeFirstResponder in its func viewWillAppear()
visualEffectView.addSubview(self.children[0].view, positioned: NSWindow.OrderingMode.above, relativeTo: nil)
Related problems/topics I found while researching:
Basic segmented control not working
Adding and Removing Child View Controllers
NSSegmentedControl - Odd appearance when placed in blur view
How to set first responder to NSTextView in Swift?
How to use #selector in Swift 2.2 for the first responder
Accessing methods, actions and/or outlets from other controllers with swift
How to use Child View Controllers in Swift 4.0 programmatically
Container View Controllers
issues with container view
Control a NSTabViewController from parent View
How to detect when NSTextField has the focus or is it`s content selected cocoa
SOLUTION
let parentViewControllerInstance = self.parent as! ParentViewController
segmentedControl.target = parentViewControllerInstance
In my case I just had to set the delegate as the target of the sendAction method.
Background
Ok, after hours of reading the AppKit Documentation I am now able to answer my own question.
First, debugging the UI showed that the problem was definitely not in the ViewHierarchy.
So I tried to think about the nature of NSButton and NSSegmentedControl. At some point I noticed that both are subclasses of NSControl.
class NSSegmentedControl : NSControl
class NSButton : NSControl
The AppKit Documentation says:
Discussion
Buttons are a standard control used to initiate actions within your app. You can configure buttons with many different visual styles, but the behavior is the same. When clicked, a button calls the action method of its associated target object. (...) You use the action method to perform your app-specific tasks.
The bold text points to the key of the solution – of its associated target object. Typically I define the action of an control item like this:
button.action = #selector(someFunc(_:))
This causes the NSControl instance to call this:
func sendAction(_ action: Selector?, to target: Any?) -> Bool
Parameter Description from the documentation:
Parameters
theAction
The selector to invoke on the target. If the selector is NULL, no message is sent.
theTarget
The target object to receive the message. If the object is nil, the application searches the responder chain for an object capable of handling the message. For more information on dispatching actions, see the class description for NSActionCell.
In conclusion the NSControl instance, which was firing the action method (in my case the NSSegmentedControl), had no target to send its action to. So it was only able to send its action method across the responder chain - which obviously has been nil while the first responder was located in another view.
I'm trying to use a custom view I created.
I use instantiation from nib, but it causes an infinite loop which I'm not sure how to fix. Any idea?
Here is the image of the run result:
And here's the code that causes the issue:
// MARK: - Init & Setup
// Needed for IBDesignable
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setup()
}
func setup(){
view = loadViewFromNib()
view.frame = bounds
view.autoresizingMask = UIViewAutoresizing(rawValue: UIViewAutoresizing.RawValue(UInt8(UIViewAutoresizing.flexibleWidth.rawValue) | UInt8(UIViewAutoresizing.flexibleHeight.rawValue)))
addSubview(view)
}
func loadViewFromNib() -> UIView{
let bundle = Bundle(for:type(of: self))
let nib = UINib(nibName: "LoginView", bundle: bundle) // TEST: changin bundle from bundle-> nil
let view = nib.instantiate(withOwner: self, options: nil)[0] as! UIView
return view
}
Edit: Here's an image of the connection
Thanks :)
Quick answer:
Since the top-level view in the Xib had its custom class set to YourCustomeView, the xib loading process loadViewFromNib will then call your initWithCoder method again ⛔️🚫♽.
Quick fix:
In the Xib, instead of setting the custom class of the view as YourCustomeView, set YourCustomeView as The File Owner of the Xib.
More info
https://medium.com/#anandin02/loading-custom-views-in-ios-the-right-way-bedfc06a4fbd
It is not clear from your example (please next time provide the whole file, not just parts of it), but it looks like you are trying to instantiate LoginView from itself.
init() -> setup() -> loadViewFromNib() -> init() -> ...
The problem is that the instantiate will call the LoginView's init() method, which will again call loadViewFromNib(). I hope you see the problem now.
What are you trying to do with loadViewFromNib?
Edit: In the top right corner of your second image there is a "Custom class" section. There, in the "class" field you have to provide the name of your controller (LoginViewController or something like that). This way you connect your view and controller, and you don't need that custom loadViewFromNib method that causes your problem.
For anyone having this issue, if you register a Nib for a table or collection view, you are telling that parent view to go and load a nib named 'x' whenever it needs to dequeue a cell.
Normally with Nib code, you'll want a method to go and load the actual XML that makes your layout to tie it to the Nib class, but when you register a reusable view, your registration means that the parent view is responsible for doing this. It will literally go and load an XML file for you and try and tie that to a class when you cast it. By adding another loadNib call inside of this will then cause an infinite loop to happen.
All you need to do is set the cell Nib's class to your custom class, register it and it will do the rest for you with reusable cells - remove the loadNib method from any initialisers inside your cell and add registration code on the collection or table view class.
The main ViewController is embedded in a UINavigationController subclass, and the VC has a subview that is loaded from a nib. The subview is called MenuView, and contains UIButtons that will link to other VCs.
To keep my main ViewController less unruly, I have put all these buttons into a subview that loads from a nib that animates the menu opening and closing.
However, I would like to present other view controllers from these, sometimes "Modally", sometimes "Show". What I have done seems to work, but I just want to know if this is alright, or if I have caused some unwanted effects that I'm unaware of (like a strong reference cycle that would cause a memory leak, or something). Or is there a better way to do this?
Some code:
In MenuView.swift
class MenuView: UIView {
var navigationController = CustomNavigationController()
func combinedInit(){
NSBundle.mainBundle().loadNibNamed("MenuViewXib", owner: self, options: nil)
addSubview(mainView)
mainView.frame = self.bounds
}
#IBAction func optionsAction(sender: AnyObject) {
self.navigationController.performSegueWithIdentifier("presentOptions", sender: self)
}
In ViewController.swift
menuView.navigationController = self.navigationController as! CustomNavigationController
Short answer: No, it is not alright to access a view controller from within some view in the hierarchy, because that would break all the MVC rules written.
UIView objects are meant to display UI components in the screen and are responsible for drawing and laying out their child views correctly. That's all there is. Nothing more, nothing less.
You should handle those kind of interactions between views and controllers always in the controller in which the view in question actually belong. If you need to send messages from a view to its view controller, you can make use of either the delegate approach or NSNotificationCenter class.
If I were in your shoes, I would use a delegate when view needs some information from its view controller. It is more understandable than using notification center as it makes it much easier to keep track of what's going on between. If the view controller needs some information from a view (in other words, the other way around), I'd go with the notification center.
protocol MenuViewDelegate: class {
func menuViewDidClick(menuView: MenuView)
}
class MenuView: UIView {
var weak delegate: MenuViewDelegate?
#IBAction func optionsAction(sender: AnyObject) {
delegate?.menuViewDidClick(self)
}
}
Let's look at what's going on at the view controller side:
class MenuViewController: UIViewController, MenuViewDelegate {
override func viewDidLoad() {
...
self.menuView.delegate = self
}
func menuViewDidClick(menuView: MenuView) {
navigationController?.performSegueWithIdentifier("presentOptions", sender: self)
}
}
For more information about communication patterns in iOS, you might want to take a look at this great article in order to comprehend how they work.
I have a document window that contains a number of NSView subclasses, switched between using a tab control. Each of the subclasses, and the window's ViewController, support different user actions accessed through menu items tied to the First Responder.
I'd like to perform a segue from one of those views in response to a menu item. However, NSView does not support performSegueWithIdentifier, it appears to be something that is part of NSViewController alone.
Can someone suggest a way around this? I have seen suggestions to pass the VC into the views, but I am not clear how to do that. Or perhaps there is a better way?
view.containingController.performSegue()
note: you have to add containingController to your views
I WOULD add the viewController to the responder chain and then make containingController a computed property in an extension!
e.g. add vc as responder:
override func awakeFromNib() {
super.awakeFromNib()
self.nextResponder = self.view
for subview in self.view.subviews {
subview.nextResponder = self
}
}
e.g. containingController in extension
extension NSView {
var containingController: NSViewController? {
get {
while(self.nextResponder != nil) {
if(self.nextResponder is NSViewController) {
return self.nextResponder
}
}
return nil
}
}
}
You could do that (see Daij-Djan's answer), however it is not what I would recommend, since a hypothetical programmer who will be using your code, but is not familiar with it (let's say, you in a year :) ) might be caught by surprise by such behaviour.
I would recommend you to add a delegate (conforming to your custom protocol, let's call it MyViewDelegate) to your NSView with a method like viewRequiresToPerformTransition(view: YourViewSubclass). Then you implement this method (more generally, you conform to MyViewDelegate protocol) in your view controller and inside its implementation perform any segue you want.
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)