I'm new to iOS development, but I'm having an issue with one of the views that I'm working on. I have a UIDatePicker that can either be hidden or visible depending on the state of a UISwitch. It seems that the associated #IBAction does not trigger when the view starts out hidden. It does work when the date picker starts out visible, so the IBAction is working.
Here's a simplified version of my code:
import UIKit
class StatusEditorViewController: UIViewController {
#IBOutlet var expiryPicker: UIDatePicker!
#IBOutlet var enableExpirySwitch: UISwitch!
var editingObject: StoredStatus?
private var pickerIsVisible = false
private var expiresIn: TimeInterval?
override func viewDidLoad() {
// Set a default value
expiryPicker.countDownDuration = TimeInterval(3600)
// If this view got passed an object to edit, use that for expiresIn
if let status = editingObject {
if let expires = status.expiresIn.value {
expiresIn = TimeInterval(expires)
}
}
// Hide the picker and turn off the "enable expiry" switch if we don't
// have a value yet. We'll show the picker once the switch has been pressed
pickerIsVisible = expiresIn != nil
enableExpirySwitch.isOn = expiresIn != nil
updatePicker()
}
func updatePicker() {
expiryPicker?.isHidden = !pickerIsVisible
}
#IBAction func expiryDidUpdate(_ sender: UIDatePicker) {
expiresIn = sender.countDownDuration
print(expiresIn!)
}
#IBAction func expirySwitchDidUpdate(_ sender: UISwitch) {
pickerIsVisible = sender.isOn
updatePicker()
// If the user just turned on the switch, we want to make sure we store the
// initial value already, in case the user navigated away
if (sender.isOn && expiresIn == nil) {
expiresIn = expiryPicker.countDownDuration
}
}
}
I'm not sure what's going wrong. I tried manually attaching a target (e.g. self.expiryPicker.addTarget(self, action: #selector(setExpiryValue), for: .allEditingEvents))
once the view becomes available, but that didn't work either.
I hope someone can tell me what I'm doing wrong. I'm guessing there's something fundamental that I'm doing wrong, but so far no search on Google or SO has led me to the answer.
Thanks in advance
f.w.i.w, I'm running XCode 11.7, with Swift 5, with a deployment target of iOS 13.7
Related
I'm using modal sheets (slide down from top) to get user input. I currently have 2 that I think are identical except for the UI, each a NIB + NSWindowController-subclass pair. One works as expected, binding input to an array controller and table view. When trying to use the other, the window property of the NSWindowController is nil.
This code works:
#IBAction func addItemButtonClicked(_ button: NSButton) {
let window = document?.windowForSheet
let windowController = NewItemSheetController()
windowController.typeChoices = newItemSheetTypeChoices
windowController.windowTitle = newItemSheetTitle
print(#function, windowController.window) // output below
window?.beginSheet(windowController.window!, completionHandler: { response in
// The sheet has finished. Did user click OK?
if response == NSApplication.ModalResponse.OK {
let structure = (self.newItemSheetController?.structure)!
self.document?.dataSource.structures.append(structure)
}
// All done with window controller.
self.newItemSheetController = nil
})
newItemSheetController = windowController
}
The output of the print statement: "addItemButtonClicked(_:) Optional()"
This code doesn't:
#IBAction func addItemButtonClicked(_ button: NSButton) {
let window = document?.windowForSheet
let windowController = NewRecurrenceItemSheetController()
windowController.windowTitle = newItemSheetTitle
print(#function, windowController.window)
window?.beginSheet(windowController.window!, completionHandler: { response in
// The sheet has finished. Did user click OK?
if response == NSApplication.ModalResponse.OK {
let recurrence = (self.newItemSheetController?.recurrence)!
self.document?.dataSource.recurrences.append(recurrence)
}
// All done with window controller.
self.newItemSheetController = nil
})
newItemSheetController = windowController
}
The output of the print statement: "addItemButtonClicked(_:) nil"
Classes NewItemSheetController and NewRecurrenceItemSheetController are subclasses of NSWindowController and differ only with NSNib.Name and properties related to differing UI. As far as I can see, the XIBs and Buttons are "wired" similarly. The XIBs use corresponding File's Owner. Window objects have default class.
#objcMembers
class NewItemSheetController: NSWindowController {
/// other properties here
dynamic var windowTitle: String = "Add New Item"
override var windowNibName: NSNib.Name? {
return NSNib.Name(stringLiteral: "NewItemSheetController")
}
override func windowDidLoad() {
super.windowDidLoad()
titleLabel.stringValue = windowTitle
}
// MARK: - Outlets
#IBOutlet weak var titleLabel: NSTextField!
#IBOutlet weak var typeChooser: NSPopUpButton!
// MARK: - Actions
#IBAction func okayButtonClicked(_ sender: NSButton) {
window?.endEditing(for: nil)
dismiss(with: NSApplication.ModalResponse.OK)
}
#IBAction func cancelButtonClicked(_ sender: NSButton) {
dismiss(with: NSApplication.ModalResponse.cancel)
}
func dismiss(with response: NSApplication.ModalResponse) {
window?.sheetParent?.endSheet(window!, returnCode: response)
}
}
Why does one return instantiate a windowController object with a nil-valued window property?
In Interface Builder, the XIB Window needed to be attached to File's Owner with a Window outlet and delegate. Thanks #Willeke.
I am new to Swift and Xcode, but I have been reading on here and watching videos on YouTube to guide me along with starting my app. I can't seem to get my button to save its state once the app is closed and re-opened. I used UserDefault To Save Button State as an example, but following it still did not get the button state saved.
I set the state with the Interface Builder and so far have the below code:
#IBAction func ownedButton(_ sender UIButton) {
sender.isSelected = !sender.isSelected
UserDefaults.standard.set(sender.isSelected, forKey: "isSaved")
UserDefaults.standard.synchronize()
}
Clicking the button will keep it selected until clicked again, so it is partially working. It looks like I need some code to in the viewDidLoad section, but I haven't been able to figure out what it should be.
Thank you for any help!
A habit from my Objective-C days is to write a wrapper around the properties in UserDefaults. This way, everything is compile-time checked and the use of strings as keys is minimized:
// Properties.swift
import Foundation
fileprivate var standardDefaults = UserDefaults.standard
class Properties {
static func registerDefaults() {
standardDefaults.register(defaults: [
kIsButton1Selected: false,
kIsButton2Selected: true
])
}
fileprivate static let kIsButton1Selected = "isButton1Selected"
static var isButton1Selected: Bool {
get { return standardDefaults.value(forKey: kIsButton1Selected) as! Bool }
set { standardDefaults.set(newValue, forKey: kIsButton1Selected) }
}
fileprivate static let kIsButton2Selected = "isButton2Selected"
static var isButton2Selected: Bool {
get { return standardDefaults.value(forKey: kIsButton2Selected) as! Bool }
set { standardDefaults.set(newValue, forKey: kIsButton2Selected) }
}
}
Then in your View Controller:
override func viewDidLoad() {
// Always call registerDefaults before you use UserDefaults
// for the first time in your app
Properties.registerDefaults()
button1.isSelected = Properties.isButton1Selected
button2.isSelected = Properties.isButton2Selected
}
#IBAction func ownedButton(_ sender: UIButton) {
sender.isSelected = !sender.isSelected
switch sender {
case button1:
Properties.isButton1Selected = sender.isSelected
case button2:
Properties.isButton2Selected = sender.isSelected
default:
break
}
}
You can replace the switch with key-value observing but remember to remove the KVO on deinit.
I'm trying to save a bool value to UserDefaults from a UISwitch, and retrieve it in another view. However, I've tried following multiple tutorials and stack answers and none seem to work.
This is how I'm saving it:
class SettingsViewController: UITableViewController {
#IBOutlet weak var soundSwitchOutlet: UISwitch!
#IBAction func soundSwitch(_ sender: UISwitch) {
UserDefaults.standard.set(soundSwitchOutlet.isOn, forKey: "sound")
}
and this is how I'm trying to retrieve it in another view:
if let savedValue = UserDefaults.standard.bool(forKey: "sound") {
boolValue = savedValue
}
//this is inside viewDidLoad and "boolValue" was declared outside viewDidLoad//
For a reason this code is giving me errors and none of the things I've tried have worked. How can I save a bool to UserDefaults and retrieve it in another view?
Edit: I think I fixed the first part. However, the way I'm retrieving the boolean seems to be totally wrong. Also: No other stackExchange answer responds to what I'm asking, at least not in swift.
As Leo mentioned in the comments bool(forKey returns a non-optional Bool. If the key does not exist false is returned.
So it's simply
boolValue = UserDefaults.standard.bool(forKey: "sound")
Calling synchronize() as suggested in other answers is not needed. The framework updates the user defaults database periodically.
Do it like this.
In your first view controller.
create an IBoutlet connection to your UISwitch
And then the action for your UISwitch. so in the end, your first view controller should look like this.
import UIKit
class FirstViewController: UIViewController {
#IBOutlet weak var myswitch: UISwitch! // Outlet connection to your UISwitch (just control+ drag it to your controller)
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
#IBAction func myswitchAction(_ sender: Any) { // Action for your UISwitch
var myswitctBool : Bool = false // create a local variable that holds your bool value. assume that in the beginning your switch is offed and the boolean value is `false`
if myswitch.isOn == true { // when user turn it on then set the value to `true`
myswitctBool = true
}
else { // else set the value to false
myswitctBool = false
}
// finally set the value to user default like this
UserDefaults.standard.set(myswitctBool, forKey: "mySwitch")
//UserDefaults.standard.synchronize() - this is not necessary with iOS 8 and later.
}
}
End of the first view controller
Now in your second view controller
you can get the value of userdefault, which you set in first view controller. I put it in the viewdidload method to show you how it works.
import UIKit
class SecondViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let myswitchBoolValuefromFirstVc : Bool = UserDefaults.standard.bool(forKey: "mySwitch")// this is how you retrieve the bool value
// to see the value, just print those with conditions. you can use those for your things.
if myswitchBoolValuefromFirstVc == true {
print("true")
}
else {
print("false")
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}
Hope this will help to you. good luck
Use this line of code:
#IBAction func soundSwitch(_ sender: UISwitch) {
UserDefaults.standard.set(soundSwitchOutlet.isOn, forKey: "sound")
}
insteadof :
#IBAction func soundSwitch(_ sender: UISwitch) {
UserDefaults.standard.set(soundSwitchOutlet, forKey: "sound")
}
Try this:
#IBAction func soundSwitchs(_ sender: Any)
{
UserDefaults.standard.set(soundSwitchOutlet.isOn, forKey: "sound")
UserDefaults.standard.synchronize()
}
//this is inside viewDidLoad and "boolValue" was declared outside viewDidLoad//
boolValue = UserDefaults.standard.bool(forKey: "sound")
I'm learning how to program and am playing with a Swift project in Xcode. The main storyboard has two view controllers. The first view controller is simply called ViewController and the second view controller is called HelpScreenViewController.
In ViewController I have a "help" button that switches the user to HelpScreenViewController. This button uses a segue called "goToHelpScreenSegue".
In HelpScreenViewController I have three buttons:
"Close" button to dismisses the view (no segue used)
"Send Feedback" button to generate a new email in the Mail app (no segue used)
"Reset Game" button to call a function that is coded within the first ViewController. This third button uses a segue called "resetGameSegue".
What I'm trying to do is...
...Get the "Reset Game" button on the HelpScreenViewController to reset the game by calling a function that's coded within the first view controller.*
To try and get this to work the way I want, I've used the following code:
WITHIN first main ViewController
import UIKit
import iAd
import AdSupport
import AVFoundation //audio
import GameplayKit
class ViewController: UIViewController, ADBannerViewDelegate, MyResetGameProtocol {
#IBOutlet weak var Banner: ADBannerView!
#IBOutlet weak var buttonA: UIButton!
#IBOutlet weak var buttonB: UIButton!
#IBOutlet weak var buttonC: UIButton!
#IBOutlet weak var buttonD: UIButton!
#IBOutlet weak var labelQuestion: UILabel!
#IBOutlet weak var labelScore: UILabel!
#IBOutlet weak var labelTotalQuestionsAsked: UILabel!
#IBOutlet weak var labelFeedback: UILabel!
#IBOutlet weak var buttonNext: UIButton!
var score :Int! = 0
var totalquestionsasked :Int! = 0
var allEntries : NSArray!
var shuffledQuestions: [AnyObject]!
var nextQuestion = -1
var currentCorrectAnswerIndex : Int = 0
var audioPlayer = AVAudioPlayer()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.Banner?.delegate = self
self.Banner?.hidden = true
LoadAllQuestionsAndAnswers()
if #available(iOS 9.0, *) {
shuffledQuestions = GKRandomSource.sharedRandom().arrayByShufflingObjectsInArray(allEntries as [AnyObject])
nextQuestion++
LoadQuestion(nextQuestion)
// Fallback on earlier versions
}else{
let randomNumber = Int(arc4random_uniform(UInt32(allEntries.count)))
LoadQuestionPreiOS9(randomNumber)
}
LoadScore()
AdjustInterface()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let viewController = segue.destinationViewController as! HelpScreenViewController
viewController.controller = self
}
func ResetGame() {
PlaySoundReset()
score = 0
totalquestionsasked = 0
SaveScore()
LoadScore()
}
func PlaySoundReset()
{
let alertSound = NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("pcbeep", ofType: "wav")!)
do {
audioPlayer = try AVAudioPlayer(contentsOfURL: alertSound)
} catch {
}
audioPlayer.prepareToPlay()
audioPlayer.play()
}
func SaveScore()
{
let defaults = NSUserDefaults.standardUserDefaults()
defaults.setInteger(score, forKey: "Score")
defaults.setInteger(totalquestionsasked, forKey: "Out of")
}
func LoadScore()
{
let defaults = NSUserDefaults.standardUserDefaults()
score = defaults.integerForKey("Score")
totalquestionsasked = defaults.integerForKey("Out of")
labelScore.text = "Score: \(score)"
labelTotalQuestionsAsked.text = "out of \(totalquestionsasked)"
}
and so on....
WITHIN the second HelpScreenViewController
import UIKit
protocol MyResetGameProtocol {
func ResetGame()
}
class HelpScreenViewController: UIViewController, MyResetGameProtocol {
var controller: MyResetGameProtocol? // reference to the delegate alias First Controller
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
}
*/
#IBAction func SendFeedback(sender: AnyObject) {
UIApplication.sharedApplication().openURL(NSURL(string: "mailto:feedback#felice.ws?")!)
}
#IBAction func DismissView(sender: AnyObject) {
self.dismissViewControllerAnimated(true, completion: nil) }
#IBAction func buttonResetGame(sender: AnyObject) {
controller.ResetGame()
}
}
Now, at the moment with the above code what happens is that if the user taps the "help" button in the first main ViewController (i.e. goToHelpScreenSegue), not only does it take the user to the help screen, but it also calls the function I want activated when the user taps on the "Reset Game" button instead. That is, at the moment, it's the "help" button that resets the game before taking the user to the help screen.
Now, within the help screen, the first two buttons work normally (but they're not using segues). Tapping on the third button (the Reset Game one) simply returns the user back to the main screen. It doesn't call the function, doesn't reset the game.
I've lost count of the times I've changed the code around to try and get it to work right, but I've obviously missed something really obvious.
In particular, I've tried using the following code instead within the main ViewController:
override func prepareForSegue(segue: UIStoryboardSegue?, sender: AnyObject?) {
if segue?.identifier == "resetGameSegue" {
let viewController = segue!.destinationViewController as! HelpScreenViewController
viewController.controller = self
}
However, this results in nothing happening. What I mean is that the button on the main screen works properly (taking the user to the help screen and not incorrectly calling the resetGame function). And, within the help screen the first two buttons work as expected, but the "Reset Game" button just returns the user to the first screen but without calling the ResetGame function.
I also tried removing the IBActions from both my code and the connections inspector for the "Reset Game" button, but that made no difference either.
Any assistance would be most appreciated as I'm just not getting it! :(
I'm agree with MikeG, that you should probably learn about how delegates should be implemented. But the thing you're doing wrong inside this code is that you're not actually calling ResetGame() function on your delegate. Try to implement your #IBAction function in this way:
#IBAction func buttonResetGame(sender: AnyObject) {
controller?.ResetGame()
}
And yeah, if I understand your logic correctly your HelpScreenViewController should not implement MyResetGameProtocol cause your ViewController is the one who's implementing it.
I am attempting to detect which Radio Button is currently selected using Xcode 7's new Radio Button template (NSButton).
I have created a simple action that will print to log the title of the sender when a radio button is selected. This does work:
#IBAction func radioButtonClicked(sender: AnyObject)
{
print(sender.selectedCell()!.title);
}
But what I am really looking for is the ability to know which radio button is selected elsewhere in my codes (specifically on an IBAction for a button click). I have tried:
#IBAction func uploadButtonPressed(sender: AnyObject)
{
print (radioButton.selectedCell()!.title);
}
This does compile and execute, the problem is it always gives me the title of the first radio button not the one that is actually selected.
Any ideas?
The "closest" I can get (which is not very clean, but works "kinda") is to see if radioButton.cell?state = 1. This tells me that the first radio button is selected. But this is a very poor way to code this and only allows for 2 radio button options.
if (radioButton.cell?.state == 1)
{
print ("Radio 1 Selected");
}
else
{
print ("Radio 2 Selected");
}
Use the identifier or tag property in Interface Builder to distinguish between radio buttons like:
#IBAction func selectOption(sender: AnyObject) {
let id:String = sender.identifier!!
case "first identifier":
// do some stuff
// ...
default:
// do default stuff
}
Another option would be a switch-case statement and defining outlets for each radio button like:
#IBOutlet weak var firstOption: NSButton!
#IBOutlet weak var secondOption: NSButton!
#IBOutlet weak var thirdOption: NSButton!
#IBAction func selectOption(sender: AnyObject) {
switch sender as! NSButton {
case firstOption:
print("firstOption")
case secondOption:
print("secondOption")
case thirdOption:
print("thirdOption")
default:
print("won't be called when exhaustive but must always be implemented")
}
}
I ended up finding a method for this.
First I setup a variable to store which item was checked (and pre-set the value to the value I want for the first radio button)
var databaseUploadMethod = "trickle-add";
Then I compare to see the title value of the selected item:
#IBAction func radioButtonClicked(sender: AnyObject)
{
if ((sender.selectedCell()!.title) == "Trickle Add")
{
databaseUploadMethod = "trickle-add";
}
else if ((sender.selectedCell()!.title) == "Bulk Add All Now")
{
databaseUploadMethod = "bulk-add";
}
}
For reference: I have two radio buttons, the first has a title of "Trickle Add" and the second is "Bulk Add All Now". Those are the values I am comparing in my if statement.