I have created a UIView class (SegmentControl.swift) and added the UISegmentControl using an xib. I have another viewcontroller where I refer this UIView class to add the segment control.
My question here is since I have the UISegmentControl in another UIView class, how will I update the index and load the respective containerViews in the ViewController?
#IBAction func didChangeIndex(_ sender: UISegmentedControl) { } will work only if I have Segment control in ViewController.
Please provide your suggestions on how can I load the containerviews when the UIControlSegment is in another class.
This is the code I have:
SegmentControl.swift
class SegmentControl: UIView {
#IBOutlet weak var segmentView: UISegmentedControl!
// Loading nibs are there.. just that I didn't include here
func create(titles: [String]) {
items.enumerated().forEach { (index, item) in
segmentView.setTitle(item, forSegmentAt: index)
}
}
}
ViewController.swift
func showSegmentControl() {
let segmentedView = GenericSegmentedView.create(items: ["A", "B"])
stackView.addArrangedSubView(segmentedView)
}
Two container views --> aInfoView and bInfoView are intialised in View Controller.
How will I load them on switching the segments since they are in UIView class. I couldnt find any answers here. Please help!
Thank you!!
You can add a target to the segmented control even if it's contained within another view. The segmented control is an accessible property on your SegmentControl class. From the SegmentControl's parent view controller add the target action to the your SegmentControl's child segmentView.
func showSegmentControl() {
let segmentedView = GenericSegmentedView.create(items: ["A", "B"])
stackView.addArrangedSubView(segmentedView)
segmentedView.segmentView.addTarget(self, action: #selector(segmentControlChanged(_:)), for: .valueChanged)
}
// Function will be called when value changed on the SegmentControl's segmentView
#objc func segmentControlChanged(_ sender: UISegmentedControl) {
print(sender.selectedSegmentIndex)
}
Something as aside, interchanging segmentControl and segmentView can be confusing to people not familiar with your code. Maybe a more descriptive name for the SegmentControl like SegmentControlContainer or something would help make the distinction.
Related
I'm a beginner in swift, I'm making an app in storyboard UIKit, and I need some help basically I need to set up a view controller that has buttons on it that when clicked add a string on the bottom of the VC, and if clicked again it will remove that same string. On the VC there going to be multiple buttons like this for options also on the bottom of the VC I need the label to update during the app also it should display like this for example. "Football","Basketball","Golf". It needs to be displayed just like that on the bottom with quotes and commas. I've to turn to make action buttons with a global array and put that inside each button but I can't figure out how to remove it when the button clicked again, also if you click the button again it'll add the same thing again so in the array you'll have two of the same strings. Anything would help.
P.S I need to do this in UIkit and Storyboard
You can make list of outlets to an array UIButton, handle list of actions when click into UIButton with a function. Using 'isSelected' property of UIButton to distinguish 'delete' or not.
class ViewController: UIViewController {
#IBOutlet weak var descriptionLabel: UILabel!
#IBOutlet var allButtons: [UIButton]!
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func didTapButton(_ sender: UIButton) {
sender.isSelected.toggle()
_updateDescription()
}
private
func _updateDescription() {
descriptionLabel.text = allButtons
.filter { $0.isSelected }
.compactMap { $0.titleLabel?.text }
.map { "\"\($0)\"" }
.joined(separator: ", ")
}
}
So I have a 'ListViewController' that has a subview called 'ListView'
ListView is the master view that holds all remaining subviews.
Inside listView, there is a subview called PhotoView and inside it, it has a UIButton that toggles the constraints of PhotoView, resizing based on arbitrary values.
Hierarchy is as follows:
ListViewController <- ListView <- PhotoView
The reason I've done this is to minimize the amount of code inside each view, to segment it out.
My question is: Who should be in charge of the 'resizing' function? My
understanding is that a viewController should generally handle the
main functions that are inside it pertaining to its subviews.
However in this case, it is being handled inside its subviews subview, 'PhotoView'. Should I use protocols to persist it to the ListViewController? PhotoView(Protocol) -> ListView(Protocol) -> ListViewController?
Is this a correct method? Or is there a more efficient way of handling subview functions?
Thanks guys
If you move all logics into ListViewController, everything is very simple as you can assign any UIControl in the VC:
class ListViewController : UIViewController{
#IBOutlet var goButton: UIButton! //In the DetailView
#IBOutlet var photoView: PhotoView!
#IBOutlet var detailView: DetailView!
// MARK: --
#IBAction func testCommand(_ sender: Any){
PhotoView.backgroundColor = UIColor.red
detailView.backgroundColor = UIColor.red
}
// MARK: --
#IBAction func photoViewCommand(_ sender: Any){
PhotoView.backgroundColor = UIColor.red
detailView.backgroundColor = UIColor.red
}
// MARK: --
#IBAction func detailViewCommand(_ sender: Any){
PhotoView.backgroundColor = UIColor.red
detailView.backgroundColor = UIColor.red
}
}
You don't need to even know the ListView. Use IB can assign all UIViews , not only direct children, but all subview trees, including UIControls, like buttons and labels , as long as they lies in the scene of same UIViewController and their methods is in the same VC not in other separated views.
If you have the code of views, you can move it to the VC easily. Just one class to control all. If you need to know who is who. Adding Mark is enough for small files.
im developing an app that utilises many buttons( possibly 20 buttons) on one primary view controller that can are all able to activate a singular picker view within a pop up on a seperate view controller. i don’t think the answer is lots and lots segues. Is there a better approach I should be considering?
I’m thinking - some kind of multiuse segue that can be activated by any of the buttons, but nonidea how this is done.
Appreciate any advice
Mike
Set up all buttons to same action such as:
#IBAction func keyPressed(_ sender:UIButton){
// use button title string
self.keyString = sender.titleLabel?.text as! String
// or tag
self.keyTag= sender.tag?
self.performSegue(withIdentifier: "TheSegue", sender: self)
}
Then you would want to set up the View Controller that you are going to navigate to based on the state of the sender. So you would override the prepare:forSegue method as below.
override func prepare(for segue:UIStoryboardSegue, sender:Any?) {
let destController = segue.destination as! Dest_Controller_Class
// use tag or keyTitle to set controller attributes
// before view is shown
destController.keyTag = self.keyTag
destController.keyString = self.keyString
}
Now once you've navigated to the Dest_Controller_Class, you will have the properties of the button pressed locally in the view controller and could update the view as you see fit:
class Dest_Controller_Class: UIViewController {
var keyString: String?
var keyTag: Int?
#IBOutlet weak var label: UILabel!
override func viewDidLoad() {
if (keyString != nil) {
label.text = keyString;
// or likewise use tag
} else {
label.text = "keyString not set"
}
}
}
base ViewController
import UIKit
class SubViewPost: UIViewController {
#IBOutlet weak var content: UILabel!
#IBOutlet weak var recommendCount: UILabel!
#IBOutlet weak var recommendButton: UIButton!
var postInfo:PostInfo!
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.
}
}
child ViewController
import UIKit
class SubViewOne: SubViewPost {
#IBAction func likeWorry(_ sender: Any) {
Option.recommend(postInfo: postInfo, mRecommendCount: recommendCount, mRecommendButton: recommendButton)
}
}
and another child viewController
import UIKit
class SubViewTwo: SubViewPost {
override func viewDidLoad() {
recommendCount.alpha=0
recommendButton.alpha=0
}
}
i want add subviewOne or SubViewTwo
My ParentView
var subViewPost:SubViewPost
if postType == 1{
subViewPost = storyboard?.instantiateViewController(withIdentifier: "SubViewPost") as! SubViewOne
}else{
subViewPost = storyboard?.instantiateViewController(withIdentifier: "SubViewPost") as! SubViewTwo
}
containerView.addSubview(subViewPost.view)
raise error
Could not cast value of type
'MyApp.SubViewPost' (0x101151728) to 'MyApp.SubViewOne' (0x10114d9d0).
2018-07-10 14:40:56.007436+0900 MyApp[7207:209932]
Could not cast value of type 'MyApp.SubViewPost' (0x101151728) to 'MyApp.SubViewOne' (0x10114d9d0).
how to chagne view controller by According to postType
SubView One have Recommned
but SubView Two haven't Recommend
SubView 1,2 have same UI
The UViewController class for your scene "SubViewPost" in your storyboard is set to SubViewPost and that is what instantiateViewController will be returning. You cannot downcast an instance of SubViewPost to SubViewOne or SubViewTwo.
You could define two identical scenes in your storyboard, each with the appropriate view controller class, but that would require a lot of duplication.
Since the only difference is the visibility of the recommendButton and recommendCount elements, why not just handle that via a property:
var subViewPost = storyboard?.instantiateViewController(withIdentifier: "SubViewPost") as! SubViewPost
subViewPost.recommendVisible = (postType == 1)
SubViewPost.swift
var recommendVisible = true
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
recommendCount.isHidden = !recommendVisible
recommendButton.isHidden = !recommendVisible
}
The error message is clear. When you say
storyboard?.instantiateViewController(withIdentifier: "SubViewPost")
what you get from the storyboard is a view controller whose class is SubViewPost. You cannot wave a magic casting wand and claim that it is a SubViewOne instead; it isn't.
If you wanted this view controller to be a SubViewOne, then you should have declared it as a SubViewOne in the storyboard in the Identity inspector.
I think I see what you are trying to do, and why you are confused about why you can't do it this way.
What's in the storyboard is an instance, not a class. Yes, it is an instance of some class, but it is an instance of that class. So when you design the interface in the storyboard, you are designing the interface associated with that one instance of that one class.
If your goal is to have a single interface associated with multiple classes, the interface must be generated in code or loaded from a View .xib file — not designed in a storyboard.
However, you would be better off not trying to use subclassing in this situation in the first place. What I do in a similar situation is give my view controller an enum property that says which "kind" of view controller it is, and obey accordingly in code. That a way, a single class serves multiple purposes.
All of the searches I've done focus on passing data between view controllers. That's not really what I'm trying to do. I have a ViewController that has multiple Views in it. The ViewController has a slider which works fine:
var throttleSetting = Float()
#IBAction func changeThrottleSetting(sender: UISlider)
{
throttleSetting = sender.value
}
Then, in one of the Views contained in that same ViewController, I have a basic line that (for now) sets an initial value which is used later in the DrawRect portion of the code:
var RPMPointerAngle: CGFloat {
var angle: CGFloat = 2.0
return angle
}
What I want to do is have the slider's value from the ViewController be passed to the View contained in the ViewController to allow the drawRect to be dynamic.
Thanks for your help!
EDIT: Sorry, when I created this answer I was having ViewControllers in mind. A much easier way would be to create a method in SomeView and talk directly to it.
Example:
class MainViewController: UIViewController {
var view1: SomeView!
var view2: SomeView!
override func viewDidLoad() {
super.viewDidLoad()
// Create the views here
view1 = SomeView()
view2 = SomeView()
view.addSubview(view1)
view.addSubview(view2)
}
#IBAction func someAction(sender: UIButton) {
view1.changeString("blabla")
}
}
class SomeView: UIView {
var someString: String?
func changeString(someText: String) {
someString = someText
}
}
Delegate:
First you create a protocol:
protocol NameOfDelegate: class { // ": class" isn't mandatory, but it is when you want to set the delegate property to weak
func someFunction() // this function has to be implemented in your MainViewController so it can access the properties and other methods in there
}
In your Views you have to add:
class SomeView: UIView, NameOfDelegate {
// your code
func someFunction() {
// change your slider settings
}
}
And the last step, you'll have to add a property of the delegate, so you can "talk" to it. Personally I imagine this property to be a gate of some sort, between the two classes so they can talk to each other.
class MainViewController: UIViewController {
weak var delegate: NameOfDelegate?
#IBAction func button(sender: UIButton) {
if delegate != nil {
let someString = delegate.someFunction()
}
}
}
I used a button here just to show how you could use the delegate. Just replace it with your slider to change the properties of your Views
EDIT: One thing I forgot to mention is, you'll somehow need to assign SomeView as the delegate. But like I said, I don't know how you're creating the views etc so I can't help you with that.
In the MVC model views can't communicate directly with each other.
There is always a view controller who manages the views. The views are just like the controllers minions.
All communication goes via a view controller.
If you want to react to some view changing, you can setup an IBAction. In the method you can then change your other view to which you might have an IBOutlet.
So in your example you might have an IBAction for the slider changing it's value (as in your original question) from which you could set some public properties on the view you would like to change. If necessary you could also call setNeedsDisplay() on the target view to make it redraw itself.