Maybe it is the wrong idea completely to use the same xib multiple times in one viewcontroller, but it looked in some way better than creating an x amount of views with the same labels and the same buttons..
And of course some fun with xibs:)
To give you a quick impression of what I achieved so far:
In the class belonging to the xib, I created a delegate so I could catch a button press in my main view controller.
import UIKit
protocol TimerViewDelegate : class {
func timerButtonTapped(buttonState : NSInteger)
}
class TimerView: UIView {
var delegate : TimerViewDelegate?
var currentButtonState = 0
#IBOutlet var view: UIView!
#IBOutlet var timerLabel: UILabel!
#IBOutlet var button: UIButton!
required init(coder aDecoder: NSCoder){
super.init(coder: aDecoder)
NSBundle.mainBundle().loadNibNamed("TimerView", owner: self, options: nil)
self.addSubview(self.view)
}
#IBAction func buttonTapped(sender:UIButton) {
if currentButtonState == 0{
currentButtonState = 1
} else{
currentButtonState = 0
}
self.delegate?.timerButtonTapped(currentButtonState)
}
}
I know it is not super fancy stuff, but at the moment I'm only evaluating if its any use to do this at all.
In my main view controller I registered outlets for the xibs in a way like:
#IBOutlet weak var timerView1 : TimerView!
#IBOutlet weak var timerView2 : TimerView!
#IBOutlet ...
And in viewDidLoad():
self.timerView1.delegate = self
self.timerView2.delegate = self
self...
Later I can catch the button presses in the following method:
func timerButtonTapped(buttonState: NSInteger) {
println("button press from nib, with state \(buttonState)")
}
From here it does make a difference if I press the button from the top xib or another one, since they keep track of their own buttonstate.
But how can I distinguish the different xibs from each other like this?
I can give the xibs themselves a tag, but I don't know if that has any use. Also talking to their labels from my main view, will have a simular problem..
Even if this is a completely wrong approach of using xibs, I'm still interested how to solve this.
Thank you for your time!
You pretty much have your solution already, you just need to improve your protocol method specification, basically by adding the TimerView that is passing on the button press.
(compare to a delegate protocol like UITableViewDelegate, where the table view always passes itself...)
So, something like:
protocol TimerViewDelegate : class {
func timerButtonTapped(sender: TimerView, buttonState : NSInteger)
}
and then the delegate can find out which TimerView is associated and do something with it.
Incidentally, it's likely best to store the TimerView instances in an array, sorted in some way, so that you can easily access the details.
You can use the tag property safely. Apple documentation says:
An integer that you can use to identify view objects in your application.
Related
I'm developing an app for my school that helps students better understand their grades by getting an analysis on their portfolio of assignments for each class. Right now I am at the point of letting the user create the classes they are in and customize the information within it that is displayed in a tableview with custom cells. The user gives the majority of the information in a child view where they input information such as class name, teacher, grade weighting, etc. I wanted to give the user the ability to change the color of the cell once they are viewing the TableView with all the cells - classes - they made. I decided to go about this by having the cells have a UIButton that they can click on for their determined cell to then pull up a UIColorPickerViewController.
What I wanted to happen was...
User taps button in cell
UIPickerViewController is pulled up
User selects their desired color
User exits UIPickerViewController
Cell is changed to the color
What is actually happening is this
User taps button in cell
Cell background becomes black right as UIPickerViewController is presented
User selects their desired color
User exits UIPickerViewController
Cell remains black
I used a delegate to send the information from the cells and then I used the "colorPickerViewControllerDidFinish()" function and it's still not working out. When I did some debugging I found that the value of the UIColorPickerViewController is actually being stored in the variable I am using, but only after I have already assigned it's value to the cell background so I'm unsure what to do. As you can probably tell, I'm new to swift so apologies for any stupid mistakes in my code.
Custom Cell File
// Protocol for VC's to conform to so they can distinguish which cell has a button being tapped
protocol newlyCreatedCellDelegate: AnyObject
{
func didTapButton(title: String, cellView: UIView)
}
class newlyCreatedClass: UITableViewCell {
// Telling the delegate what to do once they are assigned
weak var delegate: newlyCreatedCellDelegate?
#IBOutlet weak var classContentView: UIView!
#IBOutlet weak var classUIView: UIView!
#IBOutlet weak var classNameLabel: UILabel!
#IBOutlet weak var classTeacherNameLabel: UILabel!
#IBOutlet weak var pointType1NameLabel: UILabel!
#IBOutlet weak var pointType2NameLabel: UILabel!
#IBOutlet weak var pointType3NameLabel: UILabel!
#IBOutlet weak var percent1Label: UILabel!
#IBOutlet weak var percent2Label: UILabel!
#IBOutlet weak var percent3Label: UILabel!
#IBOutlet weak var colorButton: UIButton!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
colorButton.layer.cornerRadius = 21
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
// Essentially creating the prep list for the delegate. If they are called - whoever it is - they will go through this 'checklist'
#IBAction func colorButtonTapped(_ sender: Any)
{
delegate?.didTapButton(title: classNameLabel.text!, cellView: classUIView)
}
}
ViewController Extensions
extension ClassSelection: newlyCreatedCellDelegate
{
func didTapButton(title: String, cellView: UIView)
{
let colorPickerVC = UIColorPickerViewController()
colorPickerVC.delegate = self
present(colorPickerVC, animated: true, completion: nil)
colorPickerViewControllerDidFinish(colorPickerVC)
// 'cellBackgroundColor' is a variable declared in the VC to transfer the UIColor value
cellView.backgroundColor = cellBackgroundColor
}
}
extension ClassSelection: UIColorPickerViewControllerDelegate
{
func colorPickerViewControllerDidFinish(_ viewController: UIColorPickerViewController) {
cellBackgroundColor = viewController.selectedColor
}
}
You should implement one more UIColorPickerViewControllerDelegate method:
func colorPickerViewControllerDidSelectColor(_ viewController: UIColorPickerViewController) {
cellBackgroundColor = viewController.selectedColor
}
It's a great start! As a really direct answer to your original question:
The reason for your problem is that in your didTapButton function you are presenting the color picker, but then immediately telling the app that the user is done with the picker, and then immediately setting the background color to cellBackgroundColor, which I assume has a default value of UIColor.black.
Instead you should delete those last 2 lines in your didTapButton function - just initialize the picker, set the delegate, and present the picker. Then the delegate method you chose - colorPickerViewControllerDidFinish isn't really the correct one for your purpose. Instead consider using the didSelect delegate method (see docs). When that method is called it will pass you the color the user selected, which you can simply use to set your background color and refresh your tableView cell if needed.
Since you mention you are a new Swift dev I will also mention that UITableView reuses its cells, so simply setting the background color of a cell once will not have the result you are expecting. You will see that as you scroll the cells up and down the colors will change in the various cells, so ultimately you'll need to store the color selections in another way so that each time a cell is being dequeued you can set the correct color based on user input. That part is outside of the scope of the original question, but just letting you know.
I understand it’s rather basic, but I’m only trying to get a grasp on basic functions.
I have produced some code by partially my own knowledge and partial bits from different guides.
I am not getting any errors, but the label is not displaying itself as “Text”. I believe it’s to do with the order/place my code is put.
Please help explain how I can fix this!
Please note as well:
I have just a single label called myLabel (named under the document section of my the identity inspector
It is has the text “Loaded” put into it already when I put it in.
I have no other code anywhere, only the default new project code.
I renamed the ViewController to ViewManager to avoid a class error.
First image: This is the image just so you know the location and other bits. I’ll attach the code too:
Second image: What I get, with no errors:
Third image: My main storyboard file:
And now it in code:
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var myLabel: UILabel!
#IBAction func labelSet() {
myLabel.text = "Text"
}
}
Make sure that the IBAction is connected to Touch Up Inside in Interface Builder.
Change the signature of the IBAction to
#IBAction func labelSet(_ sender: UIButton) {
Your function func labelSet() isn't called anywhere. Neither in the Storyboard nor elsewhere.
You can call it in viewDidLoad() like this:
override func viewDidLoad() {
super.viewDidLoad()
labelSet()
}
Alternatively call it after the label has loaded.
#IBOutlet weak var myLabel: UILabel! {
didSet {
labelSet()
}
}
maybe I am missing something really fundamental here, but after staring at the code for an hour or so, my brain is going trough cycles and I would appreciate a fresh glance at this problem.
I have the following UIView:
import UIKit
protocol DetailViewWillShowUpDelegate {
func sendDetailOpened(_ openedBool: Bool)
}
class locationXIBController: UIView {
#IBOutlet weak var loationLabel: UILabel!
#IBOutlet weak var vsedniOteviraciDobaLabel: UILabel!
#IBOutlet weak var prijmajiKartyLabel: UILabel!
#IBOutlet weak var detailViewButtonOutlet: UIButton!
#IBOutlet weak var backgroundViewButton: UIButton!
let openedBool = true
var detailViewWillShowUpDelegate: DetailViewWillShowUpDelegate?
override func awakeFromNib() {
super.awakeFromNib()
}
#IBAction func vecerkaDetailButtonPressed(_ sender: UIButton) {
detailViewWillShowUpDelegate?.sendDetailOpened(openedBool)
print("pressed")
}
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
if let result = detailViewButtonOutlet.hitTest(convert(point, to: detailViewButtonOutlet), with: event) {
return result
}
return backgroundViewButton.hitTest(convert(point, to: backgroundViewButton), with: event)
}
}
Now the problem is, that when I call/press the vecerkaDetailButtonPressed function I get "pressed" output in the console but the protocol for some reason doesn't go trough.
The other side looks like this (stripped for simplicity):
class MapViewController: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate {
let locationXIB = locationXIBController()
let isVecerkaDetailOpened = false
override func viewDidLoad() {
locationXIB.detailViewWillShowUpDelegate = self
}
extension MapViewController: DetailViewWillShowUpDelegate {
func sendDetailOpened(_ openedBool: Bool) {
isVecerkaDetailOpened = openedBool
print("success")
}
}
I know the protocol value at the moment of execution is nil. As I said, any help is appreciated, thanks!
First, a couple of naming convention issues:
The name locationXIBController is a bad choice for a UIView object. It is a view object, not a controller object.
Second, class names in Swift should start with an upper-case letter. So LocationXIBView would be a much better name for that view class.
Next, your code
let locationXIB = locationXIBController()
...is wrong. That creates a brand-new instance of your locationXIBController class that you never install in your view hierarchy. You should make that line an IBOutlet:
#IBOutlet weak var locationXIB: locationXIBController!
And then you should control-drag from the locationXIBController in your StoryBoard onto the outlet in your view controller. That will cause Interface Builder to connect the outlet.
Now when you run your program the variable locationXIB will be connected to the locationXIBController view from your storyboard/XIB when it's loaded.
In addition to the answer of #Duncan C, you might check whether you need super.viewDidLoad() at the top of the viewDidLoad() method in the MapViewController class? Not doing that can lead to quirky things in your app.
I asked:
So does detailViewWillShowUpDelegate actually point at anything, or is it nil?
And you replied:
I just tried debugging and it is actually nil
So that's the problem... you need to set detailViewWillShowUpDelegate to point to a valid delegate object. This is often done in the .xib file or storyboard, and sometimes people forget to make that connection, so check there if it makes sense. Else you'll just need to get a reference to the delegate at some point before the code in question can run and set it up.
Answer to the credit of #Paulw11
I finally managed to get it working by communicating like so:
step 1) 1:1 communication via protocol between MKAnnotation and MKAnnotationView
step 2) 1:1 communication via protocol between MKAnnotationView and MapViewController passing the same data
Finally works like a charm, thanks!
I have to set up a project that has to contain several targets. The goal is to have a code base to share it with all the targets that will be created later. I make an example : I will have a UIViewController for the login, but this will be different for every target. My idea is to have a code base to share with every specific LoginViewController. What is the best approach to structure the code? I started writing a protocol, here it is :
protocol LoginProtocol {
weak var txtUsername: UITextField? { get set }
weak var txtPassword: UITextField? { get set }
weak var btnLogin: UIButton? { get set }
func login()
}
The idea is to implement this protocol in every controller.
The other approach is to write a sort of base view controller that every other controller will inherit from. Like this :
// MARK: - Instance vars and IBOutlets
class LoginViewController: UIViewController {
#IBOutlet weak var txtUsername: UITextField?
#IBOutlet weak var txtPassword: UITextField?
#IBOutlet weak var btnLogin: UIButton?
override func viewDidLoad() {
super.viewDidLoad()
}
}
extension LoginViewController {
func login() {
print("Hello")
}
}
What do you think? What is the best choice, architecturally?
Tough to "answer" this since it is to some extent opinion...but here's my input:
I think it boils down to common behavior: If you use a protocol, but then feel like you are writing almost the same code every time you implement it...then you probably want a base class. I love protocols and use them heavily, but I think people are too quick to dismiss base classes these days. (There ARE pros and cons, but so many people blindly make protocols without thinking about it.)
I will sometimes use a hybrid of a base class that has a delegate to "configure" certain parts.
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.