I have customView and and there is UITextField, and in my ViewController, I am using a lot of this views. So in customView.swift I have UITextFieldDelegate. But I want to do some actions on this callback in my ViewController. Example :
when I tap on textfield, delegate executes
func textFieldDidBeginEditing(textField: UITextField) {
println("delegate")
}
and after this I want some function that works with ViewController UI to execute, example:
func textFieldDidBeginEditing(textField: UITextField) {
println("delegate")
ViewController().check()
}
But it gets nil, so I want to create some callback, can you advise right way to do this?
Create a custom property of type ViewController in your customView class. In the viewDidLoad function of ViewController, call
theCustomView.viewController = self
(where theCustomView is the instance - you probably have a reference to this as well, otherwise create an IBOutlet)
Then, in the textFieldDidBeginEditing function you can just use
self.viewController.check()
Related
I wrote a custom class called PressableView. It recognizes taps and then calls a protocol function on its delegate object. Since it is a subclass of UIView, it does not allow the connection of IBActions by default.
I was wondering whether it is possible to connect a function inside the view controller, the pressable view is in, to the object, so it calls that method on tap – just like you would with a UIButton.
I already tried things like:
class PressableView: UIView {
// ...
#IBOutlet var action: (() -> Void)?
// ...
}
...but, Xcode doesn't allow that type to be an IBOutlet.
Any ideas?
change PressableView parent class as UIControl class then you can connect for actions and handle it.
UIControl is subclass of UIView class only. so you will have all the properties of UIView as well.
class PressableView: UIControl {
#IBAction func uicontrolEventAction(_ sender: Any) {
}
}
I have a custom UIControl that has three subviews. Each of those subviews, I add a target:
button.addTarget(self, action: #selector(buttonTapped(clickedBtn:)), for: .touchUpInside)
Within that function buttonTapped, it does some special animations to do some transitions (It mimics the segmented control).
Now, within the ViewController that this custom UIControl exists in must know when it's touched. I created an #IBAction function that interacts with the touch events for the custom UIControl.
The problem is, that isn't possible (as far as I know). If I add a target touch event to the subviews, the parent touch events won't get called. To have the parent view called the #IBAction function, I must set all the subview's setUserInteractiveEnabledtotrue`. When I do that, the subview's touch event functions won't get called.
I need both touch event functions to be called. How can I do this? Or what's the best way to get around this?
Use delegates, add a protocol in your UIControl that needs to be implemented in your ViewController.
This way you can detect if a button is clicked in your UIControl and invoke a specific function in your VC.
For Example:
//YourUIControl.Swift
protocol YourUIControlDelegate {
func didTapFirstButton()
}
class YourUiControl : UIView { //I'm assuming you create your UIControl from UIView
var delegate : YourUIControlDelegate?
//other codes here
.
.
.
#IBAction func tapFirstButton(_ sender: AnyObject) {
if let d = self.delegate {
d.didTapFirstButton()
}
}
}
//YourViewController.Swift
extension YourViewController : UIControlDelegate {
func didTapFirstButton() {
//handle first button tap here
}
}
For simplicity, let's say I want to create a custom UITextField and I want to add a simple behaviour to it; Which is, if the textfield becomes the first responder, the background color would be changed to green.
To do so, in my custom class I have to set the class as the delegate to receive the event of becoming first responder. But the thing is that if the user of this custom textfield set itself as the delegate the events are not sent to the custom textfield(Since only one object can be the delegate of another object)
I can manually forward all the events, but I'm looking for a cleaner and more scalable solution.
Here's a sketch of the situation:
class MyTextField: UITextField {
override func awakeFromNib() {
super.awakeFromNib()
delegate = self
}
}
extension MyTextField: UITextFieldDelegate {
func textFieldDidBeginEditing(textField: UITextField) {
backgroundColor = UIColor.greenColor()
}
}
but if the user of MyTextField do this:
class ViewController: UIViewController {
#IBOutlet weak var myTextField: MyTextField!
override func viewDidLoad() {
super.viewDidLoad()
myTextField.delegate = self
}
}
the behaviour won't work; because the delegation relationship to MyTextField is gone.
NOTE: I'm not only interested in becoming first responder problem, rather it's about using any methods of the delegate, with capability of the user of my custom UITextField setting itself as the delegate, at the same time.
Thanks, in advance.
As you say, most delegation is restricted to a single object as the delegate.
Since a text field is a responder, you should be able to override func becomeFirstResponder() -> Bool to change the color, while letting the user of the object handle the delegation as it expects.
UIResponder docs: "Subclasses can override this method to update state or perform some action such as highlighting the selection."
I'm a noob here and in iOS world. I am having trouble dismiss keyboard on a specific case in my very simple todo list iOS app.
I'd like the keyboard to get dismiss when user taps anywhere outside the current text field or the keyboard itself. So far, I got the keyboard dismisses just fine (thanks to you guys here in stack overflow) when user taps on the UITableView, or most element on my app. HOWEVER, when user taps on another UITextField, the keyboard does not go away.
FYI, here's the list of existing threads I researched so far but have yet to solve this issue.
1) How to dismiss keyboard iOS programmatically
2) Resigning First Responder for multiple UITextFields
3) Dismissing the First Responder/Keyboard with multiple Textfields
4) (a few more at least but I lost track :( )
Here's what I did so far:
(in viewDidLoad())
// Add 'tap' gesture to dismiss keyboard when done adding/editing to-do item
var tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "tapOutside:")
tap.cancelsTouchesInView = true
self.view.addGestureRecognizer(tap)
func tapOutside(tapOutside: UIGestureRecognizer) {
// Dismiss keyboard
self.view.endEditing(true)
}
#IBAction func EditingDidBegin(sender: UITextField) {
// Highlight the text field which user is editing
self.highlightTextField(sender, highlight: true)
}
#IBAction func EditingDidEnd(sender: UITextField) {
// Undo text field highlight
self.highlightTextField(sender, highlight: false)
self.view.endEditing(true) // try this option and not working
self.setEditing(false, animated: true) // try this option and not working
sender.resignFirstResponder() // try this option and not working
UIApplication.sharedApplication().becomeFirstResponder() // try this option and not working
... // below is my code to update the todo item
}
I also tried to print out all subviews.isFirstResponder() of my view. All of it return false. I also tried override touchesBegan of my UIViewController, and inside it just calls self.view.endEditing(true) and call its super's. This also does not work.
Please help. :(
TIA!
UPDATE:
You guys are awesome! :D I got it working now thanks to you guys. There were several mistakes / messed up as I'm learning new framework. So here's what I did.
1) I did not set UITextField delegate correctly.
Mistake: I ctrl-draged textfield in xcode and link my viewController as delegate and thought that should work out. I will still need to research and understand better why.
Solution: I removed that ctrl-drag link and explicitly call myTextField.delegate = self in tableView:cellForRowAtIndexPath. And that did it. Thanks #Sidewalker
2) Mistake: I have a mixed of textFieldShouldBeginEditing, etc. and #IBAction func EditingDidBegin. So I got myself into the situation where textFieldShouldBeginEditing got the call, but EditingDidBegin did not get call.
Solution: Once I set the delegate = self explicitly and stick with implementing textField... methods and not use any #IBAction for textField, things just work.
Here's one option... We're going to add a boolean flag to determine whether or not we're in a textField when an edit attempt for another textField begins
Make your class adhere to UITextFieldDelegate
class MyClass: UIViewController, UITextFieldDelegate
Don't forget to set the delegate, we'll add the flag as well
myTextField.delegate = self
var inField = false
Implement "textFieldShouldBeginEditing" and "textFieldDidBeginEditing"
func textFieldShouldBeginEditing(textField: UITextField) -> Bool {
if inField {
inField = false
return false
}
return true
}
func textFieldDidBeginEditing(textField: UITextField) {
inField = true
}
I prefer tracking things like this rather than identifying subviews as it allows the flag to be utilized elsewhere and cuts down code complexity.
Well the keyboard isn't going away because it doesn't expect to have to. The new UITextField is just becoming the first responder while the other resigns. If you don't want a textField to become the first responder if another is already, you're going to have to cut it off before it gets the chance to. I would try to implement textFieldShouldBeginEditing and figuring out the logic there.
I'm not in love with the way this looks but this should do something along those lines.
func textFieldShouldBeginEditing(textField: UITextField) -> Bool {
for subView in self.view.subviews{
if(subView.isKindOfClass(UITextField)){
if(subView.isFirstResponder()){
subView.resignFirstResponder();
return false;
}
}
}
return true;
}
First set all the UITextField (your are creating) delegate as self and create one UITextField member variable. Now implement "textFieldDidBeginEditing" delegate method and assign the textfield to your member UITextField variable. As given below
func textFieldDidBeginEditing(textField: UITextField) {
yourMemberVariable = textField;
}
So now whenever you want to dismiss the keyboard call the dismiss method on "yourMemberVariable" object. It should work !!
What I usually do is implementing this two method:
The first one add a UITapGestureRecognizer to the whole UIViewController view
func hideKeyboard() {
let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboard))
view.addGestureRecognizer(tap)
}
The second one just get called every time the user touch anywhere on the UIViewController's view
func dismissKeyboard() {
self.view.resignFirstResponder()
}
I add the first one to the viewDidLoad method of the UIViewController. Or better yet if you want to use that on all the app just make that an extension for your UIViewController.
How about doing this in viewController, It works for me
func dismissKeyboard() {
//All the textFields in the form
let textFields = [textField1, textField2, textField3, textField4, textField5]
let firstResponder = textFields.first(where: {$0.isFirstResponder ?? false })
firstResponder?.resignFirstResponder()
}
I'm new in stackoverflow, I have a problem with new swift code.
I have custom the return button on keyboard with "Done", but when I tap on it, don't befall anything... How can I hide the keyboard on tap it?
I have added a code (found on this site) for hide the keyboard when you tap somewhere ,not in the keyboard, but I can't custom it with tap on "done" button... Thank you before!!
You need to implement delegate method which is called when you hit done button:
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
You also need to conform to UITextFieldDelegate protocol:
// I assume you override UIViewController class. If not add UITextFieldDelegate to your class
class MyViewController: UIViewController, UITextFieldDelegate
The last thing is set up your class to be a text field delegate:
textField.delegate = self
textField.delegate = self
can be replaced by
This will create the necessary connections between your View, its component and will make the textFieldShouldReturn method work as expected.
The protocol methods have new signatures (Swift 4.1). IE:
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
As the protocol methods are optional, using a wrong signature will silently fail.