tap on TextField reseting the view position - ios

Here is my problem:
I have a first form that needs to be completed, once completed you can access the second form, it's an UIView that slide from the left to my view.
At the moment when I tap on one of the text fields of the second form, the position of the view got reseted and I have a view on the first form again.
Here is my code for sliding:
#IBAction func Postulate(sender: AnyObject) {
UIView .animateWithDuration(0.5, animations: { () -> Void in
self.formView.frame = CGRectMake(0, 64, 414, 736)
})
}
How can tapping on a textfield reset the view ? And how can I counter it ?
I tried to reslide the view with a duration of 0 when a textfield is tapped but it's not working.

Set the VC to be textField delegate then use the delegate method, textFieldBeganEditing or something like that to recognize when user tap on the text field.
class ClassName:UIViewController, UITextFieldDelegate {
#IBOutlet week var textField: UITextField! {
didSet { textField.delegate = self }
}
func textFieldDidBeginEditing(textField: UITextField){
//user tapped on the textField, do what you wanna do here
}
}

Well, finally I found a hack to bypass this.
I started the position of my second form view at 0 (on the view) and with the hidden state set as true. Then I make it slide to the left out of screen (being hidden) like this:
formView.hidden = true;
UIView .animateWithDuration(0, animations: { () -> Void in
self.formView.frame = CGRectMake(-425, 64, 414, 736)
})
When the button to go on my form view is pressed I put my form view hidden state to false and I make it slide to the right so the user can see it.
When I tap on the field, the position reset, but because the form view position was created in the view, it doesn't change.
Finally, when I click on my "return" button from the form view, I make it slide back to the left and make it's hidden state to true. With so on, when the user want to change anything on the first form, the positions are reseted, but the hidden state allow the user to see the form he wants to see and not the other.
Hope I helped someone.
THIS IS JUST A SWIFT HACK, this work, but it's probably not the best solution, if you have a better solution, give it so I can accept your answer.

Related

Show or hide items by clicking button

I have four imageview contents in an XIB and a button that covers all my XIB. I want to make when the user tap the button, the first imageview is shown, the next tap is hidden and the second imageview is displayed and so on until all my imageview is shown / hidden. What would be the most efficient way to do it?
Save all your UIImageViews to an array, and current showing imageView to a variable, it may look like this:
var imageViews: [UIImageView] = []
var currentImageViewIndex = 0 {
didSet {
if currentImageViewIndex >= imageViews.count { currentImageViewIndex = 0 }
imageViews[oldValue].isHidden = true
imageViews[currentImageViewIndex].isHidden = false
}
}
func handleTap() {
currentImageViewIndex += 1
}
I suggest you use a state variable that contains an enum listing the various states (firstImageVisible, secondImage.... ) then you can have a function inside the enum that switches to the nextState (being the target of your button action) you can also easily iterate through states of an enum, check the documentation for the CaseIterable protocol. Often having a property observer (didSet) on the state is a handy place to update other parts of the UI which need to change every time the state changes.

UITapGestureRecognizer on a text field not as expected

In my class I have 11 UITapGestureRecognizers in an array textViewRecognizer attached to 11 out of 100 UITextFields in an array boxArray. When a Textfield is tapped containing a UIGestureRecognizer it runs tappedTextView where I try to get the index of the first responder.
However, due to some weird ordering in how things are executed, the action function only gives me the first responder of the previous first responder to the one that was just tapped.
Also, I have to double tap to even select the text field I was going for! I need to use the tap function and not the text delegates so this has been a real headache.
I have...
#objc func tappedTextField(_ sender: UITapGestureRecognizer) {
for i in 0...99 {
if (boxArray[i]?.isFirstResponder)! {
if let index = boxArray.index(of: boxArray[i]) {
print(index)
break
}
}
}
}
in my viewDidLoad I have
for i in 0...10 {
textFieldTapRecognizer[i].addTarget(self, action: #selector(self.tappedTextField(_:)))
}
In my class I have
I want to set 11 out of 100 textFields to have this a tap recognizer depending on some conditions (I'm just going to use a regular for loop here)
for i in 0...10 {
boxArray[i]?.addGestureRecognizer(textFieldTapRecognizer[i])
}
Is there anyway I can get it to give me the actual first responder, after the tap was made?
Is there anyway to go around the double tap to select the text field that has a UITapGesture?
Any help is greatly appreciated.
Edited: properly named functions
It sounds like you want to remove the automatic editing behavior on a UITextView. You can grab more control over that with the textViewShouldBeginEditing(_ textView: UITextView) -> Bool UITextViewDelegate method, documented here.
If you return false for that method, this should avoid needing a double tap to get to your gesture recognizer. Depending on your use case, you can then "allow" the tap to go to the text view by returning true for the textView you want to be actually edited.
While I'm not 100% clear on the first responder part of your question, since the textView won't be grabbing first responder if it's not starting it's editing mode, this should address that concern I believe. Good luck!
I would add a Tag to my UITextView and set the UITextViewDelegate to my ViewController.
Then I would add the following Delegate method:
func textViewShouldBeginEditing(_ textView: UITextView) -> Bool {
print("Textview tag: ", textView.tag)
return false
}

How to disable UIControlEventEditingChanged

I have a UIViewController with several UITextFields. When tap one text field, it should present the barcode scanning view controller. Once the scanning is completed, my barcode scanning viewcontroller is disappearing (used "dismissViewcontroller") and the scanned value should entered into the text field I tapped. This is working fine. I have set the delegate for each text field like this.
[field addTarget:metrixUIViewControllerIn action:#selector(executeScriptOnTextFieldChange:) forControlEvents:UIControlEventEditingChanged];
The problem is this :
Lets say I have set an alert to display inside this executeScriptOnTextFieldChange method. Once I tapped on the 1st text field, then the barcode scanner comes. Once I scanned barcode scanner closes and set the value for the first text field and fire the alert.Thats ok. But then if scanned by tapping the 2nd textfield and the string will set to that textfield and fire the alert related to 2nd textfield also fire the alert related to first textfield as well. I want to stop happening this. Is there any way to disable the delegate for one textfield? This happens because I am refreshing the view in the viewDidAppear. But I have to do that as well. Please help me.
UIControlEventEditingChanged for a textField can fire at many different events that are not even directly related to that textField, but related inderectly.
For instance, when your ViewController is presenting the barcodeScanner it may trigger a "resignFirstResponder" event on the textField. Also when the 2nd textField is tapped, cause the 2nd becomes first responder and the 1st suffers a "resignFirstResponder".
I suggest trying to use a UITapGestureRecognizer in your textField instead. Example:
Swift 4
#IBOutlet weak var textField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
self.textField.tag = 1
self.textField.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(fireTextField(_:))))
}
#objc func fireTextField(_ sender: UIGestureRecognizer){
let view = sender.view
guard view != nil else{
//Do nothing
return
}
let condition = view!.tag == 1
if condition{
//or do whatever other stuff you need
self.textField.becomeFirstResponder()
}else{
//Whatever for other textFields
}
}
This way, you could use the "tag" attribute to determine which textField is firing and so adjust "condition". You could also filter the flow with a switch using the "tag".
Not sure if any of this will really help as I would need more info about the flow you need to accomplish. Hope it does help!

iOS: Why does hidden button still receive tap events?

According to the Apple docs, hidden UIButtons should not receive tap events.
However, our app has a UIButton receiving tap events despite being hidden.
This function is the IB Action invoked when the button is tapped. When the button is removed from Storyboard, this function doesn't get invoked. When the button is added to Storyboard, the function gets invoked -- even though the button is hidden.
To verify that the button is hidden, we put a breakpoint inside the function and ran expr sender.hidden from the Xcode debugger. The result: true.
The stack trace shows the IB Action is triggered by code in UIApplicationMain, not our code.
Through the Connections Inspector, we confirmed there is no other trigger for the IB Action except the mysterious button.
Thoroughly confused. Suggestions?
#IBAction func buttonTapped(sender: UIButton) {
// If here, handle tap
...
}
Try to set enable = false like this:
button.enabled = false
For Swift 3 would be:
button.isEnabled = false
The problem was an incomplete UIButton extension that didn't account for visibility in determining hit tests.
This function correctly handles the case where UIButtons are hidden.
extension UIButton {
public override func hitTest(point: CGPoint, withEvent event: UIEvent?) -> UIView? {
// Ignore if button hidden
if self.hidden {
return nil
}
// If here, button visible so expand hit area
let hitSize = CGFloat(56.0)
let buttonSize = self.frame.size
let widthToAdd = (hitSize - buttonSize.width > 0) ? hitSize - buttonSize.width : 0
let heightToAdd = (hitSize - buttonSize.height > 0) ? hitSize - buttonSize.height : 0
let largerFrame = CGRect(x: 0-(widthToAdd/2), y: 0-(heightToAdd/2), width: buttonSize.width+widthToAdd, height: buttonSize.height+heightToAdd)
return (CGRectContainsPoint(largerFrame, point)) ? self : nil
}
}
A situation I encountered was that I was toggling between two different buttons based on application state. When I created the second of these two buttons, I copied and pasted the first. This also copied the first button's outlets.
I thought that the first button was being pressed when only the second button was showing, but in reality the second button was sending events to both the outlet I intended AND the one that was set when I copied the first button.
To determine if this is the case in your situation, go to the interface builder, select your button, and check that the touch events are set up exactly how you want in the connections inspector. If any of the connections are wrong, you can remove them by clicking the little 'x'.

What's the simplest way to receive tap events on a disabled UIButton?

I have a UIButton on a form, and want to put it in a disabled state when the form is incomplete. However, I still want to be able to detect if a user attempts to press the button even in its disabled state so that the interface can let the user know that certain required fields on the form are not filled-in yet (and perhaps scroll to that field and point it out, etc.).
There doesn't seem to be any straightforward way to do this. I tried simply attaching a UITapGestureRecognizer to the UIButton but it doesn't respond when the button is in a disabled state.
I'd like to avoid subclassing UIButton if possible, unless it's the only way.
Create a fallback button. Put it behind the main button. Set its background and text colors to [UIColor clearColor] to ensure it won't show up. (You can't just set its alpha to 0 because that makes it ignore touches.) In Interface Builder, the fallback button should be above the main button in the list of subviews, like this:
Give it the same frame as the main button. If you're using autolayout, select both the main and fallback buttons and create constraints to keep all four edges equal.
When the main button is disabled, touches will pass through to the fallback button. When the main button is enabled, it will catch all the touches and the fallback button won't receive any.
Connect the fallback button to an action so you can detect when it's tapped.
Based on #rob idea, I sub-class a UIButton, and add a transparent button before someone addSubview on this button.
This custom UIButton will save many time about adjusting the UI components on the storyboard.
Update 2018/08
It works well, and add some enhanced detail to this sub-class. I have used it for 2 years.
class TTButton : UIButton {
// MARK: -
private lazy var fakeButton : UIButton! = self.initFakeButton()
private func initFakeButton() -> UIButton {
let btn = UIButton(frame: self.frame)
btn.backgroundColor = UIColor.clearColor()
btn.addTarget(self, action: #selector(self.handleDisabledTouchEvent), forControlEvents: UIControlEvents.TouchUpInside)
return btn
}
// Respect this property for `fakeButton` and `self` buttons
override var isUserInteractionEnabled: Bool {
didSet {
self.fakeButton.isUserInteractionEnabled = isUserInteractionEnabled
}
}
override func layoutSubviews() {
super.layoutSubviews()
// NOTE: `fakeButton` and `self` has the same `superView`.
self.fakeButton.frame = self.frame
}
override func willMoveToSuperview(newSuperview: UIView?) {
//1. newSuperView add `fakeButton` first.
if (newSuperview != nil) {
newSuperview!.addSubview(self.fakeButton)
} else {
self.fakeButton.removeFromSuperview()
}
//2. Then, newSuperView add `self` second.
super.willMoveToSuperview(newSuperview)
}
#objc private func handleDisabledTouchEvent() {
//NSLog("handle disabled touch event. Enabled: \(self.enabled)")
self.sendActionsForControlEvents(.TouchUpInside)
}
}
You have a great misunderstanding of user experience.
If a button is disabled, it is meant to be non-interactable.
You can not click on a disabled button, that is why it is disabled.
If you want to warn users about something when that button is clicked (e.g. form not filled correctly or completely), you need to make that button enabled. And just warn users when they click on it, instead of proceeding further with app logic.
Or you can keep that button disabled until form criteria are met, but show what is wrong with the form using another way, like putting exclamation marks near text fields, changing text field colors to red, or something like that...
But never try to add gesture recognizers, or hidden fallback buttons to a disabled button.
Check those and let me know if you see a disabled button:
https://airbnb.com/signup_login
https://spotify.com/us/signup/
https://netflix.com/signup/regform
https://reddit.com/register/
https://twitter.com/signup
https://facebook.com/r.php
https://appleid.apple.com/account
https://accounts.google.com/SignUp
https://login.yahoo.com/account/create
https://signup.live.com/signup
All the proceed buttons on these websites are always enabled, and you get feedback about what is wrong when you try to continue.
And here is really good answer: https://ux.stackexchange.com/a/76306
Long story short: disabled UI elements meant to be not-interactable.
Trying to make them interactable while they are disabled is the same to making them enabled in the first place.
So, for your question's case, it is just a styling issue. Just try styling your button, instead of making it disabled/enabled.

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