I added a today extension to my app. I edited the vanilla widget a little bit and made it look like this:
Please notice the UIButton titled "Went 1st". When it gets pressed (touched up inside to be exact), it triggers this action:
#IBAction func coinChanged(sender: UIButton) {
if sender.titleLabel?.text == "Went 1st" {
coin = true
sender.titleLabel!.text = "Went 2nd"
} else {
coin = false
sender.titleLabel!.text = "Went 1st"
}
}
It basically alters between two states, changing its title and a variable accordingly.
Here is the problem though - when I press it, it indeed changes its title, but immediately changes it back, ending up on the same title as it had initially. My first thought was the action gets called twice after a press, but when I checked with print I found out it gets called only once. Sometimes the prints didn't even show up in console, but that's a different story.
So, that's one problem. There's one more, though - when I press the button, the whole widget gets misplaced. To know what I mean, look at the first picture (that's the widget before any presses) and now on this one (after the button gets pressed):
You can see that the borders are now on the very edge of TodayView. For reference, here are the constraints of the first segmented control:
Edit: Here are the constraints for "Went 1st/2nd" button:
Edit 2: Be sure to tell me what's wrong if you downvote, so I can avoid making the same mistakes next time
The problem is you should not be setting the button text like that. The title label is primarily used to set text size, font, color, etc. To set the title use something like this:
sender.setTitle("Button Title", forState: UIControlState.Normal)
So the new ib action should look like:
#IBAction func coinChanged(sender: UIButton) {
if sender.titleLabel?.text == "Went 1st" {
coin = true
sender.setTitle("Went 2nd", forState: UIControlState.Normal)
} else {
coin = false
sender.setTitle("Went 1st", forState: UIControlState.Normal)
}
}
Related
I have a button with accessibility label #"a". When the button is pressed, I have a callback that sets the accessibility label button.accessibilityLabel = #"b". I know this line of code runs. However, if I tap the button again, VoiceOver still reads a. Unfortunately, the code I'm working with is proprietary, so I can't share it directly.
However, in general, I would like to know what issues might cause VoiceOver to not recognize an update to a label.
THE BEST way to handle dynamic accessibility labels is to override the property functions on the views that are being focused (EX: on a UIButton). This allows TWO things. A: it's a lot easier to maintain than setting the property everywhere it can change. B: you can log information and see when the system is requesting that information, so you can better understand WHY things are happening. So even if it doesn't directly fix your issue, seeing WHEN the system requests your value, and logging that data, is inherently valuable.
Doing this in Objective C
#implementation YourUIButton
-(NSString*)accessibilityLabel {
if(someCondition) {
return #"a";
} else {
return #"b";
}
}
#end
In Swift
public class YourUIButton : UIButton
override public var accessibilityLabel: String? {
get {
if (someCondition) {
return "a"
} else {
return "b"
}
}
set {
NSException.raise(NSException("AccessibilityLabelException", "You should not set this accessibility label.", blah))
}
}
}
You could also use this logic JUST to debug, and allow setting and such.
There are a lot of potential issues here. Race conditions, which view is actually getting focus, is there some parent child relationship going on, etc. Overriding the property and adding logging statements to the above code will help you understand what view is actually getting the accessibility label requested and when. Super valuable information!
Use this while changing button text
UIAccessibility.post(notification: .layoutChanged, argument: yourButton)
Try to add UIAccessibilityTraitUpdatesFrequently to your buttons property accessibilityTraits
- (void)viewDidLoad {
myButton.accessibilityTraits |= UIAccessibilityTraitUpdatesFrequently
}
Also, when changing accessibilityLabel be sure that you're on main thread.
dispatch_async(dispatch_get_main_queue(), ^{
myButton.accessibilityLabel = #"b";
});
You don't really need a way to refresh the voice over labels. Its done automatically. I have tried this and it works as expected.
class ViewController: UIViewController {
var tapCount = 0
var button: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
button = UIButton(type: .system)
button.setTitle("Hello", for: .normal)
button.frame = CGRect(x: 10, y: 10, width: 100, height: 50)
view.addSubview(button)
button.accessibilityLabel = "Hello Button"
button.accessibilityHint = "Tap here to start the action"
button.accessibilityIdentifier = "hello_button"
button.addTarget(self, action: #selector(buttonTap(sender:)), for: .touchUpInside)
}
#IBAction func buttonTap(sender:UIButton) {
tapCount = tapCount + 1
sender.accessibilityLabel = "Hello button, tapped \(tapCount) times"
}
}
What Voice oversays:
Hello Button-pause-Button-pause-Tap here to start the action
On button tap
Hello button, tapped one times
Another tap
Hello button, tapped two times
I work on Swift 3, and I'm trying to make checkboxes that behave like radio buttons. I explain myself : I have 8 buttons ; each has an "unchecked" image and a "checked" image. I want only 1 button to be selected (so, showing ITS "checked" image) at the time. The principle of radio buttons.
So I tried using the #IBAction with each button, I've this :
#IBAction func tona1_changed(_ sender: Any) {
if test_tona1.isSelected == true
{
test_tona1.setBackgroundImage(UIImage(named: "0b_unchecked"), for: UIControlState.normal)
test_tona1.isSelected = false
}
else
{
test_tona1.setBackgroundImage(UIImage(named: "0b_checked"), for: UIControlState.normal)
test_tona1.isSelected = true
}}
It actually make the image switch between "uncheck" and "check" but I don't know at all how to make it interact with the other buttons.
I tried using an array with the buttons's tags inside but I didn't have something working. I also tried to make a class but I don't know how it can work.
Thanks!
You can achieve that in several ways. One of the most trivial would be to:
Have a datasource. Most of the time an array.
Create an UIButton for each item in your datasource, and insert each button into another array. Each button would have a tag corresponding at the
index of the array. Also set different images for selected state and normal.
Add an action for each button, with the target function being something like:
func buttonPressed(sender:UIButton) {
for button in buttons {
button.isSelected = false
// deselect your model datasource[button.tag]
}
sender.isSelected = true
// select your model datasource[button.tag]
}
I leave the abstraction / improvements / safety to you. The key point is just to use a collection of buttons, iterate through them, and select / deselect them accordingly, and not using a big if/else checking for the button tag everytime.
I currently use an app and I'm trying to replicate an action that occurs in the app.
Here's an example:
As you can see, when my finger is on the selected "UIButton" (at least that's what I think they are), the background image is highlighted. Without releasing my finger, scrolling through the different options highlight that specific UIButton.
I believe each one is a UIButton with no text label, and they've just added a UILabel for each UIButton.
I've done something similar as soon:
However, what I can't figure out is how they managed to make the background highlighted between each selection.
It looks like a combination of a UIControlEvents.TouchDown and UIControlEvents.TouchUpInside.
I've coded up something similar:
cameraButton.addTarget(self, action: #selector(AddClothesViewController.selectCameraOptions(_:)), forControlEvents: .TouchUpInside)
cameraButton.addTarget(self, action: #selector(AddClothesViewController.selectCameraOptionsHighlighted(_:)), forControlEvents: .TouchDown)
func selectCameraOptionsHighlighted(button: UIButton)
{
if button == cameraButton
{
print("GO HERE")
cameraButton.setImage(UIImage(named: "highlighted background"), forState: .Normal)
}
}
func selectCameraOptions(button: UIButton)
{
if button == cameraButton
{
// DO STUFF
}
}
However this approach does not work, because if I perform a .TouchDown, somehow the camera options disappear. If I just add a target for .TouchUpInside, that obviously doesn't work neither because it's only highlighted once I release my finger, and by that time, it would have already taken me to a different view, i.e. Camera or Photo Library.
What's the best approach for how to achieve this?
Thanks.
I have an app with some buttons, when those buttons are pressed the image on them should change. I assume that the TouchUpInside runs when you tap and remove the finger while still holding inside the area of the element, however it only works rarely and I'm not sure why.
The reason I use TouchUpInside instead of TouchDown is because I want the user to be able to cancel the action.
I'm sorry if I've misunderstood anything about those events and if this has already been asked. I couldn't find an answer to my problem searching the web.
//The IBAction is set to trigger on TouchUpInside
#IBAction func action11(sender: UIButton) {
setTile(sender)
}
func setTile(sender: UIButton) {
if turn {
print("O's turn")
sender.setImage(xTile, forState: .Normal)
turn = false
}
}
EDIT: Added the necessary code
There are some properties of UIButtons which you can use to achieve what you want.
You can use Default and selected state of uibutton to set two different images.
In XIB select state "Default" and assign default image to that state again select state to "Selected" and assign image which you want after button section.
and add following line in button selection method.
-(IBAction)buttonTapped:(UIButton *)sender{
sender.selected = !sender.selected;
}
Your understanding is correct, you need to use touchUpInside.
I assume you are trying to create a button that has a toggle function. On one touch you want the button to have the value Say "X" and when touched again the button has a value "O".
Take a look at this code below, this should do the job.
class ViewController: UIViewController {
var isButtonPressed = false{
// Adding a Property Observer, that reacts to changes in button state
didSet{
if isButtonPressed{
// Set the Value to X.
}else{
// Set the Value to O.
}
}
}
#IBAction func changeButtonValue(sender: UIButton) {
// Toggle the button value.
isButtonPressed = !isButtonPressed
}
}
If you don't set turn=true after the first time, this code is executed it will be executed only one.
if turn {
print("O's turn")
sender.setImage(xTile, forState: .Normal)
turn = false
}
Check if the button frame is large enough to get finger touch.
Apple says at least 35x35 pixel.
I have a #IBAction function that accepts a sender: UIButton! as a parameter.
#IBAction func buttonPress(sender: UIButton!)
At some point in the function, I am copying the sender to another variable which was previously declared as a UIButton()
anotherVar = sender
I understand this is a reference to the original sender given UIButton is a class
However at some point of the code, I want to break the reference to sender and "reset" anotherVar to a plain vanilla UIButton(). How would I do this?
EDIT:
I feel I should expand on what I'm doing, perhaps I'm going about this the wrong way...
I have eight buttons all calling the same #IBAction function called buttonPress(). The idea is for the user to tap a button, see an image and then tap another button (out of the remaining seven) to find the matching image. When buttonPress() gets called, the code:
1. Checks to see if this is a first button being tapped
- if it is, it shows the button image and then assigns sender to anotherVar;
- if it is the second button being pressed (i.e. another button was previously clicked), the code runs a match to compare the sender's image to anotherVar's image which was set above
2. If there is a match, I "lock" the buttons so the matching logic doesn't get executed if the user taps the buttons again
3. If there is no match, I want to "clear out" anotherVar ready for another matching task. I don't want to "lock" the buttons as the same button may still need to be clicked.
Here's the full code:
#IBAction func buttonPress(sender: UIButton!) {
var buttonImage = UIImage()
buttonImage = UIImage(named: listOfImages[sender.tag])!
if (!imageIsDone[sender.tag] && (sender.tag != buttonToCompare.tag)) {
// Only execute button logic if match for image not already found and the user isn't tapping the same image
if (imageAwaitingCheck) {
// User has made their first image selection, do matching logic on image clicked
sender.setImage(buttonImage, forState: .Normal)
if (sender.currentImage == buttonToCompare.currentImage) {
// Tapped image macthes previously clicked image
println("Match")
// "Lock" the buttons as they've been matched
imageIsDone[sender.tag] = true
imageIsDone[buttonToCompare.tag] = true
imageAwaitingCheck = false
}
else {
// Tapped image does not match previously clicked image
println("No match")
imageAwaitingCheck = false
buttonToCompare.tag = 100
// ********ERROR IS HERE*********I forced this so that
// (sender.tag != buttonToCompare.tag) is true above when
// the user taps on the first button again after no match is found.
// However, this is a REFERENCE to the original sender and sets the
// button tag to 100 which causes the condition to fail and hence
// tapping button 1, then button 2, no match, then clicking button 1
// again doesn't execute any of this logic
}
}
else {
// User has selected this as the first image, simply show it
sender.setImage(buttonImage, forState: .Normal)
imageAwaitingCheck = true
buttonToCompare = sender // I am copying sender to buttonToCompare. Ideally this would create a copy but because UIButton is a class, this is creating a buttonToCompare as a reference
}
}
}
As long as anotherVar is assigned as var, not let, you can simply do the following when you're done with the sender:
anotherVar = UIButton()
This will "overwrite" the previous value of anotherVar and "reset" it to a new instance of UIButton.
However, you probably don't need to do this at all if the only place you're accessing anotherVar is this function - as long as you call anotherVar = sender, that will also replace the reference to the previous button with the new sender button.
To achieve what you describe after your edit, you don't really need to make a lot of changes. In this if-statement: if (sender.currentImage == buttonToCompare.currentImage) add buttonToCompare = UIButton() at the very end. In the else-statement, do the same instead of changing it's tag.
Alternatively, if you want the sender to be copied, you can do that like this:
let archivedData = NSKeyedArchiver.archivedDataWithRootObject(button)
let buttonCopy = NSKeyedUnarchiver.unarchiveObjectWithData(archivedData)