Use Uitapgesture recognizer on multiple image views that are not declared - swift

My swift code uses func addBox to add and append image views to the uiview controller. All I want to do is when one of the image views are tapped is for func viewClicked to be activated. Right now nothing is happening and nothing is being written into the debug area.
import UIKit
class ViewController: UIViewController {
var ht = -90
var ww = 80
var hw = 80
var arrTextFields = [UIImageView]()
var b7 = UIButton()
override func viewDidLoad() {
[b7].forEach {
$0.translatesAutoresizingMaskIntoConstraints = false
view.addSubview($0)
$0.backgroundColor = .systemOrange
}
b7.frame = CGRect(x: view.center.x-115, y: view.center.y + 200, width: 70, height: 40)
b7.addTarget(self, action: #selector(addBOx), for: .touchUpInside)
for view in self.arrTextFields {
view.isUserInteractionEnabled = true
view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(viewClicked)))
}
}
#objc func viewClicked(_ recognizer: UITapGestureRecognizer) {
print("tap")
}
//func that adds imageview.
#objc func addBOx() {
let subview = UIImageView()
subview.isUserInteractionEnabled = true
arrTextFields.append(subview)
view.addSubview(subview)
subview.frame = CGRect(x: view.bounds.midX - 0, y: view.bounds.midY + CGFloat(ht), width: CGFloat(ww), height: 35)
subview.backgroundColor = .purple
ht += 50
arrTextFields.append(subview)
}
}

You need to enable user interation
for view in self.arrTextFields {
view.isUserInteractionEnabled = true
view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(viewClicked)))
}
#objc func viewClicked(_ recognizer: UITapGestureRecognizer) {
print("tap")
}

Related

create a if statement where only one button at a time can have a border

I want my swift code to use a if statement or another sequence to only display a border on one of the buttons if click at a time. So a border can only be seen on one button at a time that button would be the last one pressed. I know I could say layer.border with 0 on each button that should be selected but I want to see if there is a more efficient way to do this.
import UIKit
class ViewController: UIViewController {
var ba = UIButton()
var bb = UIButton()
var bc = UIButton()
override func viewDidLoad() {
super.viewDidLoad()
[ba,bb,bc].forEach {
$0.translatesAutoresizingMaskIntoConstraints = false
view.addSubview($0)
}
ba.frame = CGRect(x: 0, y: 0, width: 100, height: 100)
bb.frame = CGRect(x: 100, y: 0, width: 100, height: 100)
bc.frame = CGRect(x: 200, y: 0, width: 100, height: 100)
ba.backgroundColor = .blue
bb.backgroundColor = .orange
bc.backgroundColor = .darkGray
ba.addTarget(self, action: #selector(pressa), for: .touchDown)
bb.addTarget(self, action: #selector(pressb), for: .touchDown)
bc.addTarget(self, action: #selector(pressc), for: .touchDown)
}
#objc func pressa(){
ba.layer.borderWidth = 2
}
#objc func pressb(){
bb.layer.borderWidth = 2
}
#objc func pressc(){
bc.layer.borderWidth = 2
}
}
you can add target to all buttons at the forEach and be only one method as #Sh_Khan mention
import UIKit
class ViewController: UIViewController {
var ba = UIButton()
var bb = UIButton()
var bc = UIButton()
override func viewDidLoad() {
super.viewDidLoad()
[ba,bb,bc].forEach {
$0.translatesAutoresizingMaskIntoConstraints = false
view.addSubview($0)
$0.addTarget(self, action: #selector(pressAll(_:)), for: .touchDown)
}
ba.frame = CGRect(x: 0, y: 0, width: 100, height: 100)
bb.frame = CGRect(x: 100, y: 0, width: 100, height: 100)
bc.frame = CGRect(x: 200, y: 0, width: 100, height: 100)
ba.backgroundColor = .blue
bb.backgroundColor = .orange
bc.backgroundColor = .darkGray
}
#objc func pressAll(_ sender:UIButton) {
[ba,bb,bc].forEach { $0.layer.borderWidth = 0 } // reset all
sender.layer.borderWidth = 2
}
}
See how you have used an array in [ba,bb,bc].forEach { ... } to reduce code duplication? Using arrays is the key. Rather than putting the three buttons in an array inline like that, create a property instead:
var buttons: [UIButton]!
override func viewDidLoad() {
super.viewDidLoad()
buttons = [ba,bb,bc]
buttons.forEach {
$0.translatesAutoresizingMaskIntoConstraints = false
view.addSubview($0)
$0.addTarget(self, action: #selector(buttonPressed), for: .touchDown)
}
...
}
I have used the same selector buttonPressed for all three buttons. buttonPressed can accept a parameter of type UIButton, that tells us which button is pressed:
#objc func buttonPressed(_ sender: UIButton) {
buttons.forEach { ba.layer.borderWidth = 0 } // deselect all buttons first...
sender.layer.borderWidth = 2 // select the tapped button
}
If you have more than 3 buttons to manage, I suggest you don't use UIButtons at all. You should use a UICollectionView. (Learn how to use them) This view will handle the selection for you. It also allows scrolling when there's not enough space to show all the buttons. You just need to create a custom UICollectionViewCell and override its isSelected property:
override var isSelected: Bool {
didSet {
if isSelected {
self.layer.borderWidth = 2
} else {
self.layer.borderWidth = 0
}
}
}
It could be 1 method like this
[ba,bb,bc].forEach { $0.addTarget(self, action: #selector(pressAll(_:)), for: .touchDown) }
}
#objc func pressAll(_ sender:UIButton) {
[ba,bb,bc].forEach { $0.layer.borderWidth = 0 } // reset all
sender.layer.borderWidth = 2
}

change color of uiimageview in a empty array by pressing on it

My swift code below has a button and when touch places a imageview on the viewcontroller. The only thing I want to do is when a individual imageview not all of the imageview just the one select is touch I would like to change the color from purple to blue only if touched and one at a time.
import UIKit
class ViewController: UIViewController {
var count: Int = 0
var ht = -90
var ww = 80
var moveCounter = 0
var counter = 0
var arrTextFields = [UIImageView]()
var b7 = UIButton()
override func viewDidLoad() {
super.viewDidLoad()
[b7].forEach {
$0.translatesAutoresizingMaskIntoConstraints = false
view.addSubview($0)
$0.backgroundColor = .systemOrange
}
b7.frame = CGRect(x: view.center.x-115, y: view.center.y + 200, width: 70, height: 40)
b7.addTarget(self, action: #selector(addBOx), for: .touchUpInside)
}
//func that adds imageview.
#objc func addBOx() {
let subview = UIImageView()
subview.isUserInteractionEnabled = true
arrTextFields.append(subview)
view.addSubview(subview)
subview.frame = CGRect(x: view.bounds.midX - 0, y: view.bounds.midY + CGFloat(ht), width: CGFloat(ww), height: 35)
subview.backgroundColor = .purple
subview.tag = count
count += 1
ht += 50
arrTextFields.append(subview)
}}
You already set the isUserInteractionEnabled property of the image view to true. To respond to touch events, create a UITapGestureRecognizer and add it to the image view like so:
let gestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(imageViewTapped))
subview.addGestureRecognizer(gestureRecognizer)
Then inside of the imageViewTapped method you can extract the image view from the sender argument:
#objc func imageViewTapped(sender: UITapGestureRecognizer) {
if let imageView = sender.view as? UIImageView {
// Change the imageView's background here
}
}

Is there any easier way to view UIImageView programmatically?

I have 8 buttons and I want to display a picture every time I press the buttons.
What I wonder is, do I need to have 8 functions to display these images?
Or is there any easier ways?
Here is how I've done it, it works as it should, but I do not want to repeat the same things over and over again?
var imageView1:UIImageView!
var imageView2:UIImageView!
var imageView3:UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
showImage1()
showImage2()
showImage3()
tapGestureRecognizerFunc()
}
#objc func button1Tap() {
if self.imageView1.isHidden {
self.imageView1.isHidden = false
}else{
self.imageView1.isHidden = true
}
}
#objc func button2Tap() {
if self.imageView2.isHidden {
self.imageView2.isHidden = false
}else{
self.imageView2.isHidden = true
}
}
#objc func button3Tap() {
if self.imageView3.isHidden {
self.imageView3.isHidden = false
}else{
self.imageView3.isHidden = true
}
}
func showImage1() {
imageView1 = UIImageView(frame: CGRect(x: 271, y: 8, width: 29, height: 29))
imageView1.image = UIImage(named: "Done.png")
imageView1.contentMode = .scaleAspectFit
View1.addSubview(imageView1)
imageView1.isHidden = true
}
func showImage2() {
imageView2 = UIImageView(frame: CGRect(x: 271, y: 8, width: 29, height: 29))
imageView2.image = UIImage(named: "Done.png")
imageView2.contentMode = .scaleAspectFit
View2.addSubview(imageView2)
imageView2.isHidden = true
}
func showImage3() {
imageView2 = UIImageView(frame: CGRect(x: 271, y: 8, width: 29, height: 29))
imageView2.image = UIImage(named: "Done.png")
imageView2.contentMode = .scaleAspectFit
View3.addSubview(imageView2)
imageView2.isHidden = true
}
func tapGestureRecognizerFunc () {
let exercise1Tap = UITapGestureRecognizer(target: self, action: #selector(button1Tap))
exercise1Tap.numberOfTapsRequired = 2
View1.addGestureRecognizer(exercise1Tap)
let exercise2Tap = UITapGestureRecognizer(target: self, action: #selector(button2Tap))
exercise2Tap.numberOfTapsRequired = 2
View2.addGestureRecognizer(exercise2Tap)
let exercise3Tap = UITapGestureRecognizer(target: self, action: #selector(button3Tap))
exercise3Tap.numberOfTapsRequired = 2
View3.addGestureRecognizer(exercise3Tap)
}
yes i'm newbie
Since I don't know, where and how you create the Buttons it is difficult to answer.
The following is just a tip.
You should use an array of UIImageView
Your callback should use the Form buttonAction(sender : UIButton)
You could use a tag for the button to get the number of the corresponding button
For example:
class ViewController: UIViewController {
var imageviews : [UIImageView] = []
override func viewDidLoad() {
super.viewDidLoad()
for i in 1...8 {
let imageview = UIImageView()
view.addSubview(imageview)
imageview.tag = i
imageviews.append(imageview)
let button = UIButton(frame: CGRect(x: 0, y: CGFloat(i)*50.0, width: 100, height: 30))
view.addSubview(button)
button.setTitle("Button \(i)", for: .normal)
button.setTitleColor(.black, for: .normal)
button.tag = i
button.addTarget(self, action: #selector(buttonAction), for: .touchUpInside)
}
}
#objc func buttonAction(sender : UIButton) {
let index = sender.tag
print("Button \(index) pressed")
imageviews[index].isHidden = !imageviews[index].isHidden
}
}

Swift - detect touched coordinate of UIView

I am trying to make a custom jump bar which can be attached to UITableView.
What I want to achieve now is if user touches A and slides through Z, I want print out A, B, C, D..., Z. Currently, it only prints A, A, A...A. Is there anyway I can achieve it?
Each letter is UIButton subview of UIView.
class TableViewJumpBar{
let tableView: UITableView
let view: UIView
let jumpBar: UIView!
private var jumpIndexes: [Character]
init(tableView: UITableView, view: UIView){
self.view = view
self.tableView = tableView
jumpBar = UIView(frame: .zero)
jumpBar.backgroundColor = UIColor.gray
let aScalars = "A".unicodeScalars
let aCode = aScalars[aScalars.startIndex].value
jumpIndexes = (0..<26).map {
i in Character(UnicodeScalar(aCode + i)!)
}
}
func setFrame(x: CGFloat, y: CGFloat, width: CGFloat, height: CGFloat){
guard jumpIndexes.count > 0 else{
print("Jump indexes cannot be empty")
return
}
//Remove jumpbar and remove all subviews
jumpBar.removeFromSuperview()
for subView in jumpBar.subviews{
subView.removeFromSuperview()
}
jumpBar.frame = CGRect(x: x, y: y, width: width, height: height)
let height = height/CGFloat(jumpIndexes.count)
for i in 0..<jumpIndexes.count{
let indexButton = UIButton(frame: CGRect(x:CGFloat(0.0), y: CGFloat(i)*height, width: width, height: height))
indexButton.setTitle(String(jumpIndexes[i]), for: .normal)
indexButton.addTarget(self, action: #selector(jumpIndexButtonTouched(_:)), for: .allEvents)
jumpBar.addSubview(indexButton)
}
self.view.addSubview(jumpBar)
}
///Touch has been begun
#objc private func jumpIndexButtonTouched(_ sender: UIButton!){
print(sender.titleLabel?.text)
}
this code works and print start and finish characters.
class ViewController: UIViewController {
#IBOutlet weak var myTableView: UITableView!
#IBOutlet weak var myView: UIView!
var startChar = ""
var finishChar = ""
override func viewDidLoad() {
super.viewDidLoad()
let table = TableViewJumpBar(tableView: myTableView, view: myView)
table.setFrame(x: 0, y: 0, width: 100, height: self.view.frame.size.height)
print(myView.subviews[0].subviews)
setPanGesture()
}
func setPanGesture() {
let pan = UIPanGestureRecognizer(target: self, action: #selector(panRecognized))
self.myView.addGestureRecognizer(pan)
}
#objc func panRecognized(sender: UIPanGestureRecognizer) {
let location = sender.location(in: myView)
if sender.state == .began {
for button in myView.subviews[0].subviews {
if let button = button as? UIButton, button.frame.contains(location), let startCharacter = button.titleLabel?.text {
self.startChar = startCharacter
}
}
} else if sender.state == .ended {
for button in myView.subviews[0].subviews {
if let button = button as? UIButton, button.frame.contains(location), let finishCharacter = button.titleLabel?.text {
self.finishChar = finishCharacter
}
}
print("start with \(startChar), finish with \(finishChar)")
}
}
}
In your code I delete Button action. you can use labels instead Buttons.
class TableViewJumpBar {
let tableView: UITableView
let view: UIView
let jumpBar: UIView!
private var jumpIndexes: [Character]
init(tableView: UITableView, view: UIView){
self.view = view
self.tableView = tableView
jumpBar = UIView(frame: .zero)
jumpBar.backgroundColor = UIColor.gray
let aScalars = "A".unicodeScalars
let aCode = aScalars[aScalars.startIndex].value
jumpIndexes = (0..<26).map {
i in Character(UnicodeScalar(aCode + i)!)
}
}
func setFrame(x: CGFloat, y: CGFloat, width: CGFloat, height: CGFloat){
guard jumpIndexes.count > 0 else{
print("Jump indexes cannot be empty")
return
}
jumpBar.removeFromSuperview()
for subView in jumpBar.subviews{
subView.removeFromSuperview()
}
jumpBar.frame = CGRect(x: x, y: y, width: width, height: height)
let height = height/CGFloat(jumpIndexes.count)
for i in 0..<jumpIndexes.count{
let indexButton = UIButton(frame: CGRect(x:CGFloat(0.0), y: CGFloat(i)*height, width: width, height: height))
indexButton.setTitle(String(jumpIndexes[i]), for: .normal)
jumpBar.addSubview(indexButton)
}
self.view.addSubview(jumpBar)
}
}
Some output results:

UISwipeGestureRecognizer not recognized when added to UIView's subviews

I currently have a subclass of UIView which contains numerous subviews. I wish to add a UISwipeGesture to the subviews but unfortunately the swipe gesture is not recognized. I've set userInteractionEnabled = true and direction of the swipe gesture but nothing works.
public class CardStackView: UIView{
public var dataSource = [UIImage]()
private var swipeGuesture: UISwipeGestureRecognizer!
override public func layoutSubviews() {
for img in dataSource{
let view = AppView(image: img, frame: self.frame)
self.addSubview(view)
}
animateSubview()
self.userInteractionEnabled = true
}
func animateSubview(){
for (index, sView) in self.subviews.enumerate() {
swipeGuesture = UISwipeGestureRecognizer(target: self, action: #selector(self.swipeGuestureDidSwipeRight(_:)))
swipeGuesture.direction = .Right
sView.addGestureRecognizer(swipeGuesture)
sView.userInteractionEnabled = true
let move: CGFloat = CGFloat(-20 + index * 20)
let opacity = Float(1 - 0.2 * CGFloat(index))
sView.shadowOpacity(opacity).shadowOffset(CGSizeMake(20 - CGFloat(index) * 5, 20 - CGFloat(index) * 5)).shadowRadius(5).moveX(-move).moveY(-move).gravity().shadowColor(UIColor.grayColor()).duration(1)
.completion({
}).animate()
}
}
func swipeGuestureDidSwipeRight(gesture: UISwipeGestureRecognizer) {
print("Swiped right")
let subview = self.subviews[0]
subview.moveX(-60).duration(1).animate()
}
}
Example
class ExampleController: UIViewController {
var stackView: CardStackView!
override func viewDidLoad() {
super.viewDidLoad()
stackView = CardStackView(frame: CGRect(x: 20, y: 80, width: 200, height: 200))
stackView.dataSource = [UIImage(named: "2008")!, UIImage(named: "2008")!]
self.view.addSubview(stackView)
}
}
self.view.bringSubviewToFront(yourSubview)
try this code for all your subviews and if it doesn't work try this in your controller class for your CardStackView.
Try to call setNeedsLayout for stackView:
override func viewDidLoad() {
super.viewDidLoad()
stackView = CardStackView(frame: CGRect(x: 20, y: 80, width: 200, height: 200))
stackView.dataSource = [UIImage(named: "2008")!, UIImage(named: "2008")!]
stackView.setNeedsLayout()
self.view.addSubview(stackView)
}