I have a function in my controller I call
private func toggleLauncher() {
let launcher = CommentsLauncher()
launcher.showLauncher()
}
This essentially adds a view on top of the current view, with a semi transparent background.
I'd like to then render a custom inputAccessoryView at the bottom of the newly added view.
class CommentsLauncher: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor(white: 0, alpha: 0.5)
}
func showLauncher() {
if let window = UIApplication.shared.keyWindow {
window.addSubview(view)
}
}
override var inputAccessoryView: UIView? {
get {
let containerView = UIView()
containerView.frame = CGRect(x: 0, y: 0, width: view.frame.width, height: 50)
containerView.backgroundColor = .purple
return containerView
}
}
override var canBecomeFirstResponder: Bool {
return true
}
}
All that happens though is the semi transparent background is visible but I see no inputAccessoryView added to the view also and I am unsure why.
Your CommentsLauncher never become the first responder in the code you provided. A UIResponder's inputAccessoryView is displayed when the responder becomes first responder.
Change your showLauncher method to something like this:
func showLauncher() {
if let window = UIApplication.shared.keyWindow {
window.addSubview(view)
becomeFirstResponder()
}
}
And you should see the input accessory view.
I'm trying to create a subclass of UIView in order to let expand the view with a pan over it. It should work this way: if the user makes a pan toward the top the view's height decrease, instead if the pan is toward the bottom it should increase. In order to achieve that functionality, I'm trying to add a UIPanGestureRecognizer to the view but it doesn't seem to work. I've done it this way:
The first snippet is the uiView subclass declaration
class ExpandibleView: UIView {
//Here I create the reference to the recognizer
let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(handlePan(_:)))
//And here I set its minimumNumberOfTouches and maximumNumberOfTouches properties and add it to the view
func initialize() {
panGestureRecognizer.minimumNumberOfTouches = 1
panGestureRecognizer.maximumNumberOfTouches = 1
self.addGestureRecognizer(panGestureRecognizer)
}
//here's the function that should handle the pan but who instead doesn't seem to been called at all
#objc func handlePan(_ sender:UIPanGestureRecognizer) {
//Here's I handle the Pan
}
}
The second one instead is the implementation inside the View Controller.
class MapViewController: UIViewController {
#IBOutlet weak var profileView: ExpandibleView!
//MARK: - ViewController Delegate Methods
override func viewDidLoad() {
super.viewDidLoad()
//Here I set the View
profileView.isUserInteractionEnabled = true
profileView.initialize()
profileView.minHeight = 100
profileView.maxHeight = 190
}
}
I set inside the storyboard the view's class as the subclass I created but the recognizer doesn't trigger at all the handler.
The problem you're experiencing is due to your definition of the panGestureRecognizer variable in the class definition here:
//Here I create the reference to the recognizer
let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(handlePan(_:)))
You can initialize it this way, but it seems like self is not setup when this variable is created. So your action is never registered.
There are a couple ways you can fix this using your code, you can continue to initialize it as an instance variable, but you'll need to setup your target/action in your initialize() function
let panGestureRecognizer = UIPanGestureRecognizer()
func initialize() {
// add your target/action here
panGestureRecognizer.addTarget(self, action: #selector(handlePan(_:)))
panGestureRecognizer.minimumNumberOfTouches = 1
panGestureRecognizer.maximumNumberOfTouches = 1
addGestureRecognizer(panGestureRecognizer)
}
Or you can simply initialize your gesture recognizer in your initialize function and not use an instance variable
func initialize() {
let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(handlePan(_:)))
panGestureRecognizer.minimumNumberOfTouches = 1
panGestureRecognizer.maximumNumberOfTouches = 1
addGestureRecognizer(panGestureRecognizer)
}
My original answer
Here's a solution that works using constraints with a view defined in the storyboard or by manipulating the frame directly.
Example with Constraints
import UIKit
// Delegate protocol for managing constraint updates if needed
protocol MorphDelegate: class {
// tells the delegate to change its size constraints
func morph(x: CGFloat, y: CGFloat)
}
class ExpandableView: UIView {
var delegate: MorphDelegate?
init() {
// frame is set later if needed by creator when using this init method
super.init(frame: CGRect.zero)
configureGestureRecognizers()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
configureGestureRecognizers()
}
override init(frame: CGRect) {
super.init(frame: frame)
configureGestureRecognizers()
}
// setup UIPanGestureRecognizer
internal func configureGestureRecognizers() {
let panGR = UIPanGestureRecognizer.init(target: self, action: #selector(didPan(_:)))
addGestureRecognizer(panGR)
}
#objc func didPan(_ panGR: UIPanGestureRecognizer) {
// get the translation
let translation = panGR.translation(in: self).applying(transform)
if let delegate = delegate {
// tell delegate to change the constraints using this translation
delegate.morph(x: translation.x, y: translation.y)
} else {
// If you want the view to expand/contract in opposite direction
// of drag then swap the + and - in the 2 lines below
let newOriginY = frame.origin.y + translation.y
let newHeight = frame.size.height - translation.y
// expand self via frame manipulation
let newFrame = CGRect(x: frame.origin.x, y: newOriginY, width: frame.size.width, height: newHeight)
frame = newFrame
}
// reset translation
panGR.setTranslation(CGPoint.zero, in: self)
}
}
If you want to use this class by defining it in the storyboard and manipulating it's constraints you'd go about it like this.
First define your view in the storyboard and constrain it's width and height. For the demo I constrained it's x position to the view center and it's bottom to the SafeArea.bottom
Create an IBOutlet for the view, as well as it's height constraint to your ViewController file.
I set the background color to blue for this example.
In the view controller I defined a function to setup the view (currently only sets the delegate for constraint manipulation callbacks) and then defined an extension to handle delegate calls for updating constraints.
class ViewController: UIViewController {
#IBOutlet weak var expandingView: ExpandableView!
#IBOutlet weak var constraint_expViewHeight: NSLayoutConstraint!
override func viewDidLoad() {
super.viewDidLoad()
// call to configure our expanding view
configureExpandingView()
}
// this sets the delegate for an expanding view defined in the storyboard
func configureExpandingView() {
expandingView.delegate = self
}
}
// setup the delegate callback to handle constraint manipulation
extension ViewController: MorphDelegate {
func morph(x: CGFloat, y: CGFloat) {
// this will update the view's height based on the amount
// you drag your finger in the view. You can '+=' below if
// you want to reverse the expanding behavior based on pan
// movements.
constraint_expViewHeight.constant -= y
}
}
Doing it this way via constraints gives me this when I run the project:
Example with frame manipulation
To use this and manipulate the height using just the frame property the view controller might implement the view creation something like this:
override func viewDidLoad() {
super.viewDidLoad()
setupExpandingView()
}
func setupExpandingView() {
let newView = ExpandableView()
newView.backgroundColor = .red
newView.frame = CGRect(x: 20, y: 200, width: 100, height: 100)
view.addSubview(newView)
}
Using just frame manipulation I get this:
Try change this
class ExpandibleView: UIView {
func initialize() {
}
//here's the function that should handle the pan but who instead doesn't seem to been called at all
func handlePan() {
//your function
}
}
class MapViewController: UIViewController {
#IBOutlet weak var profileView: ExpandibleView!
//MARK: - ViewController Delegate Methods
override func viewDidLoad() {
super.viewDidLoad()
let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(handlePan(_:)))
panGestureRecognizer.minimumNumberOfTouches = 1
panGestureRecognizer.maximumNumberOfTouches = 1
profileView.addGestureRecognizer(panGestureRecognizer)
//Here I set the View
profileView.isUserInteractionEnabled = true
profileView.initialize()
profileView.minHeight = 100
profileView.maxHeight = 190
}
#objc func handlePan(_ sender:UIPanGestureRecognizer) {
profileView.handlePan()
}
}
Or you can create a delegate for call in other view.
good luck!
Here I have a simple example. im calling FirstResponder in viewDidLoad. But accessory view only shows up after tapping the screen. Why isn't it showing from the start?
class TestViewController: MainPageViewController {
private let accessoryView = UIView() //TextInputView() // MessageInputAccessoryView()
override var inputAccessoryView: UIView {
return accessoryView
}
override var canBecomeFirstResponder: Bool { return true }
override func viewDidLoad() {
super.viewDidLoad()
accessoryView.backgroundColor = .red
accessoryView.frame = CGRect(x: 0, y: 0, width: 300, height: 50)
self.becomeFirstResponder()
// Do any additional setup after loading the view.
let tap = UITapGestureRecognizer(target: self, action: #selector(tappo))
self.view.isUserInteractionEnabled = true
self.view.addGestureRecognizer(tap)
tappo()
}
func tappo() {
self.becomeFirstResponder()
}
}
viewWillAppear is a better place to put the becomesFirstResponder. Try that.
So something was resigning my first responder (as I was using UIPageViewController). So I've added this to my UIViewControler :
override var canResignFirstResponder: Bool { return false }
That's it. Cheers!
I have a Visual Effect View on storyboard connected to my ViewController as an outlet. The effect is burring an ImageView behind it and works great. I'm trying to change the UIBlurEffectStyle from Light to Dark inside a button click IBAction. Any help here would be much appreciated!
#IBOutlet weak var blurView: UIVisualEffectView!
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func changeBlurView() {
// This is wrong, but is my best attempt so far.
self.blurView(UIBlurEffectStyle.Dark)
}
While creating my own app I faced to a similar problem. I do not use IB at all, so everything is done programatically. I looked into the UIVisualEffectView.h and it does not provide any effect change on the fly (hopefully this will change in the future).
So here is my solution (I'm using the latest Swift version, so there is an as! operator):
class CustomVisualEffectView : UIVisualEffectView
{
deinit
{
println("UIVisualEffectView will be destroyed.")
}
}
class ViewController: UIViewController
{
var _blurEffect = UIBlurEffect() // global so you can use it for vibrancy effect view as well
var _blurredEffectView = CustomVisualEffectView()
let _someSubView = UIView()
let _someOtherSubView = UIView()
let _effectChanger = UIButton.buttonWithType(.System) as! UIButton
override func viewDidLoad()
{
super.viewDidLoad()
self.view.backgroundColor = UIColor.orangeColor()
/* create a button to change the effect */
_effectChanger.setTitle("Change effect!", forState: UIControlState.Normal)
_effectChanger.frame.size = CGSize(width: 100, height: 20)
_effectChanger.center = self.view.center
_effectChanger.addTarget(self, action: Selector("buttonClicked"), forControlEvents: UIControlEvents.TouchUpInside)
self.view.addSubview(_effectChanger)
/* here is our effect view */
_blurEffect = UIBlurEffect(style: self.randomBlurEfffectStyle())
_blurredEffectView = CustomVisualEffectView(effect: _blurEffect)
self.layoutEffectView()
self.view.addSubview(_blurredEffectView)
/* create two subviews and put them on the effect view */
_someSubView.frame = CGRectMake(10, 10, 10, 10)
_someSubView.backgroundColor = UIColor.redColor()
_blurredEffectView.contentView.addSubview(_someSubView)
_someOtherSubView.frame = CGRectMake(30, 30, 10, 10)
_someOtherSubView.backgroundColor = UIColor.greenColor()
_blurredEffectView.contentView.addSubview(_someOtherSubView)
}
func layoutEffectView()
{
_blurredEffectView.frame.size = CGSize(width: 100, height: 80)
_blurredEffectView.center = CGPointMake(_effectChanger.center.x, _effectChanger.center.y - 50)
}
func buttonClicked()
{
var tempArray = [AnyObject]()
/* get all subviews from the effect view */
for view in _blurredEffectView.contentView.subviews
{
tempArray.append(view)
view.removeFromSuperview()
}
/* modify your effect view */
_blurEffect = UIBlurEffect(style: self.randomBlurEfffectStyle())
/* IMPORTANT: so the old effect view can be destroyed by arc */
_blurredEffectView.removeFromSuperview()
_blurredEffectView = CustomVisualEffectView(effect: _blurEffect)
/* I think this will be really tricky if you will use auto layout */
self.layoutEffectView()
self.view.addSubview(_blurredEffectView)
/* put all subviews back to the effect view*/
for view in tempArray
{
_blurredEffectView.contentView.addSubview(view as! UIView)
}
}
func randomBlurEfffectStyle() -> UIBlurEffectStyle
{
let randomBlurEffectStyle : UIBlurEffectStyle
switch Int(arc4random_uniform(3)) // [0,1,2]
{
case 0:
randomBlurEffectStyle = .ExtraLight
case 1:
randomBlurEffectStyle = .Light
default:
randomBlurEffectStyle = .Dark
}
return randomBlurEffectStyle
}
}
After initialisation of by subclass of UIImageView I have the following line of code:
self.userInteractionEnabled = true
self.addGestureRecognizer(UITapGestureRecognizer(target: self, action: "handleTap:"))
I created the necessary associated function :
func handleTap(gestureRecognizer: UITapGestureRecognizer) {
print("In handler")
}
On tapping on the view in question, "In handler was never printed to the console". I then removed the handler function to see if the compiler would complain about the missing function. It didn't.
I'm positively stumped. I'd truly appreciate any light people can shed on this.
Update: My class is actually a UIImageView as opposed to UIView
I was using UITapGestureRecognizer that I placed on a UILabel using Storyboard.
To get this to work I also had to place a checkmark in the block labeled: "User Interaction Enabled" in the UILabel Attributes Inspector in the Storyboard.
I discovered the answer after carefully combing through my code.
One of the parent views was created without supplying a frame:
While it's a noobish enough error to warrant deletion of this questions, odds are someone else will also have the same issue in the future...
Try this
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
self.view.userInteractionEnabled = true
var tapGesture = UITapGestureRecognizer(target: self, action: Selector("handleTap:"))
self.view.addGestureRecognizer(tapGesture)
}
func handleTap(sender : UIView) {
println("Tap Gesture recognized")
}
In addition to the other answers, this can be caused by adding the gesture recognizer to multiple views. Gesture recognizers are for single views only.
Reference: https://stackoverflow.com/a/5567684/6543020
I ran into this problem with programmatic views.
My UIView with the gesture recognizer had .isUserInteractionEnabled = true, but it did not respond to taps until I set .isUserInteractionEnabled = true for its parent views as well.
Most likely you add UIGestureRecognizer in wrong place. Here is working sample with UIView from storyboard. If you create your UIView dynamically then you should put this initialization in the correct constructor.
class TestView: UIView
{
override func awakeFromNib()
{
self.userInteractionEnabled = true
self.addGestureRecognizer(UITapGestureRecognizer(target: self, action: "handleTap:"))
}
func handleTap(gestureRecognizer: UITapGestureRecognizer)
{
println("Here")
}
}
I found the solution to this problem after lot of trial and error. So there are two solution two this
1. Either add the GestureRecognizer in viewDidLoad() and turn
userInteractionEnabled = true
2. If using computed property use lazy var instead of let to the property.
lazy var profileImageView: UIImageView = {
let iv = UIImageView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
iv.image = #imageLiteral(resourceName: "gameofthrones_splash")
iv.contentMode = .scaleAspectFill
iv.translatesAutoresizingMaskIntoConstraints = false
iv.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleSelectProfileImageView)))
iv.isUserInteractionEnabled = true
return iv
}()
For anyone that is still having problems even with all the previous answers, make sure you are using UITapGestureRecognizer instead of UIGestureRecognizer, I kept missing this detail while trying to find what was wrong.
This Code works for me with XCode 7.0.1
import UIKit
class ImageView: UIImageView {
init(frame: CGRect, sender: Bool, myImage: UIImage) {
super.init(frame: frame)
self.image = myImage
initBorderStyle(sender)
// enable user interaction on image.
self.userInteractionEnabled = true
let gesture = UITapGestureRecognizer(target: self, action: "previewImage:")
addGestureRecognizer(gesture)
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
func previewImage(myGesture: UITapGestureRecognizer? = nil) {
print("i'm clicked")
}
private func initBorderStyle(sender: Bool) {
self.layer.masksToBounds = true
self.layer.cornerRadius = 8
self.layer.borderWidth = 0.5
self.layer.borderColor = getBorderColor(sender)
self.backgroundColor = getColor(sender)
}
func getBorderColor(sender: Bool) -> CGColor {
var result: CGColor
if sender {
result = UIColor(red: 0.374, green: 0.78125, blue: 0.0234375, alpha: 0.5).CGColor
} else {
result = UIColor(red: 0.3125, green: 0.6015625, blue: 0.828125, alpha: 0.5).CGColor
}
return result
}
}
Xcode 11.4 Swift 5.2
UserInteraction is enabled by default on Custom UIView
import UIKit
class YourView: UIView {
override init(frame: CGRect) {
super.init(frame: frame)
commonInit()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
commonInit()
}
func commonInit() {
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(tapped))
self.addGestureRecognizer(tapGesture)
}
#objc func tapped() {
// do something
}
}
If you want to be notified elsewhere that the custom UIView has been tapped, then it is convenient to use a Notification.
It is best to create this as an extension to prevent it being Stringly typed.
extension Notification.Name {
static let DidTapMyView = Notification.Name("DidTapMyView")
}
In your custom UIView when the tapped function is called
#objc func tapped() {
NotificationCenter.default.post(name: .DidTapMyView, object: self)
}
In your UIViewController where you want to listen for the Notification:
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(myViewWasTapped), name: .DidTapMyView, object: nil)
}
#objc func myViewWasTapped() {
// Notified here - do something
}
Here's a list of my findings in 2021, XCode 13:
Make sure both your view and all of its superviews have set width & height constraints(this one is crucial)
Set isUserInteractionEnabled = true for your view
There's no need to set explicit frame or isUserInteractionEnabled for other super views
In addition the above (userInteractionEnabled, clipsToBounds, etc.), if you are working with a view in a child view controller be sure that you have added it as a child with myParentViewController.addChild(myChildViewController) — we've run into a couple of situations now where visible views were not firing recognizing gestures because their view controllers hadn't been added, and presumably the VCs themselves were not being retained.
It turned out that my gesture didn't work because it was in a normal class, and not a subclass of UIView or anything.
I solved the issue by creating a subclass of UIView that I had an instance of in this normal class and placed the gesture logic in that.
I solved my issue by setting the height to the UIView.
optionView.heightAnchor.constraint(equalToConstant: 18).isActive = true
I had the same issue in my programmatically created ViewController. The bug was fixed when I added a backgroundColor to the view.
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .systemBackground
let tap = UITapGestureRecognizer(target: self.view, action: #selector(UIView.endEditing))
view.addGestureRecognizer(tap)
}
}