I just finished my first app. I was about to submit it when I figured out a (10MB) memory leak. According to this post it is caused by the segues I am using.
As I understand it, currently my app generates a new view every time I perform a segue. I have been reading a lot of posts that ended up confusing me.
Should I use dissmissViewController? Unwind Segue?
This post was really helpful regarding unwind segue. But on a UI point of view, I like the current performSegueWithIdentifier solution as I have made nice horizontal sliding segues. Is there a way to customize transition when using an unwind segue?
I wish there was a possibility to simply "kill" the previous ViewController in the custom segue code...
ps: Here is the code of one of the segue:
import UIKit
class FirstCustomSegueUnwind: UIStoryboardSegue {
override func perform() {
var firstVCView = self.sourceViewController.view as UIView!
var secondVCView = self.destinationViewController.view as UIView!
let screenWidth = UIScreen.mainScreen().bounds.size.width
let screenHeight = UIScreen.mainScreen().bounds.size.height
secondVCView.frame = CGRectMake(-screenWidth, 0.0, screenWidth, screenHeight)
let window = UIApplication.sharedApplication().keyWindow
window?.insertSubview(secondVCView, aboveSubview: firstVCView)
UIView.animateWithDuration(0.4, animations: { () -> Void in
firstVCView.frame = CGRectOffset(firstVCView.frame, screenWidth, 0.0)
secondVCView.frame = CGRectOffset(secondVCView.frame, screenWidth, 0.0)
}) { (Finished) -> Void in
self.sourceViewController.presentViewController(self.destinationViewController as! UIViewController, animated: false, completion: nil)
}
}
}
Related
My app contains a modal UIView that can be presented from anywhere. How this works is the present method attaches the view as a subview on the key window:
func present(_ completion: ((Bool) -> ())? = { _ in }) {
guard !isPresented else {
return
}
if !isBackgroundReady {
initializeBackground()
}
UIApplication.shared.keyWindow?.addSubview(backgroundView)
UIApplication.shared.keyWindow?.addSubview(self)
UIView.animate(withDuration: 0.3, animations: {
self.backgroundView.alpha = 0.35
self.alpha = 1.0
}, completion: { _ in
self.isPresented = true
completion?(true)
})
}
private func initializeBackground() {
backgroundView.backgroundColor = UIColor.black
backgroundView.alpha = 0.0
backgroundView.frame = CGRect(x: UIScreen.main.bounds.midX, y: UIScreen.main.bounds.midY, width: UIScreen.main.bounds.width * 1.2, height: UIScreen.main.bounds.height * 1.2)
backgroundView.center = CGPoint(x: UIScreen.main.bounds.midX, y: UIScreen.main.bounds.midY)
}
This modal contains an email link that users can click that opens up an email prompt (or an email action sheet if they long press it). This link is added by using the an NSAttributedString and it's .link attribute on a UITextView:
let supportString = NSMutableAttributedString(
string: "general.supportEmail".localized(),
attributes: [
.link: "mailto:\("general.supportEmail".localized())",
]
)
supportTextView.attributedText = supportString
However, when the email prompt or action sheet appears, it is displayed behind the modal view:
Is it possible to get the prompt/action sheet to appear above the modal view with the current way I present the modal, or will I need to add some sort of recognizer somewhere that detects when one of these views appears and temporarily dismiss the modal until my app view comes back into focus? If it's the later, how would I accomplish that?
The quick answer as to why this is happening is that you are presenting your custom modal view on top of the Window, which will be on top of everything, and your UIAlertController will be presented on the UIViewController presenting it (which is below your custom view).
One quick solution would be to always add your custom view as a subview on the current "top" UIViewController. You can do that with a UIViewController extension - something like this:
extension UIViewController {
static func topViewController(_ viewController: UIViewController? = nil) -> UIViewController? {
let viewController = viewController ?? UIApplication.shared.keyWindow?.rootViewController
if let navigationController = viewController as? UINavigationController, !navigationController.viewControllers.isEmpty {
return self.topViewController(navigationController.viewControllers.last)
} else if let tabBarController = viewController as? UITabBarController,
let selectedController = tabBarController.selectedViewController
{
return self.topViewController(selectedController)
} else if let presentedController = viewController?.presentedViewController {
return self.topViewController(presentedController)
}
return viewController
}
}
This extension will handle any UIViewController that is "on top", whether it's in a UINavigationController, a UITabBarController, or just presented modally, etc. Should cover all cases.
After that you can adjust your present method to take this into account:
func present(_ completion: ((Bool) -> ())? = { _ in }) {
guard !isPresented else {
return
}
if !isBackgroundReady {
initializeBackground()
}
guard let topViewController = UIViewController.topViewController() else { return }
topViewController.view.addSubview(backgroundView)
topViewController.view.addSubview(self)
UIView.animate(withDuration: 0.3, animations: {
self.backgroundView.alpha = 0.35
self.alpha = 1.0
}, completion: { _ in
self.isPresented = true
completion?(true)
})
}
Instead of adding in the window, add the modal in the navicontroller -> topviewcontroller.
Link: https://developer.apple.com/documentation/uikit/uinavigationcontroller/1621849-topviewcontroller.
This might help you.
I am trying to create a series of pages that work in tandem using custom segues. These segues work fine until I have them execute in a certain series. From VC1 I go to VC2 via the default modal segue (it pops up over the original segue). Then, from VC2 I go to VC3 using a custom horizontal segue (code below). Finally, I go back from VC3 to VC1 using a custom unwind horizontal segue. The problem is that when I go back to VC1, VC2 appears instead. I checked and ViewDidLoad does not execute in VC2 when it appears, but I can still interact with it when triggered. My best guess as to what is happening is that VC2 covers VC1 so when I go back to VC1, VC2 is displayed on top of it. Even if this is the problem, I don't know how to fix it. Code below:
Horizontal Segue:
class HorizontalSegue: UIStoryboardSegue {
override func perform() {
let src = self.source as UIViewController
let dst = self.destination as UIViewController
src.view.superview?.insertSubview(dst.view, aboveSubview: src.view)
dst.view.transform = CGAffineTransform(translationX: src.view.frame.size.width, y: 0)
UIView.animate(withDuration: 0.2, delay: 0.0, options: [.curveEaseOut], animations: {
dst.view.transform = CGAffineTransform(translationX: 0, y: 0)
},
completion: { finished in
src.present(dst, animated: false, completion: nil)
})
}
}
Unwind Horizontal Segue:
class UnwindHorizontalSegue: UIStoryboardSegue {
override func perform() {
let src = self.source as UIViewController
let dst = self.destination as UIViewController
src.view.superview?.insertSubview(dst.view, belowSubview: src.view)
src.view.transform = CGAffineTransform(translationX: 0, y: 0)
UIView.animate(withDuration: 0.2, delay: 0.0, options: [.curveEaseIn], animations: {
src.view.transform = CGAffineTransform(translationX: src.view.frame.size.width, y: 0)
},
completion: { finished in
src.dismiss(animated: false, completion: nil)
})
}
}
The first thing I noticed is that you said ViewDidLoad is not called for VC2. Please see if ViewDidAppear (or will appear) is being called instead.
ViewDidLoad is only called when the view loads (initially, when it wasn't there before). ViewDidAppear should fire always, when the view is brought into the user's screen.
After that, log dst in your custom UIStoryBoardSegue. If that's an instance of VC2, you are simply pushing the wrong view controller.
I also see you're using src.present and src.dismiss in your UIStoryboardSegue. This means you're not actually pushing views, but presenting them "on top" of an active view controller. Try to rethink that logic, since this is very much likely where the problem lies.
I would rather try and push the view controllers (normally, instead of 'presenting' them) and change the UIStoryboardSegue appearance to fake the animation if that's what you're after.
So i have a viewcontroller which is basically an alert window which is supposed to be a popup and be dismissed by the tap on outside its frame.
But whenever i call that VC, it is always displayed as fullscreen and not as a pop up window.
I have tried a couple of ways to do this, namely as mentioned below.
if let exp : String = expiredVehicles[i] {
expiredVehicleNumber = expiredVehicles[i]
let popUpVC = SubscriptionExpired()
popUpVC.modalTransitionStyle = .crossDissolve
popUpVC.modalPresentationStyle = .popover // also tried other presentation styles but none work and it is still fullscreen
popUpVC.view.backgroundColor = UIColor.white.withAlphaComponent(0.8)
self.present(popUpVC, animated: true, completion: nil)
}
in case anyone need to see the definition of that VC, i will be glad to share it
i feel i should mention that the VC to be displayed as a popup is inheriting UIViewController
Any insight that might help would be great.
Thanks for the input
One potential way is to add a tap gesture recognizer to your View, which dismisses the VC.
But this will only be helpful if this popup has read-only info and doesn't require any further action from the user.
func addTapRecognizer(){
let tap = UITapGestureRecognizer(target: self, action: #selector(self.handleTap))
self.view.addGestureRecognizer(tap)
}
#objc func handleTap(){
// dismiss the VC here
}
}
You can call following method to show popup:
let popupVC = SubscriptionExpired()
popupVC.modalPresentationStyle = .overCurrentContext
self.addChild(popupVC)
popupVC.view.frame = self.view.frame
self.view.addSubview(popupVC.view)
popupVC.didMove(toParent: self)
}
Then, for removing that popup you can use:
UIView.animate(withDuration: 0.25, animations: {
self.view.transform = CGAffineTransform(scaleX: 1.3, y: 1.3)
self.view.alpha = 0.0
}, completion: { (finished) in
if finished {
self.view.removeFromSuperview()
}
})
In that case I have a button inside popup and whenever that button pressed above method triggers. Can you please try it? I can edit my answer according to your needs.
You need to implement this in you presenting view controller:
func adaptivePresentationStyle(for controller: UIPresentationController) -> UIModalPresentationStyle {
// Return no adaptive presentation style, use default presentation behaviour
return .none
}
UIPopoverPresentationController displaying popover as full screen
I had asked a question similar to this once before but I didn't realize and don't think I can use the same method due to the nuances of the two methods. (How to stop slide transition into Second VC before it covers UIView?)
I ultimately learned how to do the transition using APPCoda's lesson(http://www.appcoda.com/custom-segue-animations/)
The original question resulted in an answer providing a solution using container views and hard coded views. What I am wondering is if I can get the same effect using two separate view controllers and linking them through a segue with a gesture recognizer.
What I would like to accomplish is:
Have my initial view controller
Tap Button and have Second View Controller Overlap the first View Controller Partially (By partially I mean I have a UIView on the first View Controller that I want to remain visible. So the top of the second view controller will slide up until it hits the bottom of the UIView).
What I currently have is the original view controller being pushed up and out of the screen by the second view controller sliding up from the bottom of the screen.
Code that handles the transition using a segue from one VC to the sliding VC:
import Foundation
class CustomSegueToSecondVC: UIStoryboardSegue
{
override func perform() {
let originalVC = self.sourceViewController .view as UIView!
let slidingVC = self.destinationViewController.view as UIView!
let screenWidth = UIScreen.mainScreen().bounds.size.width
let screenHeight = UIScreen.mainScreen().bounds.size.height
slidingVC.frame = CGRect(x: 0.0, y: screenHeight, width: screenWidth, height: screenHeight)
let window = UIApplication.sharedApplication().keyWindow
window?.insertSubview(slidingVC, aboveSubview: originalVC)
UIView.animateWithDuration(0.4, animations: { () -> Void in
originalVC.frame = CGRectOffset(originalVC.frame, 0.0, -screenHeight)
slidingVC.frame = CGRectOffset(slidingVC.frame, 0.0, -screenHeight)
}) { (Finished) -> Void in
self.sourceViewController.presentViewController(self.destinationViewController as UIViewController, animated: false, completion: nil)
}
}
};
Situation: I've got a UITableViewController loading some data asynchronously from a service. During this time I would like to place a full screen (except navigation bar) view over the table view showing my custom indicator and text.
Problem: The problem I'm facing is that when my custom view (it has a red background) is placed over the UITableView the lines of the table view are shown trough my custom view (see image below).
What I tried:
I tried to use insertBelow and above, didn't work. I also tried to do: tableview.Hidden = true, but this also hides the custom view for some reason as seen on image 2.
Image1: For some reason I can see the lines threw my view.
Image 2: Tableview + custom view gone when hidden = true used.
My code:
public override void ViewDidLoad ()
{
base.ViewDidLoad ();
UIView view = new UIView (new RectangleF (0, 0, this.TableView.Frame.Width, this.TableView.Frame.Height));
view.BackgroundColor = UIColor.Red;
this.TableView.AddSubview (view);
TableView.Source = new SessionTableViewSource ();
}
You can use self.navigationController.view as view for adding subview.
The issue is that the View of a UITableViewController is a UITableView, so you cannot add subviews to the controller on top of the table.
I'd recommend switching from a UITableViewController to a simple UIViewController that contains a UITableView. This way the controller main view is a plain UIView that contains a table, and you can add subviews to the main UIView and they will be placed on top of the table view.
You can try to add the view to the window instead of nesting it in the table view like this:
UIWindow* mainWindow = [[UIApplication sharedApplication] keyWindow];
[mainWindow addSubview: overlayview];
UIWindow* window = [[UIApplication sharedApplication].delegate.window;
[window addSubview: your-overlayview];
Swift / Storyboard Solution
Note: The code below assumes one has a custom view (ratingView in my case) that is to be presented over a UITableView.
I've read many answers to this and similar questions on SO. The other answers from these sources worked to varying degrees for me (e.g.,view loaded but not shown or not accessible,...). I am using Swift 2.0+ and I am sharing the complete solution for doing this using a UITableViewController.
Create an outlet to the Navigation Bar and the view, which you want to bring over the tableview.
//MARK:Outlets
#IBOutlet weak var navBar:UINavigationBar!
#IBOutlet var ratingView: MNGStarRating!
In my case I also wanted to animate the view over the tableview so I used a class variable to hold a reference to the inflection point and a point above the scene (off-screen).
var centerYInflection:NSLayoutConstraint!
var aPointAboveScene = -(max(UIScreen.mainScreen().bounds.width,UIScreen.mainScreen().bounds.height) * 2.0)
Then in viewDidLoad I called a function (configureRatingViewAutoLayout) which configures and adds the constraints for the new view to be animated over the tableview.
func configureRatingViewAutoLayout() {
//REQUIRED
self.navBar.superview?.addSubview(self.ratingView)
var newConstraints:[NSLayoutConstraint] = []
newConstraints.append(self.ratingView.leadingAnchor.constraintEqualToAnchor(self.view.leadingAnchor,constant: 10))
newConstraints.append(self.ratingView.trailingAnchor.constraintEqualToAnchor(self.view.trailingAnchor,constant: 10))
newConstraints.append(self.ratingView.centerXAnchor.constraintEqualToAnchor(self.view.centerXAnchor))
//hides the rating view above the scene
self.centerYInflection = self.ratingView.centerYAnchor.constraintEqualToAnchor(self.view.centerYAnchor, constant: self.aPointAboveScene)
//the priority must be set below 1000 if you intend to change it after it has been added to a view
self.centerYInflection.priority = 750
newConstraints.append(self.centerYInflection)
//constraints must be added to the container view of the two items
self.ratingView.superview?.addConstraints(newConstraints)
}
Nota Bene - On a UITableViewController; the self.view is the
self.tableView. They point to the same thing so I guess one could also
use the self.tableView reference above.
Sometime later... In response to a UIControl event I call this method.
#IBAction func toggleRatingView (sender:AnyObject?){
//REQUIRED
self.ratingView.superview?.layoutIfNeeded()
UIView.animateWithDuration(1.0, delay: 0.0, usingSpringWithDamping: 0.37, initialSpringVelocity: 0.99, options: [.CurveEaseOut], animations: { () -> Void in
if CGRectContainsRect(self.view.frame, self.ratingView.frame) {
//in frame ~ animate away
//I play a sound to alert the user something is happening
self.centerYInflection.constant = self.aPointAboveScene
self.centerYInflection.priority = UILayoutPriority(950)
//I disable portions of the UI
self.disableUIElements(nil)
} else {
//out of frame ~ animate in
//I play a different sound here
self.centerYInflection.constant = 0
self.centerYInflection.priority = UILayoutPriority(950)
//I enable the UI fully
self.enableUIElements(nil)
}
//REQUIRED
self.ratingView.superview?.setNeedsLayout()
self.ratingView.superview?.layoutIfNeeded()
}) { (success) -> Void in
//do something else
}
}
These helper methods can be configured to control access to elements in your scene during the presentation of the view.
func disableUIElements(sender:AnyObject?) {
//UI
}
func enableUIElements(sender:AnyObject?) {
//UI
}
Caveats
My view is a custom view in the Storyboard (sitting outside of the
tableview but connected to the TableView Controller). The view has a
required user runtime attribute defined layer.zPosition with a Number value set to 2 (this ensures that it presents in front of the
UITableView).
One could also try playing around with bringSubviewToFront:
and sendSubviewToBack: methods if you don't want to set the zPosition
(I think zPosition is simpler to use)
Try this to hook a button at bottom of the UITableViewController
declare button as a variable:
var submitButton: UIButton!
and in viewDidLoad:
submitButton = UIButton(frame: CGRect(x: 5, y: UIScreen.main.bounds.size.height - 50, width: UIScreen.main.bounds.size.width - 10, height: 50))
submitButton.backgroundColor = UIColor.init(red: 180/255, green: 40/255, blue: 56/255, alpha: 1.0)
submitButton.setTitle("Submit", for: .normal)
submitButton.titleLabel?.font = UIFont(name: "Arial", size: 15)
submitButton.titleLabel?.textColor = .white
submitButton.addTarget(self, action: #selector(submit), for: .touchUpInside)
submitButton.layer.cornerRadius = 5
self.view.addSubview(submitButton)
and implement this method:
override func scrollViewDidScroll(_ scrollView: UIScrollView) {
submitButton.frame = CGRect.init(x: submitButton.frame.origin.x, y: UIScreen.main.bounds.size.height + scrollView.contentOffset.y - 50, width: submitButton.frame.width, height: submitButton.frame.height)
}
This works for me:
if let myTopView = Bundle.main.loadNibNamed("MyTopView", owner: self, options: nil)?.first as? MyTopView {
if let view = UIApplication.shared.keyWindow{
view.addSubview(myView);
myTopView.translatesAutoresizingMaskIntoConstraints = false
myTopView.topAnchor.constraint(equalTo: view.topAnchor ).isActive = true
myTopView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
myTopView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
myTopView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
}
}