I've removed the back button's text by manually setting it to " " on each navigation item, however there is still extra padding between the button and the navigation item's title for no reason.
Does anyone know how to get rid of this annoying spacing?
In a few real case scenarios in my app, the title does concatenate as it gets slightly too long, even though it wouldn't need to if that space were not there.
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(true)
let arrayViews = (self.navigationController?.navigationBar.subviews)
if let itemView = arrayViews?[1] {
for lbl in itemView.subviews {
lbl.frame = CGRect(x: -25, y: lbl.frame.origin.y, width: lbl.frame.size.width, height: lbl.frame.size.height)
}
}
}
You should create a custom UIBarButtonItem which uses popToViewController to go back to the previous item on your stack. That way, you can manually set the frame of your custom back button.
Related
When added UIButton on UITabbar to middle as shown in figure.
The button action on above the UITabBar unable to click
func setupMiddleButton() {
plusButton = UIButton(frame: CGRect(x: 0, y: 0, width: 64, height: 64))
var menuButtonFrame = plusButton.frame
menuButtonFrame.origin.x = tabBar.bounds.width/2 - menuButtonFrame.size.width/2
let hasNotched :Bool? = UIDevice.current.hasNotch
if hasNotched != nil {
menuButtonFrame.origin.y = tabBar.bounds.height - menuButtonFrame.height - 15
} else {
menuButtonFrame.origin.y = tabBar.bounds.height - menuButtonFrame.height - 50
}
plusButton.frame = menuButtonFrame
plusButton.setTitle("+", for: .normal)
plusButton.titleLabel?.font = UIFont.helveticaNeue(ofSize: 40)
plusButton.backgroundColor = UIColor.init(hexString: "5E71FE")
plusButton.titleEdgeInsets = UIEdgeInsets(top: 0,left: 10,bottom: 10,right: 10)
tabBar.addSubview(plusButton)
plusButton.layer.cornerRadius = menuButtonFrame.height/2
plusButton.addTarget(self, action: #selector(plusButtonAction(sender:)), for: .touchUpInside)
}
You need to override the hitTest method in your custom tab bar class like this
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView?
{
guard !clipsToBounds && !isHidden && alpha > 0 else { return nil }
for member in subviews.reversed()
{
let subPoint = member.convert(point, from: self)
guard let result = member.hitTest(subPoint, with: event)
else { continue }
return result
}
return nil
}
Basically the problem is that upper part is not clickable because it is outside of the bounds of main content view of tab bar.
This method will check if the tap is inside the bounds of the view, if it is it will return the view and the action for that button will get called.
Documentation by apple: Link
P.s I was facing the same issue recently and got this help which worked smooth.
I suspect that what you are trying to do is not possible, or at the least, not supported by Apple. (And thus not recommended since you might find a way to make it might work today but not in some future OS version.)
As a rule, Apple does not support you adding custom view objects to system components like tab bars, navigation bars, stack views, table/collection view controllers, etc except through a documented API.
I would suggest NOT doing what you are trying to do. instead, add a button in the content view of the tab bar controller. I don't know if you'll be able to make it partly cover the tab bar like you are trying to do however.
Add the button to the view of the UITabbarController instead of adding to the TabBar. And then reposition the button, it will work.
I have a toolbar that's instantiated on viewDidLoad on top of a webkit. When I take a snapshot on the simulator, the toolbar is missing which is what I would like. When built on the device, the toolbar is there.
I tried to hide the toolbar with:
toolbar.isHidden = true
but the application crashes with toolbar being nil. If I change it to:
toolbar?.isHidden = true
It still shows up considering it still thinks it's nil.
The toolbar is set up on viewDidLoad by calling another function:
var toolbar : UIToolbar!
override func viewDidLoad() {
super.viewDidLoad()
setUpToolBar()
}
func setUpToolBar() {
let saveButton = UIBarButtonItem(barButtonSystemItem: .save, target: self, action: #selector(takeScreenshot))
...
let toolbar = UIToolbar(frame: CGRect(x: 0, y: 300, width: 200, height: 50))
toolbar.setItems([saveButton,flexibleSpaceFillerLeft,userAgentButton,flexibleSpaceFillerRight,doneButton], animated: true)
view.addSubview(toolbar)
}
The code for my snapshot is below. This is where I tried to hide the toolbar before taking the snapshot.
#objc func takeScreenshot() {
webView.takeSnapshot(with: nil, completionHandler: { (image,error) in
if let image = image {
self.screenshotOfWindow = image
self.showScreenshotEffect()
self.saveAllData()
} else {
print (error?.localizedDescription as Any)
}
})
}
Here's the screen I need to take a screenshot of:
The red box in the screenshot is the bar that I need to disappear from the screenshot.
I'd like to be able to take the screenshot without the bottom bar in view. As stated before, this works in the simulator, but the device always shows the bar. There's also a "navigation controller" gap at the top of the screenshot since the top bar covers part of the screen at top, but this is just blank and something I can address later.
I just wanted to come back and answer how I solved this. The webview is embedded in a navigation controller, but I was creating the toolbar programmatically on viewDidLoad by calling a setupToolBar function I had created early on in the project. I could hide the toolbar, but it was still being captured while taking the screenshot. I commented all of that code out and used the navigation controller's toolbar instead. Now when I take the screenshot, the bottom and top bar of the navigation controller is not part of the screenshot.
After reading a few articles about custom UITabBarControllers, I am left more confused than before I even started doing the research in the first place.
My goal is to create a custom TabBar with 3 important properties:
No text, just icons
The active icon is marked by a circle filled with a color behind it, and therefore needs a different icon color
Here's what I am trying to achieve:
I've been able to remove the text and center the icon by following another StackOverflow answer (Remove tab bar item text, show only image), although the solution seems like a hack to me.
How would I go about creating a circle behind the item and change the active item's color?
Also, would someone mind explaining the difference between the XCode inspector sections "Tab Bar Item" and "Bar Item", which appear directly under each other?
The first step is simple: leaving the title property of the UITabbarItem empty should hide the label.
Your second step can actually be broken down into two steps: changing the color of the icon and adding a circle behind it.
The first step here is simple again: you can set a different icon to use for the currently selected ViewController (I use Storyboards, this process is pretty straightforward). What you'd do is add a white version of the icon to be shown when that menu option is selected.
The final step is displaying the circle. To do this, we'll need the following information:
Which item is currently selected?
What is the position of the icon on the screen?
The first of these two is pretty easy to find out, but the second poses a problem: the icons in a UITabBar aren't spaced around the screen equally, so we can't just divide the width of the tabbar by the amount of items in it, and then take half of that to find the center of the icons. Instead, we will subclass UITabBarController.
Note: the tabBar property of a UITabBarController does have a .selectionIndicatorImage property. You can assign an image to this and it will be shown behind your icon. However, you can't easily control the placement of this image, and that is why we still resort to subclassing UITabBarController.
class CircledTabBarController: UITabBarController {
var circle: UIView?
override func viewDidLoad() {
super.viewDidLoad()
let numberOfItems = CGFloat(tabBar.items!.count)
let tabBarItemSize = CGSize(width: (tabBar.frame.width / numberOfItems) - 20, height: tabBar.frame.height)
circle = UIView(frame: CGRect(x: 0, y: 0, width: tabBarItemSize.height, height: tabBarItemSize.height))
circle?.backgroundColor = .darkGray
circle?.layer.cornerRadius = circle!.frame.width/2
circle?.alpha = 0
tabBar.addSubview(circle!)
tabBar.sendSubview(toBack: circle!)
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
let index = -(tabBar.items?.index(of: tabBar.selectedItem!)?.distance(to: 0))!
let frame = frameForTabAtIndex(index: index)
circle?.center.x = frame.origin.x + frame.width/2
circle?.alpha = 1
}
override func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {
let index = -(tabBar.items?.index(of: item)?.distance(to: 0))!
let frame = frameForTabAtIndex(index: index)
self.circle?.center.x = frame.origin.x + frame.width/2
}
func frameForTabAtIndex(index: Int) -> CGRect {
var frames = tabBar.subviews.compactMap { (view:UIView) -> CGRect? in
if let view = view as? UIControl {
for item in view.subviews {
if let image = item as? UIImageView {
return image.superview!.convert(image.frame, to: tabBar)
}
}
return view.frame
}
return nil
}
frames.sort { $0.origin.x < $1.origin.x }
if frames.count > index {
return frames[index]
}
return frames.last ?? CGRect.zero
}
}
Now use this subclass of UITabBarController instead of the base class.
So why this approach over simply changing the icon to a circled one? Because you can do many different things with this. I wrote an article about animating the UITabBarController in a similar manner, and if you like, you can easily use above implementation to add animation to yours too.
The easiest and actually cleanest way to do it is to design your icons and import them as images to the .xcassets folder. Then you can just set the different icons for the different states for each of the viewControllers with:
ViewController.tabBarItem = UITabBarItem(title: "", image: yourImage.withRenderingMode(.alwaysOriginal), selectedImage: yourImage)
your selected image will be the one with the circle and the image will be without. It is way easier than manipulating the images in xcode and it is also less expensive since the compiler only has to render the images and doesn't have to manipulate them.
About the other question UIBarItem is
An abstract superclass for items that can be added to a bar that appears at the bottom of the screen.
UITabBarItem is a subclass of UIBarItem to provide extra funtionality.
I have got a label that appears in the NavigationBar when the View of the FirstViewController opens for the first time. The label shows a number that should be able to change. If I click a button on the FirstViewController the View of the SecondViewController shows up in which's NavigationBar the label of the FirstViewController is still visible. When I change the number that is written in the label by clicking on a button in the SecondViewController the number of the label only changes when I go back to the View of the FirstViewController. That is because I update the title in the ViewDidLoad String loop.
Now my question is:
I want the number of the label to be changed at the moment when I click the button in the SecondViewController, although the label was defined in the Code of the FirstViewController. The number of the label shows an amount of money.
This is the Code of the FirstViewController:
var moneyLabel: UILabel?
override func viewDidLoad() {
super.viewDidLoad()
setupNavigationLabel()
let newMoney:String = String(format: "%f", money)
updateTitle(title: "\(newMoney)")
}
func updateTitle(title: String) {
if let myTitleView = self.moneyLabel {
myTitleView.text = title
}
}
func setupNavigationLabel() {
let navigationBar = self.navigationController?.navigationBar
let moneyFrame = CGRect(x: 300, y: 0, width:
(navigationBar?.frame.width)!/2, height: (navigationBar?.frame.height)!)
moneyLabel = UILabel(frame: moneyFrame)
moneyLabel?.text = "\(money)"
navigationBar?.addSubview(moneyLabel!)
}
It seems that your problem is with the second ViewController but you are not sharing any code!!! Use the below to achieve your objective.
class secondViewControler:UIViewController{
var money:Int
var moneyLabel:UILAbel?
override func viewDidLoad(){
self.money= //pass the amount, i dont know which way you use to store and retrieve the amount
moneyLabel.text="\(money)"
}
#IBAction updateMoney(){
//get the amount from the textfield say the output is X
money=X
moneyLabel.text="\(money)"
}
}
I have a horizontal UICollectionView which works fine and scrolls. When I tap an item I update my data and call reloadData. This works and the new data is displayed in the UICollectionView.
The problem is the scroll position doesn't change and it is still viewing the last place. I want to reset the scrolling to the top (Or left in my case). How can I do this?
You want setContentOffset:. It takes a CGPoint as and argument that you can set to what ever you want using CGPointMake, but if you wish to return to the very beginning of the collection, you can simply use CGPointZero.
[collectionView setContentOffset:CGPointZero animated:YES];
You can use this method to scroll to any item you want:
- (void)scrollToItemAtIndexPath:(NSIndexPath *)indexPath
atScrollPosition:(UICollectionViewScrollPosition)scrollPosition
animated:(BOOL)animated
I use this quite often in different parts of my app so I just extended UIScrollView so it can be used on any scroll view and scroll view subclass:
extension UIScrollView {
/// Sets content offset to the top.
func resetScrollPositionToTop() {
self.contentOffset = CGPoint(x: -contentInset.left, y: -contentInset.top)
}
}
So whenever I need to reset the position:
self.collectionView.resetScrollPositionToTop()
In Swift:
collectionView.setContentOffset(CGPointZero, animated: true)
If you leave the view that houses the collection view, make a change in the 2nd view controller, and need the collection view to update upon returning:
#IBAction func unwindTo_CollectionViewVC(segue: UIStoryboardSegue) {
//Automatic table reload upon unwind
viewDidLoad()
collectionView.reloadData()
collectionView.setContentOffset(CGPointZero, animated: true)
}
In my situation the unwind is great because the viewDidLoad call will update the CoreData context, the reloadData call will make sure the collectionView updates to reflect the new CoreData context, and then the contentOffset will make sure the table sets back to the top.
If you view controller contains safe area, code:
collectionView.setContentOffset(CGPointZero, animated: true)
doesn't work, so you can use universal extension:
extension UIScrollView {
func scrollToTop(_ animated: Bool) {
var topContentOffset: CGPoint
if #available(iOS 11.0, *) {
topContentOffset = CGPoint(x: -safeAreaInsets.left, y: -safeAreaInsets.top)
} else {
topContentOffset = CGPoint(x: -contentInset.left, y: -contentInset.top)
}
setContentOffset(topContentOffset, animated: animated)
}
}
CGPointZero in my case shifted the content of the collection view because you are not taking in count the content inset. This is what it worked for me:
CGPoint topOffest = CGPointMake(0,-self.collectionView.contentInset.top);
[self.collectionView setContentOffset:topOffest animated:YES];
Sorry I couldn't comment at the time of this writing, but I was using a UINavigationController and CGPointZero itself didn't get me to the very top so I had to use the following instead.
CGFloat compensateHeight = -(self.navigationController.navigationBar.bounds.size.height+[UIApplication sharedApplication].statusBarFrame.size.height);
[self.collectionView setContentOffset:CGPointMake(0, compensateHeight) animated:YES];
Hope this helps somebody in future. Cheers!
To deal with an UINavigationController and a transparent navigation bar, I had to calculate the extra top offset to perfectly match the position of the first element.
Swift 1.1 code:
let topOffest = CGPointMake(0, -(self.collectionView?.contentInset.top ?? O))
self.collectionView?.setContentOffset(topOffest, animated: true)
Cheers!
SWIFT 4.2 SOLUTION-
Say I have a tableView with each tableViewCell containing a HorizontalCollectionView
Due to reuse of cells, even though first tableViewCell is scrolled to say page 4, downwards, other cell is also set to page 4.
This works in such cases-
In the cellForRowAt func in tableView,
let cell = //declaring a cell using deque
cell.myCollectionView.contentOffset = CGPoint(x:0,y:0)