I am pretty much trying to replicate the same tabBar popup as you see in the yelp app (before and after screenshots at the bottom) where no matter what view your in you can press on the center tabBar item and pop up will appear.
Coincidentally I have 5 tabBar items (like Yelp) and I am trying to have three popups with a image and title for each (like Yelp). Seeing that what I am trying to do is already done in an app shows me that this is possible, but I do not know how to do it. I have tried to change the types of relationships between view controllers or do it programmatically, but nothing seems to work. What am I missing or doing wrong?
Tabbar Controller Code:
func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
if viewController.tabBarItem.tag == 1 {
return false
} else {
return true
}
}
Before Press
After Press
One solution could be to adopt the UITabBarControllerDelegate.
This way we can use the func tabBarController(UITabBarController, didSelect: UIViewController) method of the delegate to alter the regular presentation behavior and show our popups instead. We could find the offset required (in terms of CGPoint) relative to the tab bar button and then apply that offset and add the popup buttons to as a subview. Note that for this method you would need to programmatically set the frames of your popup buttons.
Alternatively, you could also make a bunch of popup buttons and set their alphas to zero and one when clicked. Hope this helped! Thanks :)
Custom action for tab bar
UITabBarControllerDelegate documentation
Related
I'm using XCode 13.0, Swift 5.5 and Storyboard. This is a mobile app for iPhone with iOS 15.
I have altogether 7 tabs, all of them with icons. I have 4 tabs and a "More" tab in the tab bar of my app.
3 additional tabs show up after the user clicks on the "More" tab. I'd like the first 2 of these additional tabs to be disabled. They need to be grey coloured and when the user clicks on any of these 2, I'd like to app to do nothing (not to show any page, not to navigate anywhere). I'm using the original UITabBarController and moreNavigationController defined by Apple, I didn't subclass any of them.
On my storyboard I added 2 UIViewControllers to these 2 disabled tabs, but I set them disabled this way:
This didn't work at all. When the user clicks on the 2 disabled tabs, they show 2 empty ViewControllers. I'd expect them not to show anything.
I also tried accessing the moreNavigationController's tabs from the page my UITabBarController first opens. I tried setting these 2 tabs disabled programmatically. However I didn't manage to access these 2 tabs, I only manage to access the main tabs that show up in the tab bar (I don't need to access these). How can I disable and colour grey the tabs that show up after clicking on the More tab?
let moreControllerItems = tabBarController?.moreNavigationController.toolbarItems
if let tabArray = moreControllerItems {
let tabBarItem1 = tabArray[0]
let tabBarItem2 = tabArray[1]
tabBarItem1.isEnabled = false
tabBarItem2.isEnabled = false
}`
This code doesn't work, the moreControllerItems variable is nil. The tabBarController variable isn't nil, I can access my UITabBarController from here, but it doesn't help me much.
I googled this issue lots of different ways but I couldn't find the solution. Any help would be appreciated. I really need to solve this, please write a comment if you have any idea how to solve this. Thank you!
You can disable tabBar items from TabBarController.
class TabVC: UITabBarController {
override func viewDidLoad() {
super.viewDidLoad()
}
func disableTabBar(itemNo: Int) {
if let items = tabBar.items, itemNo < items.count {
items[itemNo].isEnabled = false
}
}
And you can access this function from
any child Viewcontroller attached to TabBarController
class MoreVC: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
if let tabBarVC = tabBarController as? TabVC {
tabBarVC.disableTabBar(itemNo: 1)
}
}
In short: You cannot disable it. If you want to disable the item in the More Viewcontroller, you have to use a custom Viewcontroller in the fifth Tab
I am explaining here why we cannot do it and what limitations we have.
Apple will show the More tab if items are more than five in the UITabBarController. And more tab holds the UINavigationController which is attached to a kind of UIMoreListController. you can check by
print moreNavigationController.viewControllers[0]
UIMoreListController is not accessible. In your case, the remaining three items are listed in the UIMoreListController. Although we can still access the Viewcontroller's tabBarItem and we can disable it. You can check by clicking the edit option.
But still, users can click on it as long as it is in the UIMoreListController. Because we are not interacting with the tabBar instead we are interacting with the items on the list. Users can't click once you move the item to any of the first four positions using the edit option in the MoreViewcontroller.
I am having this issue where I am using a UISplitViewController MainSplitVC, and I am unable to present the master view controller over the detail view controller. Basically, when testing this on an iPad, I want the master and detail VC to be visible side by side, but on an iPhone (portrait mode), I want only the master VC. Currently, this works on iPad, but on an iPhone in portrait mode, Swift is showing the detail view controller first, and I have to click the back button in the navigation bar to return to the master view controller.
I have tried every possible approach that I could think of. For instance, I created a class for the Split View Controller, MainSplitVC, where I subclass UISplitViewController and UISplitViewControllerDelegate. Then, in viewDidLoad(), I set the preferred display mode to oneBesideSecondary (since allVisible was replaced by that according to Xcode). I also include the function collapseSecondary() to always collapse back to the master view controller.
class MainSplitVC: UISplitViewController, UISplitViewControllerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
self.delegate = self
print("viewDidLoad called")
self.preferredDisplayMode = UISplitViewController.DisplayMode.oneBesideSecondary
}
func splitViewController(
_ splitViewController: UISplitViewController,
collapseSecondary secondaryViewController: UIViewController,
onto primaryViewController: UIViewController) -> Bool {
print("collapseSecondary called")
return true
}
}
I have consulted many other posts regarding this issue, and all the posts indicate that using the collapseSecondary() function and setting preferredDisplayMode to oneBesideSecondary or allVisible should do the job. However, none of this is working. What's more is that the collapseSecondary() function is not even being called, even though I included UISplitViewControllerDelegate in the class header.
Could anyone clarify if I made any mistakes in the code below? When the app opens, I just want the master view controller to be shown; the detail view controller is simply a blank view controller that changes to another when something in the tableview of the master view controller is clicked.
The links I used for reference were as follows:
UISplitViewController showing detail view controller first on iPhone, also delegate not calling proper functions
UISplitViewController in portrait on iPhone shows detail VC instead of master
Open UISplitViewController to Master View rather than Detail
Thanks!
EDIT 2/3/21: I've resolved the issue. I instead extended SceneDelegate under UISplitViewControllerDelegate and included the following function:
func splitViewController(_ svc: UISplitViewController, topColumnForCollapsingToProposedTopColumn proposedTopColumn: UISplitViewController.Column) -> UISplitViewController.Column {
return .primary
}
The collapseSecondary function didn't work apparently because there is a bug where "Interface Builder doesn’t allow creating a classic style UISplitViewController. (65966010) (FB8107534)", so I get the error message "Skipping delegate callback, splitViewController:collapseSecondaryViewController:ontoPrimaryViewController:. Unsupported for UISplitViewController style DoubleColumn".
Thanks!
Returning .primary should solve your issue.
#available(iOS 14.0, *)
public func splitViewController(_ svc: UISplitViewController, topColumnForCollapsingToProposedTopColumn proposedTopColumn: UISplitViewController.Column) -> UISplitViewController.Column {
return .primary
}
[From Documentation]
Asks the delegate to provide the column to display after the split view interface collapses.
When the split view controller transitions from a horizontally regular to a horizontally compact size class, it calls this method and asks you for the column to display when that transition is complete. Use this method to customize the view controller you’re collapsing to.
I'm having the hardest time implementing a presentation of a drawer sliding partway up on the screen on iPhone.
EDIT: I've discovered that iOS is not respecting the .custom modalTransitionStyle I've set in the Segue. If I set that explicitly in prepareForSegue:, then it calls my delegate to get the UIPresentationController.
I have a custom Segue that is also a UIViewControllerTransitioningDelegate. In the perform() method, I set the destination transitioningDelegate to self:
self.destination.transitioningDelegate = self
and I either call super.perform() (if it’s a Present Modal or Present as Popover Segue), or self.source.present(self.destination, animated: true) (if it’s a Custom Segue, because calling super.perform() throws an exception).
The perform() and animationController(…) methods get called, but never presentationController(forPresented…).
Initially I tried making the Segue in the Storyboard "Present Modally" with my custom Segue class specified, but that kept removing the presenting view controller. I tried "Present as Popover," and I swear it worked once, in that it didn't remove the presenting view controller, but then on subsequent attempts it still did.
So I made it "Custom," and perform() is still being called with a _UIFullscreenPresentationController pre-set on the destination view controller, and my presentationController(forPresented…) method is never called.
Other solutions dealing with this issue always hinge on some mis-written signature for the method. This is mine, verbatim:
public func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController?
I've spent the last four days trying to figure out “proper” custom transitions, and it doesn't help that things don’t seem to behave as advertised. What am I missing?
Instead of using a custom presentation segue, you could use a Container View for your drawer. This way, you can use a UIViewController for your Drawer content, while avoiding the issue with the custom segue.
You achieve this in two steps:
First pull a Container View into your main view controller and layout it properly. The storyboard would look like this: (You can see you have two view controllers. One for the main view and one for the drawer)
Second, you create an action that animates the drawer in and out as needed. One simple example could look like this:
#IBAction func toggleDrawer(_ sender: Any) {
let newHeight: CGFloat
if drawerHeightConstraint.constant > 0 {
newHeight = 0
} else {
newHeight = 200
}
UIView.animate(withDuration: 1) {
self.drawerHeightConstraint.constant = newHeight
self.view.layoutIfNeeded()
}
}
Here, I simply change the height constraint of the drawer, to slide it in and out. Of course you could do something more fancy :)
You can find a demo project here.
I'm working on Apple TV project. The project contains tab bar view controller, normally the tab bar will be appeared when swiping up on remote and hidden when swiping down. But now I reverse that behavior and I want to force focus another view when swiping up(normally focus on tab bar). Any way to do that? Thank you.
In your UIViewController, override shouldUpdateFocusInContext. If you detect an upward navigation into the tab bar, return false to prevent focus from reaching the tab bar. Then use a combination of preferredFocusEnvironments + setNeedsFocusUpdate to redirect focus somewhere else:
override func shouldUpdateFocus(in context: UIFocusUpdateContext) -> Bool {
if let nextView: UIView = context.nextFocusedView{
if ( context.focusHeading == .up && nextView.isDescendant(of: tabBar) ){
changeFocusTo(myView)
return false
}
}
}
internal var viewToFocus: UIView?
func changeFocusTo(_ view:UIView? ){
viewToFocus = view
setNeedsFocusUpdate()
}
override var preferredFocusEnvironments: [UIFocusEnvironment]{
return viewToFocus != nil ? [viewToFocus!] : super.preferredFocusEnvironments
}
This is a generally useful technique for customizing focus updates. An alternative technique is to use UIFocusGuide. You could insert a focus guide underneath the tab bar or surround the tab bar with a focus guide to redirect focus. Though focus guides are useful for simple cases, I have generally had better results using the technique I am describing instead.
I got the same issue with focus of UITabbarController before and I found the solution in Apple Support
Because UIViewController conforms to UIFocusEnvironment, custom view
controllers in your app can override UIFocusEnvironment delegate
methods to achieve custom focus behaviors. Custom view controllers
can:
Override the preferredFocusedView to specify where focus should start
by default. Override shouldUpdateFocusInContext: to define where focus
is allowed to move. Override
didUpdateFocusInContext:withAnimationCoordinator: to respond to focus
updates when they occur and update your app’s internal state. Your
view controllers can also request that the focus engine reset focus to
the current preferredFocusedView by callingsetNeedsFocusUpdate. Note
that calling setNeedsFocusUpdate only has an effect if the view
controller contains the currently focused view.
For more detail, please check this link
https://developer.apple.com/library/content/documentation/General/Conceptual/AppleTV_PG/WorkingwiththeAppleTVRemote.html#//apple_ref/doc/uid/TP40015241-CH5-SW14
I want to use the cool swipe animation between screens - UIPageViewController (yes, you know the style from the intro screen), but all the code I found on the Internet and Github was useless for me.
I found demos with just one UIViewController in the Storyboard interface and almost all the apps showed how to change an image source from an array. I read the Apple reference, but I do not understand it.
I need a few ViewControllers on my Storyboard (I want to design all the screens in the UIPageViewController differently, they will be connected to own ViewControllers classes) who will be presented in the UIPageViewController.
Or of course if you know a better way how do that please say so! But I need the feature that if you swipe, the screen moves with you.
Does someone know how to do that?
There's nothing in UIPageViewController that requires the various view controllers to be same class. So, just implement viewControllerBeforeViewController and viewControllerAfterViewController that return different types of view controllers. If you want to reference child view controllers from the storyboard, just give those scenes unique storyboard ids, and then you can use instantiateViewControllerWithIdentifier. You might, for example, have an array of storyboard identifiers, and use that to determine which type of scene is "before" and "after" the current one.
There are tons of ways of implementing this, but you could do something like:
class ViewController: UIPageViewController, UIPageViewControllerDataSource {
let identifiers = ["A", "B", "C", "D"] // the storyboard ids for the four child view controllers
override func viewDidLoad() {
super.viewDidLoad()
self.dataSource = self
setViewControllers([viewControllerForPage(0)!], direction: .Forward, animated: false, completion: nil)
}
func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {
var page = (viewController as PageDelegate).pageNumber + 1
return viewControllerForPage(page)
}
func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {
var page = (viewController as PageDelegate).pageNumber - 1
return viewControllerForPage(page)
}
func viewControllerForPage(page: Int) -> UIViewController? {
if page >= 0 && page < identifiers.count {
let controller = storyboard?.instantiateViewControllerWithIdentifier(identifiers[page]) as? UIViewController
(controller as PageDelegate).pageNumber = page
return controller
}
return nil
}
}
Clearly, if you wanted to be more elegant here, you could maintain a cache of previously instantiated view controllers, but make sure you respond to memory pressure and purge that cache if necessary. But hopefully this illustrates the fact that there's nothing about page view controllers that dictates that the children are a particular class of controller.
By the way, the above assumes that each of the child view controllers conforms to a protocol to keep track of the page number.
/// Page delegate protocol
///
/// This is a protocol implemented by all of the child view controllers. I'm using it
/// just to keep track of the page number. In practical usage, you might also pass a
/// reference to a model object, too.
#objc protocol PageDelegate {
var pageNumber: Int { get set }
}
If you want to go a completely different direction, another approach is to use standard storyboard where you have segues that present one view controller after another, and then for each view controller implement swipe gesture recognizers, where swiping from the right performs the segue to transition to the next scene (e.g. an IBAction that does performSegueWithIdentifier), and another swipe gesture recognizer (left to right) will dismiss the view controller.
Finally, if you want these gesture recognizers to be interactive (e.g. to follow along with the user's finger), you could use custom transitions, combined with interactive transitions. For more information, see WWDC 2013 video Custom Transitions Using View Controllers or WWDC 2014 videos View Controller Advancements in iOS 8 (which, about 20 minutes into the video, describes how custom transitions have been enhanced in iOS 8 with presentation controllers) and A Look Inside Presentation Controllers.
I think you might take advantage of View Controller Containment.
We are dealing with 4 elements at play here.
Main View Controller
scroll view
UIPage control
Detail View Controllers
You would add the scroll view and the page control as the main view controller's properties. The main controller would handle the scrolling logic, basically syncing the horizontal scrolling between the scrollview and the page control.
The contents of the scroll view would be constituted by root views of all the detail view controllers.