I've added a custom UIView to my base UITabBarController. I start by hiding the default tabBar. The viewdidload looks like this in UITabBarController:
override func viewDidLoad() {
super.viewDidLoad()
//hide default tab bar
self.tabBar.isHidden = true
tabBarArea.frame.size.width = self.view.frame.width
tabBarArea.frame.origin.y = self.view.frame.height - tabBarArea.frame.height
self.view.addSubview(tabBarArea)
}
That works well. The tabBarArea is defined in the storyboard as a custom view for the UITabBarController. The custom view sits between the First Responder and the Exit icons in the top bar.
Now, the problem is that the UITabBarController will disappear as soon as we load a child view controller and this custom UIView area will vanish with it.
Is there a way to make this root custom view always present even when child view controllers are loaded in?
Thanks for input. I like the idea of this custom UIView area but this approach needs refinement. I also don't need it to be a traditional UITabBarController with tab bar items, etc. I'd like to break out of that mold and just have custom UIButtons are whatever in this view area.
I added child view controller to parent view controller programmatically in swift 3.0.
But I do not want the child view controller width as full screen, I want to customise the width and height of the child view controller. I tried to open the custom size child view controller, but it is not working.
// Here is my code
let secondViewController = storyboard.instantiateViewController(withIdentifier: storyBoardName)
secondViewController.modalPresentationStyle = UIModalPresentationStyle.custom
secondViewController.view.frame = CGRect(x: 0, y: 0, width: self.view.bounds.width-500, height: self.view.bounds.height)
self.present(secondViewController, animated: false, completion: nil)
Is there a way to achieve this?
In your code, you are not adding the secondViewController as childview controller. You are presenting that view controller. There is a difference.
You are trying to use UIModalPresentationStyle.custom to present viewcontroller using custom style. But using this custom style is not this trivial.
From documentation:
Creating a custom style involves
subclassing UIPresentationController and using its methods to animate
any custom view onto the screen and to set the size and position of
the presented view controller. The presentation controller also
handles any adaptations that occur because of changes to the presented
view controller’s traits
It tells you that you need to subclass UIPresentationController and subclass its method(with other methods) - (CGRect)frameOfPresentedViewInContainerView to set the frame of the presented viewcontroller.
More is explained in this link.
You can ofcourse achieve all this by actually adding a childviewcontroller.
Steps would be like this:
Create your child viewcontroller instance.
Set its view frame to whatever you want.
Add its view as a subview on to parent view controller's view using addSubview:
Call [addChildViewController] on parent viewcontrller (https://developer.apple.com/documentation/uikit/uiviewcontroller/1621394-addchildviewcontroller)
It depends on what you're trying to do, when I want to show some UI on top of another UIViewController I usually use a fullscreen view controller with self.modalPresentationStyle = .overFullScreen. Then I create another view which has the visible size I actually want to show to the user. This allows you to do pretty much anything you want.
But if you want an actual child viewcontroller, you need to use the appropriate functions for it.
i have a uicollectionviewcontroller as rootviewcontroller in my navigationController. whenever i return from another controller that is pushed onto this stack. the collectionview jumps up 25pix. i have tried some tips from other questions like self.automaticallyAdjustsScrollViewInsets = false, changing contentOffset after collection appears but none of them work.
i have no idea what causes this problem.
this is a sample off whats happening
This property is applied only to view controllers that are embedded in a container such as UINavigationController
The window’s root view controller does not react to this property. The default value of this property is UIRectEdge.all
Setting it to UIRectEdge.none should resolve it
self.edgesForExtendedLayout = UIRectEdge.None
Seems that you have this problem because of tabbar.ishidden = true and then after pop the view controller you will again set the tabbar.ishidden = false .
this would fix with a review in your constraint in storyboard, e.g if you have your bottom constraint to tabbar, change it to superView. this would prevent relayouting your collecitonView.
I want to give a UIViewController's view a size that is different from the device's screen size. I know I can usually achieve this by adding the view controller as a child view controller of another parent UIViewController that has defined a frame for the child, but I am in a situation that seems a little different.
I have a UIWindow that only takes up a portion of the screen (it's got a frame that's basically (0, 0, DEVICE_WIDTH, HEIGHT_LESS_THAN_DEVICE_HEIGHT). This window shows up with the proper sizing and positioning when presented. I am setting a view controller as the rootViewController of the window, and then presenting the window by setting its hidden value to false. When this happens, the view controller's view ends up sized to fill the device's screen (i.e. a frame of (0, 0, DEVICE_WIDTH, DEVICE_HEIGHT)).
What I would like is for the view controller to inherit its sizing from the UIWindow it is set as the root view controller of. Is there a way to do this?
I have also tried overriding loadView() and returning a custom-sized view there. Logging the view shows that the view controller's view object is correctly sized during viewDidLoad, but is overwritten with the default size by viewWillAppear:. I would be open to using loadView() to size the view controller if inheriting sizing from the window isn't possible, but I don't know how to make the custom size stick.
Note: The reason why I am trying to add a view controller to the window is because I want to take advantage of the view controller lifecycle methods such as viewDidAppear:, which is why I am not just creating a simple UIView and adding it as a subview of the window.
As counter intuitive as it may seem, if you set set self.view.frame on viewWillAppear (IOS 8) or viewDidAppear (IOS 7) you will be able to make it work.
Swift code (IOS 8):
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
// Banner style size, for example
self.view.frame = CGRectMake(0, 0, 320, 50)
}
For IOS 7, I had to use viewDidAppear, which is obviously an unsatisfactory solution. So I had to start the view with alpha = 0.0 and set alpha = 1.0 on viewDidAppear, after modifying self.view.frame.
Hope it helps.
I have been reading a lot about iOS7 UI transition.
I am not able to get what these three properties automaticallyAdjustsScrollViewInsets, extendedLayoutIncludesOpaqueBars, edgesForExtendedLayout??
For example I am trying to make my view controllers start below the status bar but I am not able to achieve it.
Starting in iOS7, the view controllers use full-screen layout by default. At the same time, you have more control over how it lays out its views, and that's done with those properties:
edgesForExtendedLayout
Basically, with this property you set which sides of your view can be extended to cover the whole screen. Imagine that you push a UIViewController into a UINavigationController. When the view of that view controller is laid out, it will start where the navigation bar ends, but this property will set which sides of the view (top, left, bottom, right) can be extended to fill the whole screen.
Let see it with an example:
UIViewController *viewController = [[UIViewController alloc] init];
viewController.view.backgroundColor = [UIColor redColor];
UINavigationController *mainNavigationController = [[UINavigationController alloc] initWithRootViewController:viewController];
Here you are not setting the value of edgesForExtendedLayout, therefore the default value is taken (UIRectEdgeAll), so the view extends its layout to fill the whole screen.
This is the result:
As you can see, the red background extends behind the navigation bar and the status bar.
Now, you are going to set that value to UIRectEdgeNone, so you are telling the view controller to not extend the view to cover the screen:
UIViewController *viewController = [[UIViewController alloc] init];
viewController.view.backgroundColor = [UIColor redColor];
viewController.edgesForExtendedLayout = UIRectEdgeNone;
UINavigationController *mainNavigationController = [[UINavigationController alloc] initWithRootViewController:viewController];
And the result:
automaticallyAdjustsScrollViewInsets
This property is used when your view is a UIScrollView or similar, like a UITableView. You want your table to start where the navigation bar ends, because you wont see the whole content if not, but at the same time you want your table to cover the whole screen when scrolling. In that case, setting edgesForExtendedLayout to None won't work because your table will start scrolling where the navigation bar ends and it wont go behind it.
Here is where this property comes in handy, if you let the view controller automatically adjust the insets (setting this property to YES, also the default value) it will add insets to the top of the table, so the table will start where the navigation bar ends, but the scroll will cover the whole screen.
This is when is set to NO:
And YES (by default):
In both cases, the table scrolls behind the navigation bar, but in the second case (YES), it will start from below the navigation bar.
extendedLayoutIncludesOpaqueBars
This value is just an addition to the previous ones. By default, this parameter is set to NO. If the status bar is opaque, the views won't be extended to include the status bar, even if you extend your view to cover it (edgesForExtendedLayout to UIRectEdgeAll).
If you set the value to YES, this will allow the view to go underneath the status bar again.
If something is not clear, write a comment and I'll answer it.
How does iOS know what UIScrollView to use?
iOS grabs the first subview in your ViewController's view, the one at index 0, and if it's a subclass of UIScrollView then applies the explained properties to it.
Of course, this means that UITableViewController works by default (since the UITableView is the first view).
Not sure if you are using storyboards, but if you are, to make your view controllers start below the status bar (and above the bottom bar):
Select the view controller in IB,
In the attributes inspector, deselect 'Extend Edges - Under Top Bars' and 'Extend Edges - Under Bottom Bars'.
I am using storyboards and using the above advice worked however I wasn't exactly sure how to implement it. Below is a short example in swift of how it cleared up the problem by putting the recommended solution into the ViewController.
import Foundation
import UIKit
// This ViewController is connected to a view on a storyboard that
// has a scrolling sub view.
class TheViewController: UIViewController {
// Prepares the view prior to loading. Putting it in viewDidAppear didn't work.
override func viewWillAppear(animated: Bool) {
// this method is an extension of the UIViewController
// so using self works as you might expect.
self.automaticallyAdjustsScrollViewInsets = false
// Default is "true" so this sets it to false tells it to use
// the storyboard as you have it placed
// and not how it thinks it should place it.
}
}
My Problem:
Auto Adjust set to true by default causing a difference between storyboard design and simulator
Resolved:
Code above applied, turning off the auto-adjust.
I solved this problem by adding this line, but my problem was related to a UIView, not UIScrollView
self.navigationController.navigationBar.translucent = NO;
Just bare in mind that
automaticallyAdjustsScrollViewInsets
property works only if some kind of scroll view (table view, collection view,...) is either
The view of VC, or
First subview of this view
Other suggested, that it doest work even if it is the first subview, but there are other scroll views in the view hierarchy.
EDIT (extension DIY)
If you want similar behaviour even if you can't fulfil these conditions (e.g. you have a background image below the scroll view), you can adjust the scroll view insets manually. But please don't set it to constant like 44 or 64 or even 20 like many suggest around SO. You can't know the size ever. There can be the incall/gps/audio notification, navigation bar doesn't have to be always 44 pts etc.
I think the best solution is to use layoutGuide length in didLayoutSubviews:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
scrollView.contentInset = UIEdgeInsets(top: topLayoutGuide.length, left: 0, bottom: 0, right: 0)
scrollView.scrollIndicatorInsets = scrollView.contentInset
}
You can use the bottomLayoutGuide in the same way.