I followed this blog post that explains how you can implement a custom UINavigationBar that has an increased height, if for example you wanted to put additional ui elements in the nav bar underneath the rest of the bar content that will persist between navigation on the stack. This code works really well in the case where you always want it to be that increased height.
In my app, I need to start the navigation bar at its default height, then increase it later, adding more content, after the user performs a given action. Very similar to the song info and controls in the iTunes Store:
So I put some checks in place to not reposition anything if a BOOL property is NO. When I set it to YES, I call [self setNeedsDisplay] which will call layoutSubviews to position everything appropriately based on that boolean value. sizeThatFits is also called and I return the proper height.
The problem is, I can't call [self setTransform:CGAffineTransformMakeTranslation(0, -(NavigationBarHeightIncrease))]; in initialize. Instead I call that at the same time I change the boolean value to YES. Because of this, all of my elements are moved up that amount. But if I don't call setTransform, the elements in the nav bar are in the proper position, but the bar itself is positioned too far down, so that the custom view I've added to the bar is shown overtop the view controller's view - it bleeds out, and the extra space I added is black not the navigation bar's background color.
If I call setTransform in initialize, when the height is the default height, the elements are moved up when they shouldn't be.
So, how can I properly dynamically change the height and positioning of a UINavigationBar subclass?
As suggested in the comments, to achieve the behavior where a custom navigation bar (not subclassing the native control) persists across pushes and pops of controllers in a navigation controller, you'll need to have a single controller with the custom navigation bar and then a single embedded view that resolves to a UINavigationController with its view controllers underneath. Then, it will also be necessary to set the navigation controller's delegate to the root controller so that the title and other properties can be updated as the sub-controllers are pushed and popped. I've provided a screenshot below of what the storyboard version of this might look like:
An option is to create a UIViewController in storyboard which has only the control view you wish to show below the navigation bar with everything else transparent. The advantage here is you design this using the normal tools. Use constraints to place it just below the navigation bar and to set the heights, widths etc of your views.
When you wish to show the control, you can create an instance of this UIViewController and remove the content view from it and add it to the view hierarchy of what is on screen.
There are two options for inserting the extracted base view:
If you add this control view to the view controller at the top of
the navigation stack (what is on screen), it would be covered when
you push on a new controller. This is not what you said you wanted.
If you add this control view to self.navigationController.view, then
it will persist across pushes and pops. This is what you said you wanted.
I use this approach to provide popup help bubbles to describe what is on screen. Depending on whether I use option 1 or 2, I can persist help across multiple pushes/pops.
I got the idea from this tutorial which describes the general approach: http://blog.typpz.com/2013/12/09/ios-sdk-create-a-pop-up-window/
That link provides a full code example on how to bring up the view and remove the view.
This would let you design it in IB, present and dismiss it as required and persist it across navigation sequences.
Hope this helps.
Related
I am new to IOS Swift development. I have a navigation bar design which includes, increasing the height (thus increased text size with custom colors), custom UIButton for closing (instead of the usual back button)
and title at the left side (instead of center)
Basically a lot of customization to do. My question is, is it okay to do a custom UIView to act as a navigation bar or should I push through with a NavigationController and just customize it via code?
Thank you.
First of all the navigation bar offer the push navigation through different view controllers in a smarter way, it stacking all the view controllers pushed and it offers some useful features; for example pushing another view controller from storyboard you don't have the need to set the back button and you can come back to the main controller in a simple way.
You can set a custom image for left/right button, set custom fonts and also change the height without big problems; I suggest to keep the navigation bar and evaluate, you should discover in a short time if a nav bar is enough for your needs.
I'm trying to create a tabbed application with navigation elements inside the tab bar, as seen in the picture below (the red bar) using Swift/XCode 6.2. Basically those three icons in the middle will direct the user to different view controllers. The other two icons would be context-based. For example, on a table view page you would see the menu icon and add new icon as seen in the image. However, clicking on a row would change the menu icon to a back icon, and the add icon to something else.
That's the general idea, but I'm having a very hard time implementing something even close to this. The first issue is that whenever I embed a view in a Tab Bar Controller, I can't move the tab bar to the top. However, when I create a custom UITabView in a View Controller, Control + Click and dragging a Tab Bar Item to another view doesn't create a segue. I haven't even begun to tackle having the navigation elements inside the bar.
I guess what I'm asking is just for a little guidance on what route to take to tackle this. I'm assuming I can't use a Tab Bar Controller or Navigation Controller because it doesn't seem like I can customize them all that much. So custom Tab Bar and Navigation Bars, and then implemnt the segues and button changes programmatically?
Thanks.
I will try to guide you from an architectural perspective (so you won't find much code below).
Using a UITabBarController
In order to achieve what you are suggesting, you are right you cannot use a UITabBarController straight away, among several reasons, the most immediate one is that they are meant to be always at the bottom and you want it in top (check Apple's docs). The good news is that probably you don't need it!
Note: If you still want to go with a UITabBarController for whatever reason, please see #Matt's answer.
Using a UINavigationController
You can use a UINavigationController to solve this task, since the UINavigationBar of a UINavigationController can be customized. There are multiple ways on how you can organize your view's hierarchy to achieve what you propose, but let me elaborate one option:
To customize a UINavigationBar's to add buttons, you just need to set its navigationItem's title view:
// Assuming viewWithTopButtons is a view containing the 3 top buttons
self.navigationItem.titleView = viewWithTopButtons
To add the burger menu functionality on a UINavigationController you can find several posts on how to do it and infinite frameworks you can use. Check this other SO Question for a more detailed answer (e.g. MMDrawerController, ECSlidingViewController to mention a couple).
About organizing your view hierarchy, it really depends on if when the user taps one of the main top buttons, it will always go to the first view controller in the new section or if you want to bring him back to the last view in the section where he was.
3.1 Switching sections displays the first view of the new section
Your app's UIWindow will have a single UINavigationController on top of the hierarchy. Then each of the 3 top buttons, when tapped, will change the root view controller of the UINavigationController.
Then, when the user changes section, the current navigation hierarchy is discarded by setting the new section view controller as the UINavigationController root view controller.
self.navigationController = [sectionFirstViewController]
3.2 Switching sections displays the last displayed view in the new section
This will require a slightly modified version of the above, where your each of your sections will have its own UINavigationController, so you can always keep a navigation hierarchy per section.
Then, when the user taps one of the top buttons to switch section, instead of changing as previously described, you will change the UIWindowroot view controller to the new section's UINavigationController.
window.rootViewController = sectionNavigationController
Using a custom implementation
Of course, the last and also very valid option would be that you implement yourself your own component to achieve your requirements. This is probably the option requiring the biggest effort in exchange of the highest customizability.
Choosing this option is definitely not recommend to less experienced developers.
I'd like to take a stab at this--I think it is possible to use a tab bar controller here.
Your topmost-level view controller will be a UITabBarController with a hidden UITabBar.
Each tab is contained in a UINavigationController.
All view controllers in the navigation controller will be a subclass of a view controller (say, SwitchableViewController).
In SwitchableViewController's viewDidLoad, you set the navigation item's title view (i.e. whatever's at the center; self.navigationItem.titleView) to be the view that holds the three center buttons. Could be a UISegmentedControl, or a custom view.
Whenever you tap on any of the buttons, you change the topmost UITabBarController's selected index to the view controller you want to show.
Issues you may encounter:
Table views inside tabs will have a scrollIndicatorOffset at the bottom even if the tab bar is hidden.
Solution: Play around with the automaticallyAdjustsScrollViewInsets of the tab bar controller, or the inner view controller. https://stackoverflow.com/a/29264073/855680
Your title view will be animated every time you push a new view controller in the navigation stack.
Solution: Take a look at creating a custom transition animation for the UINavigationController.
I want to present a modal view that shows over the UITabBar but not over the UINavigationBar.
From what I understand the best way to overlay a view on top of everything is to position it in its own UIWindow. This works great, and if I make the y origin of the view in the window lower than the navigation bar it works perfectly.
However, getting it lower than that y origin is really hard. I can use the topLayoutGuide.length property to position the y, but when I rotate that no longer is true as the navigation bar height changes.
How should I be doing this?
I had to deal with something similar recently, and ultimately to modally present a new view you'll be looking to call the navigation controller and then set its setDefinesPresentationContext: to Yes.
setDefinesPresentationContext: is needed so that a presenting view controller will restrict the bounds of a presented view to the visible area of the presenting view. As a result, the view controller is kept within the bounds of the currently visible window (The default is no, in which case the presented view keeps asking for a defining context up through the VC hierarchy until it reaches a VC that claims this role, or until it hits the UIWindow).
With this method, you won't have to calculate the bounds of your view, it'll just be done automagically. Check out the Apple docs on this method for the full explanation though.
(and shameless plug, I wrote about it on my blog. it's under "Presenting the Search Bar".. pardon the formatting, still a work in progress)
I am developing an application that requires a scrolling UITabBarController. The customary 5 tab items max with the 5th being the More.. tab just won't do. I have found some pretty great third party classes such as https://github.com/Marxon13/M13InfiniteTabBar and they are great and have the functionality I would like but still, things aren't perfect. When I rotate my device to landscape things become glitchy.
Basically, I am fed up and want to create my own custom UITabBarController with scrolling..how would I go about doing this? I understand I would most likely put a UITabBar within UIScrollView but I am lost without a detailed tutorial of sorts..
Any help would be greatly appreciated! Thanks!!
The way I would approach this is to avoid modifying the UITabBar, since it is highly specialized, and create a UIViewController subclass that will provide this functionality for you. This view controller should have a container view (take a look at this Apple documentation for more detailed information) that will have each child view controller's content view.
For the actual tab bar itself, you have a few options depending on what you similar you want it to the standard UITabBar.
You could have a super basic tab bar that consists of a UIScrollView with standard UIButtons that change/load the correct content view controller. Creating the tab bar would be then easy, simply add the buttons to the scroll view inside some type of loop (you could have the x positions be a multiple of the tab index to make positioning easier). UIButtons have support for a selected button state that you can use. You can change the scroll view's background.
You could have a fancy tab bar which is constructed essentially like the above, but by having a custom UIButton subclass instead of a standard UIButton. This will allow you to implement a more intricate design (i.e. with and more customized touch handling.
Tips:
Use [myImage imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate] to have your tab images tinted like the standard tabs when selected.
Design the basics of your custom view controller in your storyboard. It is really easy to add the child container view and the scroll view this way.
Hope this helps!
I am developping a Master-Detail based iApp and I would like a specific button in the Master pane to trigger the apparition of a "settings" Form Window.
I then set my segue as "modal" and I get a form view covering the whole screen. This form comes from the bottom of the screen.
How do I get my view to appear from a slot at the top of the window and to cover, say, 2-thirds of the screen width and 3-quarters of its height?
Thanks!
You can't readily do it using the modal presentation styles, as they are fixed sizes. It is possible to work around but you need to mess around with resizing private views and it quickly starts to feel a bit fragile and messy.
It's simpler to create your own view controller at whatever size you like, add it as a child view controller and animate it into position yourself. You can even add your own background dimming view.
You lose the convenience of segues and the dismissal code, as you're no longer "presenting" the new VC, but that's not hard to recreate.