I have already developed an IOS app in Objective C, Xcode 6 in which I have disabled the auto layouts and size classes.
Is it now possible to use auto layout after having disabled it earlier?
If yes, how can I implement it? When I enable the auto layouts and size classes and I implement the constraint on the label, the background colour of the label changes to white. When I do this for other object types, they become invisible.
To answer your first question, yes: it is indeed possible to use Auto Layout in an app after having disabled it. Each Xcode project template just gives you an initial starting point – nothing is set in stone.
For the second question, the best way of implementing Auto Layout in an app is to just take it one view at a time. You don't need to go all-or-nothing with Auto Layout; it's possible to just use it in certain cases but use frame based layout in others. Start on smaller, easier views and go from there.
The last issue around background colors is a little trickier without having screenshots or code samples. I have had views disappear on me after implementing Auto Layout and the issue always boiled down to bad constraints. The best solution I can give there is to just do the usual view-debugging work (as in, printing frames and manually setting bright colors to see where views actually are) and figure out what is going wrong.
Having the background color change to white is interesting, though... Auto Layout should not be affecting that at all. It sounds like the background color got changed somehow while the constraints were being created.
Related
I've been doing iOS for a while now, but when it comes to dynamically hiding / showing elements, I'm a bit lost.
Coming from Android, I'm used to being able to simply set views to visibility gone, but this doesn't exist on iOS.
So let's say I have the following scenario:
Basically I want to have a table, but the table should not fill the entire view controller. Instead it should leave place for optionally either a button, a multiline label, or possibly both at the bottom (if visible, these should be fixed, not scroll).
One way to solve this would be to use auto layout and modify constraints, like adding a zero height constraint. But that would make iOS kill one of the other constraints, which would make it hard to change it again. For the label, I wouldn't always want to have a height constraint, because it could be multiline, and should take the size it needs.
Maybe it's easier to skip autolayout here and modify frames instead, I don't know.
My question is: What approach would be best here?
Is there some other way of doing this I haven't thought of, or do I have to try to do what I described above?
I'm not primarily looking for code (code can be ok), but I'm more interested in a description of how it can be done.
I'd like to support iOS 7.
This problem had a variety of solutions, and opinion based, but I'm facing such questions a lot, when I don't know what to choose and what would be the "right thing".
So, I my opinion, the best solution here is using autolayout, you need to set height of label manually, but you have a few methods for this, at least you can play with it and if you don't succeed ask question about it. Using frames, you'll face same problem of calculating height, right? But with auto layout, you only need to set height, vertical space to 0, when you need to hide message.
You can also use constrains with priority lower 1000, and remove completely constraints from message (button, label) if you don't need it at all anymore.
For example, taking your layout image, you can make UIView with subviews: button, label. Top constraint connect to the UITableView, other constraints to the sides.Label and button will calculate the view's height. The only question here is label height.
So in ios assuming that the background of both these objects is opaque only the front most view in the Heirarchy will be visible and interactable, An easy solution would be to change the different frames of these two things you need and make sure they are in the back of your view heirachy, and when you need them to appear use view.bringSubviewToFront(mySubview) and view.pushSubviewToBack(mySubview) to make it disappear again. View obviously would be referring to main view of your view controller.
I'm designing an iOS app in Swift, not using auto-layout. I'm not using auto-layout because if i do, when my labels update, the design resets. For now, I'm designing for an iPhone 4.7 inch, but when i run it on the simulator for any other size device, the design is completely messy.
UPDATE:
I designed my storyboard with the proper constraints. I added my UIImages in the override func viewDidLayoutSubviews and positioned them outside of the screen. When a button is tapped, there should be a sequence of animations which are triggered as well as a UILabel which should have its value updated.
I commented out some code and kept running it to find the problem, and I found that the UIView reset whenever the UILabel updated. The values are being queried from Parse.com.
The design works when the label is NOT being updated. But once the value changes, the view resets...
I tried disabling auto-layout and it works. However, if I have auto-layout turned on it doesn't.
What do I do?
Thanks in advance
You should really use Auto Layout. It is the way forward for UI layout. The problem with your labels can surely be fixed with proper constraints.
Make sure you modify constraints instead of frames. The layout engine will calculate the new frames when needed, as helpfully mentioned by #rdelmar.
I am using XCode 6 to make a simple calculator using Swift. Anyway, I compiled the code with the initial GUI and it works. However when I change the positioning of some buttons, it does not show up in the compiled app running on iOS simulator. Does anyone know what should be done?
Also, I've changed the code as well, and the code is updated. Ie, pressing button 1 will show 1 in the main textbox, but the interesting thing is the position of the button, which I have changed, still remains in the same position I set it to be initially.
How are you changing the positions of the buttons? If you're doing this by setting frames in code, and your original GUI is laid out in a storyboard, then you're probably fighting against auto layout.
Your storyboard layout will be driven by constraints, which determine the size and position of all the elements of your GUI. Setting a frame manually doesn't change these constraints, so the layout engine resets everything.
Either turn off auto layout (bad idea, since you now have to cope with every screen size manually) or move your buttons by adjusting your constraints.
If anyone have Google+ App can certainly understand what I'm trying to implement.
(explained here: UIViewController Containment with animation like Google+)
I think it has something related with the new effect in iOS 7 Calendar App.(explained here: Recreating iOS 7 Calendar UIView Animation)
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This is a common animation effect that I'm seeing in many apps these days.
Months ago, the fellow Rob tried to help me with this his answer:
Now I was trying to implement it but there's a problem. Images explains better:
INITIAL STATE
WHAT HAPPEN WITH CURRENT IMPLEMENTATION
WHAT SHOULD HAPPEN
I've created a super simple project that shows the implementation (few lines).
Can someone help me to find where's the problem?
REPO: https://github.com/socksz/MovingTableViewCellContent
The problem is that you're trying to change the view's frame with Auto Layout on. You can't do that. The Auto Layout system will overwrite your changes. Try turning off Auto Layout in your storyboard and you'll see that it works.
So your options are:
Don't use Auto Layout
Use/manipulate constraints instead of frames.
For (2) you can just go into the storyboard and set up width and height constraints on the container view and it will work. If fixed size isn't the exact behavior you want, you'll need to be more explicit in your requirements.
The default constraints you're getting now are attached to the parent view and aren't getting carried along for the ride when you move the view to a new parent.
I have an app which has a different UI for portrait and landscape. I've heard wonderful things about Auto Layout but in all my readings it seems to handle simple cases, where UI widgets resize and reposition simply. In my UI UI widgets move. Is this a case where I should try and get auto layout to work or should I just make 2 xibs and be done with it?
You can see in the portrait version that the green element is below the magenta one, but it is above it and next to the orange one in the landscape orientation.
Sorry, one auto layout setting will not allow you to rearrange views like that. You could still use auto-layout for positioning and spacing, but you'll need two sets of settings.
You could still use one xib file and change the auto layout settings at run time, but most likely multiple xibs makes more sense because you'll be able to see and edit your UI WYSIWYG style.
Update
Also, take a look at iOS 9's new UIStackView.