I want to have certain views in exact places, and constraints aren't working for me. How can I place, say, a collectionView in the lower 80% of the screen, and an ImageView in the top 20%?
In case it matters, I am planning this app to work only for iPads in landscape view.
You can use NSLayoutConstraints, it will not take long to get familiar with the system. This way you can customize your views with ease. Bigger applications are made without storyboards. This a good tutorial http://makeapppie.com/2014/07/26/the-swift-swift-tutorial-how-to-use-uiviews-with-auto-layout-programmatically/
Does it have to be programmatically? You could add constraint between the two in the interface builder and achieve the same. To do this,
control drag from the smaller to the larger and select aspect ratio,
then select one of the views and go to the size inspector on the
right bar
under Constraints, select the constraint that was just added, double
click it
under First Item select shorterView.Height
under Relation select Less Than or Equal
under Second Item select tallerView.Height
make sure Constant is 0 and Priority is 1000
set the Multiplier to 1:4 (I believe this is the correct ratio, but I always just mess around with these numbers until I'm satisfied with the views)
I'm currently using this in one of my projects, and it's working really well, so hopefully it will work for you, too!
(The top answer here might also help :] )
Related
I am trying to create a simple UI that works on all devices (obviously) and I haven't had much success. The program consists of two labels, a button, an image view and a textfield, I am also using a universal storyboard.
I implemented a top constraint, horizontally centred and fixed the width and height for all labels, buttons and textfields. The only exception I made with the image view was that instead of implementing a top constraint, I used a bottom one instead as I have found that utilising the former would result in it being only partially displayed. I would then switch from the universal storyboard to one with base values. From their I would delete the existing constraints and add new ones after moving the UI elements to their new locations on the different sized screen.
When I run my app on an iPhone 4S, the layout, whilst mostly correct, is still not perfect (i.e. a label is far too close to the image). Does anyone know how I can make my layouts look correct? I have been following this guide, Adaptive Layout Tutorial in iOS 9.
Thanks so much for your help!
[Example of the constraints for the picture1
I am not sure how familiar are you with autolayout, therfore I'd suggest you watch Stanford university lecture regarding autolayout.
In short, according to the lecture and after looking at your picture, you should almost never set constraints with actual numbers. Use "Standart value" and when you can't choose "Standart value" write 0.
I'd recommend watching the above lecture and the rest of the examples in there.
Your label has 2 problematic constraints
1. Top space (30 points) to "how old is your dog"
2. Top space (28 points) to button
That means that your button is 2 points height (really small!!)
Or - because the button has already a fixed height, the label and the text field are too close (and maybe even overlaps the button)
You should delete the top space constrain (to "How old is your dog") and do something else, or give it more points height
Good luck!
I would like to change view size depending on the screen size of the device.
For example, the view should not have the same size on iphone 4s and iphone 6.
The best way would be to use size class, but iphone 4s and iphone 6 are in the same.
Is there a way to add custom size class in order to do that ?
Or should I set auto-layout constraint programmaticaly depending on screen size ?
Thanks
At this point in time you really only have one solution, and it is using constraints.
Constraints have been existing for a long time now and should be used in all iOS projects. Never EVER change view sizes using their frames. Always adjust the constraint instead.
You can achieve pretty much anything using constraints. There are many tutorials / stack posts about it, you'll be able to look it up.
From what I understand here, you want your view to be bigger on bigger screens, and smaller on smaller screens. Without any other information i can only show you a very trivial example.
Add 4 constraints in storyboard (or in code, but it's just easier in storyboard I believe) from your resizing view to another view. Those four constraints should be Top, Bottom, Leading and Trailing (Up, Down, Left and Right).
Each constraint will basically say "my view should be X units from its superview, on that side".
If you go in the constraints attributes you can configure different things, like "I want my left side to be X units from the right side of that other view".
I suggest you mess around with colored empty views and see how they work, and if you can, have a more experienced programmer answer your questions on the side, because constraints, as simple as they are, are quite confusing at first. It took me about 2 months to be what i consider comfortable with it, and I'm a full time developer.
I can answer a couple more questions here if you want, but I'm pretty sure we'll be off topic really fast !
Have fun using constraints, they're great !
I'm wondering if xCode auto layout / constraints are really as frustrating as I think, or am I just not understanding them. For example, I started with this basic label in the view controller:
Fair enough. A box with text that has equal margins on the left/right and a smaller top margin. Now when I run any size device, that gets skewed/cut off from the device view. So right away for some reason Xcode thinks that despite me putting the entire label in the view controller, it things it should display halfway off the screen. Don't get it but okay, so I went ahead and added auto layout constraits to the right, left and top margins. The result is:
So it centered it, which is nice, but now it just ignores the fact that I made the width larger and it just shrinks it down anyways? For something so simple this seems to be very...unreliable. I then added the "aspect ratio" constraint and it seemed to look fine in all of the devices...finally!
I curiously also simply tried to get rid of all those, and simply add the "aspect ratio" constraint and the "horizontal center in container" constraint. On the main storyboard preview (not the simulator) it looked like this:
Not what I'm looking for, as it's not stretched downward like I want, they shrunk it again. However...when actually running it in the simulator...it looks perfect, the way I want it to in the first picture of the view controller.
Why the preview and simulator differed, I suppose (from reading other questions) it's because there were a few warnings after I added these. One was that the horizontal and vertical positions are one initially and will be different at run time. But when I ran it, it definitely held the initial ones and not the ones they said it would be at run time. It also told me that vertical position was ambiguous...well yeah I only set a center and aspect ratio...pretty obvious and not sure how I'd even solve that error. It solves it when I delete the horizontal center...but now it's not centered which is a step back from what I wanted.
Long story short, how do I deal with this. My previews and simulations aren't accurate with each other even for the simplest auto layout specifics. Apps nowadays are so complicated and on every device they scale and work beautifully, and this seems to not agree with even just one label.
Does anybody have any good articles, advice, or anything that would help me? This auto layout stuff seems to be so picky and that's really all I know so I have to deal with it. And don't even get me started on why the text doesn't scale with the label...why would I want the text on an iphone 4 to be the same on an ipad even when my label is increasing in size with the device?
A lot to go through, but it's just very frustrating and I can't see myself doing much else before I try to understand these basics. Thank you and much appreciated.
I think you have to understand constraints first...without that you always made things frustrating....For understand the constraints you can check this links
http://www.raywenderlich.com/50317/beginning-auto-layout-tutorial-in-ios-7-part-1
http://mathewsanders.com/designing-adaptive-layouts-for-iphone-6-plus/
It takes a bit of experience to get used to it, but once you get it, you get it for good and it's very easy.
Basically the rule of thumb is don't trust exactly what you see in storyboard when it comes to the size of the actual object. Say you have a UIView centered horizontally and vertically in the main view. True it will try to keep the size of that UIView but center it in any size device, but I would never just leave it at that. I would either:
Add width and height constraints
Add a width/height constraint and an aspect ratio constraint
Add a width constraint and top and bottom constraints
Add a height constraint and leading and trailing constraints
Add top, bottom, leading, and trailing constraints
In other words, the exact size of the object should always be determined via the constraints, and not by the UIView itself. This gets away from the finicky behavior and also ensures that it's displayed on any device exactly the way you intend it to.
In the new "Xcode 6" the ability to change the center of measure of a button is missing.
In Xcode 5: http://imgur.com/jWHJp4v
Xcode 6: http://imgur.com/rsNayVZ
When I put an item (like a button or label) somewhere, I am unsure of the center, so my code that deals with the item is incorrect.
The "center" shown here in Xcode 6 is measured from the top left of the item, not the actual center.
How should I fix this so it is measured from the center like here, in Xcode 5?
You can't “fix it”. That control is gone in Xcode 6. I suspect they removed it to encourage you to use constraints instead of setting frames directly. You can use constraints to pin the center, right, or bottom of a view.
It's driving me crazy that the origin widget has been removed. It has made the placement of any object relative to another very difficult. I always use auto layout and I'm not sure how this improves it. Also, I'm not sure I follow the logic of improving a feature by making it more difficult to use. In the past, it was very helpful to set the "anchor point" of the origin and then adjust the object's position or size and have the frame grow on the unanchored sides. Now i have to break out the calculate and add position + size and then add buffer space to figure out where next object should start. And if I adjust the first object's frame in any way I need to break out the calculator again. Once you have a few objects that are relative to each other, it becomes vary painful to tweak any object's frame without having to recalculating everything.
As a side note, the removal of the ability to delete a constraint right in the size inspect is also a confusing choice. Instead we have to go through the document outline and manually delete them there. This is not a big deal for the size constraints as they are keep in the object's sub-directory however finding edge related constrains is much more difficult as they are grouped with the rest of the edge constrains and can be difficult to find. Again, is this an example of encouraging / improving auto layout? Very frustrating!
The feature has been removed from Xcode. I believe this is to account for the various sizes of devices now available, and as a result, the use of constraints is the way to go.
If you are using auto layout then this two will help you place you control in center for all the view different size of devices.
simple:
http://technet.weblineindia.com/mobile/using-auto-layout-in-xcode-6-for-universal-ios-app-development/
Advance:
http://www.youtube.com/watch?v=G53PuA_TlXk&feature=youtu.be&list=UUtc1Jt_UTPsXpAGtvlr0nUQ
Apple has removed this feature as there are 4 different size of devices only for iphone and it would be difficult to set frame for all controller and will increase the length of code and will become a tedious task as it check's the size of device and then set frame so in XCode 6.0.1 we need to use auto layout + size class and prepare our view based on the constraints set in storyboard or Xib.
Hope the above link's will help in solving your problem.
If your layout isn't too complex you can "Pin" your button or view to the top or bottom, sides, etc.
Or you can do your constraints manually here:
The first method works really well and is super easy! I had a similar problem as you looking for tools that have been left out in Xcode 6 and found this wonderful tutorial on Auto Layout:
http://www.raywenderlich.com/50317/beginning-auto-layout-tutorial-in-ios-7-part-1
If you are trying to center it I would click on the button or view you are working on and look at the size inspector here:
Look at where I circled and make sure that the bottom space and the top space are equal to the same amount (mine aren't equal), but that should give you the center.
In a View Controller I have two UILabels.
I'm trying to start to understand the AutoLayout feature, but I'm finding tutorials using storyboards, complex layouts, scrollViews and other components that are absolutely more complex of what I'm trying to achieve and understand.
This is my very basic setup:
What I simply want - to start to dive in the subject - is:
have the distance between the two labels preserved when testing it on 3.5' and 4' screens
have the bottom and top margin of both the labels to be proportionally preserved when testing it on 3.5' and 4' screens. EDIT: please consider that the desired position it's not the exact center
I have tried to add constraints via the "Pin" option, but with no success at all. Maybe I should put them inside another view to act as a container?
This is a very easy question, but right now this AutoLayout feature is really confusing me. And maybe this can be a good starting point to understand what right now looks to me to be designed by a crazy scientist :)
Put both UILabels in a containerView, and align containerView vertically center.
I would support #RoboticCat for the statement he made. But I would try to deliver what I learned from those videos.
For first requirement:
Ctrl+click on any of the label & drag n drop it on another label. Select "Vertical spacing" option from the popup. this will full fill your first requirement.
For second one:
Ctrl+click on top label & drag n drop it on view of viewController. select "Top space..." option from popup.
repeat previous step between bottom label & view. This time select "Bottom space.. " option from popup.
Now navigate to Size Inspector of each label. There you can find the constraints just created. Click them to perform Edit.
Decrease priority of top & bottom constraints to 500 from concerned labels. This will solve your issue.
Let me know if more info needed.. :)