I need bigger button & image sizes for iPad devices compared to iPhone. Before Size classes, I used to have images ending as #2x~ipad to have different version for iPad. However, it is not clear if the same approach is applicable when using Size classes and Trait collections, or there is a better approach? Also, is iPad Pro 12.9 inch #3x or #2x? I see conflicting responses, but if it is #2x, how do we have bigger image size for iPad Pro?
You are confusing Size with Resolution.
If you have a UIImageView at 150 x 150 points, and you have MyPic.png + MyPic#2x.png + MyPic#3x.png, the image view's frame will always be 150 x 150 points, but UIKit will automatically select the proper resolution image for the device. See https://developer.apple.com/design/human-interface-guidelines/ios/icons-and-images/image-size-and-resolution/
If you want different size frames for your buttons and images, based on device / view size, use Trait Variations, or code, or percentage-based constraints.
Again, if you have MyPic.png + MyPic#2x.png + MyPic#3x.png files of the same image, the appropriate resolution image will be used, regardless of frame size.
There is a lot of flexibility when working with images by using Asset Catalogs. For example:
You can add different resolution images for 1x 2x and 3x... you can add image sets specific to iPhone / iPad / etc.
EDIT
Additional example. Asset is named "RoundSwift256x256". I have 3 resolutions for iPhone, 2 resolutions for iPad (no iPads use #3x) - using different colors to make it very obvious.
In Storyboard, I added an imageView, set its image to RoundSwift256x256. then set the Assistant Editor to Preview and selected iPhone 8 and iPad Pro 9.7". As you see, it uses my iPhone image for iPhone, and my iPad image for iPad.
Related
I'm a bit confused here. If, say, I want to set an image as background (full screen) for my ios app (iphone), what are the sizes for the image I have to make? I googled and found no clear answer yet.
Using image assets gives no explanation either. I tried creating new image set, it just shows 3 slots for 1x, 2x, and 3x. How the xcode differentiate between what image to use for iphone 5 and iphone 6 (different ratio)?
EDIT
I seem to be unclear about my question. If the image for iphone 5 and 6 is the same, doesn't the aspect ratio differ? It will be stretched on one device or vice versa on the other and I don't want that. Back before the iphone 6, I just create image .png, #2x.png, and -568h#2x.png with the size 320x480, 640x960, and 640×1136. So my question is, for iphone 6 and 6+, what is the naming and size for my images?
If, say, I want to set an image as background (full screen) for my ios app (iphone), what are the sizes for the image I have to make?
You can use [UIScreen mainScreen].bounds's width & height to setup your view frame.
it just shows 3 slots for 1x, 2x, and 3x
They're not used for handling ratio of displaying, just for display solution (retina or not). You can just use xxx.png in your code, and it'll choose to use xxx#2x.png or xxx#3x.png appropriately.
How the xcode differentiate between what image to use for iphone 5 and iphone 6 (different ratio)?
UIImageView has an instance method called -setContentMode:, you can use UIViewContentModeScaleAspectFill mode for displaying in different devices w/ different ratio, i.e., some parts will be cut off.
This link should give you an overview of the differences between the 1x, 2x and the 3x image assets which we get once we create a new image asset.
http://9to5mac.com/2014/08/29/support-for-3x-image-assets-found-in-latest-ios-8-beta-ahead-of-larger-display-iphone-6/
Also when you create a new image asset, you can select image for specific devices such as (iPhone and iPad), if you are only developing for certain devices.
Select the devices as "Device Specific" from the Image Set Shown on the right side of the image.
As for you question, iPhone 5 and iPhone 6, xcode will take the same image assets i.e. 2x, for iPhone 6 Plus it takes the 3x image.
App Icon and Launch Image
Now for the App icon and the Launch image, this following link will guide you through.
http://www.iphonelife.com/blog/31369/unleash-your-inner-app-developer-managing-images-xcode-5-asset-catalogs
https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/MobileHIG/IconMatrix.html
for the launch image there are different options available, such as you can individually set images for the landscape and portrait images for different devices.
My existing app has two Storyboards (for iPhone and iPad), and it supports iOS7+. I am now planning to convert it to one storyboard using Autolayouts and Size Classes, but I have few confusions:
What will the size of the images? For instance, right now without Size Classes and Autolayouts, I ask designer to slice images for iPhone5, and iPad and make them #2x and #3x respectively. But for Autolayouts, what size they will have to slice i.e what screen size will they choose and then will give me images accordingly for #2x and #3x, i.e what universal screen size? For instance, I ask them to give me a background image of screen size. What size will they give me? From what I understand, it should not be iPhone specific or iPad specific as the app will be universal.
I am aware of the fact that Size Classes support iOS8 onwards, so what about iOS7? I will have to do things programatically for iOS7? Will I have to use device-specific images or can I use universal size images for iOS7 as well?
size classes doesnt mean you cant be specific with things anymore, you should still set the background to be a suitable phone sized image for when the size class is the shape of a phone (compact x regular), and set a suitable iPad sized image when its the size of an iPad (regular x regular).
it seems like you can still use size classes in iOS 7 with some limitations
i think you are viewing the size classes as having one generic storyboard that will solve your problems of having a specific iPad and iPhone storyboard like before, which is partly true, all it really does is save you having two separate storyboards, so if your ipad and iphone screens differ, you would need to have the differences layout out in the different size classes (in your case the different sized backgrounds are a difference). it might just save you having to specify your autolayouts twice in 2 different storyboards (and even then maybe not)
For images, you still need different images from design team as:
imageName#2x.png: 640 x 960 (iPhone 4. iPhone 4s)
imageName-568h#2x.png: 640 x 1136 (iPhone 5, iPhone 5s)
imageName-667h#2x.png: 750 x 1334 (iPhone 6, Portrait)
imageName-736h#3x.png: 1242 x 2208 (iPhone 6 Plus, Portrait)
imageName~ipad.png: 750 x 1334 (iPad)
imageName~ipad#2x.png: 1242 x 2208 (iPad Retina)
For icons, we will prefer to make a font file from svg of the icons using icomoon.io website.
During development, we need to validate image name on device level. Just look into this utility:
https://github.com/victorjiang/UIImage-VJDeviceSpecificMedia/blob/master/UIImage%2BVJDeviceSpecialMedia.m
I have a simple view with a text and an Image. I ran this app on iPhone6Plus and iPhone5. Then I made a screenshot of both and enlarged the iPhone5 screenshot such that it matches the size of the screenshot from iPhone6Plus. Here is the result:
As you can se the size of the text the size of the image and there positions are not identical but they should be to look the same on different screen sized.
Here is an example of a weather app running on different screens:
As you can see the sizes and the positions of text and image are identical.
The image is loaded from asset catalog:
imageView.image = UIImage(named: "shower3")
self.view.addSubView(imageView)
imageView.center = self.view.center
I have only created a 128x128 image and put it into the #1x version in the asset cataloge.
Let me rephrase this. I run the wether app on iPhone5 make ascreenshot and iPhone6 make a screenshot. Then I resize both screenshots to the same size. Then I see that both fontsize as well as images dimension are exactly equal on both screenshots. This means that on each device font and image must have different dimensions. How can I do that?
How can I achieve that text and image have identical proportions on different screen sizes? How does the Weather App do it?
Images
I am the creator and one of the developers of the Swift Weather app. The app doesn't use three versions of images because I didn't make those images and it was a Pull Request from another developer. I don't have the origin images.
As #Daniil Korotin mentioned, iOS uses points to calculate image and font sizes. iOS uses let screenScale = UIScreen.mainScreen().scale to retrieve the screen scale and pick up the proper size (1x, 2x or 3x) of the image. If we don't provide the proper size of the image, for example, in SwiftWeather app, we have only 1x version of the image (as the screenshot below), iOS will upscale the image to render on retina devices. On iPhone 6 Plus, it actually does downsampling for 3x assets. Please have a look at iPhone 6 Screens Demystified. In some case, if you don't provide 2x or 3x images, on retina devices, the image upscaled from 1x may looks blurry. We should always provide 1x, 2x and 3x images if possible.
Fonts
iOS renders fonts according to the specified points. It will automatically convert the points to certain pixel based on the devices' screen scale (as mentioned above).
How can I achieve that text and image have identical proportions on different screen sizes? How does the Weather App do it?
The answer is Auto Layout
You can see we set constraints for the image view (used for the weather icon) as below.
The width and height are always 150 points, please notice it is points nor pixels. It will render the same size (for look and feel, not for exactly pixels) for different devices. For your first image (iPhone 6 Plus vs. iPhone 5), it looks different because maybe your simulators have different scale. A better way to check how auto layout elements lay on the screen is to use Preview in Interface Builder.
Open the main storyboard, and click on Assistant Editor. On the right hand side, select Preview (on the top left). And click the plus sign ( on the bottom left) to add different devices. You can see they are identical proportions on different screen sizes.
If you have any questions, please let me know.
Something maybe off topic
If I design the images/assets, I would like to use some vector base tool like Sketch to design the assets and export them to three different sizes. Please have a look my another project iOSAnimationSample. It has a Sketch file for the design.
Sketch design
Export assets to different sizes
In that case, iOS can pick up the proper assets for different devices.
The app you are referring to does not correctly support multiple screen sizes. The interface is scaled up to run on the 6 and 6 plus, which is why everything appears the same size.
Look at the screenshots from your app - the status bar is much smaller on the 6 plus. This is because it is supposed to take up less room on the screen. It's 20 points high on all devices.
Now look at the screenshot from the weather app - the status bars are the same size. Because the weather app does not support multiple screen sizes, iOS simply takes the smaller interface and scales it up to fill the screen.
If you want to achieve the same effect (which you shouldn't) then remove the LaunchScreen.xib file and use a launch image instead. But people don't buy larger phoned screens because they want to have the same content, but bigger. That would be achieved more cheaply by simply holding the phone closer to one's face.
You're supposed to take advantage of larger displays by allowing more content to be shown at once on the screen - more rows of data in a table, more text from a book, more images from a photo library.
In the case of a weather app the extra space should be used to display more rows of an hourly forecast or something, not just a larger version of a fairly useless icon depicting the type of weather.
I suspect it is only game support that means supporting larger screens properly is not already a requirement for app store submission. Supporting the 4 inch screen became mandatory quite quickly, you should expect a similar rule to be introduced for the 6 and 6 plus before too long.
If you want a specific element to always take up 50% of the width of the screen, or a label to always be the same size as an image, then you use autolayout constraints with multipliers. An autolayout constraint is of the basic structure:
attribute of A = (attribute of B * multiplier) + constant
Most of the time the multiplier is left as one, so you're just saying that this is 20 points to the left of that, or whatever, but you can use the multiplier as well, and say that A is the width of B, multiplied by 2 or 0.5 or whatever you like.
iOS uses points to calculate image and font sizes. On non-retina screen 1 point equals 1 pixel, on retina screens — 2 pixels, and for iPhone 6 Plus it is equal to 3 pixels (some downscaling is applied, though). If you want to scale the image and font based on the actual pixel size of the screen, you can get the number of pixel per point like this:
CGFloat screenScale = [[UIScreen mainScreen] scale];
The iPhone 5, 6 and 6 Plus screen aspect ratios are the same, while resolutions differ. If you want to simply keep proportions, then you have to pick a 'base' screen width or height (say, the iPhone 5 screen width, which is 320.0 points) and then calculate the proportion by dividing the actual device screen width (say, iPhone 6 Plus screen width, which is 414.0 points) by that 'base' width (414.0 / 320.0 = 1.29375). You can get the screen size like this:
CGRect screenBounds = [[UIScreen mainScreen] bounds];
Dividing screenBounds's width by base width gives you the proportion. Then you just multiply all the sizes and margins with that proportion (1.29375 in our case for iPhone 6 Plus). Hope you get the idea.
P.S. A good guide to resolutions is here.
P.P.S. And in your case, as skorolkov mentioned below, the app just upscales everything for bigger screens (add/remove splash screens to enable/disable this upscaling).
UPD: Ok, now I see what confuses you. Here's the thing: when Apple initially released iPhone 6 and 6 Plus many apps didn't support their larger screens and bigger resolutions. So they decided that if an app lacks splash screens specifically made for those phones, it should use the iPhone 5 resolution.
That's why you get the exact same pictures after manually resizing screenshots: the system does that too. It simply takes iPhone 5 'picture' and stretches it so that it fits larger screens. The drawback is clear (and visible, especially on iPhone 6 Plus): the fonts and images are blurry and upscaled (system interface elements, like status bar, get upscaled too). So basically you get the iPhone 5 picture on all larger-screened devices (you can check that by taking a screenshot on an iPhone 5, resizing it manually to fit iPhone 6/6 Plus resolution and comparing the actual iPhone 6/6 Plus screenshot to it).
To be clear: that's the behavior you currently get, but it's not good. To keep everything properly scaled using the devices' native resolution, use the method I described above (manual multiplication) or autolayouts with equal height/width set to desired ratios for interface elements.
Weather App is using upscale mode to run on iPhone 6+. You can enable it by removing launch screens for 6/6+.
Go to asset catalog, select your launch image and unset 'iOS 8 or Later' checkbox in Attributes Inspector.
Screenshot - your app has this set
Screenshot from WeatherApp
in programatically (X and Y) we pre define the values in constant :
#define XScale [[UIScreen mainScreen] bounds].size.width / 320.0f
#define YScale [[UIScreen mainScreen] bounds].size.height / 568.0f
Then create UIImageView programatically
var imageView : UIImageView
imageView = UIImageView(frame:CGRectMake(XScale *someValue, YScale * someValue, XScale *someValue, YScale *someValue));
imageView.image = UIImage(named:"image.jpg")
self.view.addSubview(imageView)
based on your screen size we need to set Constant values. We use for iPhone5 and 4s screen.
You need to set Layout constraint to all the views to make them look at same places and sizes in all screens sizes provided that the aspect ratio of screens are same.
Have you tried to remove autoResizingfunctionality from view?
Click on inner arrow to remove autoResize view as per superview
First turn off auto layout, auto resizing and size classes in storyboard.
Click on Images.xcassets icon and select all your graphics. In attribute inspector set Devices property to "Device Specific" and set the checkbox checked against "iPhone" and "Retina 4-inch"
Place all your graphics in 2x image set. You may place a higher resolution image set for better results with iPhone 6/6+.
Design your view for a reference device say iPhone 5 (320x568 portrait).
In your viewDidLoad method paste the following code
self.view.transform=CGAffineTransformScale(CGAffineTransformIdentity,self.view.frame.size.width/320, self.view.frame.size.height/568);
And you will have same result on iPhone 5/5s, iPhone 6/6+.
I'm building an app that designers only gave me one canvas size for (9x16 aspect ratio at 1242x2208). I started an app that doesn't fully leverage the iPhone 6+'s screen space. Instead, all devices will use the same layout and assets. I did this by removing the #3x launch screen image. The goal is to use the same point system for all devices (320x568 - including for iPhone 4S - the 320x568 will be in a scroll view to fit all the content since the app is designed for 9x16 aspect and the 4S is not).
With that said, for simplicity of the question, lets say I have a full screen image (320x568 points). What are the 3 necessary pixel resolutions I need for 1x, 2x, and 3x?
When I use an app like Prepo that takes a 3x image and scales it down to 2x and 1x automatically for me, this is what happens:
I add a 3x asset at 1242x2208. It spits out:
#2x with px dimensions of 828x1472
#1x with px dimensions of 414x736
That doesn't seem right to me, but then again the whole iOS retina resolutions thing confuses me quite a bit. Shouldn't the 1x resolution end up being 320x568?
It may be that you are mentally confusing apples with oranges. Let's say you have an app that is to run on both iPhone 4s and iPhone 6 Plus (the extremes). Then you have two concerns:
Resolution. The 4s screen has 2 pixels per point, while the 6 Plus screen has 3 pixels per point. Images must come in a 3x size for the 6 Plus and a 2x size for the 4s in order to look good on both screens. This is something that the Asset Catalog will help you with.
Layout. The two screens have different sizes and different proportions. Things will need to grow and shrink in order to fit nicely and look good on both. This is something that Auto Layout (constraints) will help you with.
The two things are both involved where images are to be displayed on the screen, but in two different ways. You will have different resolution images, and they will be displayed in differently sized UIImageViews that adjust the image's display size.
Currently working on a universal SpriteKit project. I'll be supporting the following devices:
iPhone 4/s,
iPhone 5/c/s,
iPhone 6,
iPhone 6+
iPad non-ret,
iPad retina
I am confused on the iPhone part. I already have 4 versions for my background sprite for the 4 different screen resolutions of the iPhones. But which goes to which?
I know the 3x is for the 6+, and I think the 5/c/s goes to the Retina 4 2x, but I do not know where the iPhone4/s, and 6 go. Anyone know?
Side note, when I create a Launch Image inside my xcassets file, I am shown these options, which basically has all the device I am supporting. Just wondering why this is not also the case when creating an Image Set
Also how do you guys approach creating images/sprites for a universal application? Now that the new iPhone 6, and 6 plus are out, I have 2 more resolutions to support which is still confusing for me as I'm still a beginner.
This is a little confusing - here's how I understand it (this is in reference to the top image):
1x images are for the original iPhone through the 3GS - 'standard' resolution devices (3.5" screens)
2x images are for the iPhone 4 and 4S (3.5" Retina screens) and are also used for the iPhone 6.
Retina 4 2x are for the iPhone 5 and 5s (4" Retina screens)
3x images are for the new iPhone 6+ (5.5" super-Retina [3x] screen)
I believe that the iPhone 6 (4.7" screen) will use the Retina 4 2x images, but I would have to test it.
Side note, when I create a Launch Image inside my xcassets file, I am shown these options, which basically has all the device I am supporting. Just wondering why this is not also the case when creating an Image Set
If you compare the two images, the lower one has everything the upper one does, except for a 1x iPhone graphic. You don't need that if you're only supporting iOS 7 and above, since iOS 7 doesn't run on any non-Retina phone-form devices. To be honest, I don't understand why the top image has a 1x iPhone form graphic option - maybe because you checked the "iPhone" box in the sidebar?
Also how do you guys approach creating images/sprites for a universal application
For most non-fullscreen images (like a logo), you really only have 3 resolutions to support - standard (1x), Retina (2x), and the iPhone 6+ (3x). These are simply different quality of images, not really different sizes. So if you have a 10x10 image on a standard device, that would mean you need a 20x20 image on a Retina device and a 30x30 image on an iPhone 6+. On all devices, they would show up as a 10x10 image.
A great tool I used for managing different resolutions of icons is iConify.
I create them at the highest size I need (30x30 [#3x] for an image I want to be 10x10 on a device), then save it as a png and resize copies to 20x20 [#2x] and 10x10 [standard]. A better solution would be to create and use vector graphics, which would resize better to any size.
In 1x place image with resolution 320 x 480.
In 2x place image with resolution 640 x 960.
In Retina 4 2x place image with resolution 640 x 1136.
in 3x place image with resolution 1242 x 2208.
Images of Retina 4 2x will upscale to resolution 750 x 1334.
Images 3x will downscale to resolution 1080 x 1920.
You can also visit this links for launch screen images:
http://www.paintcodeapp.com/news/iphone-6-screens-demystified
http://www.paintcodeapp.com/news/ultimate-guide-to-iphone-resolutions
For all other images resolution and size:
https://developer.apple.com/ios/human-interface-guidelines/graphics/launch-screen/
https://developer.apple.com/ios/human-interface-guidelines/graphics/image-size-and-resolution/
https://developer.apple.com/ios/human-interface-guidelines/graphics/custom-icons/
How to use Image.xcassets:
https://www.youtube.com/watch?v=_36Y6rDcKP0&list=PLXCowKcXAVgrCe2Lezv0acRf4adQLshv2
Hope this will be more helpful.
If you have your launch images in an xcasset file, you can do the following in Xcode 6.
Select the launch image asset, select a specific resolution (1x, 2x, Retina 4, etc) and open the attributes inspector (see image below).
Under the "Image" section, you will have a "Expected Size" attribute.
Inside images.xcassets, you can add different devices support by right clicking as shown in the snap
Edit: Well, it doesn't seem working when I drag n drop images to placeholders. It gets messed up as shown next
I don't know why it is acting odd on my Xcode 6.4 though.
Edit#2:
I see a bug from apple here. I can select 'Universal' along with any device upon right click as you can see in the first image above. But via attribute inspector I can correctly select either 'Universal' or specific devices as shown here
Edit#3:
In Xcode 7 the attribute inspector has been changed and now it gives option same like the right click. So instead of either 'Universal' or specific devices, now it offers to select all.
There is one tool : AVXCassets Generator with which you can directly generate XCAssets file for all your icons and images just by one click.
hope you will like it.