In my iPhone app, I have a control that takes on quite different sizes on different screens. For example, (in the iOS point coordinates)
3.5 inch devices (iPhone 4S): 242x295
4 inch devices (iPhone 5 series, SE): 242x383
4.7 inch devices (iPhone 6 series): 297x482
5.5 inch devices (iPhone 6 Plus series): 336x551
As you can see, these control sizes are not proportional.
The problem
This control has an image as its background. That particular image is important for brand identity and the custom appearance that my company's designer wants to go with. The image gives the appearance of a material and has a texture. It also has shadows within itself. I would like to apply this image on to controls of different screen sizes (my control sizes are determined at runtime according to available space, as Apple may come up with new screen sizes anytime).
My current solution
The designer makes separate PNGs for me for each screen size and I hard code it with onto my control using an if-else for screen size (after determining the size mathematically before hand). As you can probably tell, this is a horrible approach for robustness. I'm also looking to expand to iPad and having a better scaling system will certainly help.
An idea
I take an image that's the smallest unit of the repeating texture and apply it to my control with the scaling option that repeats it throughout to obtain a final image.
HOWEVER, I lose my shadows and rounded edges this way. (I tried simply using the largest image as well and the disproportionate scaling makes the rounded edges horrible)
I tried looking for solutions and most resources do not deal with such images. I simply cannot lose any part of this image and it should be fully applied to the control, shadows and corners included.
I apologize if any or all of this is naive or if I didn't look for answers using the correct words. This is my first time posting here at Stack Overflow, and I'm looking forward to hearing from you guys.
Thanks!
p
Edit:
This is applied to a custom UIButton based control to give the appearance of a card.
Edit 2: Wain seems to have suggested a perfect answer. I will try it and let everyone know the results.
I'd use tiling as you describe, and I'd combine that with changing the view layer corner radius and applying a shadow offset. In this way you can separate the important part of the image and make it nicely reusable and you can leverage the capability of CALayer.
Note that when you set the shadowOffset of the layer you should also look at the shadowColor, shadowRadius and shadowOpacity.
You can used Assets.xcassets for managing images in ios. you can make image in 1x,2x and 3x scale.
For example you want an icon of size 50x50 pixel then 1x should be 50x50,
2x should be 100x100 and 3x should be 150x150. then ios automatically take appropriate image from this set.
Hope this will help :)
The aspect ration of iPhone 5, iPhone 6 and iPhone 6P are almost same. however the aspect ration of iPhone 4 is different.
Here is the steps which helps you.
So you need one image which image is suitable for iPhone 5 and its
#2x, and #3x image and iPhone 4 and its #2x image,
i.e if you have image with 242x383 for iPhone 5 then you need images
with its #2x, and #3x images. and you need image which is compatible
with iPhone 4 size.
You need to set UIImageView's contentMode as aspectFit.
So the idea is, make iPhone 5's image and its #2x, #3x images and iPhone 4's image differently. or you can put all things in UIScrollView and for iPhone 4 set contentSize of scrollView is 568. and make different image for iPad.
As of yesterday I had an app using mostly static sizes to fit an iphone 5 screen (320 points width). It was working fine in iphone 6 as well thanks to the system scaling up automatically.
Then I decided to add a retina hd launch image and everything became a lot smaller on iphone 6. So I decided to modify my whole application to use dynamic sizes and fonts so that it would fit the two iphone types the same way. And now it is working quite good.
But after these few hours of extra work, I keep asking myself the same question... what was the point? Why would you want to use dynamic sizes that fit both iphones when you can make it work for iphone 5 and let the system scale up automatically?
the use is: more screen estate. You can fit more on the screen.. at the least images or maps could be bigger while buttons retain there size -- they normally don't need to be bigger :) same for the keyboard.
you don't just get everything scaled but you can decide what is scaled and what isnt
I am trying to figure out how to use the xcassets folder in Xcode 6 and I have to say Apple could have done a way better job. I'm a big fan of Xcode but their images storage per type of screen / phone is a nightmare.
First, in my application I am using images which will have a height of half their width. From what I understood, taking pictures of around 1200x600px should do for all types of iphones (full width minus small margin). So I put them in 3x universal, right? If I gave the maximum size why would apple need 1x and 2x ...? Just resize it yourself, no? Is it compulsory for me to give something or will it work by itself? Images are not vector but simple PNGs. In the simulator nothing is complaining and it works well for all types of iphones. Is it okay to leave the other two empty? From I see from the simulator iphone 6 will use downsized #3x images so what is the point of having two images? Only ratio is important and they have the same ...
Secondly, I just added today a launch screen for retina hd 5.5 / 4.7 and now when I run the app in the simulator my uitableviews only take around 4/5 of the full width instead of full width .... can't figure out why adding a launch screen would modify layout of my uitableviews ....? Navigation bar and other screens seem untouched though ...
Any help appreciated.
you need to add the images for the 2x & 3x because when you add large size image then at the run time this image get resize as per the actual width of the image it utilize memory lots of memory to do this & some time if your application have too many images then you will get memory issues
if you want to test this then run your application in iPhone 5 then see the memory utilisation by first keeping the high resolution image now take image which will be of appropriate size to iPhone 5 & then run again you will see the difference
so the best practice is to use different image for different size & not images in this fashion.
The answer to your second Question
if you are not adding the splash screen for iPhone 6/6+ then iOS stretches your UI of iphone 5 to fit into the size of the iPhone 6/6+.
But when you add splash screen it stops doing that.
late to the party but yes you need to manage all this resolution by yourself. Otherwise it will consume more memory.
but yes there is one tool which will make your work less by generating all assets for you
AVXCassets Generator
I'm targeting iOS8 to release an application. So it'll be available on 4S, 5's, 6, 6+, and iPad 2+.
I have a ViewController where, I present a UIImageView that is the entire size of my UIViewController's View.
My question is... what sizes do I need the image in. Am I going to need it in a special size for each device? Or does the 4s/5/6 all use the same ratios for example, while the 6+ has its own unique ratio? Or do I just use 1 image size and let it auto scale it (or will that stretch/skew the image)?
Also, what's the minimal size the image should be? If it's smaller than the native size of the iPhone 6+ for example, won't the quality of the image deteriorate?
In iOS8, you can use different size classes for different screens
use this post to begin.
Also refer this for more info about using different graphics for varying resolution.
The image in Imageview in 4s/5/6 devices render at #2x while that in 6+ it renders at #3x.So take an image and name it as Demo#2x.png and other image for 6+ having higher resolution , name it as Demo#3x.png.So When the image is placed in imageview , It will automatically takes Demo#2x.png for 4s/5/6 and Demo#3x.png for 6+.
you need special size for each device by using image.xcassets.And this will help you alot -
https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/MobileHIG/IconMatrix.html
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+.