iOS dark mode - image assets not redrawn - ios

I'm implementing the dark mode for iOS. The problem occurs with the images:
I've opened the Assets.xcassets and changed the "appearances" "to Any, Dark"
Of course I've added the new image.
Unfortunately the images are not being redrawn when overriding the environment interface style in xcode.
I've tried catching the traitCollectionDidChange method in my viewController and it is properly called. I could set the new image (origImage_dark), but shouldn't it be automatic? That's what the asset settings are made for. I'm using the .alwaysOriginal rendering of the image.

Running the app with dynamic resolve of the image helped:
let image = UIImage(named: "someImage")
let asset = image?.imageAsset
let resolvedImage = asset?.image(with: traitCollection)
After this, reverting back to the original way of setting the images seemed to work. Xcode, thanks a lot!

Related

Using PDFs for icon images in Xcode 7.2

I'm attempting to use PDF files as icons in an app I'm working on. The issue I'm encountering is I'm getting inconsistent tint colors.
If I set a button image from interface builder, the icon image shows up black at runtime. Every time. Regardless of what I attempt to set from interface builder.
I tried setting my button icon image via code and instead of showing up black, it's white:
let myGraphicFile = UIImage(named: "myPDFImage")
let myButtonImage = myGraphicFile?.imageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate)
myButton.setImage(myButtonImage, forState: .Normal)
From code, regardless of what I attempt to set the tint to, it's always white from code.
I discovered this post relating to Xcode 6.x, but I think it might be dated, as I'm able to partially do it, but I can't set the tint.
Use PDF in XCode for an AppIcon (.appiconset collection)
I create the icons in Inkscape, save as PDF 1.5. I add the file to Images.xcassets. In Images.xcassets' attributes inspector, I'm setting:
Devices to Universal
Scale factor to Single Vector.
Summary: I can get it to show up and scale properly, but it's either black from interface builder or white from code. I suspect I'm missing something re: how to save the file from Inkscape.
Thank you for reading. If you have any suggestions, I welcome them.
I have figured out how to create vector icons with Inkscape. When you use PDFs to display icons in iOS, you need to alter the Attributes Inspector for your icon in xcAssets as follows:
1) Drag the PDF into xcAssets
2) Set devices (I did Universal and it worked fine)
3) If your PDF icon is under 1x, 2x, or 3x size class, drag it to Universal and delete the rest of them.
4) Set Scale Factors to Single Vector.
5) Render as Template Image.
Once it's configured there, then you just treat it was you would any other image in interface builder. It's essentially the same thing I was doing in code, but I don't think it gets done in code...it's gotta be done on xcAssets where the image lives. It's my understanding iOS renders vector images for the size class at run time. I think by attempting to tweak it in code wasn't working because the image had already been rendered.
If anyone has any questions on this, I found this link helpful in resolving my issue.
Additionally, this post covers the topic, too. https://stackoverflow.com/a/25804358/4475605

Image copied to clipboard is cropped when pasted

I'm building a keyboard extension in Swift (Xcode 7.0.1, iOS 9.0.2). Since images cannot be directly inserted into the text field, I'm using UIPasteboard to copy the image from the app and then the user would paste manually into the text field. I have already modified info.plist to give the app full permission. I initially tried
UIPasteboard.generalPasteboard().image = UIImage(named: "1.png")
but I would receive the error
changing property masksToBounds in transform-only layer, will have no effect
I wasn't able to find anything to fix this error and nothing would be pasted into the clipboard. I then tried
let image = UIImage(named: "1.png")
let data = NSData(data: UIImagePNGRepresentation(image!)!)
UIPasteboard.generalPasteboard().setData(data, forPasteboardType: "public.png")
This works perfectly for larger images, but smaller images are cropped on the right side.
1) Is there a way to programmatically resize the image as a UIImage before I send it to NSData?
2) Has anyone else experienced this issue or know why it's occurring? I'd ideally like the photos being pasted to be small but this is obviously problematic.
Thanks.
I haven't found a proper solution, but adding some transparent padding to the right edge of the image is an effective workaround.

iOS App Issue - Can't access image from image asset catalog

I'm new to iOS development, so apologies for advance. I know this has been covered earlier but I can't seem to find anything that helps with my issue.
Its a fairly simple but annoying issue.
I have a image in assets with a file name of hollwood.png but a xcode name, "hollywood" (no png).
I am trying to set a UIImageView to display it.
So in ViewDidLoad I have the following: (imageContainer is the UIImageView IBOutlet)
- (void)viewDidLoad {
super viewDidLoad];
self.model = [Model sharedModel];
self.imageContainer.image = [UIImage imageNamed:#"hollywood"];
}
I can not get it to display the image from Assets.
I know the UIImageView outlet works correctly because I can have the app choose a photo from gallery and set the photo to UIImageView.
I'm having a very difficult time figuring out how to load the image I saved in the assets catalog into UIImageView.
I just had this issue. I had dragged the image and for some reason Xcode added a weird "Design" locale and I couldn't load the image using UIImage(named: ). I don't know if this is your case, but you can try right clicking on the image in the Asset Catalog, "Show in Finder", opening the folder and checking the "Contents.json" file. Each image there should only have the keys "idiom", "filename" and "scale".
Make sure your image is added in Compile Sources
AppTarget->Build Phases-> Compile Sources
If not try to add that and check.

Programatically Set UIImage Animation with WatchKit

I can't seem to figure out how to programmatically set a new image, via the outlet, and make it start animating.
Sequence
zeroEntering0.png
zeroEntering1.png
zeroEntering2.png
zeroEntering3.png
zeroEntering4.png
I imported the sequence of images into the Image.xcassets inside the WatchKit App
I can set the image in the interface builder to "zeroEntering" and set animating to "Yes" and it works correctly.
However, I want something more dynamic, I need a button press to choose a new animation sequence and start it off. If I try and set the image programmatically using the same name from the interface builder, the UIImage is nil.
What naming convention should I use when programmatically setting the UIImage? "zeroEntering", "zeroEntering0", "zeroEntering.png" or "zeroEntering0.png"
I tried using the two non-nil options and the image did not animate and went black.
The answer is subtle and definitely got my wheels spinning for too long.
According to this beautiful article,
You should use setImageNamed(:) when the image you want to display is either cached on the watch on is in an asset catalog in the watch app’s bundle, and use setImage(:) when the image isn’t cached — this will transfer the image data to the Apple Watch over the air!
So, I kept my images in the assets catalog on the watch app, and switch to use,
[self.testImage setImageNamed:#"zeroEntering"];
[self.testImage startAnimatingWithImagesInRange:NSMakeRange(0, 4) duration:0.2 repeatCount:100];
Set the image as [UIImage imageNamed:#"entering"] then call startAnimatingWithImagesInRange:duration:repeatCount:
Check it out here: https://developer.apple.com/library/prerelease/ios/documentation/WatchKit/Reference/WKInterfaceImage_class/#//apple_ref/occ/instm/WKInterfaceImage/startAnimatingWithImagesInRange:duration:repeatCount:
Make sure to follow the tips here: https://developer.apple.com/watchkit/tips/

UIImage imageNamed returns nil

I am pretty new to iOS and Xcode.
I tried to load an image with
[UIImage imageNamed:#"imageName.png/jpg and so on"];
but it only returns nil. The image should be in my project bundle, considering the fact that I can choose it from drag and drop menus in the InterfaceBuilder and it was added to Xcode via the "Add files to "projectname"..." menu.
It makes no difference whether I use .png or .jpg images, the result stays the same: they work via IB but not if I try to run the imageNamed method myself.
There are only a few reasons why an image would come back nil with imageNamed:
The image is not in your bundle. Make sure the image is actually in your project. Make sure the target is checked by clicking on the file and selecting the target it belongs to.
You have the image name spelled incorrectly or a problem with the extension.
You are using a retina display but do not have an #2x image. Try changing your simulator to retina and see if it shows up.
If you are using an asset catalog make sure you have the correct devices selected in the attribute inspector.
Some tips:
If you are testing using simulator delete the app off of your simulator and clean your project, then re-run. If it still shows up it should show up on your phone (if it doesn't it's probably an issue with the case of the filename or the #2x version).
If you are testing on your phone and it doesn't show up, make sure you are using the same version of the simulator (if you have an iPhone 4/4s make sure to use the 4/4s simulator with retina).
One last thing according to this post: JPG image doesn't load with UIImage imageNamed There is some issue with certain JPG types working with imageNamed and no extension. IMO, you should be using PNGs anyway since iOS compresses them for you, unless you just have to use JPG.
Re Mike Weller's comment. The checkbox is ....
If you verified all of the above and are finding that your UIImage(named: "myImage") returns nil from code inside of a dynamic framework you are building, then you have to change the code to:
UIImage(named: "myImage", in: Bundle(identifier: "com.myframework.name"), compatibleWith: nil)
This should retrieve the asset from CXAssets correctly.
In my case, the PNG was malformed.
For some reason Xcode preview shown it correctly, but when I tried loading it with UIImage, it returned nil.
I just had this issue for jpg files named on disk "file.jpg"
I was trying to load without the extension, just #"file". While this works fine for pngs, it does not for jpg. Once I used #"file.jpg", it worked!
Swift 5
If you get UIImage nil in dynamic framework, you should set image with bundle identifier.
You can create an extension to Bundle like this;
Create an extension;
extension Bundle {
public static let myFramework = Bundle(identifier: "com.myFramework.bundle")
}
Then you can use like this;
UIImage(named: "myImageName", in: Bundle.myFramework, compatibleWith: nil)
Or
You can use like this;
UIImage(named: "myImageName", in: Bundle(for: type(of: self)), compatibleWith: nil)
I think the first one is more useful because it's more readable than second one.
Try re-exporting your image.
I had a similar problem, UIImage imageNamed was returning nil and none of these answers fixed my problem.
I found out that it was actually something wrong with the png file. I opened the file in GIMP image editor, saved it as a new file, exported it again as png and magically it started working.
I didn't change anything in code at all so there was definitely something wrong with the actual image file.
try
[UIImage imageNamed:#"imageName.png"];
instead (with an extension)
I had the same problem: #"photo.jpg" resulted in 'nil' UIImage.
Changing to the "actual" filespec, #"photo.JPG" works fine!
I hadn't realized there was case-sensitivity there! VERY non-intuitive.
i had a similar issue, finally the cleanup fixed it: the image showed up in the simulator, but id did not show up when running the app on the iPhone.
What I did:
1) deleted the app from the iPhone
2) performed Product/Clean
after that the bug was fixed and the image showed up!
Try to use UIImage(contentsOfFile:) instead of imageNamed. It worked for me with downloaded images.
Check that file has no space at the end.
The name like name #2x.png will fail loading, but name#2x.png is fine
Does the image work on the simulator but not on the device?
If so, in this scenario it is always to do with the case of the name. The device requires exact case and the simulator is not so fussy if I remember correctly.
e.g. for an image named image.png
[UIImage imageNamed:#"Image"];
would work on the simulator but not on the device...
Make sure you have the image for the DEVICE you are using in your .xcassets file. An image flagged for iPad won't show up on the phone (or the simulated phone).
In addition to #Inturbidus's answer:
For those who came here working on Application Extensions:
The image you are working with should belongs to both targets - hosted app and extension.
In other case you'll always getting nil trying to access it from within the extension's code.
For Xcode 6.4, click on Images.xcassets and check whether there are entries for each image that you called. You may right-click on the image and select "Show in Finder" to check if the images are the correct ones added.
Make sure the Attributes Inspector name field of the image matches exactly the name you're using. In my case the image was part of a folder and so the image name was "folder/name". Using this long name solved the problem. XCode 7.3.1
In my case, using a name with accented characters proved to be a poor idea. I changed Astéroïdes to Asteroids and it worked fine.
In my case problem was with image name in asset catalog.
For example if you have image with name "TEst" and change name to "Test", changes won't be indexed. If your teammate will pull commit with this changes, image in his asset catalog will have previous name "TEst".
Very small chance to catch this situation but it's possible.
I had multiple .xcassets in my projects and 2 had duplicate name of images. So it was not loading the image in my case.

Resources