Xcode 5 & Asset Catalog: How to reference the LaunchImage?

Question

I am using Xcode 5\'s Asset Catalog, and I would like to use my LaunchImage as the background image of my home view (a pretty common practice to make the transi

Answer 1

One can easily access Launch image by one line of code.

 UIImage *myAppsLaunchImage = [UIImage launchImage];

Please follow steps given below to achieve functionality depicted above.

Step 1. Extend UIImage class by creating a category & add following method to it.

+ (UIImage *)launchImage {
    NSDictionary *dOfLaunchImage = [NSDictionary dictionaryWithObjectsAndKeys:
                                    @"LaunchImage-568h@2x.png",@"568,320,2,8,p", // ios 8 - iphone 5 - portrait
                                    @"LaunchImage-568h@2x.png",@"568,320,2,8,l", // ios 8 - iphone 5 - landscape
                                    @"LaunchImage-700-568h@2x.png",@"568,320,2,7,p", // ios 7 - iphone 5 - portrait
                                    @"LaunchImage-700-568h@2x.png",@"568,320,2,7,l", // ios 7 - iphone 5 - landscape
                                    @"LaunchImage-700-Landscape@2x~ipad.png",@"1024,768,2,7,l", // ios 7 - ipad retina - landscape
                                    @"LaunchImage-700-Landscape~ipad.png",@"1024,768,1,7,l", // ios 7 - ipad regular - landscape
                                    @"LaunchImage-700-Portrait@2x~ipad.png",@"1024,768,2,7,p", // ios 7 - ipad retina - portrait
                                    @"LaunchImage-700-Portrait~ipad.png",@"1024,768,1,7,p", // ios 7 - ipad regular - portrait
                                    @"LaunchImage-700@2x.png",@"480,320,2,7,p", // ios 7 - iphone 4/4s retina - portrait
                                    @"LaunchImage-700@2x.png",@"480,320,2,7,l", // ios 7 - iphone 4/4s retina - landscape
                                    @"LaunchImage-Landscape@2x~ipad.png",@"1024,768,2,8,l", // ios 8 - ipad retina - landscape
                                    @"LaunchImage-Landscape~ipad.png",@"1024,768,1,8,l", // ios 8 - ipad regular - landscape
                                    @"LaunchImage-Portrait@2x~ipad.png",@"1024,768,2,8,p", // ios 8 - ipad retina - portrait
                                    @"LaunchImage-Portrait~ipad.png",@"1024,768,1,8,l", // ios 8 - ipad regular - portrait
                                    @"LaunchImage.png",@"480,320,1,7,p", // ios 6 - iphone 3g/3gs - portrait
                                    @"LaunchImage.png",@"480,320,1,7,l", // ios 6 - iphone 3g/3gs - landscape
                                    @"LaunchImage@2x.png",@"480,320,2,8,p", // ios 6,7,8 - iphone 4/4s - portrait
                                    @"LaunchImage@2x.png",@"480,320,2,8,l", // ios 6,7,8 - iphone 4/4s - landscape
                                    @"LaunchImage-800-667h@2x.png",@"667,375,2,8,p", // ios 8 - iphone 6 - portrait
                                    @"LaunchImage-800-667h@2x.png",@"667,375,2,8,l", // ios 8 - iphone 6 - landscape
                                    @"LaunchImage-800-Portrait-736h@3x.png",@"736,414,3,8,p", // ios 8 - iphone 6 plus - portrait
                                    @"LaunchImage-800-Landscape-736h@3x.png",@"736,414,3,8,l", // ios 8 - iphone 6 plus - landscape
                                    nil];
    NSInteger width = ([UIScreen mainScreen].bounds.size.width>[UIScreen mainScreen].bounds.size.height)?[UIScreen mainScreen].bounds.size.width:[UIScreen mainScreen].bounds.size.height;
    NSInteger height = ([UIScreen mainScreen].bounds.size.width>[UIScreen mainScreen].bounds.size.height)?[UIScreen mainScreen].bounds.size.height:[UIScreen mainScreen].bounds.size.width;
    NSInteger os = [[[[[UIDevice currentDevice] systemVersion] componentsSeparatedByString:@"."] objectAtIndex:0] integerValue];
    NSString *strOrientation = UIDeviceOrientationIsLandscape([[UIDevice currentDevice] orientation])?@"l":@"p";
    NSString *strImageName = [NSString stringWithFormat:@"%li,%li,%li,%li,%@",width,height,(NSInteger)[UIScreen mainScreen].scale,os,strOrientation];
    UIImage *imageToReturn = [UIImage imageNamed:[dOfLaunchImage valueForKey:strImageName]];
    if([strOrientation isEqualToString:@"l"] && [strImageName rangeOfString:@"Landscape"].length==0) {
        imageToReturn = [UIImage rotate:imageToReturn orientation:UIImageOrientationRight];
    }
    return imageToReturn;
}

Step 2. Above method should be working by adding following code also into same category of UIImage

static inline double radians (double degrees) {return degrees * M_PI/180;}

+ (UIImage *)rotate:(UIImage*)src orientation:(UIImageOrientation) orientation {
    UIGraphicsBeginImageContext(src.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    if (orientation == UIImageOrientationRight) {
        CGContextRotateCTM (context, radians(90));
    } else if (orientation == UIImageOrientationLeft) {
        CGContextRotateCTM (context, radians(-90));
    } else if (orientation == UIImageOrientationDown) {
        // NOTHING
    } else if (orientation == UIImageOrientationUp) {
        CGContextRotateCTM (context, radians(90));
    }
    [src drawAtPoint:CGPointMake(0, 0)];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

Answer 2

The LaunchImages are special, and aren't actually an asset catalog on the device. If you look using iFunBox/iExplorer/etc (or on the simulator, or in the build directory) you can see the final names, and then write code to use them - eg. for an iOS7-only iPhone-only project, this will set the right launch image:

NSString *launchImage;
if  ((UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) &&
     ([UIScreen mainScreen].bounds.size.height > 480.0f)) {
    launchImage = @"LaunchImage-700-568h";
} else {
    launchImage = @"LaunchImage-700";
}

[self.launchImageView setImage:[UIImage imageNamed:launchImage]];

I put this into viewDidLoad.

This isn't really ideal, it would be great if Apple would give us a nice API to do this.

Answer 3

@codeman's answer updated for Swift 1.2:

func splashImageForOrientation(orientation: UIInterfaceOrientation, size: CGSize) -> String? {
    var viewSize        = size
    var viewOrientation = "Portrait"

    if UIInterfaceOrientationIsLandscape(orientation) {
        viewSize        = CGSizeMake(size.height, size.width)
        viewOrientation = "Landscape"
    }

    if let imagesDict = NSBundle.mainBundle().infoDictionary as? [String: AnyObject] {
        if let imagesArray = imagesDict["UILaunchImages"] as? [[String: String]] {
            for dict in imagesArray {
                if let sizeString = dict["UILaunchImageSize"], let imageOrientation = dict["UILaunchImageOrientation"] {
                    let imageSize = CGSizeFromString(sizeString)
                    if CGSizeEqualToSize(imageSize, viewSize) && viewOrientation == imageOrientation {
                        if let imageName = dict["UILaunchImageName"] {
                            return imageName
                        }
                    }
                }
            }
        }
    }

    return nil

}

To call it, and to support rotation for iOS 8:

override func viewWillAppear(animated: Bool) {
    if let img = splashImageForOrientation(UIApplication.sharedApplication().statusBarOrientation, size: self.view.bounds.size) {
        backgroundImage.image = UIImage(named: img)
    }
}

override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
    let orientation = size.height > size.width ? UIInterfaceOrientation.Portrait : UIInterfaceOrientation.LandscapeLeft

    if let img = splashImageForOrientation(orientation, size: size) {
        backgroundImage.image = UIImage(named: img)
    }

}

Just what I needed, thanks!

Answer 4

My app currently only supports iOS 7 and later.

This is how I reference the launch image from the asset catalog:

NSDictionary *dict = @{@"320x480" : @"LaunchImage-700",
                       @"320x568" : @"LaunchImage-700-568h",
                       @"375x667" : @"LaunchImage-800-667h",
                       @"414x736" : @"LaunchImage-800-Portrait-736h"};
NSString *key = [NSString stringWithFormat:@"%dx%d",
    (int)[UIScreen mainScreen].bounds.size.width,
    (int)[UIScreen mainScreen].bounds.size.height];
UIImage *launchImage = [UIImage imageNamed:dict[key]];

You can add more key value pairs if you want to support older iOS versions.

Answer 5

- (NSString *)splashImageNameForOrientation:(UIInterfaceOrientation)orientation {
    CGSize viewSize = self.view.bounds.size;
    NSString* viewOrientation = @"Portrait";
    if (UIDeviceOrientationIsLandscape(orientation)) {
        viewSize = CGSizeMake(viewSize.height, viewSize.width);
        viewOrientation = @"Landscape";
    }

    NSArray* imagesDict = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];
    for (NSDictionary* dict in imagesDict) {
        CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);
        if (CGSizeEqualToSize(imageSize, viewSize) && [viewOrientation isEqualToString:dict[@"UILaunchImageOrientation"]])
            return dict[@"UILaunchImageName"];
    }
    return nil;
}

Answer 6

Updated to latest Swift syntax (Swift 5)

   func splashImageForOrientation(orientation: UIInterfaceOrientation) -> String? {

    var viewSize = screenSize
    var viewOrientation = "Portrait"
    if orientation.isLandscape {
        viewSize = CGSize(width: viewSize.height, height: viewSize.width)
        viewOrientation = "Landscape"
    }
    if let infoDict = Bundle.main.infoDictionary, let launchImagesArray = infoDict["UILaunchImages"] as? [Any] {
        for launchImage in launchImagesArray {
            if let launchImage = launchImage as? [String: Any], let nameString = launchImage["UILaunchImageName"] as? String, let sizeString = launchImage["UILaunchImageSize"] as? String, let orientationString = launchImage["UILaunchImageOrientation"] as? String {
                let imageSize = NSCoder.cgSize(for: sizeString)
                if imageSize.equalTo(viewSize) && viewOrientation == orientationString {
                    return nameString
                }
            }
        }
    }
    return nil
}