Update: See this answer below for Swift 4 / iOS 11 which is much, much easier Here’s a quick Swift 3 extension you can use to do rounding and optional borders. Note: if you’re using autolayout, you may need to call this in one of the view lifecycle callbacks like viewDidLayoutSubviews or layoutSubviews after the … Read more
You can use CGContextSetFillColorWithColor and CGContextFillRect for this: Swift extension UIImage { class func image(with color: UIColor) -> UIImage { let rect = CGRectMake(0.0, 0.0, 1.0, 1.0) UIGraphicsBeginImageContext(rect.size) let context = UIGraphicsGetCurrentContext() CGContextSetFillColorWithColor(context, color.CGColor) CGContextFillRect(context, rect) let image = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() return image } } Swift3 extension UIImage { class func image(with color: UIColor) -> … Read more
The code below is also a solution that detects the piece of the picture that was tapped on. The idea is to take a UIImage and use CGImageCreateWithImageInRect to crop out pieces. From the cropped piece create a new UIImage and place it in a UIImageView. In order to get the tap gesture to work … Read more
A rotation of angle a around the point (x,y) corresponds to the affine transformation: CGAffineTransform transform = CGAffineTransformMake(cos(a),sin(a),-sin(a),cos(a),x-x*cos(a)+y*sin(a),y-x*sin(a)-y*cos(a)); You may need to plug in -a instead of a depending on whether you want the rotation to be clockwise or counterclockwise. Also, you may need to plug in -y instead of y depending on whether or … Read more
You can set an environmental variable via this menu: Product -> Scheme -> Edit Scheme. Under the “Run” item, locate the “Arguments” tab, you’ll see “Environmental Variables” in the tab, Add CG_CONTEXT_SHOW_BACKTRACE and set its value to YES.
You can rotate a view, by some number of radians, regardless of whether it is less than a full rotation or many multiples of a full rotation, without having to split the rotation into pieces. As an example, the following code will spin a view, once per second, for a specified number of seconds. You … Read more
This took quite a while to figure out, mainly because I wanted to get it up and running in Swift using Core Image and CIColorCube. @Miguel’s explanation is spot on about the way you need to replace a “Hue angle range” with another “Hue angle range”. You can read his post above for details on … Read more
I’ve found a better method that uses the snapshot API whenever possible. I hope it helps. class func screenshot() -> UIImage { var imageSize = CGSize.zero let orientation = UIApplication.shared.statusBarOrientation if UIInterfaceOrientationIsPortrait(orientation) { imageSize = UIScreen.main.bounds.size } else { imageSize = CGSize(width: UIScreen.main.bounds.size.height, height: UIScreen.main.bounds.size.width) } UIGraphicsBeginImageContextWithOptions(imageSize, false, 0) for window in UIApplication.shared.windows { window.drawHierarchy(in: … Read more
If I understand your question correctly, there is a simple solution to this. During your long-running routine you need to tell the current runloop to process for a single iteration (or more, of the runloop) at certain points in your own processing. e.g, when you want to update the display. Any views with dirty update … Read more
There are many parts to your question. Getting the path Creating the path for such a segment shouldn’t be too hard. There are two arcs and two straight lines. I’ve previously explained how you can break down a path like that so I won’t do it here. Instead I’m going to be fancy and create … Read more