Top-notch video tutorials for Swift developers

We learn how to convert a CMSampleBuffer into a CIImage and how to set up our CIDetector to detect rectangles. We then draw a box around the detected rectangle and discuss why adding simple subviews won't work with full screen sublayers.

We set up the preview layer so we can see the video, then we add a sample buffer queue so we can get access to the individual frames of the video coming through the capture session.

We start by setting up the project to take photos. We start by disabling rotation, which is typical of a camera app. We then add the appropriate Info.plist entry so that we can inform the user why we need camera access. We organize the view controller intro sections to keep things tidy as we add code to the project. Finally we setup the camera capture session, which is the first step to capturing video from the camera.

In this introductory episode I show the finished version of the application we will be building in this series.

Core Graphics is a cross-platform technology, but there are some gotchas to consider when working on mac apps with AppKit. Sam will go over some of these differences to help you avoid some common pitfalls.

In this episode we’ll learn how to draw images with core graphics, then watermark a photo by drawing text overlaid on top of it.

In this episode we’ll leverage what we've learned to create a reusable control that will show progress as a path outlining a circle, complete with animation.

In this video we’ll learn how to use custom drawing with CALayers to support implicit animations.

Occasionally you will want to do some custom drawing, but not have that presented directly on the screen. Sometimes this is to "bake" the drawing into an image for faster scrolling performance (a single flattened image can be sent to the GPU easily without having to composite a bunch of views together). This is also often used to resize images that are too large for the intended view. This episode covers drawing to a custom context offscreen and obtaining an image out of it.

In this episode, Sam shows how to draw text using Core Graphics. With this technique you can easily add text to images for pre-rendering, a technique we will see in another episode in this series.

Sam shows how to use Core Graphics to draw images, which you might want to do if you want to blend techniques we’ve seen so far, such as clipping paths or gradients. Drawing images with Core Graphics is also useful to resize images if needed (perhaps if the API is returning one that is too large and you want to cache a thumbnail on device). You’ll also learn about a handy function to help you with aspect ratio math!

Transforms allow you to draw things rotated, moved, or scaled differently than you specified. You can use this technique to reuse drawing operations where they only differ by some small factor (like drawing lines on a graph), to tilt things like text, or to correct issues where the drawn element is upside down or sideways. In this episode, Sam shares a helpful technique of drawing a grid with a highlighted "origin square" to make it obvious what the transforms are doing.

Clipping paths allow you to control where drawing occurs by providing a path in which to limit future drawing operations. Since you can create arbitrary shapes with CGMutablePath (and UIBezierPath) this can be an essential technique to get the drawing effect in some situations.

Gradients are slowly returning to be part of the common iOS design aesthetic once again (after iOS 7 introduced an entirely flat design paradigm). Subtle gradients can be used to create interesting designs, provide necessary contrast for drawing text on top of photos, and provide a realistic feel to custom controls. Learn how to create linear and radial gradients, how to define custom locations to control the position and "shape" of the gradient.

What are color spaces? Sam discusses the common color spaces you might use and what they are used for. Why would you use these methods instead of just using UIColor? If you want cross-platform compatible drawing code, you’ll want to know how this works.

Learn the basics of UIBezierPath and CGPathRef for representing drawing operations as a primitive type. Paths are incredibly useful to drawing and can be used to represent arbitrary lines, curves, and shapes.

Learn how to create basic shapes using Core Graphics. We’ll start by creating a playground that we can use to quickly see the results of our work.

Sam introduces the new series on Core Graphics, what to expect, and what the series covers.

We tackle some more complex (read: realistic) scenarios where the JSON structure doesn’t quite match the structure of the objects. We’ll do this by providing custom implementations of Encodable and Decodable, talk about keyed and unkeyed containers, and how you might be able to transform the date during the encoding process

Swift 4 finally answers the long-debated question of: How should I parse JSON with Swift? In this episode we'll take a look at the new Codable protocol in Swift 4, and talk about how to use JSONEncoder and JSONDecoder to serialize your objects into JSON and back again.

We finish the CloudKitNotesManager by providing a generic save and delete methods that we can use for any CKRecordWrapper type. We also implement a custom notification when a note is saved so that we can update an interested view controllers to update their UI.

In this episode we implement a CloudKit version of our NotesManager protocol. Along the way we'll implement a reusable query function and run into a limitation with Swift generics that we will have to work around.

Since our model objects will be backed by a CKRecord, we will leverage computed properties to marshal values back and forth to the record. Doing so in a type safe way gets pretty redundant, so we can reuse a lot of this boilerplate code by extracting a protocol we’ll call CKRecordWrapper. We can leverage this protocol to give us type-safe access to record keys and to provide default implementations of identifier, modifiedAt, and createdAt fields.

So far in this series we've been using CloudKit directly from our controllers. This can be somewhat limiting. It requires you to be online or everything fails, we may want to add a caching layer, or we might want to use CloudKit as a network synchronization layer, rather than a primary data store. In this episode we'll examine an architecture that will allow you to decouple your view controllers from CloudKit as a first step to achieving more flexibility with your CloudKit implementation.