Swift 3 Xcode Playground Code GitHub

JavaScript must be enabled for the tab bar to be functional. The Swift Package Index is an open-source project entirely funded by community donations. The result comes from the multiplication of the two given CGSize structs. The result comes from the subtract of the two given CGSize struct. This method can also be used to correctly space multiple labels horizontally as in this example. I found following changes when I was migrating my code to Swift 2.2 to Swift 3.

• The change from NSIndexPath to IndexPath, on the other hand, is a bit different.
• You can use this layout class out of the box or subclass it to get some interesting behavior and visual effects.
• Users scroll horizontally to see items that don’t fit on the screen.
• Go to Editor ▸ Embed in ▸ Navigation Controller to create a navigation controller and automatically set the collection view controller as the root.

You’ll almost always want to create a subclass to easily access any content subviews you add. You can subclass UICollectionViewLayout to create your own custom layouts, but Apple has graciously provided a basic flow-based layout called UICollectionViewFlowLayout. Elements lay out one after another based on their size, like a grid view. You can use this layout class out of the box or subclass it to get some interesting behavior and visual effects. When you use a table view, you have to set a data source and delegate to provide the data to display and handle events, like row selection. After adding an activity view, you use the Flickr wrapper class to search Flickr asynchronously for photos that match the given search term.

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If you look closely, you’ll notice there are two differences beyond just the first external parameter. But don’t worry, it’s nothing to be ashamed of …yet. But one thing I’ve recently picked up on is that I’m still using ugly non-Swift-like syntax with all my CGGeometry structures. It’s been about a solid eight months since I first decided to jump completely into the Swift wormhole. Over those months I’ve slowly learned to stop writing Objective-C style code patterns with Swift syntax, and started to actually take advantage of the new language. To view the latest developer news, visit News and Updates.

The key to create a clickable UILabel is to enable user interaction. You can download the final project using theDownload Materials button at the top or bottom of this tutorial. You populate the image view with the thumbnail. Obviously, in a production app, you would want to show the user these errors.

Subtracting that from the view’s width and dividing by the number of items in a row gives you the width for each item. You then return the size as a square. With that settled, it’s time to explore the Flickr API classes. Get hands-on experience with UICollectionView by creating your own grid-based photo browsing app using the Flickr API. By Owen L Brown. How do you create an organization that is nimble, flexible and takes a fresh view of team structure?

This method controls the spacing between each line in the layout. You want this spacing to match the padding at the left and right. UICollectionViewFlowLayout also has a delegate protocol, UICollectionViewDelegateFlowLayout.

This process might also be familiar from table views. The data source uses this identifier to dequeue or create new cells. Open Main.storyboard and drag in a Collection View Controller. Go to Editor ▸ Embed in ▸ Navigation Controller to create a navigation controller and automatically set the collection view controller as the root. UICollectionViewCell doesn’t allow for much customization beyond changing the background color.

‘CGSizeMake’ is unavailable in Swift

Just use auto layout to add constraints to pin the left and top sides of the label. You will get source changes to be able to build your project using Swift 3 and take advantage of all the new features in Xcode 8.0. UICollectionView makes adding custom layouts and layout transitions, like those in Photos, simple to build. For example, this is what we saw when we opened up theGoodAsOldPhonesapp from ourSwift course, App Evolution with Swift.

In addition to the visual components described above, a collection view has a layout object responsible for the content’s size, position and other attributes. Although it might not be obvious at first, the renaming of cellForRowAtIndexPath to cellForRowAt is basically the same thing that was happening with the underscores. What’s https://bitcoin-mining.biz/ happening here is that the first parameter passed into the function no longer has an external name. This is really just a minor detail since you don’t call this method directly, and it’s a quick fix to make the compiler happy. You can either manually edit that first parameter name to _, or just let Xcode handle this for you.

When the search completes, you call the completion block with the result set of FlickrPhoto objects and any errors. Now it’s time to fetch Flickr photos to show in the collection view. Conversely, a horizontal flow layout places items from top to bottom across the left edge of the view until it reaches the bottom edge. Users scroll horizontally to see items that don’t fit on the screen. In this tutorial, you’ll stick with the more common Vertical collection view. The change from NSIndexPath to IndexPath, on the other hand, is a bit different.

To a seasoned iOS or OSX developer, with a short glance they could easily tell you what that code is doing. They don’t need argument labels on CGGeometry structures because everyone knows those arguments, and their sequence off by heart. This example shows how a label’s width can automatically resize when the text content changes.

Instance Methods

It lets you tweak the layout’s behavior to configure things like cell spacing, scroll direction and cell size. You can learn more in this Apple documentation. The delegate, UICollectionViewDelegate, gets another notification when events happen, such as when a user selects, highlights or removes a cell. Finally, you refresh the UI to show the new data. You use reloadData(), which works as it does in a table view.

Use the Attributes inspector to set the Reuse Identifier to FlickrCell. A vertical flow layout means the layout class places items from left to right across the top of the view until it reaches the view’s right edge. At which point, it moves down to the next line.

There’s one search per section, so the number of sections is the count of searches. The best way to understand what it does is to start from scratch. Choose How to Start Learning Computer Programming with Pictures iOS ▸ Source ▸ Cocoa Touch Class template and click Next. Name the new class FlickrPhotosViewController, making it a subclass of UICollectionViewController.

UICollectionViewFlowLayoutDelegate

One of the best things about UICollectionView is, like table views, it’s easy to set up collection views in the Storyboard editor visually. You can drag and drop collection views into your view controller and design your cell’s layout from within the Storyboard editor. Unfortunately, you don’t see any photos in your collection view!

These are the keys to creating and maintaining a successful business that will last the test of time. I don’t know about you, but writing that really stressed me out. Creating a newFrame struct from the view’s frame, modifying it, and then resetting the frame property on the view again.

Download the project files by clicking the Download Materials button at the top or bottom of the tutorial. Open the FlickrSearch starter project. You signed out in another tab or window. You signed in with another tab or window. After converting code to latest swift 3.0 I am shown this error. CollectionView.frame.size.width will get the width of the collectionView.

A collection view doesn’t do much unless you implement the relevant data source and delegate methods, similar to a table view. This is a placeholder method to return a blank cell. Note that collection views require you to register a cell with a reuse identifier. A runtime error will occur if you don’t. When the user taps Search after typing in a query, you want the search to execute. You already connected the text field’s delegate outlet to your collection view controller.