If you play the game, you'll see that once we miss the ball, it goes off the screen and, well, then nothing happens.
We want the miss to be detected, and then for a new ball to be placed in the center so we can continue.
Let's do that.
In the previous article, we set up the visible elements of pong and the basic physics that governs the movement of the ball.
At the end of the article, we had the ball bouncing off the walls and paddle and moving in a gravity-free, drag-free environment.
The next thing we'll tackle is letting the players move the paddles.
When you are creating and analyzing vectors in SpriteKit, it's useful to think of them as an angle and a length, not just as a
(dx, dy) pair.
Here is an extension that helps you do that.
Each node we create in the scene can optionally have a
physicsBody associated with it. If it does, then it will have velocity and acceleration and forces, like collisions and gravity, will have an effect on them.
There are some common patterns, so it's useful to extend
SKPhysicsBody. Here are two functions that are meant to be used when you create a physics body.
In a typical iOS app, you build your screens either with UIKit's
UIView and possibly storyboards or you might try SwiftUI and build out a
View based on an
Those kinds of apps often have scrollable lists of data, forms, tabs, or hierarchical navigation suitable for a to do list or an email client.
But games are something very different.
The user's running distance, heart rate, and calories expended are only available if you get permission beforehand. You also need permission to save Workouts in HealthKit so that they will show up in the Fitness app or be readable by other apps.
In this article we'll learn how to animate a countdown by manipulating how we set
countdown. The built-in animations won't work because we can't get them to change text along with the ring, so we'll to do something a little more manual.
Making a countdown animation for your workout app is really not that different than any other SwiftUI based animation you might do.
But, we have to start somewhere
If you are targeting watchOS 6, and you have several possible root views, then you define each in a Storyboard and you need to navigate between them outside of SwiftUI.
On the Apple Watch, it's possible to have a set of screens that are peers to each other. You get to each page with left and right swipes. The bottom of the screen has a dot for each page in the set, with the current one lit up.
NavigationLink has built in functionality to manage the presentation and dismissal of the subview, and automatically puts a back button on the screen for you.
But, sometimes, there is a reason to send the user back to the calling view based on other things they do. In UIKit, we'd call
dismiss, but in SwiftUI, we don't call methods on views to change them, we change state and let the view get re-rendered.
In iOS, we use
UINavigationViewController from UIKit to create a hierarchical navigation structure. Using it, we can push views onto the view controller stack, and we automatically get a back button to take us back.
UIKit and this class are not available to Apple watch developers, and so before SwiftUI, watch app developers used
pushController method and Storyboards.
Luckily, this is easier in SwiftUI.
In the last article, we drew the initial state of the the Breathe app. Now let's learn how to animate it.
If you already tried out SwiftUI on the iPhone, most of what you know works the same on the watch. If you haven't, here are simple recreations of user interfaces in two of the built-in Apple Watch apps.
This tutorial will use Xcode to make a minimal Apple Watch app. But, before you move on, it's a good idea to understand what it did so that you'll know how to add to it later.
Xcode 12 and watchOS 7 are not perfect, but they are much better than their immediate predecessors and I would say are about as capable as pre-SwiftUI WatchKit. I am confident that adopting this for any new Apple Watch app is the right decision.
At this point, you should have read Subscripts in The Swift Programming Language. You should have a Playground page for this chapter with code in it that you generated while reading the book.
We've covered the basics up to functions, and now I'll provide exercises that review topics from all of those chapters.
The intended audience for this guide are people that don't know Swift and possibly don't know any other programming language.
When you make GUI tests using XCUI directly in Xcode, it will automatically build the app for you when you run the test. Appium, however, is run completely outside of Xcode, so you must supply a build for it.
If you are considering Appium or any other GUI testing framework for iOS, like XCUI Tests, then the first thing you should do is start using accessibility identifiers. Without them, your test scripts will be much more brittle.