Swift

SwiftUI is Apple’s new declarative building framework that actually might forever change the way apps are made. It’s a remarkable piece of engineering which unifies the UI development process and works across all Apple platforms.

One of the features that makes SwiftUI stand out is its ability to create gradient backgrounds. In this article, we will show you how to add horizontal and vertical gradients in SwiftUI.

![gradient backgrounds swiftui](https:&#x2F;&#x2F;devbrite.io&#x2F;media&#x2F;cover17.jpg)
## What Are Gradient Backgrounds?

A gradient background is a gradual change of color that can be used to create a visually appealing effect in any application. Gradients are often used in web design and graphic design, but with SwiftUI, you can now add them to your iOS apps.

## Setting Up Your iOS Environment for SwiftUI

Before we dive into the code, let’s make sure we have our environment set up for SwiftUI development.

First, you need to make sure you have the latest version of Xcode installed. Xcode is Apple’s integrated development environment and can be downloaded from the Mac App Store.

Once Xcode is installed, you can open it and create a new project. Make sure you select the “SwiftUI” option when creating the project.

## Horizontal Gradients in SwiftUI

Let’s start by creating a simple horizontal gradient. To do this, you’ll need to use the LinearGradient view.

The LinearGradient view takes two parameters: the start and end points of the gradient. The start and end points are represented by the UnitPoint structure, which takes two values: a horizontal and a vertical value.

Here’s an example of how you can create a simple horizontal gradient in SwiftUI:

&#96;&#96;&#96;swift
LinearGradient(
    gradient: Gradient(colors: [.red, .blue]),
    startPoint: .leading,
    endPoint: .trailing
)
&#96;&#96;&#96;

The code above creates a simple horizontal gradient that goes from red to blue. The start point is set to &#96;.leading&#96; and the end point is set to &#96;.trailing&#96;, which makes the gradient start at the left side of the view and end at the right side.

## Vertical Gradients in SwiftUI

Creating a vertical gradient in SwiftUI is just as easy as creating a horizontal one. All you have to do is change the start and end points of the gradient.

Here’s an example of how you can create a simple vertical gradient in SwiftUI:

&#96;&#96;&#96;swift
LinearGradient(
    gradient: Gradient(colors: [.red, .blue]),
    startPoint: .top,
    endPoint: .bottom
)
&#96;&#96;&#96;

The code above creates a simple vertical gradient that goes from red to blue. The start point is set to &#96;.top&#96; and the end point is set to &#96;.bottom&#96;, which makes the gradient start at the top of the view and end at the bottom.

## More Gradient Examples in SwiftUI

Here are some more examples of gradients in SwiftUI:

### Diagonal Gradient

&#96;&#96;&#96;swift
LinearGradient(
    gradient: Gradient(colors: [.red, .blue]),
    startPoint: .topLeading,
    endPoint: .bottomTrailing
)
&#96;&#96;&#96;

The code above creates a diagonal gradient that goes from red to blue. The start point is set to &#96;.topLeading&#96; and the end point is set to &#96;.bottomTrailing&#96;, which makes the gradient start at the top left corner of the view and end at the bottom right corner.

### Radial Gradient

&#96;&#96;&#96;swift
RadialGradient(
    gradient: Gradient(colors: [.red, .blue]),
    center: .center,
    startRadius: 10,
    endRadius: 100
)
&#96;&#96;&#96;

The code above creates a radial gradient that goes from red to blue. The center of the gradient is set to &#96;.center&#96;, which makes the gradient start in the center of the view. The start radius is set to 10 and the end radius is set to 100, which makes the gradient start with a small circle and end with a large circle.

## Conclusion

In this article, we showed you how to add gradient backgrounds in SwiftUI. We discussed the different types of gradients, such as horizontal, vertical, diagonal and radial. We also provided code examples for each type of gradient.

Gradients are a great way to add visual interest to your apps, so make sure to give them a try!

How To Add Gradient Backgrounds in SwiftUI

At some point in your Swift work, you&#x27;ll want to set a timer to delay execution of some code, maybe to allow the user time to deliberate before making a decision. Read on as I spill the beans about timers and how to utilize them effectively.

Time&#x27;s up To utilize Swift in your program, you&#x27;ll need to import the Foundations framework, from which it is derived.

import Foundation

The timer functionality in your app is now available for use.

## **Scheduled Timer: The Fundamentals**

The scheduledTimer is the most fundamental use of a timer, requiring just the parameters timeInterval, selection, and repetitions to be specified. The number of seconds since the last function&#x2F;selector call is stored in the timeInterval. When the timer triggers, it invokes the selector as the function&#x2F;action to take. Last but not least, repeats is a boolean variable that determines whether or not the timer should be repeated or fired just once.

Declaring a timer as Basic:

&#96;&#96;&#96;javascript
&#x2F;&#x2F;declare blank timer variable
            var timer = Timer()
            &#x2F;&#x2F;in a function or viewDidLoad()
timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(timerAction), userInfo: nil, repeats: true)
&#x2F;&#x2F;new function
@objc func timerAction(){
       print(“timer fired!”)
    }
&#96;&#96;&#96;

You may have noticed that the function contains a @objc. That&#x27;s because we need a selector in order to build our timer, and you can&#x27;t make one without it.

Setting repeats to false ensures the timer will only go off once.

&#96;&#96;&#96;javascript
timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(timerAction), userInfo: nil, repeats: false)
&#96;&#96;&#96;

When using a selector with a recurring timer, you may terminate the timer at any moment by using the.invalidate method.

&#96;&#96;&#96;javascript
&#x2F;&#x2F;in a function or viewDidLoad()
timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(timerAction), userInfo: nil, repeats: true)
&#x2F;&#x2F;new function
@objc func timerAction(){
       print(“timer fired!”)
      timer.invalidate()
    }
&#96;&#96;&#96;

## **Automated Timer with a Preset Menu in Swift**

It is not always necessary to provide a dedicated function for a timer if it already has a selector declared. Simply follow these steps:

&#96;&#96;&#96;javascript
Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { timer in
                        print(&quot;timer fired!&quot;)
                        timer.invalidate()
            }
&#96;&#96;&#96;

Having this option gives us the ability to quickly build and control the functions that we want our timer to do. For example, if we want to establish a countdown timer, we can simply describe our timer as follows:

&#96;&#96;&#96;javascript
var timeLeft = 10
              Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { timer in
                         print(&quot;timer fired!&quot;)
                        timeLeft -= 1
                        self.timerTextField.text = String(timeLeft)
                        print(timeLeft)
                        if(timeLeft==0){
                                    timer.invalidate()
                        }
               }
&#96;&#96;&#96;

Take note that we may utilize variables in our selection; but, if you do want to use a variable, you must first define the variable before you can use it.

## **Tolerance for the timer**

The timer tolerance is the amount of delay that you are willing to accept before the timer goes off. You may be wondering why someone would want their timer to be slightly off. Simply put, the reason for this is because it may increase the amount of power that is used. Keep in mind that your program will have a difficult time maintaining your state, particularly when there is a timer running in the background. By allowing the app to have extra time to correctly execute various types of code, which is enabled by establishing a tolerance, we are able to reduce the amount of energy consumption caused by the application.

To determine the level of tolerance, just define it as:

&#96;&#96;&#96;javascript
timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(timerAction), userInfo: nil, repeats: true)
        timer.tolerance = 0.3
&#96;&#96;&#96;

&gt; Note: It is essential to keep in mind that tolerance might cause your application to run behind schedule, but it will never execute your code ahead of schedule.

## **Timer that includes RunLoop**

The vast majority of the time, while working with Timers, you will want your timer to continue operating in the background even when you are actively engaged in another task inside the app. On the other hand, a standard Timer will execute in a synchronous manner on your thread. This means that it will only run once all of your other responsibilities have been completed before it will start. Additionally, it only operates on your Main thread, which will halt whenever you start interacting with the user interface (UI).

This is where RunLoop comes into play; RunLoop will assist us in determining where on the thread we want our Timer to execute so that it can perform its work. In our particular scenario, we would want to be able to continue looping the timer even when we are currently engaging with the user interface (UI). As a result, the thread that we are going to put up will be the RunLoop. The &quot;common&quot; input modes are managed by the Mode.common thread, which is the appropriate name for this thread.

Simply inserting the following code into the &quot;common&quot; Runloop will result in the addition of a Timer:

&#96;&#96;&#96;javascript
RunLoop.current.add(timer, forMode: RunLoop.Mode.common)
&#96;&#96;&#96;

## **Conclusion**

Working with timers can be highly satisfying and may add a degree of complexity to your app that is both enjoyable and practical. This level of depth can make your app more user-friendly. However, please use caution! Because an unmonitored timer loop has the potential to be a drain on the battery and a consumer of CPU resources, it may eventually lead to issues.

The Ultimate Guide to Timer in Swift

Keyboard shortcuts are a great way to quickly navigate through applications and access specific functions. In SwiftUI, you can add keyboard shortcuts to your app, making it easier and faster to use. In this article, we&#x27;ll explain what keyboard shortcuts are, and how to add them to your SwiftUI app.

![keyboard shortcuts swiftui](https:&#x2F;&#x2F;devbrite.io&#x2F;media&#x2F;cover6.jpg)
## What Are Keyboard Shortcuts?

Keyboard shortcuts are combinations of key presses that allow you to quickly perform specific commands or actions. Keyboard shortcuts are usually a combination of modifier keys (e.g. Shift, Alt, Ctrl, etc.), along with a single key (e.g. A, B, C, etc.). When a keyboard shortcut is pressed, the action associated with it is performed.

For example, in a text editor, the keyboard shortcut &#96;Ctrl + S&#96; might be used to save the document. When the user presses &#96;Ctrl + S&#96;, the document is saved without requiring any further input from the user.

## How to Add Keyboard Shortcuts in SwiftUI

Adding keyboard shortcuts to your SwiftUI app is easy, and can be done with just a few lines of code. In this section, we&#x27;ll explain how to add keyboard shortcuts to your SwiftUI app.

### Step 1: Create a Keyboard Shortcut

The first step is to create a keyboard shortcut. To do this, you&#x27;ll need to use the &#96;.keyboardShortcut()&#96; modifier. This modifier takes two parameters: a modifier key (e.g. &#96;.command&#96;) and a key (e.g. &#96;&quot;s&quot;&#96;).

For example, to create a keyboard shortcut for saving a document, we could use the following code:

&#96;&#96;&#96;swift
Button(action: {
  &#x2F;&#x2F; Save the document
}) {
  Text(&quot;Save&quot;)
    .keyboardShortcut(.command, &quot;s&quot;)
}
&#96;&#96;&#96;

This code creates a button with the text &quot;Save&quot;, and adds a keyboard shortcut of &#96;command + s&#96;. When this shortcut is pressed, the button&#x27;s action is triggered.

### Step 2: Add an Action

The next step is to add an action to the keyboard shortcut. To do this, you&#x27;ll need to define a closure that contains the code for the action. This closure is passed to the &#96;action&#96; parameter of the &#96;.keyboardShortcut()&#96; modifier.

For example, to add an action for saving a document, we could use the following code:

&#96;&#96;&#96;swift
Button(action: {
  &#x2F;&#x2F; Save the document
  saveDocument()
}) {
  Text(&quot;Save&quot;)
    .keyboardShortcut(.command, &quot;s&quot;)
}
&#96;&#96;&#96;

This code adds an action to the keyboard shortcut, which will call the &#96;saveDocument()&#96; function when the shortcut is pressed.

### Step 3: Test Your Keyboard Shortcut

Once you&#x27;ve added the keyboard shortcut and action, you can test it out. To do this, press the shortcut while the app is running. If everything is set up correctly, the action associated with the shortcut should be triggered.

## Conclusion

In this article, we&#x27;ve explained what keyboard shortcuts are, and how to add them to your SwiftUI app. We&#x27;ve also shown how to create a keyboard shortcut, add an action to the shortcut, and test it out. With just a few lines of code, you can add keyboard shortcuts to your SwiftUI app, making it easier and faster to use.

How to Add Keyboard Shortcuts in SwiftUI

Unit testing is an important part of the software development process. It helps to ensure that the code you write is reliable and performs as expected. Unit tests are a set of automated tests that run against your code to check for any errors or unexpected behavior. In this article, we&#x27;ll take a look at how to get started with unit testing in Swift.

![unit tests swift](https:&#x2F;&#x2F;devbrite.io&#x2F;media&#x2F;cover4.jpg)
## What are Unit Tests?

Unit tests are automated tests that verify the behavior of individual pieces of code, or “units.” Unit tests are typically written using a testing framework such as XCTest, which is built into the Xcode development environment. Unit tests are written in the same language as the code they’re testing, and they’re typically written before the code is written. This allows developers to catch any potential issues early on and prevent them from becoming larger problems later.

## Writing Unit Tests in Swift

Writing unit tests in Swift is fairly straightforward. The XCTest framework provides a number of helpful methods for creating and running unit tests. Here’s a quick overview of some of the common methods used for writing unit tests in Swift.

### Setup and Tear Down

The &#96;setUp()&#96; and &#96;tearDown()&#96; methods are used to prepare the environment for running the tests. The &#96;setUp()&#96; method is called before each test is run, and it’s used to set up any necessary resources or data that the tests need. The &#96;tearDown()&#96; method is called after each test is run, and it’s used to clean up any resources or data that were used by the tests.

### Throwing Methods

The &#96;XCTAssertThrowsError()&#96; method is used to verify that a given method throws an error when it’s called. This is useful for verifying that a method behaves as expected when it’s given invalid input.

For example, here’s a method that takes an integer and throws an error if the number is less than 0:

&#96;&#96;&#96;swift
func validateNumber(number: Int) throws {
    if number &lt; 0 {
        throw NSError(domain: &quot;com.example.error&quot;, code: 0, userInfo: nil)
    }
}
&#96;&#96;&#96;

We can use the &#96;XCTAssertThrowsError()&#96; method to verify that this method throws an error when it’s called with an invalid number:

&#96;&#96;&#96;swift
func testValidateNumber() {
    XCTAssertThrowsError(try validateNumber(number: -1))
}
&#96;&#96;&#96;

### Unwrapping Optional Values

The &#96;XCTUnwrap()&#96; method is used to verify that an optional value is not &#96;nil&#96; before attempting to use it. This is useful for verifying that an optional value is present and can be safely used.

For example, here’s a method that takes an optional string and returns a non-optional string:

&#96;&#96;&#96;swift
func getString(string: String?) -&gt; String {
    guard let unwrappedString = string else {
        return &quot;&quot;
    }
    return unwrappedString
}
&#96;&#96;&#96;

We can use the &#96;XCTUnwrap()&#96; method to verify that the optional value is not &#96;nil&#96; before attempting to use it:

&#96;&#96;&#96;swift
func testGetString() {
    let testString = &quot;Test String&quot;
    let optionalString: String? = testString
    let unwrappedString = XCTUnwrap(optionalString)
    XCTAssertEqual(unwrappedString, testString)
}
&#96;&#96;&#96;

## Running Swift Unit Tests in Xcode

Once you’ve written your unit tests, you can run them in Xcode by selecting the “Test” option from the Xcode menu. This will run all of the tests in your project and display the results in the “Test Navigator” view.

You can also run individual tests by right-clicking on the test in the “Test Navigator” view and selecting “Run [Test Name]”. This will run the selected test and display the results in the “Test Navigator” view.

## Best Unit Testing Practices in Swift

When writing unit tests in Swift, it’s important to follow best practices to ensure that your tests are reliable and maintainable. Here are some of the best practices for writing unit tests in Swift:

- Write tests before writing code. This allows you to catch any errors or unexpected behavior early on, before they become larger problems.

- Make sure your tests are deterministic. This means that the tests should always return the same result when given the same input.

- Keep your tests focused. Each test should focus on a single, specific behavior.

- Make sure your tests are independent. This means that each test should not rely on any other test, and should be able to run on its own.

- Make sure your tests are readable. This means that each test should be easy to read and understand.

- Make sure your tests are reliable. This means that each test should always return the same result when given the same input.

- Make sure your tests are maintainable. This means that each test should be easy to update and modify when necessary.

By following these best practices, you can ensure that your tests are reliable and maintainable.

## Conclusion

Unit testing is an important part of the software development process. It helps to ensure that the code you write is reliable and performs as expected. In this article, we’ve taken a look at how to get started with unit testing in Swift. We’ve looked at how to write unit tests in Swift and how to run them in Xcode. We’ve also looked at some best practices for writing unit tests in Swift. By following these best practices, you can ensure that your tests are reliable and maintainable.

Swift

How To Add Gradient Backgrounds in SwiftUI

The Ultimate Guide to Timer in Swift

How to Add Keyboard Shortcuts in SwiftUI

Getting Started with Unit Tests in Swift

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