SwiftUI - Basic Components

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SwiftUI is Apple's framework designed to create simple and complex user interfaces with less code and better performance for all of Apple's platforms including iOS, macOS, watchOS, tvOs, visionOS, etc.

It uses declarative syntax, meaning we only need to describe how the user interface should look and how it will behave, and SwiftUI does the rest of the implementation. To create a rich and dynamic app SwiftUI provides the following basic components −

• Views

• Containers and Layout

• Modifiers

• State and Data Binding

• Navigation

• Gestures

Now, let's discuss each component in detail −

Views in SwiftUI

View is a fundamental building block to developing user interfaces. Or we can say that it is a portion of the user interface where developers can define the layout and appearance of the interface. Every portion of the app that is visible to the user is derived from the description given by the developer in a view. Any type that conforms to the View protocol acts as a view.

Name	Description	Syntax
Text	It is used to display text.	Text("Hello TutorialsPoint")
Image	It is used to display image.	Image(systemName: "rectangle")
Button	It is used to create a tappable button	Button(action: { print("Tapped button") }) { Text("Button") }
TextField	It is used to display a text-field or to create an editable text interface.	@State private var age: String = "" TextField("Enter your age", text: $age)

Containers and Layout

Layouts and containers are the structures that control how the children views will be arranged. Some of the commonly used containers and layouts are as follows −

Name	Description	Syntax
VStack	It is used to stack child views vertically.	VStack { Text("Hello") Text("TutorialsPoint") }
HStack	It is used to stack child views horizontally.	HStack { Text("Hello") Text("TutorialsPoint") }
ZStack	It is used to overlay child views on top of each other	ZStack { Rectangle().fill(Color.mint) Text("TutorialsPoint") }
List	It is used to display a scrollable list of data.	List { Text("Hello") Text("TutorialsPoint") }
Form	It is used to group controls for data entry .	Form { Toggle("Notification", isOn:$isOn) Toggle("Sliding Bar", isOn:$isOn) }

Modifiers in SwiftUI

Modifiers in SwiftUI are the methods that are used to change the appearance or behavior of the views. We can apply multiple modifiers on a single component in a sequence. Using them we can create easy as well as complex designs. Some of the commonly used modifiers are as follows−

Name	Description	Syntax
padding	It is used to add padding around the view.	.padding()
background	It is used to set background of the view.	.background()
foregroundColor	It is used to set the color of the text or image.	.foregroundColor()
fill	It is used to set the color of the shapes.	.fill()
font	It is used to change the font of the text.	.font()
frame	It is used to set the size of the frame.	.frame()

State and Data Binding

State and data bindings are used to manage and propagate data throughout the app. The state is used to manage the state of the view. Whenever the state is updated with a new value, SwiftUI will automatically update the view according to the new state.

Whereas, binding is used to create a relationship between the UI components and their underlying data model. It uses bidirectional communication. Following are some commonly used state and data binding objects −

Name	Description	Syntax
@State	It is a property wrapper that manage state inside a view	@State private var myState:Bool = false
@Binding	It is used to create a two-way connection to a @state property in a parent view.	@Binding var myState:Bool = false
@ObservedObject	It is used to observe external observable view in complex data models.	@ObservedObject var myData = MyObservableObject()
@EnvironmentObject	It is used to share data between all the views in the SwiftUI hierarchy.	@EnvironmentObject var myData : MyObservableObject

Navigation in SwiftUI

Navigation is a process of creating a user interface, which allows the user to move from one view to another view or screen in the app. SwiftUI provide various tools for implementing navigation and some of the common components are as follows−

Name	Description	Syntax
NavigationLink	It is to control a navigation presentation.	32
Sheet	It is used to display model view.	.sheet(isPresented:)

Gestures in Swift UI

Gestures are used to add interaction capabilities to views. They allow users to interact with the apps using tapping, dragging, swiping, rotating, etc. SwiftUI supports various in-built gestures, you can use them in your views with the help of gesture modifiers. Some of the commonly used gestures are as follows−

Name	Description	Syntax
TapGesture	It is used to detect tap on a view.	.onTapGesture()
DragGesture	It is used to detect drag movements on a view.	DragGesture()
SpatialTapGesture	It is used to recognize one or more taps and report their locations.	SpatialTapGesture()