NSTextView is a powerful and flexible text-handling class in macOS development, part of the AppKit framework. It allows developers to create rich text editing interfaces within their macOS applications. NSTextView supports various text attributes, such as fonts, colors, and styles, and provides features like spell checking, text alignment, and more. This article will guide you through the process of creating and configuring an NSTextView in a macOS application using Swift and Interface Builder.

Examples:

1. Creating an NSTextView Programmatically

   To create an NSTextView programmatically, you need to import AppKit and instantiate the NSTextView class. Below is a simple example of how to create and configure an NSTextView in a macOS application using Swift.

   import Cocoa
   
   class ViewController: NSViewController {
   
      override func viewDidLoad() {
          super.viewDidLoad()
   
          // Create a scroll view to contain the NSTextView
          let scrollView = NSScrollView(frame: self.view.bounds)
          scrollView.hasVerticalScroller = true
          scrollView.hasHorizontalScroller = true
          scrollView.autoresizingMask = [.width, .height]
   
          // Create the NSTextView
          let textView = NSTextView(frame: scrollView.bounds)
          textView.autoresizingMask = [.width, .height]
          textView.isRichText = true
          textView.isEditable = true
          textView.isSelectable = true
          textView.font = NSFont.systemFont(ofSize: 14)
   
          // Add the NSTextView to the scroll view
          scrollView.documentView = textView
   
          // Add the scroll view to the main view
          self.view.addSubview(scrollView)
      }
   }

2. Creating an NSTextView Using Interface Builder

   You can also create an NSTextView using Interface Builder in Xcode. Here are the steps:

   • Open your Xcode project and navigate to the storyboard or xib file where you want to add the NSTextView.
   • Drag a Scroll View from the Object Library onto your view.
   • Inside the Scroll View, drag a Text View from the Object Library.
   • Set the constraints for the Scroll View to ensure it resizes properly with the main view.
   • Configure the properties of the NSTextView in the Attributes Inspector, such as enabling rich text, setting the font, and more.

   Below is an example of how to connect the NSTextView to your ViewController in Swift:

   import Cocoa
   
   class ViewController: NSViewController {
   
      @IBOutlet weak var textView: NSTextView!
   
      override func viewDidLoad() {
          super.viewDidLoad()
   
          // Additional configuration if needed
          textView.font = NSFont.systemFont(ofSize: 14)
          textView.isEditable = true
          textView.isSelectable = true
      }
   }

3. Adding Functionality to NSTextView

   NSTextView supports a wide range of functionalities, including spell checking, text alignment, and more. Here’s how you can enable spell checking and set text alignment:

   import Cocoa
   
   class ViewController: NSViewController {
   
      @IBOutlet weak var textView: NSTextView!
   
      override func viewDidLoad() {
          super.viewDidLoad()
   
          // Enable spell checking
          textView.isContinuousSpellCheckingEnabled = true
   
          // Set text alignment to center
          let paragraphStyle = NSMutableParagraphStyle()
          paragraphStyle.alignment = .center
          textView.defaultParagraphStyle = paragraphStyle
      }
   }