https://github.com/eneko/consoleui

Rasterize SwiftUI views to images from macOS terminal
https://github.com/eneko/consoleui

command-line swift-package-manager swiftpm swiftui terminal

Last synced: 23 days ago
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Rasterize SwiftUI views to images from macOS terminal

• Host: GitHub
• URL: https://github.com/eneko/consoleui
• Owner: eneko
• Created: 2019-06-21T12:18:44.000Z (over 5 years ago)
• Default Branch: main
• Last Pushed: 2021-09-20T22:56:01.000Z (over 3 years ago)
• Last Synced: 2025-01-10T18:55:54.014Z (about 1 month ago)
• Topics: command-line, swift-package-manager, swiftpm, swiftui, terminal
• Language: Swift
• Size: 874 KB
• Stars: 58
• Watchers: 4
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • Funding: .github/FUNDING.yml

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README

        


# ConsoleUI

Demo repository to showcase how to **programmatically generate images from a command-line tool with [SwiftUI](https://developer.apple.com/xcode/swiftui/)**.

![](Images/test.png)

## The Basics: Hello, world!

### Create a new command-line executable

```

$ mkdir mytool && cd mytool

$ swift package init --type executable

$ swift run

Hello, world!

```

### Generate Xcode project (optional)

Xcode does not support live previews on Swift packages yet (FB8979344). To allow for realtime previews follow these steps:

1. Generate an Xcode project

2. Add a macOS target to the project

3. Add your view (see next section) to the macOS target

```

$ swift package generate-xcodeproj

$ open mytool.xcodeproj

```

### Add SwiftUI view

Create a view with a red label over white background

```swift

import SwiftUI

struct MySwiftUIView : View {

    var body: some View {

        ZStack {

            Color.blue.edgesIgnoringSafeArea(.all)

            Text("Hello, world!")

                .foregroundColor(.white)

                .font(.largeTitle)

        }

    }

}

#if DEBUG

struct MySwiftUIView_Previews : PreviewProvider {

    static var previews: some View {

        MySwiftUIView()

    }

}

#endif

```

![SwiftUI](Images/MySwiftUIView.png)

### Rasterize view and save to file

We will use this method to rasterize views to images:

```swift

func rasterize(view: NSView, format: NSBitmapImageRep.FileType) -> Data? {

    guard let bitmapRepresentation = view.bitmapImageRepForCachingDisplay(in: view.bounds) else {

        return nil

    }

    bitmapRepresentation.size = view.bounds.size

    view.cacheDisplay(in: view.bounds, to: bitmapRepresentation)

    return bitmapRepresentation.representation(using: format, properties: [:])

}

```

The following code instantiates the SwiftUI view, wrapped inside a `NSHostingView` which is then

rasterized and saved to disk

```swift

let wrapper = NSHostingView(rootView: MySwiftUIView())

wrapper.frame = CGRect(x: 0, y: 0, width: 800, height: 450)

let png = rasterize(view: wrapper, format: .png)

try png?.write(to: URL(fileURLWithPath: "test.png"))

```

![main.swift](Images/Main.png)

### Run the command and open in Preview

```

$ swift run && open test.png

```

![Preview](Images/Preview.png)