https://github.com/insidegui/macpreviewutils
Handy tools for SwiftUI previews on macOS.
https://github.com/insidegui/macpreviewutils
Last synced: 11 months ago
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Handy tools for SwiftUI previews on macOS.
- Host: GitHub
- URL: https://github.com/insidegui/macpreviewutils
- Owner: insidegui
- License: bsd-2-clause
- Created: 2022-12-24T19:33:25.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2024-04-15T17:33:14.000Z (almost 2 years ago)
- Last Synced: 2025-05-10T22:52:44.684Z (11 months ago)
- Language: Swift
- Size: 3.9 MB
- Stars: 197
- Watchers: 5
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE
Awesome Lists containing this project
README
# MacPreviewUtils
This package includes a few tools that I use all the time when developing macOS apps, whether using SwiftUI or AppKit.
These tools help make SwiftUI previews more useful for Mac app developers.
## Translucency Fix
By default, `Material` and other views that rely on an app being active in order to render properly won't look right in SwiftUI previews,
making it difficult to iterate on detailed designs that use such effects.
Just by linking against the MacPreviewUtils library, you'll get an automatic fix for translucency in SwiftUI previews.
### Example:
No code needed, just link your app target (or one of the targets it links against) to MacPreviewUtils.
## Am I a SwiftUI Preview?
The library includes a couple of extensions on `ProcessInfo` that can be used at runtime to check whether the process
is running in a SwiftUI preview. This should be used sparingly, but it can be extremely useful to adapt certain app behaviors
that can be problematic when running in SwiftUI previews.
### Example:
```swift
func doSomethingThatBreaksSwiftUIPreviews() {
guard !ProcessInfo.isSwiftUIPreview else { return }
// ...
}
```
## Pin SwiftUI Preview to a Specific Display
Sometimes you might want to be looking at your SwiftUI preview in an external display, such as an iPad connected via Sidecar.
This library includes a modifier that can do just that.
### Example:
```swift
struct MyView_Previews: PreviewProvider {
static var previews: some View {
/// This preview will show up on the connected Sidecar display.
MyView()
.pin(to: .sidecarDisplay, alignment: .center, options: [.interactiveOnly])
}
}
```
## Debug Previews Using `print()`
Breakpoints are great for debugging an app while it's running, and sometimes `print()` statements may also be a good way to debug certain values over time.
Unfortunately, while running in Xcode previews, there's no easy way to view your app's standard output, unless you're using `OSLog`/`NSLog` and filtering in the Console app.
This library includes a modifier that displays a little console window while running an Xcode preview, allowing you to debug your previews using `print` statements.
The `previewConsole()` may also be combined with the `pin(to:)` modifier mentioned above, in which case it'll follow the display and position selection from that modifier.
```swift
struct MyView_Previews: PreviewProvider {
static var previews: some View {
MyView()
.previewConsole()
}
}
```
> Note: this modifier will only show the app's standard output, so it won't display messages logged with `os_log` or `Logger`. Support for the unified logging system and stderr is planned.
## Will this mess up my app when debugging or in production?
Nope!
Most of the code in this library is in `#if DEBUG`/`#endif` statements, so it won't even be included
in release builds of the app.
The modifiers included are designed for use only in SwiftUI previews, so you should not use them
directly on view implementations. However, they all check if the code is running in a SwiftUI preview
before doing anything, so that regular debug builds are not affected.
Be sure to include `#if DEBUG`/`#endif` around your SwiftUI previews that
use this library as well, in order to prevent compiler errors when building for release.