All-in-one Quick Look plugin

Glance provides QuickLook previews for various file types that macOS doesn't support out of the box.

Glance is available on the Mac App Store: (TODO: Add link)

After opening the app for the first time, macOS will use Glance to generate previews for the supported file types.

TODO: Main app screenshot

• Source code (with Chroma syntax highlighting): .cpp, .js, .json, .py, .swift, .yml and many more

  TODO: Add screenshot

• Markdown (rendered using Blackfriday): .md, .markdown, .mdown, .mkdn, .mkd, .Rmd

  TODO: Add screenshot

• Archives: .tar, .tar.gz, .zip

  TODO: Add screenshot

• Jupyter Notebook (rendered using nbtohtml): .ipynb

  TODO: Add screenshot

• TSV (parsed using SwiftCSV): .tab, .tsv

  TODO: Add screenshot

There are existing QuickLook apps for some of the supported file types. Why create another one?

• Glance combines the features of many plugins into one and provides consistent and beautiful previews
• Glance is fully compatible with Dark Mode
• Some plugins still use the deprecated Quick Look generator API and might stop working in the future
• Glance can easily be extended to support other file types

Why does Glance require network permissions?

Glance renders some file previews in a WKWebView. All assets are stored locally and network access is disabled, but web views still need the com.apple.security.network.client entitlement to function.

Why are images in my Markdown files not loading?

Glance only has access to the file that’s being previewed (com.apple.security.files.user-selected.read-only entitlement). Any image files referenced from Markdown are therefore not loaded.

Why isn't [file type] supported?

Please feel free to open an issue or contribute!

You claim to support [file type], but previews aren't showing up.

Please note that Glance skips previews for large files.

It's possible that your file's extension or UTI isn't associated with Glance. You can easily verify this:

1. Check whether the file extension is matched to the correct class in PreviewVCFactory.swift.
2. Find your file's UTI by running mdls -name kMDItemContentType -name kMDItemContentTypeTree /path/to/your/file. Check whether the UTI is listed under QLSupportedContentTypes in Info.plist.
3. If an association is missing, please feel free to add it and submit a PR.

Suggestions and contributions are always welcome! Please discuss larger changes (e.g. adding support for a new file type) via issue before submitting a pull request.

To add previews for a new file extension, please follow these steps:

1. Create a new class for your file type in this directory. It should implement the Preview protocol. See the other files in the directory for examples.
2. Match the file extension to your class in PreviewVCFactory.swift.
3. Find your file's UTI by running mdls -name kMDItemContentType -name kMDItemContentTypeTree /path/to/your/file. Add it to QLSupportedContentTypes in Info.plist.
4. Update README.md and Credits.rtf.