[feat] Support Liquid Glass Icons for macOS 26

[suxiaoshao]

Describe the problem

Apple introduced a new way to create icons using Icon Composer. This is not a standard image format and has assets & layers bundled inside it.

However, this app creates .icon files which does not currently work with tauri icon.

Describe the solution you'd like

You can use .icon files as parameters for the tauri icon command, or set .icon files as icons for iOS and macOS.

Alternatives considered

No response

Additional context

No response

[MaciejkaG]

I tried reverse engineering Xcode's building and archiving process and realised that it uses an Assets.car inside Contents/Resources file for storing the bundled icon files. I've put together this bash script for generating an Assets.car file from a .icon file:

#!/usr/bin/env bash
ICON_PATH="./src-tauri/resources/Icon.icon"
OUTPUT_PATH="./src-tauri/resources"
PLIST_PATH="$OUTPUT_PATH/assetcatalog_generated_info.plist"

actool $ICON_PATH --compile $OUTPUT_PATH \
  --output-format human-readable-text --notices --warnings --errors \
  --output-partial-info-plist $PLIST_PATH \
  --app-icon Icon --include-all-app-icons \
  --enable-on-demand-resources NO \
  --target-device mac \
  --minimum-deployment-target 26.0 \
  --platform macosx

and then I added this into app.bundle inside tauri.conf.json:

"macOS": {
      "minimumSystemVersion": "26.0",
      "files": {
        "Resources/Assets.car": "resources/Assets.car"
      }
    }

and created an Info.plist:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>CFBundleIconName</key>
    <string>Icon</string>
</dict>
</plist>

Note how the CFBundleIconName matches the name passed to the --app-icon argument of the actool command in the bash script.

But it still doesn't work even after running pnpm tauri build. The app bundle looks similar in file structure to my sample Swift app built using Xcode. The only thing missing is a .icns file inside Contents/Resources which I haven't figured how to generate from .icon yet. Hopefully, this helps someone, and we manage to find a temporary workaround until someone figures out a native utility (it unfortunately cannot be me as I'm not yet advanced enough at macOS nor Rust).

Furthermore, here's a blog post I found that helped me with this. It's pretty vague and the author's solution didn't work for me completely, but it helps, either way, maybe I made a mistake in the process.