build: create pretty install DMG

Resolves #3257

.github/workflows/build.yml

@@ -275,6 +275,8 @@ jobs:
           HELPER_PROFILE_UUID: ${{ secrets.HELPER_PROFILE_UUID }}
           LAUNCHER_PROFILE_DATA: ${{ secrets.LAUNCHER_PROFILE_DATA }}
           LAUNCHER_PROFILE_UUID: ${{ secrets.LAUNCHER_PROFILE_UUID }}
+      - name: Install appdmg
+        run: npm install -g appdmg
       - name: Download Artifact
         uses: actions/download-artifact@v2
         with:

scripts/package_mac.sh

@@ -109,6 +109,12 @@ if [ "$MODE" == "app-store" ]; then
 	cp "$SIGNED/UTM.pkg" "$OUTPUT/UTM.pkg"
 else
 	rm -f "$OUTPUT/UTM.dmg"
-	hdiutil create -fs HFS+ -srcfolder "$SIGNED/UTM.app" -volname "UTM" "$OUTPUT/UTM.dmg"
+	command -v appdmg >/dev/null 2>&1
+	if [ $? -eq 0 ]; then
+		appdmg "$BASEDIR/resources/appdmg.json" "$OUTPUT/UTM.dmg"
+	else
+		echo "appdmg not found, falling back to non-customized DMG creation"
+		hdiutil create -fs HFS+ -srcfolder "$SIGNED/UTM.app" -volname "UTM" "$OUTPUT/UTM.dmg"
+	fi
 fi
 rm -rf "$SIGNED"

scripts/resources/appdmg.json

@@ -0,0 +1,13 @@
+{
+  "title": "UTM",
+  "icon": "UTM-drive.icns",
+  "background": "dmg-background.png",
+  "format": "UDZO",
+  "window": {
+    "size": { "width": 660, "height": 400 }
+  },
+  "contents": [
+    { "x": 480, "y": 170, "type": "link", "path": "/Applications" },
+    { "x": 180, "y": 170, "type": "file", "path": "/tmp/signed/UTM.app" }
+  ]
+}