Update DMG background and label size (#1629)

.github/workflows/release.yml

@@ -198,6 +198,11 @@ jobs:
           fi
           echo "dmg=$DMG" >> "$GITHUB_OUTPUT"
 
+      - name: Set DMG Finder label text size
+        env:
+          DMG_PATH: ${{ steps.unsigned.outputs.dmg }}
+        run: desktop/scripts/set-dmg-finder-text-size.sh "$DMG_PATH" 14
+
       - name: Codesign and Notarize
         id: codesign
         uses: block/apple-codesign-action@679535d1ab7c5a7c18e6f9afcba3464512cc3dde # v1.1.0
@@ -359,6 +364,11 @@ jobs:
           fi
           echo "dmg=$DMG" >> "$GITHUB_OUTPUT"
 
+      - name: Set DMG Finder label text size
+        env:
+          DMG_PATH: ${{ steps.unsigned.outputs.dmg }}
+        run: desktop/scripts/set-dmg-finder-text-size.sh "$DMG_PATH" 14
+
       - name: Codesign and Notarize
         id: codesign
         uses: block/apple-codesign-action@679535d1ab7c5a7c18e6f9afcba3464512cc3dde # v1.1.0

desktop/scripts/set-dmg-finder-text-size.sh

@@ -0,0 +1,82 @@
+#!/usr/bin/env bash
+# Patch Finder icon-label text size in a Tauri-generated DMG.
+#
+# Tauri's DMG config supports the background/layout fields we use, but it does
+# not expose create-dmg's text-size option. Run this before DMG signing or
+# notarization; mutating a signed DMG would invalidate the signature.
+
+set -euo pipefail
+
+if [[ $# -lt 1 || $# -gt 2 ]]; then
+  echo "Usage: $0 <path-to-dmg> [text-size]" >&2
+  exit 2
+fi
+
+DMG_PATH="$1"
+TEXT_SIZE="${2:-14}"
+
+[[ -f "$DMG_PATH" ]] || { echo "Missing DMG: $DMG_PATH" >&2; exit 1; }
+
+WORK_DIR="$(mktemp -d -t buzz-dmg-text-size)"
+MOUNT_POINT="$WORK_DIR/mount"
+RW_DMG="$WORK_DIR/work.dmg"
+OUT_DMG="$WORK_DIR/output.dmg"
+MOUNTED="false"
+
+cleanup() {
+  if [[ "$MOUNTED" == "true" ]]; then
+    hdiutil detach "$MOUNT_POINT" >/dev/null 2>&1 || true
+  fi
+  rm -rf "$WORK_DIR"
+}
+trap cleanup EXIT
+
+mkdir -p "$MOUNT_POINT"
+hdiutil convert "$DMG_PATH" -format UDRW -o "$RW_DMG" -ov >/dev/null
+hdiutil attach "$RW_DMG" -nobrowse -readwrite -noverify -mountpoint "$MOUNT_POINT" >/dev/null
+MOUNTED="true"
+
+node - "$MOUNT_POINT/.DS_Store" "$TEXT_SIZE" <<'NODE'
+const fs = require("node:fs");
+
+const dsStorePath = process.argv[2];
+const textSize = Number(process.argv[3]);
+
+if (!Number.isFinite(textSize)) {
+  throw new Error(`Invalid DMG Finder text size: ${process.argv[3]}`);
+}
+
+const data = fs.readFileSync(dsStorePath);
+if (!data.includes(Buffer.from("textSize"))) {
+  throw new Error(`${dsStorePath} does not contain Finder textSize metadata`);
+}
+
+const current = Buffer.alloc(8);
+current.writeDoubleBE(16.0, 0);
+const replacement = Buffer.alloc(8);
+replacement.writeDoubleBE(textSize, 0);
+
+const positions = [];
+let offset = 0;
+while ((offset = data.indexOf(current, offset)) !== -1) {
+  positions.push(offset);
+  offset += 1;
+}
+
+if (positions.length !== 1) {
+  throw new Error(
+    `Expected one Finder textSize value in ${dsStorePath}, found ${positions.length}`,
+  );
+}
+
+replacement.copy(data, positions[0]);
+fs.writeFileSync(dsStorePath, data);
+console.log(`Set DMG Finder textSize to ${textSize}`);
+NODE
+
+sync
+hdiutil detach "$MOUNT_POINT" >/dev/null
+MOUNTED="false"
+
+hdiutil convert "$RW_DMG" -format UDZO -imagekey zlib-level=9 -o "$OUT_DMG" -ov >/dev/null
+mv "$OUT_DMG" "$DMG_PATH"