Add macOS DMG release packaging

.github/workflows/release-builds.yml

@@ -66,6 +66,10 @@ jobs:
           fi
           tar -czf "dist/${{ matrix.archive }}" -C dist stringcast
 
+      - name: Prepare macOS DMG
+        if: runner.os == 'macOS'
+        run: packaging/macos/build_dmg.sh dist/macos/Stringcast.app dist/stringcast-macos.dmg
+
       - name: Prepare Windows artifact
         if: runner.os == 'Windows'
         shell: pwsh
@@ -82,3 +86,11 @@ jobs:
           name: ${{ matrix.archive }}
           path: dist/${{ matrix.archive }}
           if-no-files-found: error
+
+      - name: Upload macOS DMG artifact
+        if: runner.os == 'macOS'
+        uses: actions/upload-artifact@v4
+        with:
+          name: stringcast-macos.dmg
+          path: dist/stringcast-macos.dmg
+          if-no-files-found: error

docs/MACOS_APP.md

@@ -31,6 +31,18 @@ The app is written to:
 dist/macos/Stringcast.app
 ```
 
+Build a drag-to-Applications DMG:
+
+```bash
+packaging/macos/build_dmg.sh
+```
+
+The DMG is written to:
+
+```text
+dist/stringcast-macos.dmg
+```
+
 Open it:
 
 ```bash
@@ -78,13 +90,10 @@ The app does not block startup on this permission check. If permissions are miss
 ## Current Limitations
 
 - The app is unsigned.
-- There is no custom app icon yet.
 - Logs open in Finder rather than an in-app viewer.
-- Packaging does not create a DMG or installer yet.
+- The DMG is unsigned and not notarized.
 
 ## Next Packaging Steps
 
-- Add an icon.
 - Add log/status display.
 - Add code signing and notarization.
-- Produce a DMG for end users.

docs/RELEASES.md

@@ -1,20 +1,21 @@
 # Release Artifacts
 
-Stringcast can be distributed as downloadable binaries from GitHub Actions. This lets users run the Rust app without installing Cargo.
+Stringcast can be distributed as downloadable artifacts from GitHub Actions. This lets users run the Rust app without installing Cargo.
 
-The current artifacts are raw CLI binaries, not full desktop installers. A macOS app wrapper and richer desktop packaging are planned separately.
+The macOS build includes both a tarball and a drag-to-Applications DMG. Linux and Windows currently ship archive artifacts.
 
 ## Build Artifacts
 
 The `Release Builds` workflow creates:
 
 ```text
+stringcast-macos.dmg
 stringcast-macos.tar.gz
 stringcast-linux-x86_64.tar.gz
 stringcast-windows-x86_64.zip
 ```
 
-Each archive includes:
+Each platform archive includes:
 
 - `stringcast` or `stringcast.exe`
 - `Stringcast.app` in the macOS archive
@@ -54,6 +55,14 @@ gh run download <run-id> -D ./artifacts
 
 ## macOS Smoke Test
 
+For the DMG:
+
+```bash
+open stringcast-macos.dmg
+```
+
+Then drag `Stringcast.app` to Applications, or launch it directly from the mounted volume for a quick test.
+
 Unpack:
 
 ```bash

packaging/macos/build_app.sh

@@ -48,8 +48,8 @@ if ! command -v sips >/dev/null 2>&1; then
   exit 1
 fi
 
-if ! command -v iconutil >/dev/null 2>&1; then
-  echo "missing iconutil; cannot generate app icon" >&2
+if ! command -v python3 >/dev/null 2>&1; then
+  echo "missing python3; cannot generate app icon" >&2
   exit 1
 fi
 
@@ -65,21 +65,40 @@ xcrun --sdk macosx swiftc \
   -o "$MACOS_DIR/StringcastMenu"
 
 if [ -f "$ICON_SOURCE" ]; then
-  ICONSET_DIR="$OUT_DIR/StringcastIcon.iconset"
-  rm -rf "$ICONSET_DIR"
-  mkdir -p "$ICONSET_DIR"
-  sips -z 16 16 "$ICON_SOURCE" --out "$ICONSET_DIR/icon_16x16.png" >/dev/null
-  sips -z 32 32 "$ICON_SOURCE" --out "$ICONSET_DIR/icon_16x16@2x.png" >/dev/null
-  sips -z 32 32 "$ICON_SOURCE" --out "$ICONSET_DIR/icon_32x32.png" >/dev/null
-  sips -z 64 64 "$ICON_SOURCE" --out "$ICONSET_DIR/icon_32x32@2x.png" >/dev/null
-  sips -z 128 128 "$ICON_SOURCE" --out "$ICONSET_DIR/icon_128x128.png" >/dev/null
-  sips -z 256 256 "$ICON_SOURCE" --out "$ICONSET_DIR/icon_128x128@2x.png" >/dev/null
-  sips -z 256 256 "$ICON_SOURCE" --out "$ICONSET_DIR/icon_256x256.png" >/dev/null
-  sips -z 512 512 "$ICON_SOURCE" --out "$ICONSET_DIR/icon_256x256@2x.png" >/dev/null
-  sips -z 512 512 "$ICON_SOURCE" --out "$ICONSET_DIR/icon_512x512.png" >/dev/null
-  sips -z 1024 1024 "$ICON_SOURCE" --out "$ICONSET_DIR/icon_512x512@2x.png" >/dev/null
-  iconutil -c icns "$ICONSET_DIR" -o "$RESOURCES_DIR/StringcastIcon.icns"
-  rm -rf "$ICONSET_DIR"
+  ICON_WORK_DIR="$OUT_DIR/StringcastIcon.work"
+  rm -rf "$ICON_WORK_DIR"
+  mkdir -p "$ICON_WORK_DIR"
+  sips -Z 1024 "$ICON_SOURCE" --out "$ICON_WORK_DIR/icon-scaled.png" >/dev/null
+  sips --padToHeightWidth 1024 1024 --padColor FFFFFF "$ICON_WORK_DIR/icon-scaled.png" --out "$ICON_WORK_DIR/icon-1024.png" >/dev/null 2>&1
+  for size in 16 32 64 128 256 512 1024; do
+    sips -z "$size" "$size" "$ICON_WORK_DIR/icon-1024.png" --out "$ICON_WORK_DIR/icon_${size}.png" >/dev/null
+  done
+  python3 - "$RESOURCES_DIR/StringcastIcon.icns" "$ICON_WORK_DIR" <<'PY'
+import struct
+import sys
+from pathlib import Path
+
+output = Path(sys.argv[1])
+source_dir = Path(sys.argv[2])
+entries = [
+    (b"icp4", "icon_16.png"),
+    (b"icp5", "icon_32.png"),
+    (b"icp6", "icon_64.png"),
+    (b"ic07", "icon_128.png"),
+    (b"ic08", "icon_256.png"),
+    (b"ic09", "icon_512.png"),
+    (b"ic10", "icon_1024.png"),
+]
+
+chunks = []
+for icon_type, filename in entries:
+    data = (source_dir / filename).read_bytes()
+    chunks.append(icon_type + struct.pack(">I", len(data) + 8) + data)
+
+payload = b"".join(chunks)
+output.write_bytes(b"icns" + struct.pack(">I", len(payload) + 8) + payload)
+PY
+  rm -rf "$ICON_WORK_DIR"
 else
   echo "warning: icon source not found: $ICON_SOURCE" >&2
   echo "         save the app icon PNG there, or set STRINGCAST_ICON=/path/to/icon.png" >&2

packaging/macos/build_dmg.sh

@@ -0,0 +1,54 @@
+#!/bin/sh
+set -eu
+
+if [ "${1:-}" = "--help" ]; then
+  cat <<'USAGE'
+usage: packaging/macos/build_dmg.sh [app-path] [output-dmg-path] [volume-name]
+
+Builds an unsigned macOS DMG with Stringcast.app and an Applications shortcut.
+
+Defaults:
+  app-path: dist/macos/Stringcast.app
+  output-dmg-path: dist/stringcast-macos.dmg
+  volume-name: Stringcast
+USAGE
+  exit 0
+fi
+
+APP_PATH=${1:-dist/macos/Stringcast.app}
+DMG_PATH=${2:-dist/stringcast-macos.dmg}
+VOLUME_NAME=${3:-Stringcast}
+
+if [ "$(uname -s)" != "Darwin" ]; then
+  echo "macOS DMGs can only be built on macOS" >&2
+  exit 1
+fi
+
+if [ ! -d "$APP_PATH" ]; then
+  echo "missing app bundle: $APP_PATH" >&2
+  echo "run: cargo build --release && packaging/macos/build_app.sh" >&2
+  exit 1
+fi
+
+if ! command -v hdiutil >/dev/null 2>&1; then
+  echo "missing hdiutil; cannot generate DMG" >&2
+  exit 1
+fi
+
+DMG_DIR=$(dirname "$DMG_PATH")
+mkdir -p "$DMG_DIR"
+
+STAGING_DIR=$(mktemp -d "${TMPDIR:-/tmp}/stringcast-dmg.XXXXXX")
+trap 'rm -rf "$STAGING_DIR"' EXIT INT TERM
+
+cp -R "$APP_PATH" "$STAGING_DIR/Stringcast.app"
+ln -s /Applications "$STAGING_DIR/Applications"
+
+hdiutil create \
+  -volname "$VOLUME_NAME" \
+  -srcfolder "$STAGING_DIR" \
+  -ov \
+  -format UDZO \
+  "$DMG_PATH"
+
+echo "Built $DMG_PATH"