Merge pull request #6 from audiohacking/copilot/use-pywebview-for-osx-app

Replace browser launch with pywebview native window for macOS app with graceful shutdown

Author: lmangani

HeartMuLa.spec

@@ -38,6 +38,7 @@ hiddenimports += collect_submodules('heartlib')
 hiddenimports += collect_submodules('transformers')
 hiddenimports += collect_submodules('torch')
 hiddenimports += collect_submodules('torchaudio')
+hiddenimports += collect_submodules('webview')  # pywebview
 hiddenimports += ['uvicorn.logging', 'uvicorn.loops', 'uvicorn.loops.auto', 'uvicorn.protocols', 
                   'uvicorn.protocols.http', 'uvicorn.protocols.http.auto', 'uvicorn.protocols.websockets',
                   'uvicorn.protocols.websockets.auto', 'uvicorn.lifespan', 'uvicorn.lifespan.on',

README.md

@@ -154,7 +154,7 @@ Open http://localhost:5173
 
 ## macOS App (Beta)
 
-HeartMuLa Studio is available as a standalone macOS application optimized for Apple Metal GPUs.
+HeartMuLa Studio is available as a standalone macOS application with a native app window, optimized for Apple Metal GPUs.
 
 ### Download
 
@@ -193,9 +193,10 @@ This ensures:
 ### Features
 
 - **Standalone App**: No Python or Node.js installation required
+- **Native Window**: Uses pywebview for a native macOS app experience (single instance only)
 - **Apple Metal GPU**: Optimized for M1/M2/M3 and Intel Macs with Metal support
 - **Auto-Download**: Models are automatically downloaded on first launch (~5GB)
-- **Native macOS**: Code-signed and packaged with PyInstaller
+- **Code-Signed**: Packaged with PyInstaller and ad-hoc code signing
 
 ### System Requirements
 

build/macos/README.md

@@ -22,6 +22,8 @@ build/macos/
 - Node.js 18+
 - Homebrew (for icon generation tools)
 
+**Note**: The app uses pywebview for native window rendering. This is automatically included in the build.
+
 ### Automated Build Script
 
 For the easiest local build experience, use the provided build script:

launcher.py

@@ -8,11 +8,22 @@
 import os
 import sys
 import subprocess
-import webbrowser
 import time
 import shutil
 import threading
 from pathlib import Path
+import socket
+import urllib.request
+import urllib.error
+import atexit
+
+# Single instance lock port
+SINGLE_INSTANCE_PORT = 58765
+
+# Global references for cleanup
+_server_thread = None
+_lock_socket = None
+_cleanup_done = False
 
 def setup_environment():
     """Set up the macOS app environment."""
@@ -58,41 +69,151 @@ def setup_environment():
 
     return app_dir, logs_dir
 
+def check_single_instance():
+    """Check if another instance of the app is already running."""
+    # Try to bind to a port to ensure single instance
+    try:
+        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        sock.bind(('127.0.0.1', SINGLE_INSTANCE_PORT))
+        return sock  # Keep socket open to maintain lock
+    except OSError:
+        # Port is already in use - another instance is running
+        return None
+
+def cleanup():
+    """Cleanup resources on shutdown. Idempotent - safe to call multiple times."""
+    global _lock_socket, _cleanup_done
+    
+    # Prevent multiple cleanup calls
+    if _cleanup_done:
+        return
+    _cleanup_done = True
+    
+    print("\nCleaning up resources...")
+    
+    # Close the lock socket
+    if _lock_socket:
+        try:
+            _lock_socket.close()
+            print("✓ Released instance lock")
+        except (OSError, Exception):
+            pass
+    
+    # Note: Server thread is daemon and will be terminated automatically
+    print("✓ Server shutdown initiated")
+    print("Goodbye!")
+
+def wait_for_server(url='http://127.0.0.1:8000/health', timeout=30):
+    """Wait for the server to be ready by polling the health endpoint."""
+    print("Waiting for server to start...")
+    start_time = time.time()
+    while time.time() - start_time < timeout:
+        try:
+            response = urllib.request.urlopen(url, timeout=1)
+            if response.getcode() == 200:
+                print("Server is ready!")
+                return True
+        except (urllib.error.URLError, ConnectionError, OSError):
+            # Server not ready yet, wait a bit
+            time.sleep(0.5)
+    print(f"Warning: Server did not respond within {timeout} seconds")
+    return False
+
 def launch_server(app_dir, logs_dir):
     """Launch the FastAPI server."""
+    global _server_thread
+    
     # Import and run the FastAPI app
     sys.path.insert(0, str(app_dir))
 
     # Configure uvicorn to run the app
     import uvicorn
     from backend.app.main import app
 
-    # Open browser after a short delay
-    def open_browser():
-        time.sleep(3)
-        webbrowser.open("http://localhost:8000")
-    
-    browser_thread = threading.Thread(target=open_browser, daemon=True)
-    browser_thread.start()
-    
-    # Run the server
-    print(f"Starting HeartMuLa Studio server...")
-    print(f"Logs directory: {logs_dir}")
-    print(f"Opening browser at http://localhost:8000")
-    
-    uvicorn.run(
-        app,
-        host="127.0.0.1",
-        port=8000,
-        log_level="info",
-        access_log=True
-    )
+    # Run the server in a thread so pywebview can take control of main thread
+    def run_server():
+        print(f"Starting HeartMuLa Studio server...")
+        print(f"Logs directory: {logs_dir}")
+        
+        uvicorn.run(
+            app,
+            host="127.0.0.1",
+            port=8000,
+            log_level="info",
+            access_log=True
+        )
+    
+    _server_thread = threading.Thread(target=run_server, daemon=True)
+    _server_thread.start()
+    
+    # Wait for server to be ready
+    wait_for_server()
+    
+    # Launch pywebview window
+    try:
+        import webview
+        print("Opening HeartMuLa Studio window...")
+        
+        # Create window with custom settings - window object not needed
+        webview.create_window(
+            'HeartMuLa Studio',
+            'http://127.0.0.1:8000',
+            width=1400,
+            height=900,
+            resizable=True,
+            fullscreen=False,
+            min_size=(800, 600),
+            background_color='#1a1a1a',
+            text_select=True,
+            on_top=False,  # Keep in foreground but not always on top
+            focus=True     # Get focus on creation
+        )
+        
+        # Register cleanup handler for graceful shutdown
+        atexit.register(cleanup)
+        
+        # Start the webview - this blocks until window is closed
+        # When window closes, this returns and the program continues to exit
+        webview.start(gui='cocoa')  # Explicitly use Cocoa for macOS
+        
+        # Window has been closed by user
+        print("\nWindow closed by user")
+        
+    except ImportError:
+        print("Warning: pywebview not available, falling back to browser")
+        import webbrowser
+        webbrowser.open("http://127.0.0.1:8000")
+        # Keep the server running
+        while True:
+            time.sleep(1)
+    except Exception as e:
+        print(f"Error launching window: {e}")
+        print("Falling back to browser...")
+        import webbrowser
+        webbrowser.open("http://127.0.0.1:8000")
+        # Keep the server running
+        while True:
+            time.sleep(1)
 
 def main():
     """Main entry point."""
+    global _lock_socket
+    
     try:
+        # Check if another instance is already running
+        _lock_socket = check_single_instance()
+        if _lock_socket is None:
+            print("Another instance of HeartMuLa Studio is already running.")
+            print("Only one instance can be opened at a time.")
+            sys.exit(0)
+        
         app_dir, logs_dir = setup_environment()
         launch_server(app_dir, logs_dir)
+        
+        # If we reach here, the window was closed gracefully
+        # cleanup() will be called by atexit
+        sys.exit(0)
+        
     except KeyboardInterrupt:
         print("\nShutting down HeartMuLa Studio...")
         sys.exit(0)

requirements_macos.txt

@@ -45,5 +45,5 @@ triton>=2.0.0; platform_machine != "arm64"
 # PyInstaller for macOS App Bundle
 pyinstaller>=6.0,<7.0
 
-# PyWebView for native macOS UI (optional, for future native UI - not currently used)
-# pywebview>=4.0
+# PyWebView for native macOS UI
+pywebview>=4.0