factory.py•5.83 kB
"""
Backend factory for creating appropriate KiCAD API backend
Auto-detects available backends and provides fallback mechanism.
"""
import os
import logging
from typing import Optional
from pathlib import Path
from kicad_api.base import KiCADBackend, APINotAvailableError
logger = logging.getLogger(__name__)
def create_backend(backend_type: Optional[str] = None) -> KiCADBackend:
"""
Create appropriate KiCAD backend
Args:
backend_type: Backend to use:
- 'ipc': Use IPC API (recommended)
- 'swig': Use legacy SWIG bindings
- None or 'auto': Auto-detect (try IPC first, fall back to SWIG)
Returns:
KiCADBackend instance
Raises:
APINotAvailableError: If no backend is available
Environment Variables:
KICAD_BACKEND: Override backend selection ('ipc', 'swig', or 'auto')
"""
# Check environment variable override
if backend_type is None:
backend_type = os.environ.get('KICAD_BACKEND', 'auto').lower()
logger.info(f"Requested backend: {backend_type}")
# Try specific backend if requested
if backend_type == 'ipc':
return _create_ipc_backend()
elif backend_type == 'swig':
return _create_swig_backend()
elif backend_type == 'auto':
return _auto_detect_backend()
else:
raise ValueError(f"Unknown backend type: {backend_type}")
def _create_ipc_backend() -> KiCADBackend:
"""
Create IPC backend
Returns:
IPCBackend instance
Raises:
APINotAvailableError: If kicad-python not available
"""
try:
from kicad_api.ipc_backend import IPCBackend
logger.info("Creating IPC backend")
return IPCBackend()
except ImportError as e:
logger.error(f"IPC backend not available: {e}")
raise APINotAvailableError(
"IPC backend requires 'kicad-python' package. "
"Install with: pip install kicad-python"
) from e
def _create_swig_backend() -> KiCADBackend:
"""
Create SWIG backend
Returns:
SWIGBackend instance
Raises:
APINotAvailableError: If pcbnew not available
"""
try:
from kicad_api.swig_backend import SWIGBackend
logger.info("Creating SWIG backend")
logger.warning(
"SWIG backend is DEPRECATED and will be removed in KiCAD 10.0. "
"Please migrate to IPC backend."
)
return SWIGBackend()
except ImportError as e:
logger.error(f"SWIG backend not available: {e}")
raise APINotAvailableError(
"SWIG backend requires 'pcbnew' module. "
"Ensure KiCAD Python module is in PYTHONPATH."
) from e
def _auto_detect_backend() -> KiCADBackend:
"""
Auto-detect best available backend
Priority:
1. IPC API (if kicad-python available and KiCAD running)
2. SWIG API (if pcbnew available)
Returns:
Best available KiCADBackend
Raises:
APINotAvailableError: If no backend available
"""
logger.info("Auto-detecting available KiCAD backend...")
# Try IPC first (preferred)
try:
backend = _create_ipc_backend()
# Test connection
if backend.connect():
logger.info("✓ IPC backend available and connected")
return backend
else:
logger.warning("IPC backend available but connection failed")
except (ImportError, APINotAvailableError) as e:
logger.debug(f"IPC backend not available: {e}")
# Fall back to SWIG
try:
backend = _create_swig_backend()
logger.warning(
"Using deprecated SWIG backend. "
"For best results, use IPC API with KiCAD running."
)
return backend
except (ImportError, APINotAvailableError) as e:
logger.error(f"SWIG backend not available: {e}")
# No backend available
raise APINotAvailableError(
"No KiCAD backend available. Please install either:\n"
" - kicad-python (recommended): pip install kicad-python\n"
" - Ensure KiCAD Python module (pcbnew) is in PYTHONPATH"
)
def get_available_backends() -> dict:
"""
Check which backends are available
Returns:
Dictionary with backend availability:
{
'ipc': {'available': bool, 'version': str or None},
'swig': {'available': bool, 'version': str or None}
}
"""
results = {}
# Check IPC (kicad-python uses 'kipy' module name)
try:
import kipy
results['ipc'] = {
'available': True,
'version': getattr(kipy, '__version__', 'unknown')
}
except ImportError:
results['ipc'] = {'available': False, 'version': None}
# Check SWIG
try:
import pcbnew
results['swig'] = {
'available': True,
'version': pcbnew.GetBuildVersion()
}
except ImportError:
results['swig'] = {'available': False, 'version': None}
return results
if __name__ == "__main__":
# Quick diagnostic
import json
print("KiCAD Backend Availability:")
print(json.dumps(get_available_backends(), indent=2))
print("\nAttempting to create backend...")
try:
backend = create_backend()
print(f"✓ Created backend: {type(backend).__name__}")
if backend.connect():
print(f"✓ Connected to KiCAD: {backend.get_version()}")
else:
print("✗ Failed to connect to KiCAD")
except Exception as e:
print(f"✗ Error: {e}")