move general funcs to interface module

1 files changed, 61 insertions, 6 deletions

diff --git a/pymba/interface.py b/pymba/interface.py
index a035b0a..fdd4675 100644
--- a/pymba/interface.py
+++ b/pymba/interface.py
@@ -1,29 +1,84 @@
-from ctypes import byref
+from ctypes import byref, sizeof, c_uint32
+from typing import List
 
 from .vimba_object import VimbaObject
 from .vimba_exception import VimbaException
 from . import vimba_c
 
 
+def _interface_infos() -> List[vimba_c.VmbInterfaceInfo]:
+    """
+    Gets interface info of all available interfaces.
+    """
+    # call once just to get the number of interfaces
+    num_found = c_uint32(-1)
+    error = vimba_c.vmb_interfaces_list(None,
+                                        0,
+                                        byref(num_found),
+                                        sizeof(vimba_c.VmbInterfaceInfo))
+    if error:
+        raise VimbaException(error)
+
+    # call again to get the features
+    num_interfaces = num_found.value
+    vmb_interface_infos = (vimba_c.VmbInterfaceInfo * num_interfaces)()
+    error = vimba_c.vmb_interfaces_list(vmb_interface_infos,
+                                        num_interfaces,
+                                        byref(num_found),
+                                        sizeof(vimba_c.VmbInterfaceInfo))
+    if error:
+        raise VimbaException(error)
+
+    return list(vmb_interface_info for vmb_interface_info in vmb_interface_infos)
+
+
+def _interface_info(interface_id: str) -> vimba_c.VmbInterfaceInfo:
+    """
+    Gets interface info object of specified interface.
+    :param interface_id: the ID of the interface object to get.
+    """
+    for vmb_interface_info in _interface_infos():
+        if interface_id == vmb_interface_info.interfaceIdString.decode():
+            return vmb_interface_info
+    raise VimbaException(VimbaException.ERR_INSTANCE_NOT_FOUND)
+
+
+def interface_ids() -> List[str]:
+    """
+    Gets IDs of all available interfaces.
+    """
+    return list(vmb_interface_info.interfaceIdString.decode()
+                for vmb_interface_info in _interface_infos())
+
+
 class Interface(VimbaObject):
     """
     A Vimba interface object. This class provides the minimal access
     to Vimba functions required to control the interface.
     """
 
-    def __init__(self, id_string: str):
-        self._id_string = id_string.encode()
+    def __init__(self, interface_id: str):
+        if interface_id not in interface_ids():
+            raise VimbaException(VimbaException.ERR_INSTANCE_NOT_FOUND)
+        self._interface_id = interface_id
         super().__init__()
 
     @property
-    def id_string(self):
-        return self._id_string.decode()
+    def interface_id(self):
+        return self._interface_id
+
+    @property
+    def info(self) -> vimba_c.VmbInterfaceInfo:
+        """
+        Get info of the interface. Does not require the interface to be opened.
+        """
+        return _interface_info(self.interface_id)
 
     def open(self):
         """
         Open the interface.
         """
-        error = vimba_c.vmb_interface_open(self._id_string,
+        error = vimba_c.vmb_interface_open(self.interface_id.encode(),
                                            byref(self._handle))
         if error:
             raise VimbaException(error)