reworked pattern generator

python/slsdet/pattern.py

@@ -5,11 +5,14 @@ from . import _slsdet
 from ._slsdet import Pattern
 
 
-class patternParameters(_slsdet.patternParameters):
-    def __init__(self):
-        super().__init__()
-        self.view = self.numpy_view()
-        self.names = self.view.dtype.names
+class _StructViewMixin:
+    """
+    Exposes the fields of a numpy structured dtype view as attributes.
+    """
+
+    def _init_view(self, view):
+        self.__dict__["view"] = view
+        self.__dict__["names"] = view.dtype.names
 
     def __getattr__(self, name):
         if name in self.names:
@@ -18,9 +21,7 @@ class patternParameters(_slsdet.patternParameters):
             raise KeyError(f"Key: {name} not found")
 
     def __setattr__(self, name, value):
-        if name in ["view", "names"]:
-            self.__dict__[name] = value
-        elif name in self.names:
+        if name in self.names:
             self.view[name] = value
         else:
             raise KeyError(f"Key: {name} not found")
@@ -29,27 +30,24 @@ class patternParameters(_slsdet.patternParameters):
     def __dir__(self):
         return self.names
 
+    def copy(self):
+        """
+        Return a new instance with the same field values.
+        """
+        new = type(self)()
+        new.view[:] = self.view
+        return new
 
-class Pattern(_slsdet.Pattern):
+    __copy__ = copy
+
+
+class patternParameters(_StructViewMixin, _slsdet.patternParameters):
     def __init__(self):
         super().__init__()
-        self.view = self.data().numpy_view()
-        self.names = self.view.dtype.names
+        self._init_view(self.numpy_view())
 
-    def __getattr__(self, name):
-        if name in self.names:
-            return self.view[name][0]
-        else:
-            raise KeyError(f"Key: {name} not found")
 
-    def __setattr__(self, name, value):
-        if name in ["view", "names"]:
-            self.__dict__[name] = value
-        elif name in self.names:
-            self.view[name] = value
-        else:
-            raise KeyError(f"Key: {name} not found")
-
-    # Provide custom dir for tab completion
-    def __dir__(self):
-        return self.names
+class Pattern(_StructViewMixin, _slsdet.Pattern):
+    def __init__(self):
+        super().__init__()
+        self._init_view(self.data().numpy_view())