Panels: __len__, __getitem__, __iter__

Author: PierreRaybaut

cdl/core/gui/main.py

@@ -1013,7 +1013,7 @@ def calc(self, name: str, param: gds.DataSet | None = None) -> None:
     # ------GUI refresh
     def has_objects(self) -> bool:
         """Return True if sig/ima panels have any object"""
-        return sum(panel.object_number for panel in self.panels) > 0
+        return sum(len(panel) for panel in self.panels) > 0
 
     def set_modified(self, state: bool = True) -> None:
         """Set mainwindow modified state"""
@@ -1365,7 +1365,7 @@ def __edit_settings(self) -> None:
                     widget = dock.widget()
                     if isinstance(widget, DockablePlotWidget):
                         widget.update_toolbar_position()
-            if option == "ima_defaults" and self.imagepanel.object_number > 0:
+            if option == "ima_defaults" and len(self.imagepanel) > 0:
                 answer = QW.QMessageBox.question(
                     self,
                     _("Visualization settings"),

cdl/core/gui/panel/base.py

@@ -185,6 +185,12 @@ class AbstractPanel(QW.QSplitter, metaclass=AbstractPanelMeta):
     def __init__(self, parent):
         super().__init__(QC.Qt.Vertical, parent)
         self.setObjectName(self.__class__.__name__[0].lower())
+        # Check if the class implements __len__, __getitem__ and __iter__
+        for method in ("__len__", "__getitem__", "__iter__"):
+            if not hasattr(self, method):
+                raise NotImplementedError(
+                    f"Class {self.__class__.__name__} must implement method {method}"
+                )
 
     # pylint: disable=unused-argument
     def get_serializable_name(self, obj: ObjItf) -> str:
@@ -217,11 +223,6 @@ def serialize_to_hdf5(self, writer: NativeH5Writer) -> None:
     def deserialize_from_hdf5(self, reader: NativeH5Reader) -> None:
         """Deserialize whole panel from a HDF5 file"""
 
-    @property
-    @abc.abstractmethod
-    def object_number(self):
-        """Return object number"""
-
     @abc.abstractmethod
     def create_object(self) -> ObjItf:
         """Create and return object"""
@@ -296,15 +297,18 @@ def deserialize_from_hdf5(self, reader: NativeH5Reader) -> None:
                         self.add_object(obj, group.uuid, set_current=False)
                     self.selection_changed()
 
-    @property
-    def object_number(self) -> int:
-        """Return number of objects in panel
-
-        Returns:
-            number of objects (signals or images)
-        """
+    def __len__(self) -> int:
+        """Return number of objects"""
         return len(self.objmodel)
 
+    def __getitem__(self, nb: int) -> SignalObj | ImageObj:
+        """Return object from its number (1 to N)"""
+        return self.objmodel.get_object_from_number(nb)
+
+    def __iter__(self):
+        """Iterate over objects"""
+        return iter(self.objmodel)
+
     def create_object(self) -> SignalObj | ImageObj:
         """Create object (signal or image)
 
@@ -481,7 +485,7 @@ def remove_object(self) -> None:
 
     def delete_all_objects(self) -> None:  # pragma: no cover
         """Confirm before removing all objects"""
-        if self.object_number == 0:
+        if len(self) == 0:
             return
         answer = QW.QMessageBox.warning(
             self,

cdl/core/gui/panel/macro.py

@@ -151,15 +151,18 @@ def deserialize_from_hdf5(self, reader: NativeH5Reader) -> None:
                 obj = self.deserialize_object_from_hdf5(reader, name)
                 self.add_object(obj)
 
-    @property
-    def object_number(self) -> int:
-        """Return object number
-
-        Returns:
-            int: Number of objects
-        """
+    def __len__(self) -> int:
+        """Return number of objects"""
         return len(self.__macros)
 
+    def __getitem__(self, nb: int) -> Macro:
+        """Return object from its number (1 to N)"""
+        return self.__macros[nb - 1]
+
+    def __iter__(self):
+        """Iterate over objects"""
+        return iter(self.__macros)
+
     def create_object(self) -> Macro:
         """Create object.
 

cdl/tests/scenarios/common.py

@@ -34,7 +34,7 @@ def __compute_11_operations(panel: SignalPanel | ImagePanel, number: int) -> Non
     """Test compute_11 type operations on a signal or image
 
     Requires that one signal or image has been added at index."""
-    assert panel.object_number >= number - 1
+    assert len(panel) >= number - 1
     panel.objview.select_objects((number,))
     panel.processor.compute_gaussian_filter(dlp.GaussianParam())
     panel.processor.compute_moving_average(dlp.MovingAverageParam())
@@ -56,10 +56,10 @@ def compute_common_operations(panel: SignalPanel | ImagePanel) -> None:
     First signal/image is supposed to be always the same (reference)
     Second signal/image is the tested object
     """
-    assert panel.object_number == 2
+    assert len(panel) == 2
 
     panel.objview.select_objects((2,))
-    panel.processor.compute_difference()  # difference with itself
+    panel.processor.compute_difference(panel[1])  # difference with obj #1
     panel.remove_object()
     panel.objview.select_objects((2,))
     panel.processor.compute_quadratic_difference()  # quadratic difference with itself