Initial draft on interface definition

Author: mwcraig

astrowidgets/interface_definition.py

@@ -0,0 +1,81 @@
+from typing import Protocol, runtime_checkable, Any
+from abc import abstractmethod
+
+
+@runtime_checkable
+class ImageViewerInterface(Protocol):
+    # This are attributes, not methods. The type annotations are there
+    # to make sure Protocol knows they are attributes. Python does not
+    # do any checking at all of these types.
+    click_center: bool
+    click_drag: bool
+    scroll_pan: bool
+    image_width: int
+    image_height: int
+    zoom_level: float
+    marker: Any
+    cuts: Any
+    stretch: str
+    # viewer: Any
+
+    # The methods, grouped loosely by purpose
+
+    # Methods for loading data
+    @abstractmethod
+    def load_fits(self, file):
+        raise NotImplementedError
+
+    @abstractmethod
+    def load_array(self, array):
+        raise NotImplementedError
+
+    @abstractmethod
+    def load_nddata(self, data):
+        raise NotImplementedError
+
+    # Saving contents of the view and accessing the view
+    @abstractmethod
+    def save(self, filename):
+        raise NotImplementedError
+
+    # Marker-related methods
+    @abstractmethod
+    def start_marking(self):
+        raise NotImplementedError
+
+    @abstractmethod
+    def stop_marking(self):
+        raise NotImplementedError
+
+    @abstractmethod
+    def add_markers(self):
+        raise NotImplementedError
+
+    @abstractmethod
+    def get_markers(self):
+        raise NotImplementedError
+
+    @abstractmethod
+    def remove_markers(self):
+        raise NotImplementedError
+
+    # @abstractmethod
+    # def get_all_markers(self):
+    #     raise NotImplementedError
+
+    # @abstractmethod
+    # def get_markers_by_name(self, marker_name=None):
+    #     raise NotImplementedError
+
+    # Methods that modify the view
+    @abstractmethod
+    def center_on(self):
+        raise NotImplementedError
+
+    @abstractmethod
+    def offset_to(self):
+        raise NotImplementedError
+
+    @abstractmethod
+    def zoom(self):
+        raise NotImplementedError

astrowidgets/tests/test_api.py

@@ -8,7 +8,13 @@
 
 from ginga.ColorDist import ColorDistBase
 
-from ..core import ImageWidget, ALLOWED_CURSOR_LOCATIONS
+from astrowidgets.core import ImageWidget, ALLOWED_CURSOR_LOCATIONS
+from astrowidgets.interface_definition import ImageViewerInterface
+
+
+def test_consistent_interface():
+    iw = ImageWidget()
+    assert isinstance(iw, ImageViewerInterface)
 
 
 def test_load_fits():