Merge pull request astropy#42 from mwcraig/unload-some-cruft

Combine load_ methods into single load method

Author: mwcraig

src/astro_image_display_api/dummy_viewer.py

@@ -89,7 +89,7 @@ def cursor(self, value: str) -> None:
     # The methods, grouped loosely by purpose
 
     # Methods for loading data
-    def load_fits(self, file: str | os.PathLike) -> None:
+    def load_image(self, file: str | os.PathLike | ArrayLike | NDData) -> None:
         """
         Load a FITS file into the viewer.
 
@@ -99,6 +99,22 @@ def load_fits(self, file: str | os.PathLike) -> None:
             The FITS file to load. If a string, it can be a URL or a
             file path.
         """
+        if isinstance(file, (str, os.PathLike)):
+            if isinstance(file, str):
+                is_adsf = file.endswith(".asdf")
+            else:
+                is_asdf = file.suffix == ".asdf"
+            if is_asdf:
+                self._load_asdf(file)
+            else:
+                self._load_fits(file)
+        elif isinstance(file, NDData):
+            self._load_nddata(file)
+        else:
+            # Assume it is a 2D array
+            self._load_array(file)
+
+    def _load_fits(self, file: str | os.PathLike) -> None:
         ccd = CCDData.read(file)
         self._wcs = ccd.wcs
         self.image_height, self.image_width = ccd.shape
@@ -107,7 +123,7 @@ def load_fits(self, file: str | os.PathLike) -> None:
         self.zoom_level = 1.0
         self.center_on((self.image_width / 2, self.image_height / 2))
 
-    def load_array(self, array: ArrayLike) -> None:
+    def _load_array(self, array: ArrayLike) -> None:
         """
         Load a 2D array into the viewer.
 
@@ -123,7 +139,7 @@ def load_array(self, array: ArrayLike) -> None:
         self.center_on((self.image_width / 2, self.image_height / 2))
 
 
-    def load_nddata(self, data: NDData) -> None:
+    def _load_nddata(self, data: NDData) -> None:
         """
         Load an `astropy.nddata.NDData` object into the viewer.
 
@@ -140,6 +156,12 @@ def load_nddata(self, data: NDData) -> None:
         self.zoom_level = 1.0
         self.center_on((self.image_width / 2, self.image_height / 2))
 
+    def _load_asdf(self, asdf_file: str | os.PathLike) -> None:
+        """
+        Not implementing some load types is fine.
+        """
+        raise NotImplementedError("ASDF loading is not implemented in this dummy viewer.")
+
     # Saving contents of the view and accessing the view
     def save(self, filename: str | os.PathLike, overwrite: bool = False) -> None:
         """

src/astro_image_display_api/interface_definition.py

@@ -49,41 +49,19 @@ class ImageViewerInterface(Protocol):
 
     # The methods, grouped loosely by purpose
 
-    # Methods for loading data
+    # Method for loading image data
     @abstractmethod
-    def load_fits(self, file: str | os.PathLike) -> None:
+    def load_image(self, data: Any) -> None:
         """
-        Load a FITS file into the viewer.
+        Load data into the viewer. At a minimum, this should allow a FITS file
+        to be loaded. Viewers may allow additional data types to be loaded, such as
+        2D arrays or `astropy.nddata.NDData` objects.
 
         Parameters
         ----------
-        file : str or `astropy.io.fits.HDU`
-            The FITS file to load. If a string, it can be a URL or a
-            file path.
-        """
-        raise NotImplementedError
-
-    @abstractmethod
-    def load_array(self, array: ArrayLike) -> None:
-        """
-        Load a 2D array into the viewer.
-
-        Parameters
-        ----------
-        array : array-like
-            The array to load.
-        """
-        raise NotImplementedError
-
-    @abstractmethod
-    def load_nddata(self, data: NDData) -> None:
-        """
-        Load an `astropy.nddata.NDData` object into the viewer.
-
-        Parameters
-        ----------
-        data : `astropy.nddata.NDData`
-            The NDData object to load.
+        data : Any
+            The data to load. This can be a FITS file, a 2D array,
+            or an `astropy.nddata.NDData` object.
         """
         raise NotImplementedError
 

src/astro_image_display_api/widget_api_test.py

@@ -1,4 +1,3 @@
-# TODO: How to enable switching out backend and still run the same tests?
 
 import pytest
 
@@ -76,19 +75,21 @@ def test_width_height(self):
         assert self.image.image_width == width
         assert self.image.image_height == height
 
-    def test_load_fits(self, data, tmp_path):
-        hdu = fits.PrimaryHDU(data=data)
-        image_path = tmp_path / 'test.fits'
-        hdu.header["BUNIT"] = "adu"
-        hdu.writeto(image_path)
-        self.image.load_fits(image_path)
-
-    def test_load_nddata(self, data):
-        nddata = NDData(data)
-        self.image.load_nddata(nddata)
-
-    def test_load_array(self, data):
-        self.image.load_array(data)
+    @pytest.mark.parametrize("load_type", ["fits", "nddata", "array"])
+    def test_load(self, data, tmp_path, load_type):
+        match load_type:
+            case "fits":
+                hdu = fits.PrimaryHDU(data=data)
+                image_path = tmp_path / 'test.fits'
+                hdu.header["BUNIT"] = "adu"
+                hdu.writeto(image_path)
+                load_arg = image_path
+            case "nddata":
+                load_arg = NDData(data=data)
+            case "array":
+                load_arg = data
+
+        self.image.load_image(load_arg)
 
     def test_center_on(self):
         self.image.center_on((10, 10))  # X, Y
@@ -100,7 +101,7 @@ def test_offset_by(self, data, wcs):
         # have) taken care of setting up the WCS internally if initialized with
         # an NDData that has a WCS.
         ndd = NDData(data=data, wcs=wcs)
-        self.image.load_nddata(ndd)
+        self.image.load_image(ndd)
 
         self.image.offset_by(10 * u.arcmin, 10 * u.arcmin)
 
@@ -114,7 +115,7 @@ def test_offset_by(self, data, wcs):
 
     def test_zoom_level(self, data):
         # Set data first, since that is needed to determine zoom level
-        self.image.load_array(data)
+        self.image.load_image(data)
         self.image.zoom_level = 5
         assert self.image.zoom_level == 5
 
@@ -131,8 +132,6 @@ def test_marker_properties(self):
         for key in marker_style.keys():
             assert key in m_str
 
-    # TODO: add test that checks that retrieving markers with an unknown name issues no error
-
     def test_add_markers(self):
         original_marker_name = self.image.DEFAULT_MARKER_NAME
         data = np.arange(10).reshape(5, 2)
@@ -248,7 +247,7 @@ def test_remove_marker_accepts_list(self):
 
     def test_adding_markers_as_world(self, data, wcs):
         ndd = NDData(data=data, wcs=wcs)
-        self.image.load_nddata(ndd)
+        self.image.load_image(ndd)
 
         # Add markers using world coordinates
         pixels = np.linspace(0, 100, num=10).reshape(5, 2)
@@ -294,7 +293,7 @@ def test_cuts(self, data):
         assert 'histogram' in self.image.autocut_options
 
         # Setting using histogram requires data
-        self.image.load_array(data)
+        self.image.load_image(data)
         self.image.cuts = 'histogram'
         assert len(self.image.cuts) == 2