Add tests for set/get viewport

Author: mwcraig

src/astro_image_display_api/widget_api_test.py

@@ -92,38 +92,159 @@ def test_load(self, data, tmp_path, load_type):
 
         self.image.load_image(load_arg)
 
-    def test_center_on(self):
-        self.image.center_on((10, 10))  # X, Y
+    def test_set_get_center_xy(self, data):
+        self.image.load_image(data, image_label='test')
+        self.image.set_viewport(center=(10, 10), image_label='test')  # X, Y
+        vport = self.image.get_viewport(image_label='test')
+        assert vport['center'] == (10, 10)
+        assert vport['image_label'] == 'test'
+
+    def test_set_get_center_world(self, data, wcs):
+        self.image.load_image(NDData(data=data, wcs=wcs), image_label='test')
+        self.image.set_viewport(center=SkyCoord(*wcs.crval, unit='deg'), image_label='test')
+
+        vport = self.image.get_viewport(image_label='test')
+        assert isinstance(vport['center'], SkyCoord)
+        assert vport['center'].ra.deg == pytest.approx(wcs.crval[0])
+        assert vport['center'].dec.deg == pytest.approx(wcs.crval[1])
+
+    def test_set_get_fov_pixel(self, data):
+        # Set data first, since that is needed to determine zoom level
+        self.image.load_image(data, image_label='test')
 
-    def test_offset_by(self, data, wcs):
-        self.image.offset_by(10, 10)  # dX, dY
+        self.image.set_viewport(fov=100, image_label='test')
+        vport = self.image.get_viewport(image_label='test')
+        assert vport['fov'] == 100
+        assert vport['image_label'] == 'test'
 
-        # Testing offset by WCS requires a WCS. The viewer will (or ought to
-        # 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_image(ndd)
+    def test_set_get_fov_world(self, data, wcs):
+        # Set data first, since that is needed to determine zoom level
+        self.image.load_image(NDData(data=data, wcs=wcs), image_label='test')
 
-        self.image.offset_by(10 * u.arcmin, 10 * u.arcmin)
+        # Set the FOV in world coordinates
+        self.image.set_viewport(fov=0.1 * u.deg, image_label='test')
+        vport = self.image.get_viewport(image_label='test')
+        assert isinstance(vport['fov'], SkyCoord)
+        assert vport['fov'].deg == pytest.approx(0.1)
 
-        # A mix of pixel and sky should produce an error
-        with pytest.raises(u.UnitConversionError, match='are not convertible'):
-            self.image.offset_by(10 * u.arcmin, 10)
+    def test_set_get_viewport_errors(self, data, wcs):
+        self.image.load_image(NDData(data=data, wcs=wcs), image_label='test')
 
-        # A mix of inconsistent units should produce an error
-        with pytest.raises(u.UnitConversionError, match='are not convertible'):
-            self.image.offset_by(1 * u.arcsec, 1 * u.AA)
+        # fov can be float or an angular Qunatity
+        with pytest.raises(u.UnitTypeError, match='[Ii]ncorrect unit for fov'):
+            self.image.set_viewport(fov=100 * u.meter, image_label='test')
 
-    def test_zoom_level(self, data):
-        # Set data first, since that is needed to determine zoom level
+        # try an fov that is completely the wrong type
+        with pytest.raises(TypeError, match='[Ii]nvalid value for fov'):
+            self.image.set_viewport(fov='not a valid value', image_label='test')
+
+        # center can be a SkyCoord or a tuple of floats. Try a value that is neither
+        with pytest.raises(TypeError, match='[Ii]nvalid value for center'):
+            self.image.set_viewport(center='not a valid value', image_label='test')
+
+        # Check that an error is raised if a label is provided that does not
+        # match an image that is loaded.
+        with pytest.raises(ValueError, match='[Ii]mage label.*not found'):
+            self.image.set_viewport(center=(10, 10), fov=100, image_label='not a valid label')
+
+        # Getting a viewport for an image_label that does not exist should raise an error
+        with pytest.raises(ValueError, match='[Ii]mage label.*not found'):
+            self.image.get_viewport(image_label='not a valid label')
+
+        # If there are multiple images loaded, the image_label must be provided
+        self.image.load_image(data, image_label='another test')
+
+        with pytest.raises(ValueError, match='[Ii]mage label.*not provided'):
+            self.image.get_viewport()
+
+    def test_set_get_view_port_no_image_label(self, data):
+        # If there is only one image, the viewport should be able to be set
+        # and retrieved without an image label.
+
+        # Add an image without an image label
         self.image.load_image(data)
-        self.image.zoom_level = 5
-        assert self.image.zoom_level == 5
 
-    def test_zoom(self):
-        self.image.zoom_level = 3
-        self.image.zoom(2)
-        assert self.image.zoom_level == 6  # 3 x 2
+        # Getting the viewport should not fail...
+        vport = self.image.get_viewport()
+        assert 'center' in vport
+        assert 'fov' in vport
+        assert 'image_label' in vport
+        assert vport['image_label'] is None
+
+        # Set the viewport without an image label
+        self.image.set_viewport(center=(10, 10), fov=100)
+
+        # Getting the viewport again should return the same values
+        vport = self.image.get_viewport()
+        assert vport['center'] == (10, 10)
+        assert vport['fov'] == 100
+        assert vport['image_label'] is None
+
+    def test_set_get_viewport_single_label(self, data):
+        # If there is only one image, the viewport should be able to be set
+        # and retrieved with an image label.
+
+        # Add an image with an image label
+        self.image.load_image(data, image_label='test')
+
+        # Getting the viewport should not fail...
+        vport = self.image.get_viewport(image_label='test')
+        assert 'center' in vport
+        assert 'fov' in vport
+        assert 'image_label' in vport
+        assert vport['image_label'] == 'test'
+
+        # Set the viewport with an image label
+        self.image.set_viewport(center=(10, 10), fov=100, image_label='test')
+
+        # Getting the viewport again should return the same values
+        vport = self.image.get_viewport(image_label='test')
+        assert vport['center'] == (10, 10)
+        assert vport['fov'] == 100
+        assert vport['image_label'] == 'test'
+
+    def test_get_viewport_sky_or_pixel(self, data, wcs):
+        # Check that the viewport can be retrieved in both pixel and world
+        # coordinates, depending on the WCS of the image.
+
+        # Load the data with a WCS
+        self.image.load_image(NDData(data=data, wcs=wcs), image_label='test')
+
+        input_center = SkyCoord(*wcs.val, unit='deg')
+        input_fov = 2 * u.arcmin
+        self.image.set_viewport(center=input_center, fov=input_fov, image_label='test')
+
+        # Get the viewport in pixel coordinates
+        vport_pixel = self.image.get_viewport(image_label='test', sky_or_pixel='pixel')
+        assert vport_pixel['center'] == wcs.crpix
+        # tbh, not at all sure what the fov should be in pixel coordinates,
+        # so just check that it is a float.
+        assert isinstance(vport_pixel['fov'], float)
+
+        # Get the viewport in world coordinates
+        vport_world = self.image.get_viewport(image_label='test', sky_or_pixel='sky')
+        assert vport_world['center'] == input_center
+        assert vport_world['fov'] == input_fov
+
+    @pytest.mark.parametrize("sky_or_pixel", ['sky', 'pixel'])
+    def test_get_viewport_no_sky_or_pixel(self, data, wcs, sky_or_pixel):
+        # Check that get_viewport returns the correct "default" sky_or_pixel
+        # value when the result ought to be unambiguous.
+        if sky_or_pixel == 'sky':
+            use_wcs = wcs
+        else:
+            use_wcs = None
+
+        self.image.load_image(NDData(data=data, wcs=use_wcs), image_label='test')
+
+        vport = self.image.get_viewport(image_label='test')
+        match sky_or_pixel:
+            case 'sky':
+                assert isinstance(vport['center'], SkyCoord)
+                assert vport['fov'].unit.physical_type == "angle"
+            case 'pixel':
+                assert isinstance(vport['center'], tuple)
+                assert isinstance(vport['fov'], float)
 
     def test_marker_properties(self):
         # Set the marker style