adapt to astropy/astro-image-display-api#56

Author: bmorris3

jdaviz/configs/default/aida.py

@@ -70,6 +70,12 @@ def set_viewport(self, center=None, fov=None, image_label=None, **kwargs):
         elif hasattr(center, '__len__') and isinstance(center[0], (float, int)):
             reference_center_pix = center
 
+        else:
+            raise ValueError(
+                "The AID API supports `center` arguments as SkyCoords or as "
+                f"a tuple of floats in pixel coordinates, got {type(center)=}."
+            )
+
         current_width = self.viewer.state.x_max - self.viewer.state.x_min
         current_height = self.viewer.state.y_max - self.viewer.state.y_min
 
@@ -110,12 +116,14 @@ def _get_current_fov(self, sky_or_pixel):
                 wcs = WCS(wcs.to_fits_sip())
 
             lower_left, lower_right, upper_left = wcs.pixel_to_world(
-                [x_min, y_min, x_min], [x_max, y_min, y_max]
+                [x_min, x_max, x_min], [y_min, y_min, y_max]
+            )
+            return min(
+                lower_left.separation(lower_right),
+                lower_left.separation(upper_left),
             )
-
-            return lower_left.separation(lower_right)
         else:
-            return x_max - x_min
+            return min(abs(x_max - x_min), abs(y_max - y_min))
 
     def get_viewport(self, sky_or_pixel=None, image_label=None, **kwargs):
         """
@@ -165,6 +173,9 @@ def get_viewport(self, sky_or_pixel=None, image_label=None, **kwargs):
 
         else:
             center = (center_x, center_y)
-            fov = x_max - x_min
+            fov = min(
+                abs(x_max - x_min),
+                abs(y_max - y_min)
+            )
 
         return dict(center=center, fov=fov, image_label=image_label)

jdaviz/configs/default/tests/test_aida.py

@@ -0,0 +1,65 @@
+import pytest
+import astropy.units as u
+import numpy as np
+from astropy.coordinates import SkyCoord
+from astropy.wcs import WCS
+from astropy.tests.helper import assert_quantity_allclose
+
+
+def assert_coordinate_close(coord1, coord2, atol=1 * u.arcsec):
+    # check that two coordinates are within some separation tolerance
+    separation = coord1.separation(coord2)
+    assert_quantity_allclose(separation, desired=0*u.arcsec, atol=atol)
+
+
+def assert_angle_close(angle1, angle2, atol=1 * u.arcsec):
+    # check that two angles are within some separation tolerance
+    difference = abs(angle1 - angle2)
+    assert_quantity_allclose(difference, desired=0*u.arcsec, atol=atol)
+
+
+def test_get_viewport(imviz_helper, image_hdu_wcs):
+    imviz_helper.load_data(image_hdu_wcs)
+    viewer = imviz_helper.app.get_viewer('imviz-0')
+    viewport = viewer.aid.get_viewport()
+
+    expected_center = SkyCoord(ra=337.51894337, dec=-20.83208305, unit='deg')
+    expected_fov = 0.00277778 * u.deg
+    expected_image_label = imviz_helper.app.data_collection[0].label
+
+    # by default, the viewer y-axis is the narrower axis, which is used to
+    # define the FOV parameter. Use the WCS to find what the actual
+    # viewport dimensions are in the x-axis, which maps onto RA in this case:
+    wcs = WCS(image_hdu_wcs.header)
+    ra_unit = wcs.wcs.cunit[1]
+    delta_ra = abs(wcs.wcs.cdelt[1])
+    expected_fov = (
+        abs(viewer.state.y_max - viewer.state.y_min) *
+        delta_ra * u.Unit(ra_unit)
+    )
+    assert_coordinate_close(viewport['center'], expected_center)
+    assert_angle_close(viewport['fov'], expected_fov)
+
+    assert viewport['image_label'] == expected_image_label
+
+
+def test_set_viewport(imviz_helper, image_hdu_wcs):
+    imviz_helper.load_data(image_hdu_wcs)
+    viewer = imviz_helper.app.get_viewer('imviz-0')
+
+    # change only the center:
+    new_viewport_settings = dict(
+        center=SkyCoord(ra=337.5, dec=-20.8, unit='deg'),
+        fov=0.01 * u.deg
+    )
+    viewer.aid.set_viewport(**new_viewport_settings)
+    new_viewport = viewer.aid.get_viewport()
+
+    assert_coordinate_close(new_viewport['center'], new_viewport_settings['center'])
+
+    # todo: investigate why this tolerance needs to be larger than expected:
+    assert_angle_close(new_viewport['fov'], new_viewport_settings['fov'], atol=1 * u.arcsec)
+
+    with pytest.raises(ValueError, match='The AID API supports `center` arguments as'):
+        viewer.aid.set_viewport(center=np.array([0, 1]))
+