expose zoom_to_selected in catalogs plugin api, fix default zoom level

CHANGES.rst

@@ -27,6 +27,11 @@ Imviz
 - Catalog Search plugin now exposes a maximum sources limit for all catalogs and resolves an edge case
   when loading a catalog from a file that only contains one source. [#3337]
 
+- Catalog Search plugin ``zoom_to_selected`` is now in the public API. The default
+  zoom level changed from a fixed 50 pixels to a zoom window that is a fraction of
+  the image size (default 2%) to address and issue with zooming when using a small
+  image or WCS linked. [#3369]
+
 Mosviz
 ^^^^^^
 

jdaviz/configs/imviz/plugins/catalogs/catalogs.py

@@ -29,6 +29,7 @@ class Catalogs(PluginTemplateMixin, ViewerSelectMixin, HasFileImportSelect, Tabl
     * :meth:`~jdaviz.core.template_mixin.PluginTemplateMixin.show`
     * :meth:`~jdaviz.core.template_mixin.PluginTemplateMixin.open_in_tray`
     * :meth:`~jdaviz.core.template_mixin.PluginTemplateMixin.close_in_tray`
+    * :meth:`zoom_to_selected`
     """
     template_file = __file__, "catalogs.vue"
     uses_active_status = Bool(True).tag(sync=True)
@@ -49,7 +50,8 @@ class Catalogs(PluginTemplateMixin, ViewerSelectMixin, HasFileImportSelect, Tabl
 
     @property
     def user_api(self):
-        return PluginUserApi(self, expose=('clear_table', 'export_table',))
+        return PluginUserApi(self, expose=('clear_table', 'export_table',
+                                           'zoom_to_selected'))
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
@@ -324,23 +326,62 @@ def plot_selected_points(self):
                                                            getattr(y, 'value', y))
 
     def vue_zoom_in(self, *args, **kwargs):
-        """This function will zoom into the image based on the selected points"""
+
+        self.zoom_to_selected()
+
+    def zoom_to_selected(self, padding=0.02, return_bounding_box=False):
+        """
+        Zoom on the default viewer to a region containing the currently selected
+        points in the catalog.
+
+        Parameters
+        ----------
+        padding : float, optional
+            A fractional value representing the padding around the bounding box
+            of the selected points. It is applied as a proportion of the largest
+            dimension of the current extent of loaded data. Defaults to 0.02.
+        return_bounding_box : bool, optional
+            If True, returns the bounding box of the zoomed region as
+            ((x_min, x_max), (y_min, y_max)). Defaults to False.
+
+        Returns
+        -------
+        list of float or None
+            If there are activley selected rows, and ``return_bounding_box`` is
+            True, returns a list containing the bounding
+            box coordinates: [x_min, x_max, y_min, y_max].
+            Otherwise, returns None.
+
+        """
+
+        viewer = self.app._jdaviz_helper._default_viewer
+
         selected_rows = self.table.selected_rows
 
+        if not len(selected_rows):
+            return
+
+        if padding <= 0 or padding > 1:
+            raise ValueError("`padding` must be between 0 and 1.")
+
         x = [float(coord['x_coord']) for coord in selected_rows]
         y = [float(coord['y_coord']) for coord in selected_rows]
 
+        limits = viewer.state._get_reset_limits()
+        max_dim = max((limits[1] - limits[0]), (limits[3] - limits[2]))
+        padding = max_dim * padding
+
         # this works with single selected points
         # zooming when the range is too large is not performing correctly
-        x_min = min(x) - 50
-        x_max = max(x) + 50
-        y_min = min(y) - 50
-        y_max = max(y) + 50
+        x_min = min(x) - padding
+        x_max = max(x) + padding
+        y_min = min(y) - padding
+        y_max = max(y) + padding
 
-        self.app._jdaviz_helper._default_viewer.set_limits(
-            x_min=x_min, x_max=x_max, y_min=y_min, y_max=y_max)
+        viewer.set_limits(x_min=x_min, x_max=x_max, y_min=y_min, y_max=y_max)
 
-        return (x_min, x_max), (y_min, y_max)
+        if return_bounding_box:
+            return [x_min, x_max, y_min, y_max]
 
     def import_catalog(self, catalog):
         """

jdaviz/configs/imviz/tests/test_catalogs.py

@@ -22,11 +22,12 @@
 '''
 
 import numpy as np
+from numpy.testing import assert_allclose
 import pytest
 
+from astropy.coordinates import SkyCoord
 from astropy.io import fits
 from astropy.nddata import NDData
-from astropy.coordinates import SkyCoord
 from astropy.table import Table, QTable
 
 
@@ -157,7 +158,9 @@ def test_plugin_image_with_result(self, imviz_helper, tmp_path):
         assert imviz_helper.viewers['imviz-0']._obj.state.y_min == -0.5
         assert imviz_helper.viewers['imviz-0']._obj.state.y_max == 1488.5
 
-        catalogs_plugin.vue_zoom_in()
+        # set 'padding' to reproduce original hard-coded 50 pixel window
+        # so test results don't change
+        catalogs_plugin.zoom_to_selected(padding=50 / 2048)
 
         assert imviz_helper.viewers['imviz-0']._obj.state.x_min == 858.24969
         assert imviz_helper.viewers['imviz-0']._obj.state.x_max == 958.38461
@@ -251,9 +254,83 @@ def test_offline_ecsv_catalog(imviz_helper, image_2d_wcs, tmp_path):
     assert imviz_helper.viewers['imviz-0']._obj.state.y_min == -0.5
     assert imviz_helper.viewers['imviz-0']._obj.state.y_max == 9.5
 
-    catalogs_plugin.vue_zoom_in()
+    # test the zooming using the default 'padding' of 2% of the viewer size
+    # around selected points
+    catalogs_plugin.zoom_to_selected()
+    assert imviz_helper.viewers['imviz-0']._obj.state.x_min == -0.19966
+    assert imviz_helper.viewers['imviz-0']._obj.state.x_max == 0.20034000000000002
+    assert imviz_helper.viewers['imviz-0']._obj.state.y_min == 0.8000100000000001
+    assert imviz_helper.viewers['imviz-0']._obj.state.y_max == 1.20001
+
+
+def test_zoom_to_selected(imviz_helper, image_2d_wcs, tmp_path):
+
+    arr = np.ones((500, 500))
+    ndd = NDData(arr, wcs=image_2d_wcs)
+    imviz_helper.load_data(ndd)
+
+    # write out catalog to file so we can read it back in
+    # todo: if tables can be loaded directly at some point, do that
+
+    # sources at pixel coords ~(100, 100), ~(200, 200)
+    sky_coord = SkyCoord(ra=[337.49056532, 337.46086081],
+                         dec=[-20.80555273, -20.7777673], unit='deg')
+    tbl = Table({'sky_centroid': [sky_coord],
+                 'label': ['Source_1', 'Source_2']})
+    tbl_file = str(tmp_path / 'test_catalog.ecsv')
+    tbl.write(tbl_file, overwrite=True)
+
+    catalogs_plugin = imviz_helper.plugins['Catalog Search']
+
+    catalogs_plugin._obj.from_file = tbl_file
+
+    catalogs_plugin._obj.search()
+
+    # select both sources
+    catalogs_plugin._obj.table.selected_rows = catalogs_plugin._obj.table.items
+
+    # check viewer limits before zoom
+    xmin, xmax, ymin, ymax = imviz_helper.app._jdaviz_helper._default_viewer.get_limits()
+    assert xmin == ymin == -0.5
+    assert xmax == ymax == 499.5
+
+    # zoom to selected sources
+    catalogs_plugin.zoom_to_selected()
+
+    # make sure the viewer bounds reflect the zoom, which, in pixel coords,
+    # should be centered at roughly pixel coords (150, 150)
+    xmin, xmax, ymin, ymax = imviz_helper.app._jdaviz_helper._default_viewer.get_limits()
+
+    assert_allclose((xmin + xmax) / 2, 150., atol=0.1)
+    assert_allclose((ymin + ymax) / 2, 150., atol=0.1)
+
+    # and the zoom box size should reflect the default padding of 2% of the image
+    # size around the bounding box containing the source(s), which in this case is
+    # 10 pixels around
+    assert_allclose(xmin, 100 - 10, atol=0.1)  # min x of selected sources minus pad
+    assert_allclose(xmax, 200 + 10, atol=0.1)  # max x of selected sources plus pad
+    assert_allclose(ymin, 100 - 10, atol=0.1)  # min y of selected sources minus pad
+    assert_allclose(ymax, 200 + 10, atol=0.1)  # max y of selected sources plus pad
+
+    # select one source now
+    catalogs_plugin._obj.table.selected_rows = catalogs_plugin._obj.table.items[0:1]
+
+    # zoom to single selected source, using a new value for 'padding'
+    catalogs_plugin.zoom_to_selected(padding=0.05)
+
+    # check that zoom window is centered correctly on the source at 100, 100
+    xmin, xmax, ymin, ymax = imviz_helper.app._jdaviz_helper._default_viewer.get_limits()
+    assert_allclose((xmin + xmax) / 2, 100., atol=0.1)
+    assert_allclose((ymin + ymax) / 2, 100., atol=0.1)
+
+    # and the zoom box size should reflect the default padding of 5% of the image
+    # size around the bounding box containing the source(s), which in this case is
+    # 25 pixels around
+    assert_allclose(xmin, 100 - 25, atol=0.1)  # min x of selected source minus pad
+    assert_allclose(xmax, 100 + 25, atol=0.1)  # max x of selected source plus pad
+    assert_allclose(ymin, 100 - 25, atol=0.1)  # min y of selected source minus pad
+    assert_allclose(ymax, 100 + 25, atol=0.1)  # max y of selected source plus pad
 
-    assert imviz_helper.viewers['imviz-0']._obj.state.x_min == -49.99966
-    assert imviz_helper.viewers['imviz-0']._obj.state.x_max == 50.00034
-    assert imviz_helper.viewers['imviz-0']._obj.state.y_min == -48.99999
-    assert imviz_helper.viewers['imviz-0']._obj.state.y_max == 51.00001
+    # test that appropriate error is raised when padding is not a valud percentage
+    with pytest.raises(ValueError, match="`padding` must be between 0 and 1."):
+        catalogs_plugin.zoom_to_selected(padding=5)