Better axis fonts for spectrum viewers (spacetelescope#2372)

* Reduce num ticks for Mosviz
and Specviz2D spectrum viewers to avoid crowding

Adjust axis ticks and labels

* styling tweaks

Co-authored-by: jenneh <[email protected]>

* Add change log

* DOC: Tell users how to show axes again

in Cubeviz

---------

Co-authored-by: Kyle Conroy <[email protected]>
Co-authored-by: jenneh <[email protected]>

CHANGES.rst

@@ -36,6 +36,9 @@ Specviz2d
 API Changes
 -----------
 
+- Adjusted axis ticks and labels for spectrum viewers to be more readable.
+  Axes on image viewers no longer show by default. [#2372]
+
 Cubeviz
 ^^^^^^^
 

docs/cubeviz/plugins.rst

@@ -34,6 +34,7 @@ Plot Options
 ============
 
 This plugin gives access to per-viewer and per-layer plotting options.
+To show axes on image viewers, toggle on the "Show Axes" option at the bottom of the plugin.
 
 .. seealso::
 

jdaviz/app.vue

@@ -431,4 +431,12 @@ a:active {
    * appearing */
   overflow: hidden;
 }
+
+.jupyter-widgets.bqplot.figure .axislabel {
+    /* consistent with other labels (legend, buttons, plugin expansion menu labels, etc)*/
+    font-size: 15px !important;
+    font-family: Roboto, sans-serif !important;
+    font-weight: 500 !important;
+}
+
 </style>

jdaviz/configs/cubeviz/plugins/viewers.py

@@ -36,6 +36,9 @@ def __init__(self, *args, **kwargs):
         self._subscribe_to_layers_update()
         self.state.add_callback('reference_data', self._initial_x_axis)
 
+        # Hide axes by default
+        self.state.show_axes = False
+
     @property
     def _default_spectrum_viewer_reference_name(self):
         return self.jdaviz_helper._default_spectrum_viewer_reference_name

jdaviz/configs/mosviz/plugins/viewers.py

@@ -212,10 +212,22 @@ def set_plot_axes(self):
 
         self.figure.axes[1].label = "y: pixels"
         self.figure.axes[1].tick_format = None
-        self.figure.axes[1].label_location = "start"
+        self.figure.axes[1].label_location = "middle"
 
+        # Sync with Spectrum1D viewer (that is also used by other viz).
         # Make it so y axis label is not covering tick numbers.
-        self.figure.axes[1].label_offset = "-50"
+        self.figure.fig_margin["left"] = 95
+        self.figure.fig_margin["bottom"] = 60
+        self.figure.send_state('fig_margin')  # Force update
+        self.figure.axes[0].label_offset = "40"
+        self.figure.axes[1].label_offset = "-70"
+        # NOTE: with tick_style changed below, the default responsive ticks in bqplot result
+        # in overlapping tick labels.  For now we'll hardcode at 8, but this could be removed
+        # (default to None) if/when bqplot auto ticks react to styling options.
+        self.figure.axes[1].num_ticks = 8
+
+        for i in (0, 1):
+            self.figure.axes[i].tick_style = {'font-size': 15, 'font-weight': 600}
 
 
 @viewer_registry("mosviz-profile-viewer", label="Profile 1D")
@@ -230,6 +242,10 @@ class MosvizProfileView(SpecvizProfileView):
                     ['jdaviz:sidebar_plot', 'jdaviz:sidebar_export']
                 ]
 
+    def set_plot_axes(self):
+        super().set_plot_axes()
+        self.figure.axes[1].num_ticks = 5
+
 
 @viewer_registry("mosviz-table-viewer", label="Table (Mosviz)")
 class MosvizTableViewer(TableViewer, JdavizViewerMixin):

jdaviz/configs/specviz/plugins/viewers.py

@@ -544,8 +544,19 @@ def set_plot_axes(self):
         self.figure.axes[0].label = f"{spectral_axis_unit_type} [{self.state.x_display_unit}]"
         self.figure.axes[1].label = f"{flux_unit_type} [{self.state.y_display_unit}]"
 
-        # Make it so y axis label is not covering tick numbers.
-        self.figure.axes[1].label_offset = "-50"
+        # Make it so axis labels are not covering tick numbers.
+        self.figure.fig_margin["left"] = 95
+        self.figure.fig_margin["bottom"] = 60
+        self.figure.send_state('fig_margin')  # Force update
+        self.figure.axes[0].label_offset = "40"
+        self.figure.axes[1].label_offset = "-70"
+        # NOTE: with tick_style changed below, the default responsive ticks in bqplot result
+        # in overlapping tick labels.  For now we'll hardcode at 8, but this could be removed
+        # (default to None) if/when bqplot auto ticks react to styling options.
+        self.figure.axes[1].num_ticks = 8
 
         # Set Y-axis to scientific notation
         self.figure.axes[1].tick_format = '0.1e'
+
+        for i in (0, 1):
+            self.figure.axes[i].tick_style = {'font-size': 15, 'font-weight': 600}