Hover spectrum with extra axis

CHANGES.rst

@@ -17,6 +17,8 @@ Cubeviz
 
 - Moment map plugin now supports linear per-spaxel continuum subtraction. [#2587]
 
+- Single-pixel subset tool now shows spectrum-at-spaxel on hover. [#2647]
+
 Imviz
 ^^^^^
 

docs/cubeviz/displaycubes.rst

@@ -99,9 +99,10 @@ the bottom of the UI.
 Spectrum At Spaxel
 ==================
 
-This tool allows the user to create a one spaxel subset in an image viewer. This subset will then be
+This tool allows the user to create a single-spaxel subset in an image viewer. This subset will then be
 visualized in the spectrum viewer by showing the spectrum at that spaxel.
-Activate this tool and then left-click to create the new region.
+While this tool is active, hovering over a pixel in the image viewer will show a preview of the spectrum
+at that spaxel in the spectrum viewer, and left-clicking will create a new subset at that spaxel.
 Click again to move the region to a new location under the cursor. Holding down the
 alt key (Alt key on Windows, Option key on Mac) while clicking on a spaxel creates a new subset at
 that point instead of moving the previously created region.
@@ -110,6 +111,11 @@ You can also use the subset modes that are explained in the
 :ref:`Spatial Regions <imviz_defining_spatial_regions>`
 section above in the same way you would with the other subset selection tools.
 
+Note that moving the cursor outside of the image viewer or deactivating the spectrum-at-spaxel tool
+will revert the spectrum viewer zoom limits from the zoomed-in preview view to the limits set prior
+to using the tool. Thus it may be necessary to reset the zoom to see any single-spaxel subset spectra
+created using the tool.
+
 .. _cubeviz-display-settings:
 
 Display Settings

jdaviz/configs/cubeviz/plugins/tests/test_tools.py

@@ -18,6 +18,12 @@ def test_spectrum_at_spaxel(cubeviz_helper, spectrum1d_cube):
     assert len(flux_viewer.native_marks) == 2
     assert len(spectrum_viewer.data()) == 1
 
+    # Move to spaxel location
+    flux_viewer.toolbar.active_tool.on_mouse_move(
+        {'event': 'mousemove', 'domain': {'x': x, 'y': y}, 'altKey': False})
+    assert flux_viewer.toolbar.active_tool._mark in spectrum_viewer.figure.marks
+    assert flux_viewer.toolbar.active_tool._mark.visible is True
+
     # Click on spaxel location
     flux_viewer.toolbar.active_tool.on_mouse_event(
         {'event': 'click', 'domain': {'x': x, 'y': y}, 'altKey': False})
@@ -30,6 +36,11 @@ def test_spectrum_at_spaxel(cubeviz_helper, spectrum1d_cube):
     assert len(subsets) == 1
     assert isinstance(reg, RectanglePixelRegion)
 
+    # Mouse leave event
+    flux_viewer.toolbar.active_tool.on_mouse_move(
+        {'event': 'mouseleave', 'domain': {'x': x, 'y': y}, 'altKey': False})
+    assert flux_viewer.toolbar.active_tool._mark.visible is False
+
     # Deselect tool
     flux_viewer.toolbar.active_tool = None
     assert len(flux_viewer.native_marks) == 3

jdaviz/configs/cubeviz/plugins/tools.py

@@ -1,13 +1,16 @@
 import time
 import os
 
+import bqplot
 from glue.config import viewer_tool
 from glue_jupyter.bqplot.image import BqplotImageView
 from glue.viewers.common.tool import CheckableTool
+import numpy as np
 
 from jdaviz.configs.imviz.plugins.tools import _MatchedZoomMixin
 from jdaviz.core.events import SliceToolStateMessage
 from jdaviz.core.tools import PanZoom, BoxZoom, SinglePixelRegion
+from jdaviz.core.marks import PluginLine
 
 __all__ = []
 
@@ -83,3 +86,97 @@ class SpectrumPerSpaxel(SinglePixelRegion):
     tool_id = 'jdaviz:spectrumperspaxel'
     action_text = 'See spectrum at a single spaxel'
     tool_tip = 'Click on the viewer and see the spectrum at that spaxel in the spectrum viewer'
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self._spectrum_viewer = None
+        self._extra_axis = bqplot.Axis(grid_lines='none', label="", num_ticks=8,
+                                        orientation='vertical', scale=bqplot.LinearScale(),
+                                        side='right', tick_format='0.1e',
+                                        tick_style={'font-size': 15, 'font-weight': 600},
+                                        color="#c75d2c", grid_color="#c75d2c")
+        self._previous_bounds = None
+        self._mark = None
+        self._data = None
+
+    def _reset_spectrum_viewer_bounds(self):
+        sv_state = self._spectrum_viewer.state
+        sv_state.x_min = self._previous_bounds[0]
+        sv_state.x_max = self._previous_bounds[1]
+        sv_state.y_min = self._previous_bounds[2]
+        sv_state.y_max = self._previous_bounds[3]
+
+    def activate(self):
+        # Add callbacks (click is handled by super())
+        self.viewer.add_event_callback(self.on_mouse_move, events=['mousemove', 'mouseleave', 'mouseenter'])
+        # Get the spectrum viewer if activating for first time
+        if self._spectrum_viewer is None:
+            self._spectrum_viewer = self.viewer.jdaviz_helper.app.get_viewer('spectrum-viewer')
+        # Add extra y-axis to show on right hand side of spectrum viewer
+        if self._extra_axis not in self._spectrum_viewer.figure.axes:
+            self._spectrum_viewer.figure.axes.append(self._extra_axis)
+        # Create the mark for the preview spectrum
+        if self._mark is None:
+            scales = {}
+            scales['x'] = self._spectrum_viewer.native_marks[0].scales['x']
+            scales['y'] = bqplot.LinearScale()
+            self._mark = PluginLine(self._spectrum_viewer, visible=False, scales=scales)
+            self._spectrum_viewer.figure.marks = self._spectrum_viewer.figure.marks + [self._mark]
+        # Store these so we can revert to previous user-set zoom after preview view
+        sv_state = self._spectrum_viewer.state
+        self._previous_bounds = [sv_state.x_min, sv_state.x_max, sv_state.y_min, sv_state.y_max]
+        super().activate()
+
+    def deactivate(self):
+        self.viewer.remove_event_callback(self.on_mouse_move)
+        #self._reset_spectrum_viewer_bounds()
+        # Fully remove the extra axis rather than just setting to invisible
+        if self._extra_axis in self._spectrum_viewer.figure.axes:
+            self._spectrum_viewer.figure.axes.remove(self._extra_axis)
+        self._spectrum_viewer.figure.fig_margin['right'] = 10
+        self._spectrum_viewer.figure.send_state()
+        super().deactivate()
+
+    def on_mouse_move(self, data):
+        # Set the mark and extra axis to be invisible
+        if data['event'] == 'mouseleave':
+            self._mark.visible = False
+            self._extra_axis.visible=False
+            self._extra_axis.send_state("visible")
+            self._spectrum_viewer.figure.fig_margin['right'] = 10
+            self._spectrum_viewer.figure.send_state("fig_margin")
+            #self._reset_spectrum_viewer_bounds()
+            return
+
+        elif data['event'] == 'mouseenter':
+            # Make room for the extra axis
+            self._spectrum_viewer.figure.fig_margin['right'] = 80
+            self._extra_axis.visible = True
+
+        x = int(np.round(data['domain']['x']))
+        y = int(np.round(data['domain']['y']))
+
+        # Use first visible layer for now
+        cube_data = [layer.layer for layer in self.viewer.layers if layer.state.visible][0]
+        spectrum = cube_data.get_object(statistic=None)
+
+        # Nothing to show if we're out of bounds of the data
+        if x >= spectrum.flux.shape[0] or x < 0 or y >= spectrum.flux.shape[1] or y < 0:
+            self._mark.visible = False
+            self._extra_axis.visible=False
+        else:
+            # Make the mark visible and update its y values
+            self._mark.visible = True
+            y_values = spectrum.flux[x, y, :]
+            if np.all(np.isnan(y_values)):
+                self._mark.visible = False
+                return
+            self._mark.update_xy(spectrum.spectral_axis.value, y_values)
+            # Also update the extra axis to show the correct values
+            float_y_min = float(np.nanmin(y_values.value))
+            float_y_max = float(np.nanmax(y_values.value))
+            self._extra_axis.scale.min = float_y_min
+            self._extra_axis.scale.max = float_y_max
+
+        self._extra_axis.send_state(["scale", "visible"])
+        self._spectrum_viewer.figure.send_state(["fig_margin", "axes"])