Add stretch bounds tool to plot option histogram viewer (#2513)

* Add stretch bounds tool to plot option histogram viewer
* Add changelog, test
* Change color based on tool active state
* Add short sleep to test to avoid throttle
* stretch function curve as inactive blue

---------

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

CHANGES.rst

@@ -7,6 +7,8 @@ New Features
 - Plots in plugins now include basic zoom/pan tools for Plot Options,
   Imviz Line Profiles, and Imviz's aperture photometry. [#2498]
 
+- Histogram plot in Plot Options now includes tool to set stretch vmin and vmax. [#2513]
+
 Cubeviz
 ^^^^^^^
 

jdaviz/configs/default/plugins/plot_options/plot_options.py

@@ -15,6 +15,7 @@
 from glue_jupyter.bqplot.image.state import BqplotImageLayerState
 from glue_jupyter.common.toolbar_vuetify import read_icon
 
+from jdaviz.components.toolbar_nested import NestedJupyterToolbar
 from jdaviz.core.registries import tray_registry
 from jdaviz.core.template_mixin import (PluginTemplateMixin, ViewerSelect, LayerSelect,
                                         PlotOptionsSyncState, Plot,
@@ -398,6 +399,12 @@ def state_attr_for_line_visible(state):
                                                  state_filter=is_image)
 
         self.stretch_histogram = Plot(self, viewer_type='histogram')
+        # Add the stretch bounds tool to the default Plot viewer.
+        self.stretch_histogram.tools_nested.append(["jdaviz:stretch_bounds"])
+        self.stretch_histogram.toolbar = NestedJupyterToolbar(self.stretch_histogram.viewer,
+                                                              self.stretch_histogram.tools_nested,
+                                                              ["jdaviz:stretch_bounds"])
+
         # NOTE: this is a current workaround so the histogram viewer doesn't crash when replacing
         # data.  Note also that passing x=[0] fails on SOME machines, so we'll pass [0, 1] instead
         self.stretch_histogram._add_data('ref', x=[0, 1])
@@ -709,7 +716,7 @@ def _update_stretch_curve(self, msg=None):
                     x=curve_x,
                     y=curve_y,
                     ynorm=True,
-                    color='#c75d2c',
+                    color="#007BA1",  # "inactive" blue
                     opacities=[0.5],
                 )
 

jdaviz/core/template_mixin.py

@@ -3280,7 +3280,9 @@ def __init__(self, plugin, viewer_type='scatter', app=None, *args, **kwargs):
             app = jglue()
 
         self._app = app
+        self._plugin = plugin
         self.viewer = app.new_data_viewer(viewer_type, show=False)
+        self.viewer._plugin = plugin
         self._viewer_type = viewer_type
         if viewer_type == 'histogram':
             self._viewer_components = ('x',)
@@ -3422,6 +3424,7 @@ def _add_mark(self, cls, label, xnorm=False, ynorm=False, **kwargs):
             raise ValueError(f"mark with label '{label}' already exists")
         mark = cls(scales={'x': bqplot.LinearScale() if xnorm else self.figure.axes[0].scale,
                            'y': bqplot.LinearScale() if ynorm else self.figure.axes[1].scale},
+                   labels=[label],
                    **kwargs)
         self.figure.marks = self.figure.marks + [mark]
         self._marks[label] = mark

jdaviz/core/tests/test_tools.py

@@ -1,3 +1,6 @@
+import time
+
+import numpy as np
 from numpy.testing import assert_allclose
 
 
@@ -41,3 +44,28 @@ def test_rangezoom(specviz_helper, spectrum1d):
     t.interact.selected = [14, 15]
     t.on_update_zoom()
     assert_allclose(_get_lims(sv), [6500, 7000, 14, 15])
+
+
+def test_stretch_bounds(imviz_helper):
+    imviz_helper.load_data(np.ones((2, 2)))
+
+    plot_options = imviz_helper.plugins['Plot Options']._obj
+    stretch_tool = plot_options.stretch_histogram.toolbar.tools["jdaviz:stretch_bounds"]
+    plot_options.stretch_histogram.toolbar.active_tool = stretch_tool
+
+    min_msg = {'event': 'click', 'pixel': {'x': 40, 'y': 322},
+               'domain': {'x': 0.1, 'y': 342},
+               'button': 0, 'altKey': False, 'ctrlKey': False, 'metaKey': False}
+
+    max_msg = {'event': 'click', 'pixel': {'x': 40, 'y': 322},
+               'domain': {'x': 1.3, 'y': 342},
+               'button': 0, 'altKey': False, 'ctrlKey': False, 'metaKey': False}
+
+    stretch_tool.on_mouse_event(min_msg)
+    time.sleep(0.3)
+    stretch_tool.on_mouse_event(max_msg)
+
+    assert plot_options.stretch_vmin_value == 0.1
+    assert plot_options.stretch_vmax_value == 1.3
+
+    plot_options.stretch_histogram.toolbar.active_tool = None

jdaviz/core/tools.py

@@ -1,4 +1,5 @@
 import os
+import time
 
 import numpy as np
 from echo import delay_callback
@@ -338,6 +339,47 @@ def is_visible(self):
         return len([m for m in self.viewer.figure.marks if isinstance(m, SpectralLine)]) > 0
 
 
+@viewer_tool
+class StretchBounds(CheckableTool):
+    icon = os.path.join(ICON_DIR, 'line_select.svg')
+    tool_id = 'jdaviz:stretch_bounds'
+    action_text = 'Set Stretch VMin and VMax'
+    tool_tip = 'Set closest stretch bound (VMin/VMax) with click or click+drag'
+
+    def __init__(self, viewer, **kwargs):
+        self._time_last = 0
+        super().__init__(viewer, **kwargs)
+
+    def activate(self):
+        self.viewer.add_event_callback(self.on_mouse_event,
+                                       events=['dragmove', 'click'])
+        for mark in self.viewer.figure.marks:
+            if np.any([x in mark.labels for x in ('vmin', 'vmax')]):
+                mark.colors = ["#c75d2c"]
+
+    def deactivate(self):
+        self.viewer.remove_event_callback(self.on_mouse_event)
+        for mark in self.viewer.figure.marks:
+            if np.any([x in mark.labels for x in ('vmin', 'vmax')]):
+                mark.colors = ["#007BA1"]
+
+    def on_mouse_event(self, data):
+        if (time.time() - self._time_last) <= 0.05:
+            # throttle to 200ms
+            return
+
+        event_x = data['domain']['x']
+        current_bounds = [self.viewer._plugin.stretch_vmin_value,
+                          self.viewer._plugin.stretch_vmax_value,]
+        att_names = ["stretch_vmin_value", "stretch_vmax_value"]
+        closest_bound_ind = np.argmin([abs(current_bounds[0] - event_x),
+                                       abs(current_bounds[1] - event_x)])
+
+        setattr(self.viewer._plugin, att_names[closest_bound_ind], event_x)
+
+        self._time_last = time.time()
+
+
 class _BaseSidebarShortcut(Tool):
     plugin_name = None  # define in subclass
     viewer_attr = 'viewer'