Resolve "(LearnerND) add iso-surface plot feature"

Closes #112 (closed)

adaptive/notebook_integration.py

@@ -7,34 +7,37 @@ import warnings
 
 
 _async_enabled = False
-_plotting_enabled = False
-_plotly_notebook_imported = False
+_holoviews_enabled = False
+_ipywidgets_enabled = False
+_plotly_enabled = False
+
 
 def notebook_extension():
     if not in_ipynb():
         raise RuntimeError('"adaptive.notebook_extension()" may only be run '
                            'from a Jupyter notebook.')
 
-    global _plotting_enabled
-    _plotting_enabled = False
+    global _async_enabled, _holoviews_enabled, _ipywidgets_enabled
+
     try:
-        import ipywidgets
-        import holoviews
-        holoviews.notebook_extension('bokeh')
-        _plotting_enabled = True
+        if not _holoviews_enabled:
+            import holoviews
+            holoviews.notebook_extension('bokeh')
+            _holoviews_enabled = True
     except ModuleNotFoundError:
-        warnings.warn("holoviews and (or) ipywidgets are not installed; plotting "
+        warnings.warn("holoviews are not installed; plotting "
                       "is disabled.", RuntimeWarning)
-
     try:
-        import plotly.offline
-        plotly.offline.init_notebook_mode()
+        if not _ipywidgets_enabled:
+            import ipywidgets
+            _ipywidgets_enabled = True
     except ModuleNotFoundError:
-        pass
+        warnings.warn("ipywidgets are not installed; plotting "
+                      "is disabled.", RuntimeWarning)
 
-    global _async_enabled
-    get_ipython().magic('gui asyncio')
-    _async_enabled = True
+    if not _async_enabled:
+        get_ipython().magic('gui asyncio')
+        _async_enabled = True
 
 
 def ensure_holoviews():
@@ -50,21 +53,21 @@ def ensure_plotly():
             "plotting functions using 'plotly' may only be run "
             "from a Jupyter notebook.")
 
-    global _plotly_notebook_imported
+    global _plotly_enabled
     try:
-        import plotly.graph_objs
-        import plotly.figure_factory
-        import plotly.offline
-        plotly = importlib.import_module('plotly')
-        if not _plotly_notebook_imported:
+        import plotly
+        if not _plotly_enabled:
+            import plotly.graph_objs
+            import plotly.figure_factory
+            import plotly.offline
+            # This injects javascript and should happen only once
             plotly.offline.init_notebook_mode()
-            _plotly_notebook_imported = True
+            _plotly_enabled = True
         return plotly
     except ModuleNotFoundError:
         raise RuntimeError('plotly is not installed; plotting is disabled.')
 
 
-
 def in_ipynb():
     try:
         # If we are running in IPython, then `get_ipython()` is always a global
@@ -99,7 +102,7 @@ def live_plot(runner, *, plotter=None, update_interval=2, name=None):
     dm : holoviews.DynamicMap
         The plot that automatically updates every update_interval.
     """
-    if not _plotting_enabled:
+    if not _holoviews_enabled:
         raise RuntimeError("Live plotting is not enabled; did you run "
                            "'adaptive.notebook_extension()'?")
 
@@ -153,7 +156,7 @@ def live_info(runner, *, update_interval=0.5):
     Returns an interactive ipywidget that can be
     visualized in a Jupyter notebook.
     """
-    if not _plotting_enabled:
+    if not _holoviews_enabled:
         raise RuntimeError("Live plotting is not enabled; did you run "
                            "'adaptive.notebook_extension()'?")