PR: Add new "Plotting library" option, defaulting to Matplotlib (Variable Explorer)

spyder/config/main.py

@@ -21,6 +21,7 @@
 from spyder.config.appearance import APPEARANCE
 from spyder.plugins.editor.utils.findtasks import TASKS_PATTERN
 from spyder.utils.introspection.module_completion import PREFERRED_MODULES
+from spyder.plugins.variableexplorer.plotlib import DEFAULT_PLOTLIB
 
 
 # =============================================================================
@@ -176,7 +177,8 @@
               'truncate': True,
               'minmax': False,
               'show_callable_attributes': True,
-              'show_special_attributes': False
+              'show_special_attributes': False,
+              'plotlib': DEFAULT_PLOTLIB,
              }),
             ('debugger',
              {

spyder/plugins/ipythonconsole/utils/kernelspec.py

@@ -208,6 +208,7 @@ def env(self):
             'SPY_GREEDY_O': self.get_conf('greedy_completer'),
             'SPY_JEDI_O': self.get_conf('jedi_completer'),
             'SPY_SYMPY_O': self.get_conf('symbolic_math'),
+            'SPY_VAREXP_PLOTLIB': self.get_conf('plotlib', section='variable_explorer'),
             'SPY_TESTING': running_under_pytest() or get_safe_mode(),
             'SPY_HIDE_CMD': self.get_conf('hide_cmd_windows'),
             'SPY_PYTHONPATH': pypath

spyder/plugins/plots/widgets/figurebrowser.py

@@ -772,8 +772,6 @@ def add_thumbnail(self, fig, fmt):
             parent=self, background_color=self.background_color)
         thumbnail.canvas.load_figure(fig, fmt)
         thumbnail.sig_canvas_clicked.connect(self.set_current_thumbnail)
-        thumbnail.sig_remove_figure_requested.connect(self.remove_thumbnail)
-        thumbnail.sig_save_figure_requested.connect(self.save_figure_as)
         thumbnail.sig_context_menu_requested.connect(
             lambda point: self.show_context_menu(point, thumbnail))
         self._thumbnails.append(thumbnail)
@@ -796,8 +794,6 @@ def remove_all_thumbnails(self):
         """Remove all thumbnails."""
         for thumbnail in self._thumbnails:
             thumbnail.sig_canvas_clicked.disconnect()
-            thumbnail.sig_remove_figure_requested.disconnect()
-            thumbnail.sig_save_figure_requested.disconnect()
             self.layout().removeWidget(thumbnail)
             thumbnail.setParent(None)
             thumbnail.hide()
@@ -815,8 +811,6 @@ def remove_thumbnail(self, thumbnail):
         # Disconnect signals
         try:
             thumbnail.sig_canvas_clicked.disconnect()
-            thumbnail.sig_remove_figure_requested.disconnect()
-            thumbnail.sig_save_figure_requested.disconnect()
         except TypeError:
             pass
 
@@ -945,29 +939,6 @@ class FigureThumbnail(QWidget):
         The clicked figure thumbnail.
     """
 
-    sig_remove_figure_requested = Signal(object)
-    """
-    This signal is emitted to request the removal of a figure thumbnail.
-
-    Parameters
-    ----------
-    figure_thumbnail: spyder.plugins.plots.widget.figurebrowser.FigureThumbnail
-        The figure thumbnail to remove.
-    """
-
-    sig_save_figure_requested = Signal(object, str)
-    """
-    This signal is emitted to request the saving of a figure thumbnail.
-
-    Parameters
-    ----------
-    figure_thumbnail: spyder.plugins.plots.widget.figurebrowser.FigureThumbnail
-        The figure thumbnail to save.
-    format: str
-        The image format to use when saving the image. One of "image/png",
-        "image/jpeg" and "image/svg+xml".
-    """
-
     sig_context_menu_requested = Signal(QPoint)
     """
     This signal is emitted to request a context menu.

spyder/plugins/variableexplorer/confpage.py

@@ -12,10 +12,12 @@
 # Local imports
 from spyder.config.base import _
 from spyder.api.preferences import PluginConfigPage
+from spyder.plugins.variableexplorer import plotlib
 
 class VariableExplorerConfigPage(PluginConfigPage):
 
     def setup_page(self):
+        # Filter Group
         filter_group = QGroupBox(_("Filter"))
         filter_data = [
             ('exclude_private', _("Exclude private references")),
@@ -27,20 +29,35 @@ def setup_page(self):
         ]
         filter_boxes = [self.create_checkbox(text, option)
                         for option, text in filter_data]
-
-        display_group = QGroupBox(_("Display"))
-        display_data = [('minmax', _("Show arrays min/max"), '')]
-        display_boxes = [self.create_checkbox(text, option, tip=tip)
-                         for option, text, tip in display_data]
-
         filter_layout = QVBoxLayout()
         for box in filter_boxes:
             filter_layout.addWidget(box)
         filter_group.setLayout(filter_layout)
 
+        # Display Group
+        display_group = QGroupBox(_("Display"))
+        display_data = [("minmax", _("Show arrays min/max"), "")]
+        display_boxes = [
+            self.create_checkbox(text, option, tip=tip)
+            for option, text, tip in display_data
+        ]
         display_layout = QVBoxLayout()
         for box in display_boxes:
             display_layout.addWidget(box)
+        if plotlib.AVAILABLE_PLOTLIBS:
+            plotlib_box = self.create_combobox(
+                _("Plotting library:") + "   ",
+                zip(plotlib.AVAILABLE_PLOTLIBS, plotlib.AVAILABLE_PLOTLIBS),
+                "plotlib",
+                default=plotlib.DEFAULT_PLOTLIB,
+                tip=_(
+                    "Default library used for data plotting of NumPy arrays "
+                    "(curve, histogram, image).<br><br>Regarding the "
+                    "<i>%varexp</i> magic command, this option will be "
+                    "applied the next time a console is opened."
+                ),
+            )
+            display_layout.addWidget(plotlib_box)
         display_group.setLayout(display_layout)
 
         vlayout = QVBoxLayout()

spyder/plugins/variableexplorer/plotlib.py

@@ -0,0 +1,53 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright © Spyder Project Contributors
+# Licensed under the terms of the MIT License
+# (see spyder/__init__.py for details)
+
+"""
+Variable Explorer Plugin plotting library management.
+"""
+
+# Standard library imports
+import importlib
+
+# Local imports
+from spyder.config.base import _
+
+
+# Defining compatible plotting libraries
+# (default library is the first available, see `get_default_plotlib`)
+LIBRARIES = ("matplotlib", "guiqwt")
+
+
+def is_package_installed(modname):
+    """Check if package is installed **without importing it**
+
+    Note: As Spyder won't start if matplotlib has been imported too early,
+    we do not use `utils.programs.is_module_installed` here because
+    it imports module to check if it's installed.
+    """
+    return importlib.util.find_spec(modname) is not None
+
+
+def get_available_plotlibs():
+    """Return list of available plotting libraries"""
+    return [name for name in LIBRARIES if is_package_installed(name)]
+
+
+def get_default_plotlib():
+    """Return default plotting library"""
+    names = get_available_plotlibs()
+    if names is not None:
+        return names[0]
+
+
+def get_requirement_error_message():
+    """Return html error message when no library is available"""
+    txt = ", ".join(["<b>%s</b>" % name for name in LIBRARIES])
+    return _("Please install a compatible plotting library (%s).") % txt
+
+
+AVAILABLE_PLOTLIBS = get_available_plotlibs()
+DEFAULT_PLOTLIB = get_default_plotlib()
+REQ_ERROR_MSG = get_requirement_error_message()

spyder/widgets/collectionseditor.py

@@ -60,6 +60,7 @@
 from spyder.plugins.variableexplorer.widgets.importwizard import ImportWizard
 from spyder.widgets.helperwidgets import CustomSortFilterProxy
 from spyder.plugins.variableexplorer.widgets.basedialog import BaseDialog
+from spyder.plugins.variableexplorer.plotlib import REQ_ERROR_MSG
 from spyder.utils.palette import SpyderPalette
 from spyder.utils.stylesheet import PANES_TOOLBAR_STYLESHEET
 
@@ -1132,57 +1133,41 @@ def view_item(self):
         index = index.child(index.row(), 3)
         self.delegate.createEditor(self, None, index, object_explorer=True)
 
-    def __prepare_plot(self):
-        try:
-            import guiqwt.pyplot   #analysis:ignore
-            return True
-        except:
-            try:
-                if 'matplotlib' not in sys.modules:
-                    import matplotlib  # noqa
-                return True
-            except Exception:
-                QMessageBox.warning(self, _("Import error"),
-                                    _("Please install <b>matplotlib</b>"
-                                      " or <b>guiqwt</b>."))
-
     def plot_item(self, funcname):
         """Plot item"""
         index = self.currentIndex()
-        if self.__prepare_plot():
-            if self.proxy_model:
-                key = self.source_model.get_key(
-                    self.proxy_model.mapToSource(index))
-            else:
-                key = self.source_model.get_key(index)
-            try:
-                self.plot(key, funcname)
-            except (ValueError, TypeError) as error:
-                QMessageBox.critical(self, _( "Plot"),
-                                     _("<b>Unable to plot data.</b>"
-                                       "<br><br>Error message:<br>%s"
-                                       ) % str(error))
+        if self.proxy_model:
+            key = self.source_model.get_key(
+                self.proxy_model.mapToSource(index))
+        else:
+            key = self.source_model.get_key(index)
+        try:
+            self.plot(key, funcname)
+        except (ValueError, TypeError) as error:
+            QMessageBox.critical(self, _( "Plot"),
+                                    _("<b>Unable to plot data.</b>"
+                                    "<br><br>Error message:<br>%s"
+                                    ) % str(error))
 
     @Slot()
     def imshow_item(self):
         """Imshow item"""
         index = self.currentIndex()
-        if self.__prepare_plot():
-            if self.proxy_model:
-                key = self.source_model.get_key(
-                    self.proxy_model.mapToSource(index))
+        if self.proxy_model:
+            key = self.source_model.get_key(
+                self.proxy_model.mapToSource(index))
+        else:
+            key = self.source_model.get_key(index)
+        try:
+            if self.is_image(key):
+                self.show_image(key)
             else:
-                key = self.source_model.get_key(index)
-            try:
-                if self.is_image(key):
-                    self.show_image(key)
-                else:
-                    self.imshow(key)
-            except (ValueError, TypeError) as error:
-                QMessageBox.critical(self, _( "Plot"),
-                                     _("<b>Unable to show image.</b>"
-                                       "<br><br>Error message:<br>%s"
-                                       ) % str(error))
+                self.imshow(key)
+        except (ValueError, TypeError) as error:
+            QMessageBox.critical(self, _( "Plot"),
+                                    _("<b>Unable to show image.</b>"
+                                    "<br><br>Error message:<br>%s"
+                                    ) % str(error))
 
     @Slot()
     def save_array(self):
@@ -1383,21 +1368,36 @@ def oedit(self, key):
             oedit)
         oedit(data[key])
 
+    def __get_pyplot(self):
+        """Return default plotting library `pyplot` package if available.
+        (default plotting library is an option defined in Variable Explorer 
+        plugin scope, e.g. "maplotlib" or "guiqwt")"""
+        libname = self.get_conf('plotlib', section='variable_explorer')
+        try:
+            return __import__(libname + '.pyplot',
+                              globals(), locals(), [], 0).pyplot
+        except ImportError:
+            #  This should not happen, unless plotting library has been 
+            #  uninstalled after option has been set in Variable Explorer
+            QMessageBox.critical(self, _("Import error"), REQ_ERROR_MSG)
+
     def plot(self, key, funcname):
         """Plot item"""
         data = self.source_model.get_data()
-        import spyder.pyplot as plt
-        plt.figure()
-        getattr(plt, funcname)(data[key])
-        plt.show()
+        plt = self.__get_pyplot()
+        if plt is not None:
+            plt.figure()
+            getattr(plt, funcname)(data[key])
+            plt.show()
 
     def imshow(self, key):
         """Show item's image"""
         data = self.source_model.get_data()
-        import spyder.pyplot as plt
-        plt.figure()
-        plt.imshow(data[key])
-        plt.show()
+        plt = self.__get_pyplot()
+        if plt is not None:
+            plt.figure()
+            plt.imshow(data[key])
+            plt.show()
 
     def show_image(self, key):
         """Show image (item is a PIL image)"""