Drop conditional import of figureoptions.

As far as I can tell, the only way the import of figureoptions could fail is under PyQt 4.3 or earlier (QFormLayout was introduced in Qt 4.4). PyQt 4.4 was released in 2008 and the oldest version still downloadable on SourceForge seems to be 4.9, so that seems safe... Also up the version requirement on PyQt.
tacaswell · Jul 10, 2016 · Oct 28, 2015 · Nov 12, 2015 · Nov 12, 2015 · Apr 28, 2016
commit 61a16e4e755c420868fe9f2bb43b3cd0d228ddd3
diff --git a/INSTALL b/INSTALL
@@ -233,7 +233,7 @@ backends and the capabilities they provide.
     Versions 8.6.0 and 8.6.1 are known to have issues that may result
     in segfaults when closing multiple windows in the wrong order.
 
-:term:`pyqt` 4.0 or later
+:term:`pyqt` 4.4 or later
     The Qt4 widgets library python wrappers for the Qt4Agg backend
 
 :term:`pygtk` 2.4 or later

diff --git a/doc/conf.py b/doc/conf.py
@@ -318,6 +318,9 @@ class QWidget(object):
         class QMainWindow(object):
             pass
 
+        class QPushButton(object):
+            pass
+
 
 class MySip(MagicMock):
     def getapi(*args):

diff --git a/lib/matplotlib/backends/backend_qt4.py b/lib/matplotlib/backends/backend_qt4.py
@@ -22,12 +22,7 @@
 from matplotlib._pylab_helpers import Gcf
 from matplotlib.figure import Figure
 
-
 from matplotlib.widgets import SubplotTool
-try:
-    import matplotlib.backends.qt_editor.figureoptions as figureoptions
-except ImportError:
-    figureoptions = None
 
 from .qt_compat import QtCore, QtWidgets, _getSaveFileName, __version__
 from matplotlib.backends.qt_editor.formsubplottool import UiSubplotTool

diff --git a/lib/matplotlib/backends/backend_qt5.py b/lib/matplotlib/backends/backend_qt5.py
@@ -23,10 +23,7 @@
 from matplotlib.figure import Figure
 
 from matplotlib.widgets import SubplotTool
-try:
-    import matplotlib.backends.qt_editor.figureoptions as figureoptions
-except ImportError:
-    figureoptions = None
+import matplotlib.backends.qt_editor.figureoptions as figureoptions
 
 from .qt_compat import (QtCore, QtGui, QtWidgets, _getSaveFileName,
                         __version__, is_pyqt5)
@@ -589,7 +586,7 @@ def _init_toolbar(self):
                     a.setCheckable(True)
                 if tooltip_text is not None:
                     a.setToolTip(tooltip_text)
-                if figureoptions is not None and text == 'Subplots':
+                if text == 'Subplots':
                     a = self.addAction(self._icon("qt4_editor_options.png"),
                                        'Customize', self.edit_parameters)
                     a.setToolTip('Edit axis, curve and image parameters')
@@ -620,43 +617,31 @@ def _init_toolbar(self):
             self.layout().setSpacing(12)
             self.setMinimumHeight(48)
 
-    if figureoptions is not None:
-        def edit_parameters(self):
-            allaxes = self.canvas.figure.get_axes()
-            if not allaxes:
-                QtWidgets.QMessageBox.warning(
-                    self.parent, "Error", "There are no axes to edit.")
-                return
-            if len(allaxes) == 1:
-                axes = allaxes[0]
+    def edit_parameters(self):
+        allaxes = self.canvas.figure.get_axes()
+        if not allaxes:
+            QtWidgets.QMessageBox.warning(
+                self.parent, "Error", "There are no axes to edit.")
+            return
+        if len(allaxes) == 1:
+            axes = allaxes[0]
+        else:
+            titles = []
+            for axes in allaxes:
+                name = (axes.get_title() or
+                        " - ".join(filter(None, [axes.get_xlabel(),
+                                                 axes.get_ylabel()])) or
+                        "<anonymous {} (id: {:#x})>".format(
+                            type(axes).__name__, id(axes)))
+                titles.append(name)
+            item, ok = QtWidgets.QInputDialog.getItem(
+                self.parent, 'Customize', 'Select axes:', titles, 0, False)
+            if ok:
+                axes = allaxes[titles.index(six.text_type(item))]
             else:
-                titles = []
-                for axes in allaxes:
-                    title = axes.get_title()
-                    ylabel = axes.get_ylabel()
-                    label = axes.get_label()
-                    if title:
-                        fmt = "%(title)s"
-                        if ylabel:
-                            fmt += ": %(ylabel)s"
-                        fmt += " (%(axes_repr)s)"
-                    elif ylabel:
-                        fmt = "%(axes_repr)s (%(ylabel)s)"
-                    elif label:
-                        fmt = "%(axes_repr)s (%(label)s)"
-                    else:
-                        fmt = "%(axes_repr)s"
-                    titles.append(fmt % dict(title=title,
-                                         ylabel=ylabel, label=label,
-                                         axes_repr=repr(axes)))
-                item, ok = QtWidgets.QInputDialog.getItem(
-                    self.parent, 'Customize', 'Select axes:', titles, 0, False)
-                if ok:
-                    axes = allaxes[titles.index(six.text_type(item))]
-                else:
-                    return
-
-            figureoptions.figure_edit(axes, self)
+                return
+
+        figureoptions.figure_edit(axes, self)
 
     def _update_buttons_checked(self):
         # sync button checkstates to match active mode