matplotlib_3.1.1.1.diff

diff --git lib/matplotlib/backends/backend_qt5.py lib/matplotlib/backends/backend_qt5.py
index b4562db7f..77caced86 100644
--- lib/matplotlib/backends/backend_qt5.py
+++ lib/matplotlib/backends/backend_qt5.py
@@ -17,7 +17,7 @@ from matplotlib.backends.qt_editor.formsubplottool import UiSubplotTool
 from matplotlib.backend_managers import ToolManager
 
 from .qt_compat import (
-    QtCore, QtGui, QtWidgets, _getSaveFileName, is_pyqt5, __version__, QT_API)
+    QtCore, QtGui, QtWidgets, _getSaveFileName, is_pyqt5, is_qt5, __version__, QT_API)
 
 backend_version = __version__
 
@@ -103,9 +103,9 @@ def _create_qApp():
 
     if qApp is None:
         app = QtWidgets.QApplication.instance()
-        if app is None:
+        if is_pyqt5() and app is None:
             # check for DISPLAY env variable on X11 build of Qt
-            if is_pyqt5():
+            if is_qt5():
                 try:
                     from PyQt5 import QtX11Extras
                     is_x11_build = True
@@ -128,7 +128,7 @@ def _create_qApp():
         else:
             qApp = app
 
-    if is_pyqt5():
+    if is_qt5():
         try:
             qApp.setAttribute(QtCore.Qt.AA_UseHighDpiPixmaps)
         except AttributeError:
@@ -137,7 +137,7 @@ def _create_qApp():
 
 def _allow_super_init(__init__):
     """
-    Decorator for ``__init__`` to allow ``super().__init__`` on PyQt4/PySide2.
+    Decorator for ``__init__`` to allow ``super().__init__`` on PyQt4/PySide2/PythonQt.
     """
 
     if QT_API == "PyQt5":
@@ -145,8 +145,8 @@ def _allow_super_init(__init__):
         return __init__
 
     else:
-        # To work around lack of cooperative inheritance in PyQt4, PySide,
-        # and PySide2, when calling FigureCanvasQT.__init__, we temporarily
+        # To work around lack of cooperative inheritance in PyQt4, PySide, PySide2
+        # and PythonQt, when calling FigureCanvasQT.__init__, we temporarily
         # patch QWidget.__init__ by a cooperative version, that first calls
         # QWidget.__init__ with no additional arguments, and then finds the
         # next class in the MRO with an __init__ that does support cooperative
@@ -162,7 +162,7 @@ def _allow_super_init(__init__):
             next_coop_init = next(
                 cls for cls in mro[mro.index(QtWidgets.QWidget) + 1:]
                 if cls.__module__.split(".")[0] not in [
-                    "PyQt4", "sip", "PySide", "PySide2", "Shiboken"])
+                    "PyQt4", "sip", "PySide", "PySide2", "Shiboken", "PythonQt"])
             next_coop_init.__init__(self, *args, **kwargs)
 
         @functools.wraps(__init__)
@@ -528,8 +528,16 @@ class FigureCanvasQT(QtWidgets.QWidget, FigureCanvasBase):
 class MainWindow(QtWidgets.QMainWindow):
     closing = QtCore.Signal()
 
+    def __init__(self):
+        QtGui.QMainWindow.__init__(self)
+        self._closeCallbacks = []
+
+    def connectClosing(self, callback):
+        self._closeCallbacks.append(callback)
+
     def closeEvent(self, event):
-        self.closing.emit()
+        for callback in self._closeCallbacks:
+            callback()
         QtWidgets.QMainWindow.closeEvent(self, event)
 
 
@@ -552,8 +560,9 @@ class FigureManagerQT(FigureManagerBase):
         FigureManagerBase.__init__(self, canvas, num)
         self.canvas = canvas
         self.window = MainWindow()
-        self.window.closing.connect(canvas.close_event)
-        self.window.closing.connect(self._widgetclosed)
+        self.window.setAttribute(QtCore.Qt.WA_DeleteOnClose)
+        self.window.connectClosing(canvas.close_event)
+        self.window.connectClosing(self._widgetclosed)
 
         self.window.setWindowTitle("Figure %d" % num)
         image = os.path.join(matplotlib.rcParams['datapath'],
@@ -680,7 +689,7 @@ class NavigationToolbar2QT(NavigationToolbar2, QtWidgets.QToolBar):
     def __init__(self, canvas, parent, coordinates=True):
         """ coordinates: should we show the coordinates on the right? """
         self.canvas = canvas
-        self.parent = parent
+        self._parent = parent
         self.coordinates = coordinates
         self._actions = {}
         """A mapping of toolitem method names to their QActions"""
@@ -689,7 +698,7 @@ class NavigationToolbar2QT(NavigationToolbar2, QtWidgets.QToolBar):
         NavigationToolbar2.__init__(self, canvas)
 
     def _icon(self, name):
-        if is_pyqt5():
+        if is_qt5():
             name = name.replace('.png', '_large.png')
         pm = QtGui.QPixmap(os.path.join(self.basedir, name))
         if hasattr(pm, 'setDevicePixelRatio'):
@@ -731,7 +740,7 @@ class NavigationToolbar2QT(NavigationToolbar2, QtWidgets.QToolBar):
         # Esthetic adjustments - we need to set these explicitly in PyQt5
         # otherwise the layout looks different - but we don't want to set it if
         # not using HiDPI icons otherwise they look worse than before.
-        if is_pyqt5() and self.canvas._dpi_ratio > 1:
+        if is_qt5() and self.canvas._dpi_ratio > 1:
             self.setIconSize(QtCore.QSize(24, 24))
             self.layout().setSpacing(12)
 
@@ -745,12 +754,12 @@ class NavigationToolbar2QT(NavigationToolbar2, QtWidgets.QToolBar):
     def adj_window(self):
         return None
 
-    if is_pyqt5():
+    if is_qt5():
         # For some reason, self.setMinimumHeight doesn't seem to carry over to
         # the actual sizeHint, so override it instead in order to make the
         # aesthetic adjustments noted above.
         def sizeHint(self):
-            size = super().sizeHint()
+            size = QtWidgets.QToolBar.sizeHint(self)
             size.setHeight(max(48, size.height()))
             return size
 
@@ -758,7 +767,7 @@ class NavigationToolbar2QT(NavigationToolbar2, QtWidgets.QToolBar):
         axes = self.canvas.figure.get_axes()
         if not axes:
             QtWidgets.QMessageBox.warning(
-                self.parent, "Error", "There are no axes to edit.")
+                self._parent, "Error", "There are no axes to edit.")
             return
         elif len(axes) == 1:
             ax, = axes
@@ -775,7 +784,7 @@ class NavigationToolbar2QT(NavigationToolbar2, QtWidgets.QToolBar):
                 if titles[i] in duplicate_titles:
                     titles[i] += f" (id: {id(ax):#x})"  # Deduplicate titles.
             item, ok = QtWidgets.QInputDialog.getItem(
-                self.parent, 'Customize', 'Select axes:', titles, 0, False)
+                self._parent, 'Customize', 'Select axes:', titles, 0, False)
             if not ok:
                 return
             ax = axes[titles.index(item)]
@@ -1089,11 +1098,13 @@ class _BackendQT5(_Backend):
 
     @staticmethod
     def mainloop():
-        old_signal = signal.getsignal(signal.SIGINT)
-        # allow SIGINT exceptions to close the plot window.
-        signal.signal(signal.SIGINT, signal.SIG_DFL)
-        try:
-            qApp.exec_()
-        finally:
-            # reset the SIGINT exception handler
-            signal.signal(signal.SIGINT, old_signal)
+        # PythonQt is already running the event loop
+        if QT_API != "PythonQt":
+            old_signal = signal.getsignal(signal.SIGINT)
+            # allow SIGINT exceptions to close the plot window.
+            signal.signal(signal.SIGINT, signal.SIG_DFL)
+            try:
+                qApp.exec_()
+            finally:
+                # reset the SIGINT exception handler
+                signal.signal(signal.SIGINT, old_signal)
diff --git lib/matplotlib/backends/backend_qt5agg.py lib/matplotlib/backends/backend_qt5agg.py
index 4dec3b9cb..d0b11d5c9 100644
--- lib/matplotlib/backends/backend_qt5agg.py
+++ lib/matplotlib/backends/backend_qt5agg.py
@@ -4,6 +4,8 @@ Render to qt from agg.
 
 import ctypes
 
+from qimage2ndarray import array2qimage
+
 from matplotlib.transforms import Bbox
 
 from .. import cbook
@@ -52,14 +54,15 @@ class FigureCanvasQTAgg(FigureCanvasAgg, FigureCanvasQT):
         buf = cbook._unmultiplied_rgba8888_to_premultiplied_argb32(
             memoryview(reg))
 
-        # clear the widget canvas
-        painter.eraseRect(rect)
-
-        qimage = QtGui.QImage(buf, buf.shape[1], buf.shape[0],
-                              QtGui.QImage.Format_ARGB32_Premultiplied)
+        # create a QImage from the array buffer
+        qimage = array2qimage(buf)
         if hasattr(qimage, 'setDevicePixelRatio'):
             # Not available on Qt4 or some older Qt5.
             qimage.setDevicePixelRatio(self._dpi_ratio)
+
+        # clear the widget canvas
+        painter.eraseRect(rect)
+
         origin = QtCore.QPoint(left, top)
         painter.drawImage(origin / self._dpi_ratio, qimage)
         # Adjust the buf reference count to work around a memory
diff --git lib/matplotlib/backends/qt_compat.py lib/matplotlib/backends/qt_compat.py
index 6b52284fe..7d52ac114 100644
--- lib/matplotlib/backends/qt_compat.py
+++ lib/matplotlib/backends/qt_compat.py
@@ -21,12 +21,14 @@ from matplotlib import rcParams
 QT_API_PYQT5 = "PyQt5"
 QT_API_PYSIDE2 = "PySide2"
 QT_API_PYQTv2 = "PyQt4v2"
+QT_API_PYTHONQT = 'PythonQt' # use PythonQt API for Qt5
 QT_API_PYSIDE = "PySide"
 QT_API_PYQT = "PyQt4"   # Use the old sip v1 API (Py3 defaults to v2).
 QT_API_ENV = os.environ.get("QT_API")
 # Mapping of QT_API_ENV to requested binding.  ETS does not support PyQt4v1.
 # (https://github.com/enthought/pyface/blob/master/pyface/qt/__init__.py)
 _ETS = {"pyqt5": QT_API_PYQT5, "pyside2": QT_API_PYSIDE2,
+        "pythonqt": QT_API_PYTHONQT,
         "pyqt": QT_API_PYQTv2, "pyside": QT_API_PYSIDE,
         None: None}
 # First, check if anything is already imported.
@@ -34,6 +36,8 @@ if "PyQt5.QtCore" in sys.modules:
     QT_API = QT_API_PYQT5
 elif "PySide2.QtCore" in sys.modules:
     QT_API = QT_API_PYSIDE2
+elif "PythonQt.QtCore" in sys.modules:
+    QT_API = QT_API_PYTHONQT
 elif "PyQt4.QtCore" in sys.modules:
     QT_API = QT_API_PYQTv2
 elif "PySide.QtCore" in sys.modules:
@@ -59,11 +63,11 @@ else:
     except KeyError:
         raise RuntimeError(
             "The environment variable QT_API has the unrecognized value {!r};"
-            "valid values are 'pyqt5', 'pyside2', 'pyqt', and 'pyside'")
+            "valid values are 'pyqt5', 'pyside2', 'pythonqt', pyqt', and 'pyside'")
 
 
 def _setup_pyqt5():
-    global QtCore, QtGui, QtWidgets, __version__, is_pyqt5, _getSaveFileName
+    global QtCore, QtGui, QtWidgets, __version__, is_pyqt5, is_qt5, _getSaveFileName
 
     if QT_API == QT_API_PYQT5:
         from PyQt5 import QtCore, QtGui, QtWidgets
@@ -71,18 +75,46 @@ def _setup_pyqt5():
         QtCore.Signal = QtCore.pyqtSignal
         QtCore.Slot = QtCore.pyqtSlot
         QtCore.Property = QtCore.pyqtProperty
+        _getSaveFileName = QtWidgets.QFileDialog.getSaveFileName
     elif QT_API == QT_API_PYSIDE2:
         from PySide2 import QtCore, QtGui, QtWidgets, __version__
+        _getSaveFileName = QtWidgets.QFileDialog.getSaveFileName
+    elif QT_API == QT_API_PYTHONQT:  # try importing PythonQt
+        from PythonQt import QtCore, QtGui
+        __version__ = "3.2"
+        __version_info__ = "-"
+
+        # PythonQt does not yet support a getSaveFileName variant returning the selected filter
+        def _getSaveFileName(*args, **kwargs):
+            return (QtGui.QFileDialog.getSaveFileName(*args, **kwargs), None)
+
+        # Provide color getters
+        def getHslF(c):
+            return (c.hslHueF(), c.hslSaturationF(), c.lightnessF(), c.alphaF())
+
+        def getHsvF(c):
+            return (c.hueF(), c.saturationF(), c.valueF(), c.alphaF())
+
+        def getRgbF(c):
+            return (c.redF(), c.greenF(), c.blueF(), c.alphaF())
+
+        QtGui.QColor.getHslF = getHslF
+        QtGui.QColor.getHsvF = getHsvF
+        QtGui.QColor.getRgbF = getRgbF
+
+        # PythonQt doesn't have a separate QtWidgets module
+        QtWidgets = QtGui
     else:
         raise ValueError("Unexpected value for the 'backend.qt5' rcparam")
-    _getSaveFileName = QtWidgets.QFileDialog.getSaveFileName
 
     def is_pyqt5():
-        return True
+        return QT_API in [QT_API_PYQT5, QT_API_PYSIDE2]
 
+    def is_qt5():
+        return True
 
 def _setup_pyqt4():
-    global QtCore, QtGui, QtWidgets, __version__, is_pyqt5, _getSaveFileName
+    global QtCore, QtGui, QtWidgets, __version__, is_pyqt5, is_qt5, _getSaveFileName
 
     def _setup_pyqt4_internal(api):
         global QtCore, QtGui, QtWidgets, \
@@ -130,8 +162,11 @@ def _setup_pyqt4():
     def is_pyqt5():
         return False
 
+    def is_qt5():
+        return False
+
 
-if QT_API in [QT_API_PYQT5, QT_API_PYSIDE2]:
+if QT_API in [QT_API_PYQT5, QT_API_PYSIDE2, QT_API_PYTHONQT]:
     _setup_pyqt5()
 elif QT_API in [QT_API_PYQTv2, QT_API_PYSIDE, QT_API_PYQT]:
     _setup_pyqt4()
diff --git lib/matplotlib/backends/qt_editor/formsubplottool.py lib/matplotlib/backends/qt_editor/formsubplottool.py
index a0914cab8..50a5ebed1 100644
--- lib/matplotlib/backends/qt_editor/formsubplottool.py
+++ lib/matplotlib/backends/qt_editor/formsubplottool.py
@@ -54,3 +54,9 @@ class UiSubplotTool(QtWidgets.QDialog):
             right.addWidget(widget)
 
         self._widgets["Close"].setFocus()
+
+    def accept(self):
+        QtWidgets.QDialog.accept(self)
+
+    def close(self):
+        QtWidgets.QDialog.close(self)
diff --git lib/matplotlib/pyplot.py lib/matplotlib/pyplot.py
index ce66bd894..4e77e1ec2 100644
--- lib/matplotlib/pyplot.py
+++ lib/matplotlib/pyplot.py
@@ -123,6 +123,10 @@ def install_repl_displayhook():
 
             ipython_gui_name = backend2gui.get(get_backend())
             if ipython_gui_name:
+                if ipython_gui_name.startswith('qt'):
+                    from matplotlib.backends.qt_compat import QT_API
+                    if QT_API == 'PythonQt':
+                        ipython_gui_name = 'pythonqt'
                 ip.enable_gui(ipython_gui_name)
         else:
             _INSTALL_FIG_OBSERVER = True