Merge pull request matplotlib#17640 from QuLogic/more-pyqt5-fixes

More qt fractional DPI fixes

Author: story645

lib/matplotlib/backends/backend_qt5.py

@@ -18,7 +18,7 @@
 from . import qt_compat
 from .qt_compat import (
     QtCore, QtGui, QtWidgets, __version__, QT_API,
-    _devicePixelRatioF, _isdeleted,
+    _devicePixelRatioF, _isdeleted, _setDevicePixelRatioF,
 )
 
 backend_version = __version__
@@ -710,7 +710,7 @@ def _icon(self, name):
         if QtCore.qVersion() >= '5.':
             name = name.replace('.png', '_large.png')
         pm = QtGui.QPixmap(str(cbook._get_data_path('images', name)))
-        qt_compat._setDevicePixelRatio(pm, _devicePixelRatioF(self))
+        _setDevicePixelRatioF(pm, _devicePixelRatioF(self))
         if self.palette().color(self.backgroundRole()).value() < 128:
             icon_color = self.palette().color(self.foregroundRole())
             mask = pm.createMaskFromColor(QtGui.QColor('black'),

lib/matplotlib/backends/qt_compat.py

@@ -67,7 +67,7 @@
 
 def _setup_pyqt5():
     global QtCore, QtGui, QtWidgets, __version__, is_pyqt5, \
-        _isdeleted, _devicePixelRatio, _setDevicePixelRatio, _getSaveFileName
+        _isdeleted, _getSaveFileName
 
     if QT_API == QT_API_PYQT5:
         from PyQt5 import QtCore, QtGui, QtWidgets
@@ -89,14 +89,10 @@ def _isdeleted(obj): return not shiboken2.isValid(obj)
     def is_pyqt5():
         return True
 
-    # self.devicePixelRatio() returns 0 in rare cases
-    def _devicePixelRatio(obj): return obj.devicePixelRatio() or 1
-    def _setDevicePixelRatio(obj, factor): obj.setDevicePixelRatio(factor)
-
 
 def _setup_pyqt4():
     global QtCore, QtGui, QtWidgets, __version__, is_pyqt5, \
-        _isdeleted, _devicePixelRatio, _setDevicePixelRatio, _getSaveFileName
+        _isdeleted, _getSaveFileName
 
     def _setup_pyqt4_internal(api):
         global QtCore, QtGui, QtWidgets, \
@@ -149,9 +145,6 @@ def _isdeleted(obj): return not shiboken.isValid(obj)
     def is_pyqt5():
         return False
 
-    def _devicePixelRatio(obj): return 1
-    def _setDevicePixelRatio(obj, factor): pass
-
 
 if QT_API in [QT_API_PYQT5, QT_API_PYSIDE2]:
     _setup_pyqt5()
@@ -220,6 +213,6 @@ def _setDevicePixelRatioF(obj, val):
     if hasattr(obj, 'setDevicePixelRatioF'):
         # Not available on Qt<5.6
         obj.setDevicePixelRatioF(val)
-    if hasattr(obj, 'setDevicePixelRatio'):
+    elif hasattr(obj, 'setDevicePixelRatio'):
         # Not available on Qt4 or some older Qt5.
         obj.setDevicePixelRatio(val)