Merge pull request #18876 from QuLogic/fractional-hidpi-qt

tacaswell · web-flow · commit 82442012d044 · 2020-11-19T17:44:39.000-05:00
MNT: Support fully-fractional HiDPI added in Qt 5.14.
diff --git a/lib/matplotlib/backends/backend_qt5.py b/lib/matplotlib/backends/backend_qt5.py
@@ -119,6 +119,11 @@ def _create_qApp():
                     QtCore.Qt.AA_EnableHighDpiScaling)
             except AttributeError:  # Attribute only exists for Qt>=5.6.
                 pass
+            try:
+                QtWidgets.QApplication.setHighDpiScaleFactorRoundingPolicy(
+                    QtCore.Qt.HighDpiScaleFactorRoundingPolicy.PassThrough)
+            except AttributeError:  # Added in Qt>=5.14.
+                pass
             qApp = QtWidgets.QApplication(["matplotlib"])
             qApp.lastWindowClosed.connect(qApp.quit)
             cbook._setup_new_guiapp()
