René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"test_dpi_ratio_change fails on Windows/Qt5Agg","articleBody":"```\r\n================================== FAILURES ===================================\r\n____________________________ test_dpi_ratio_change ____________________________\r\n[gw0] win32 -- Python 3.6.7 c:\\miniconda36-x64\\envs\\test-environment\\python.exe\r\n    @pytest.mark.backend('Qt5Agg')\r\n    def test_dpi_ratio_change():\r\n        \"\"\"\r\n        Make sure that if _dpi_ratio changes, the figure dpi changes but the\r\n        widget remains the same physical size.\r\n        \"\"\"\r\n    \r\n        prop = 'matplotlib.backends.backend_qt5.FigureCanvasQT._dpi_ratio'\r\n    \r\n        with mock.patch(prop, new_callable=mock.PropertyMock) as p:\r\n    \r\n            p.return_value = 3\r\n    \r\n            fig = plt.figure(figsize=(5, 2), dpi=120)\r\n            qt_canvas = fig.canvas\r\n            qt_canvas.show()\r\n    \r\n            from matplotlib.backends.backend_qt5 import qApp\r\n    \r\n            # Make sure the mocking worked\r\n            assert qt_canvas._dpi_ratio == 3\r\n    \r\n            size = qt_canvas.size()\r\n    \r\n            qt_canvas.manager.show()\r\n            qt_canvas.draw()\r\n            qApp.processEvents()\r\n    \r\n            # The DPI and the renderer width/height change\r\n            assert fig.dpi == 360\r\n            assert qt_canvas.renderer.width == 1800\r\n            assert qt_canvas.renderer.height == 720\r\n    \r\n            # The actual widget size and figure physical size don't change\r\n            assert size.width() == 600\r\n            assert size.height() == 240\r\n            assert qt_canvas.get_width_height() == (600, 240)\r\n            assert (fig.get_size_inches() == (5, 2)).all()\r\n    \r\n            p.return_value = 2\r\n    \r\n            assert qt_canvas._dpi_ratio == 2\r\n    \r\n            qt_canvas.draw()\r\n            qApp.processEvents()\r\n            # this second processEvents is required to fully run the draw.\r\n            # On `update` we notice the DPI has changed and trigger a\r\n            # resize event to refresh, the second processEvents is\r\n            # required to process that and fully update the window sizes.\r\n            qApp.processEvents()\r\n    \r\n            # The DPI and the renderer width/height change\r\n            assert fig.dpi == 240\r\n            assert qt_canvas.renderer.width == 1200\r\n\u003e           assert qt_canvas.renderer.height == 480\r\nE           assert 474.0 == 480\r\nE            +  where 474.0 = \u003cmatplotlib.backends.backend_agg.RendererAgg object at 0x000000CC215AE2B0\u003e.height\r\n```\r\nBuild log: https://ci.appveyor.com/project/Kojoley/matplotlib/builds/29921850/job/1rdi7tiyqly53n3h","author":{"url":"https://github.com/Kojoley","@type":"Person","name":"Kojoley"},"datePublished":"2020-01-06T14:24:44.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/16123/matplotlib/issues/16123"}