Fix scaling in Tk on non-Windows systems

rnhmjoj · rnhmjoj · commit f95e8ee8c3b7 · 2024-09-18T23:35:27.000+02:00
diff --git a/lib/matplotlib/backends/_backend_tk.py b/lib/matplotlib/backends/_backend_tk.py
@@ -176,8 +176,7 @@ def __init__(self, figure=None, master=None):
         self._tkcanvas_image_region = self._tkcanvas.create_image(
             w//2, h//2, image=self._tkphoto)
         self._tkcanvas.bind("<Configure>", self.resize)
-        if sys.platform == 'win32':
-            self._tkcanvas.bind("<Map>", self._update_device_pixel_ratio)
+        self._tkcanvas.bind("<Map>", self._update_device_pixel_ratio)
         self._tkcanvas.bind("<Key>", self.key_press)
         self._tkcanvas.bind("<Motion>", self.motion_notify_event)
         self._tkcanvas.bind("<Enter>", self.enter_notify_event)
@@ -234,11 +233,15 @@ def filter_destroy(event):
         self._rubberband_rect_white = None
 
     def _update_device_pixel_ratio(self, event=None):
-        # Tk gives scaling with respect to 72 DPI, but Windows screens are
-        # scaled vs 96 dpi, and pixel ratio settings are given in whole
-        # percentages, so round to 2 digits.
-        ratio = round(self._tkcanvas.tk.call('tk', 'scaling') / (96 / 72), 2)
-        if self._set_device_pixel_ratio(ratio):
+        ratio = None
+        if sys.platform == 'win32':
+            # Tk gives scaling with respect to 72 DPI, but Windows screens are
+            # scaled vs 96 dpi, and pixel ratio settings are given in whole
+            # percentages, so round to 2 digits.
+            ratio = round(self._tkcanvas.tk.call('tk', 'scaling') / (96 / 72), 2)
+        elif sys.platform == "linux":
+            ratio = self._tkcanvas.winfo_fpixels('1i') / 96
+        if ratio is not None and self._set_device_pixel_ratio(ratio):
             # The easiest way to resize the canvas is to resize the canvas
             # widget itself, since we implement all the logic for resizing the
             # canvas backing store on that event.
