matplotlib · timhoffm · Nov 1, 2023 · Nov 1, 2023
diff --git a/lib/matplotlib/backends/backend_qt.py b/lib/matplotlib/backends/backend_qt.py
@@ -261,43 +261,49 @@ def enterEvent(self, event):
        # Force querying of the modifiers, as the cached modifier state can
        # have been invalidated while the window was out of focus.
        mods = QtWidgets.QApplication.instance().queryKeyboardModifiers()
+        if self.figure is None:
+            return
        LocationEvent("figure_enter_event", self,
                      *self.mouseEventCoords(event),
                      modifiers=self._mpl_modifiers(mods),
                      guiEvent=event)._process()

    def leaveEvent(self, event):
        QtWidgets.QApplication.restoreOverrideCursor()
+        if self.figure is None:
+            return
        LocationEvent("figure_leave_event", self,
                      *self.mouseEventCoords(),
                      modifiers=self._mpl_modifiers(),
                      guiEvent=event)._process()

    def mousePressEvent(self, event):
        button = self.buttond.get(event.button())
-        if button is not None:
+        if button is not None and self.figure is not None:
            MouseEvent("button_press_event", self,
                       *self.mouseEventCoords(event), button,
                       modifiers=self._mpl_modifiers(),
                       guiEvent=event)._process()

    def mouseDoubleClickEvent(self, event):
        button = self.buttond.get(event.button())
-        if button is not None:
+        if button is not None and self.figure is not None:
            MouseEvent("button_press_event", self,
                       *self.mouseEventCoords(event), button, dblclick=True,
                       modifiers=self._mpl_modifiers(),
                       guiEvent=event)._process()

    def mouseMoveEvent(self, event):
+        if self.figure is None:
+            return
        MouseEvent("motion_notify_event", self,
                   *self.mouseEventCoords(event),
                   modifiers=self._mpl_modifiers(),
                   guiEvent=event)._process()

    def mouseReleaseEvent(self, event):
        button = self.buttond.get(event.button())
-        if button is not None:
+        if button is not None and self.figure is not None:
            MouseEvent("button_release_event", self,
                       *self.mouseEventCoords(event), button,
                       modifiers=self._mpl_modifiers(),
@@ -311,29 +317,31 @@ def wheelEvent(self, event):
            steps = event.angleDelta().y() / 120
        else:
            steps = event.pixelDelta().y()
-        if steps:
+        if steps and self.figure is not None:
            MouseEvent("scroll_event", self,
                       *self.mouseEventCoords(event), step=steps,
                       modifiers=self._mpl_modifiers(),
                       guiEvent=event)._process()

    def keyPressEvent(self, event):
        key = self._get_key(event)
-        if key is not None:
+        if key is not None and self.figure is not None:
            KeyEvent("key_press_event", self,
                     key, *self.mouseEventCoords(),
                     guiEvent=event)._process()

    def keyReleaseEvent(self, event):
        key = self._get_key(event)
-        if key is not None:
+        if key is not None and self.figure is not None:
            KeyEvent("key_release_event", self,
                     key, *self.mouseEventCoords(),
                     guiEvent=event)._process()

    def resizeEvent(self, event):
        if self._in_resize_event:  # Prevent PyQt6 recursion
            return
+        if self.figure is None:
+            return
        self._in_resize_event = True
        try:
            w = event.size().width() * self.device_pixel_ratio