From 775f1d629c9f31404f805b3a54bce705cce652db Mon Sep 17 00:00:00 2001
From: Nils Nemitz <nils.nemitz@gmx.de>
Date: Wed, 23 Jun 2021 08:17:39 +0900
Subject: [PATCH] Separate out mouse events stolen by AxisItem (#1845)

* separate out mouse events on main plot area

* work in scenepositions so that detection also works in a layout

* added comments/remove debug statements
---
 pyqtgraph/graphicsItems/AxisItem.py | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/pyqtgraph/graphicsItems/AxisItem.py b/pyqtgraph/graphicsItems/AxisItem.py
index e4f37fc5..97baebc4 100644
--- a/pyqtgraph/graphicsItems/AxisItem.py
+++ b/pyqtgraph/graphicsItems/AxisItem.py
@@ -1151,7 +1151,7 @@ class AxisItem(GraphicsWidget):
         pen, p1, p2 = axisSpec
         p.setPen(pen)
         p.drawLine(p1, p2)
-        p.translate(0.5,0)  ## resolves some damn pixel ambiguity
+        # p.translate(0.5,0)  ## resolves some damn pixel ambiguity
 
         ## draw ticks
         for pen, p1, p2 in tickSpecs:
@@ -1184,20 +1184,31 @@ class AxisItem(GraphicsWidget):
         else:
             self._updateHeight()
 
-    def wheelEvent(self, ev):
+    def wheelEvent(self, event):
         lv = self.linkedView()
         if lv is None:
             return
-        if self.orientation in ['left', 'right']:
-            lv.wheelEvent(ev, axis=1)
+        # Did the event occur inside the linked ViewBox (and not over the axis iteself)?
+        if lv.sceneBoundingRect().contains(event.scenePos()):
+            # pass event to linked ViewBox without marking it as single axis zoom
+            lv.wheelEvent(event)
         else:
-            lv.wheelEvent(ev, axis=0)
-        ev.accept()
+            # pass event to linked viewbox with appropriate single axis zoom parameter
+            if self.orientation in ['left', 'right']:
+                lv.wheelEvent(event, axis=1)
+            else:
+                lv.wheelEvent(event, axis=0)
+        event.accept()
 
     def mouseDragEvent(self, event):
         lv = self.linkedView()
         if lv is None:
             return
+        # Did the mouse down event occur inside the linked ViewBox (and not the axis)?
+        if lv.sceneBoundingRect().contains(event.buttonDownScenePos()):
+            # pass event to linked ViewBox without marking it as single axis pan
+            return lv.mouseDragEvent(event)
+        # otherwise pass event to linked viewbox with appropriate single axis parameter
         if self.orientation in ['left', 'right']:
             return lv.mouseDragEvent(event, axis=1)
         else: