From 0e7b8a4828606049ce94669c4ef02fed7da04e9c Mon Sep 17 00:00:00 2001
From: Anthony De Bortoli <anthony.debortoli@protonmail.com>
Date: Sun, 11 Apr 2021 11:40:11 +0200
Subject: [PATCH] GridItem: Add custom line width based on pen option.

---
 examples/GraphicsScene.py           | 17 +++++++++++------
 pyqtgraph/graphicsItems/GridItem.py | 19 ++++++++++---------
 2 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/examples/GraphicsScene.py b/examples/GraphicsScene.py
index 3caf87c6..39d3dc3b 100644
--- a/examples/GraphicsScene.py
+++ b/examples/GraphicsScene.py
@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
 ## Add path to library (just for examples; you do not need this)
+from PySide2.QtGui import QPen, QColor
+
 import initExample
 
 from pyqtgraph.Qt import QtCore, QtGui
@@ -15,27 +17,27 @@ class Obj(QtGui.QGraphicsObject):
     def __init__(self):
         QtGui.QGraphicsObject.__init__(self)
         GraphicsScene.registerObject(self)
-        
+
     def paint(self, p, *args):
         p.setPen(pg.mkPen(200,200,200))
         p.drawRect(self.boundingRect())
-        
+
     def boundingRect(self):
         return QtCore.QRectF(0, 0, 20, 20)
-        
+
     def mouseClickEvent(self, ev):
         if ev.double():
             print("double click")
         else:
             print("click")
         ev.accept()
-        
+
     #def mouseDragEvent(self, ev):
         #print "drag"
         #ev.accept()
         #self.setPos(self.pos() + ev.pos()-ev.lastPos())
-        
-        
+
+
 
 vb = pg.ViewBox()
 win.setCentralItem(vb)
@@ -56,6 +58,9 @@ prox.setPos(100,0)
 vb.addItem(prox)
 
 g = pg.GridItem()
+p = QPen(QColor(0, 255, 255))
+p.setWidthF(1)
+g.opts["pen"] = p
 vb.addItem(g)
 
 if __name__ == '__main__':
diff --git a/pyqtgraph/graphicsItems/GridItem.py b/pyqtgraph/graphicsItems/GridItem.py
index 4cb30bf8..2215e53a 100644
--- a/pyqtgraph/graphicsItems/GridItem.py
+++ b/pyqtgraph/graphicsItems/GridItem.py
@@ -9,7 +9,7 @@ __all__ = ['GridItem']
 class GridItem(UIGraphicsItem):
     """
     **Bases:** :class:`UIGraphicsItem <pyqtgraph.UIGraphicsItem>`
-    
+
     Displays a rectangular grid of lines indicating major divisions within a coordinate system.
     Automatically determines what divisions to use.
     """
@@ -87,7 +87,7 @@ class GridItem(UIGraphicsItem):
         self.picture = None
         #UIGraphicsItem.viewRangeChanged(self)
         #self.update()
-        
+
     def paint(self, p, opt, widget):
         #p.setPen(QtGui.QPen(QtGui.QColor(100, 100, 100)))
         #p.drawRect(self.boundingRect())
@@ -101,22 +101,22 @@ class GridItem(UIGraphicsItem):
         #p.drawLine(0, -100, 0, 100)
         #p.drawLine(-100, 0, 100, 0)
         #print "drawing Grid."
-        
-        
+
+
     def generatePicture(self):
         self.picture = QtGui.QPicture()
         p = QtGui.QPainter()
         p.begin(self.picture)
-        
+
         vr = self.getViewWidget().rect()
         unit = self.pixelWidth(), self.pixelHeight()
         dim = [vr.width(), vr.height()]
         lvr = self.boundingRect()
         ul = np.array([lvr.left(), lvr.top()])
         br = np.array([lvr.right(), lvr.bottom()])
-        
+
         texts = []
-        
+
         if ul[1] > br[1]:
             x = ul[1]
             ul[1] = br[1]
@@ -157,6 +157,7 @@ class GridItem(UIGraphicsItem):
 
                 linePen = self.opts['pen']
                 lineColor = self.opts['pen'].color()
+                lineWidth = self.opts['pen'].width()
                 lineColor.setAlpha(c)
                 linePen.setColor(lineColor)
 
@@ -170,9 +171,9 @@ class GridItem(UIGraphicsItem):
                 for x in range(0, int(nl[ax])):
                     linePen.setCosmetic(False)
                     if ax == 0:
-                        linePen.setWidthF(self.pixelWidth())
+                        linePen.setWidthF(lineWidth * self.pixelWidth())
                     else:
-                        linePen.setWidthF(self.pixelHeight())
+                        linePen.setWidthF(lineWidth * self.pixelHeight())
                     p.setPen(linePen)
                     p1 = np.array([0.,0.])
                     p2 = np.array([0.,0.])