From 2d754672a0c696c0d97da9e7f2148f8ab99fe86e Mon Sep 17 00:00:00 2001
From: Karl Bedrich <karl@bedrich.de>
Date: Thu, 10 Nov 2016 17:01:15 +0000
Subject: [PATCH] NEW show/hide gradient ticks NEW link gradientEditorItem to
 other gradients

---
 pyqtgraph/graphicsItems/GradientEditorItem.py | 33 +++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/pyqtgraph/graphicsItems/GradientEditorItem.py b/pyqtgraph/graphicsItems/GradientEditorItem.py
index 6ce06b61..55c689d4 100644
--- a/pyqtgraph/graphicsItems/GradientEditorItem.py
+++ b/pyqtgraph/graphicsItems/GradientEditorItem.py
@@ -450,7 +450,20 @@ class GradientEditorItem(TickSliderItem):
         self.addTick(1, QtGui.QColor(255,0,0), True)
         self.setColorMode('rgb')
         self.updateGradient()
-    
+        self.linkedGradients = {}
+
+    def showTicks(self, show=True):
+        for tick in self.ticks.keys():
+            if show:
+                tick.show()
+                orig = getattr(self, '_allowAdd_backup', None)
+                if orig: 
+                    self.allowAdd = orig
+            else:
+                self._allowAdd_backup = self.allowAdd
+                self.allowAdd = False #block tick creation
+                tick.hide()
+
     def setOrientation(self, orientation):
         ## public
         """
@@ -753,7 +766,9 @@ class GradientEditorItem(TickSliderItem):
         for t in self.ticks:
             c = t.color
             ticks.append((self.ticks[t], (c.red(), c.green(), c.blue(), c.alpha())))
-        state = {'mode': self.colorMode, 'ticks': ticks}
+        state = {'mode': self.colorMode, 
+                 'ticks': ticks,
+                 'ticksVisible': next(iter(self.ticks)).isVisible()}
         return state
         
     def restoreState(self, state):
@@ -778,6 +793,8 @@ class GradientEditorItem(TickSliderItem):
         for t in state['ticks']:
             c = QtGui.QColor(*t[1])
             self.addTick(t[0], c, finish=False)
+        self.showTicks( state.get('ticksVisible', 
+                                  next(iter(self.ticks)).isVisible()) )
         self.updateGradient()
         self.sigGradientChangeFinished.emit(self)
         
@@ -793,6 +810,18 @@ class GradientEditorItem(TickSliderItem):
         self.updateGradient()
         self.sigGradientChangeFinished.emit(self)
 
+    def linkGradient(self, slaveGradient, connect=True):
+        if connect:
+            fn = lambda g, slave=slaveGradient:slave.restoreState(
+                                                     g.saveState())
+            self.linkedGradients[id(slaveGradient)] = fn
+            self.sigGradientChanged.connect(fn)
+            self.sigGradientChanged.emit(self)
+        else:
+            fn = self.linkedGradients.get(id(slaveGradient), None)
+            if fn:
+                self.sigGradientChanged.disconnect(fn)
+
 
 class Tick(QtGui.QGraphicsWidget):  ## NOTE: Making this a subclass of GraphicsObject instead results in
                                     ## activating this bug: https://bugreports.qt-project.org/browse/PYSIDE-86