Over the years, there have been lots of threads here and on the old Grasshopper forum that deal with setting slider values in Grasshopper. They all have some advantages and disadvantages, but they have something in common: they too often end up breaking the Grasshopper SDK rule “never edit values while the definition is running”.
This thread shows a way of fixing that. This is a Rhino-6-only possibility, because this feature is new in Rhino 6. By overriding the Component Context menu, we can set the values outside of the solution, in a very Grasshopper-classic way.
This uses the same logic as this definition by Anders Holden Deleuran on the old Grasshopper forum.
![image]()
Here is the code:
"""
Reset named sliders.
Right-click on the component and choose "Update Sliders!" to update their values.
Inputs:
Sliders: (strings) A list with names of sliders
Values: (numbers) A list with values of sliders
Remarks: This component does not retuns any values.
"""
from ghpythonlib.componentbase import executingcomponent as component
import Grasshopper, GhPython
import System
import Rhino
import rhinoscriptsyntax as rs
class UpdateSliders(component):
def RunScript(self, Sliders, Values):
if not Sliders or not Values:
Sliders = None
Values = None
return
self.Sliders = Sliders
self.Values = Values
if len(Sliders) != len(Values):
raise Exception("Different lenghts of sliders and values")
self.Component = ghenv.Component
self.GhDef = None
if self.Component: self.GhDef = self.Component.OnPingDocument()
def AppendAdditionalComponentMenuItems(self, menu):
item = Grasshopper.Kernel.GH_Component.Menu_AppendGenericMenuItem(
menu, "Update Sliders!", self.OnClicked, self.Icon_24x24, None, True, False);
item.ToolTipText = "Update the sliders now";
def OnClicked(self, obj, args):
try:
self.UpdateValues(obj, args)
except Exception, ex:
System.Windows.Forms.MessageBox.Show(str(ex))
def UpdateValues(self, obj, args):
if not self.GhDef: return
if not self.Sliders or not self.Values: return
ghObjects = self.GhDef.Objects # Get to the GH objects
# Iterate the GH objects
for obj in ghObjects:
# Set the named slider values
if type(obj) is Grasshopper.Kernel.Special.GH_NumberSlider and \
obj.NickName in self.Sliders:
# Set min/max
#obj.Slider.Minimum = 0
#obj.Slider.Maximum = 10
# Set value
obj.Slider.Value = self.Values[self.Sliders.index(obj.NickName)]
# Update slider
obj.ExpireSolution(True)
Have a look and see if it helps!
Thanks,
Giulio
–
Giulio Piacentino
for Robert McNeel & Associates
giulio@mcneel.com
