Python eto ValueChanged in a class

Rhino Developer
,
1

hi everyone,

I am setting up a NumericUpDown with python eto in a class.
the following is a part of my code

class MyEtoClass(forms.Form):
    def __init__(self):
        self.Title = 'My Title'
    
        def addnumeric(name='myslider'):
            setattr(self, name, forms.Slider())
            setattr(getattr(self, name), 'Value', 1)
            setattr(getattr(self, name), 'MinValue', 0)            
            setattr(getattr(self, name), 'MaxValue', 10)
            setattr(getattr(self, name), 'ValueChanged', getattr(getattr(self, name), 'ValueChanged')+self.onvaluechanged)

however python doesn’t allow me to set the ValueChanged attribute like this
the original one should be:
self.myslider.ValueChanged += self.onvaluechanged

The error is:
Runtime error (TypeErrorException): unsupported operand type(s) for +: ‘BoundEvent’ and ‘instancemethod’

Traceback:
line 25, in addnumeric, “”
line 28, in init, “”
line 45, in script

Actually, I don’t know how this line works.
The Idea is to create multiple sliders within the init function so that i don’t have to repeat myself.

Could anyone explain the idea of the line or give me some other ways to do this?

Thanks

2

Hi @raylee14, i guess you cannot tread an Event like an attribute and assign it that way.

Below is an example, multiple sliders are added in a loop, all with the same event. Note that i Tag the sliders to detect them in the event code. I guess you can do the same with NumericStepper.

ETO_SliderSample.py (2.9 KB)

_
c.

3

thank you so much. let me dive into this first :laughing:
btw, what ValueChanged and OnValueChanged actually do?
and is there any other source to learn python eto?
I only found a few of it, make my job very very hard :cry:

4

slider.ValueChanged is the event which occurs if the slider property Value is changed. You can connect a function to this event by calling eg.:

 slider.ValueChanged += self.OnSliderValueChanged

The name of the function can be any name, the arguments are fixed. A good general introduction to form events can be found in the Windows Forms docs

For Eto controls you might start here and for all other things with the Eto docs

_
c.

5

I got it. What about OnValueChanged? is it doing the same thing as ValueChanged?

6

ValueChanged is the event which notifies any subscriber that the value has changed.
To explain it more understandable:
A cook saying the meal is ready for instance could name this event FoodIsReady.

Any subscriber to this event can have unique response to this. Usually calling the method responsible ‚On‘- or ‚Handle‘- .
So a waiter would have a response OnFoodIsReady which does something like Go to the kitchen, grab the food bring it to the guest.
So the OnValueChanged is a individual response to the ValueChanged event.

7

Amazing. Clear explanation. Thanks again dude :heart_eyes: