How do I change the color of my widget in Kivy at run time

[ivan limonov]

I'm having trouble changing the color of a simple widget in Kivy. I can set the color when I create the widget, but I can't change it afterwards.

Here is the simple layout definition file test.kv. It defines a circle where the color (actually just the r, from rgba), position and size are all linked to variables in the widget class.

<CircleWidget>:

    canvas.before:

        Color:

            rgb: self.rgb

        Rectangle:

            pos: self.pos

            size: self.size

class CircleWidget(Widget):

    def __init__(s, **kwargs):

        s.size= [50,50]

        s.pos = [100,50]

        s.rgb = [1,0,0]

        super(CircleWidget, s).__init__(**kwargs)

    def on_touch_down(s, touch):

        if s.collide_point(touch.x,touch.y):    

            s.pos = [s.pos[1],s.pos[0]]           # This works

            s.rgb = [0,0,1]                       # <---- This does nothing!

class TestApp(App):

    def build(s):

        parent = Widget()

        w = CircleWidget()

        parent.add_widget(w)

        return parent

if __name__ == '__main__':

    TestApp().run()

Can anyone see the problem?

[Kovak]

It looks like rgb is a regular list and not a ListProperty, regular python data types will not have event dispatching.

[ivan limonov]

Yes, I have already noticed, but how do I change the color during operation?

пятница, 22 мая 2015 г., 23:23:08 UTC+4 пользователь Kovak написал:

[Kovak]

If you defined

class CircleWidget(Widget):
    rgb = ListProperty([1., 1., 1.)]

    def __init__(s, **kwargs):
        s.size= [50,50]
        s.pos = [100,50]
        s.rgb = [1,0,0]
        super(CircleWidget, s).__init__(**kwargs)


    def on_touch_down(s, touch):
        if s.collide_point(touch.x,touch.y):    
            s.pos = [s.pos[1],s.pos[0]]           # This works
            s.rgb = [0,0,1]        

Your rgb would now be observed and it should automatically update the canvas instruction that watches it when it changes.

[ivan limonov]

Thank you, it works now, I tried to do likewise, but he not worked

пятница, 22 мая 2015 г., 23:35:31 UTC+4 пользователь Kovak написал: