Kivy test for Rotation and collide_point in on_touch_move

main.py

#!/usr/bin/env python3
# coding=utf-8

"""
Basic Kivy Rotation Test.

    minimal setup to test collide_point and rotation behavior
"""


import kivy
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.vector import Vector
from kivy.clock import Clock
from kivy.properties import (
    NumericProperty,
    ReferenceListProperty,
    ObjectProperty
)

kivy.require('1.9.0')

##########################################

##########################################


class SliderTrack(Widget):
    """
    A Track.

        could change color according to value..
    """

    pass


class SliderHandle(Widget):
    """A Handle."""

    def on_touch_move(self, touch):
        """Move Handle with touch."""
        # print(self)
        # print(touch)
        if self.collide_point(touch.x, touch.y):
            # TODO: touch point is not center..
            #  calculate realtive movement based on touch pos...
            center_y_new = touch.y
            if (
                (touch.y + (self.height/2) < self.parent.top) and
                (touch.y - (self.height/2) > self.parent.y)
            ):
                self.center_y = center_y_new
                return True


class MySlider(Widget):
    """A Slider."""

    test = NumericProperty(0)


##########################################

class TestGui(Widget):
    """The Gui."""

    pass


##########################################


class RotationTestApp(App):
    """My first Pong App."""

    def build(self):
        """Kivy entry point."""
        testgui = TestGui()
        return testgui


##########################################
if __name__ == '__main__':
    RotationTestApp().run()

rotationtest.kv

#:kivy 1.9.0
<SliderTrack>:
    size: 1, (self.parent.height-2)
    canvas:
        Color:
            rgb: (0, 0, 1)
        Rectangle:
            pos:self.pos
            size:self.size

<SliderHandle>:
    size: 50, 200
    canvas:
        Color:
            rgb: (0.7, 0.5, 1)
        Rectangle:
            pos:self.pos
            size:self.size

<MySlider>:
    handle: slider_handle
    track: slider_track
    size: 200, 500
    angle: 0
    canvas.before:
        PushMatrix
        Rotate:
            angle: self.angle
            axis: 0, 0, 1
            origin: self.center
    canvas:
        Color:
            rgb: (1, 1, 0)
        Rectangle:
            pos: self.pos
            size: self.size
    canvas.after:
        PopMatrix
    Label:
        font_size: 70
        center: self.parent.center
        # center_x: self.parent.width/2
        # center_y: (self.parent.height/2) + (self.height / 2)
        text: str(self.parent.test)
    SliderTrack:
        id: slider_track
        center_x: slider_handle.center_x
        center_y: self.parent.center_y
    SliderHandle:
        id: slider_handle
        x: self.parent.x
        center_y: self.parent.center_y

<TestGui>:
    slider1: slider_1
    slider2: slider_2

    canvas:
        Color:
            rgb: (0.5, 0.5, 0.5)
        Rectangle:
            pos: self.center_x - 5, 0
            size: 4, self.height

    MySlider:
        id: slider_1
        x: root.x
        center_y: root.center_y
        angle: 0

    MySlider:
        id: slider_2
        x: root.width-self.width
        center_y: root.center_y
        angle: 45