Kivy Blueprints

Drawing touches

To illustrate one possible scenario for reacting to the touch input, let's draw a circle every time the user touches (or clicks) the screen.

A Widget has an on_touch_down event that will come in handy for this task. We're interested in just the coordinates of every touch for the time being, and they are accessible as follows:

class CanvasWidget(Widget):
    def on_touch_down(self, touch):
        print(touch.x, touch.y)

This example prints the position of touches as they occur. To draw something on the screen instead, we will use the Widget.canvas property. Kivy's Canvas is a logical drawable surface that abstracts away the underlying OpenGL renderer. Unlike the low-level graphical API, the canvas is stateful and preserves the drawing instructions ...