Example of how to move two circles on a goocanvas with a gamepad

gamepad-goocanvas-example.py

#!/usr/bin/python
######################################################################
#
#  An example of how to use the gamepad as an input device for
#  python.
#
#  The example shows two dots that can be controlled by the
#  left and the right joystick on a gamepad.
#
#  This may be used as the basis for any analog output. E.g. to
#  control a camera tilt focus and zoom.
#
#  Note! To get this to work, input needs to be patched as follows:
#
#     self._character_file = io.open(
#       self._character_device_path, 'rb')
#     fd = self._character_file.fileno()
#     flag = fcntl.fcntl(fd, fcntl.F_GETFL)
#     fcntl.fcntl(fd, fcntl.F_SETFL, flag | os.O_NONBLOCK)
#
#  See: https://github.com/zeth/inputs/issues/7
#
#  License: This code is released under the MIT license.
#
#  2020-11-30 Mon
#  Dov Grobgeld <dov.grobgeld@gmail.com>
######################################################################

import pdb
import inputs

import gi
gi.require_version('Gtk', '3.0')
gi.require_version('GooCanvas', '2.0')
from gi.repository import Gtk, GLib, GooCanvas
import time

class MainWindow(Gtk.Window):
    def __init__(self):
        super(MainWindow, self).__init__()
        self.connect("destroy", Gtk.main_quit)
        width,height = 800,800
        self.set_size_request(800, 800)

        # Create the GooCanvas widget
        cv = GooCanvas.Canvas()
        # And ask for access to the root layer
        root = cv.get_root_item()

        rect = GooCanvas.CanvasRect(
                    parent = root,
                    x = 0, y = 0,
                    width = width, height = height,
                    fill_color = "#e0ffe0")

        self.lball = GooCanvas.CanvasEllipse(
                    parent = root,
                    x = width/2,
                    y = height/2,
                    radius_x = width/50, radius_y = width/50,
                    line_width = 3.0,
                    fill_color   = "#ff0000")

        self.rball = GooCanvas.CanvasEllipse(
                    parent = root,
                    x = width/2,
                    y = height/2,
                    radius_x = width/50, radius_y = width/50,
                    line_width = 3.0,
                    fill_color   = "#00ff00")

        self.add(cv)
        self.show_all()

        # Current speed motion speed for the left and the right ball.
        self.dxl = 0
        self.dyl = 0
        self.dxr = 0
        self.dyr = 0
        self.gamepad = inputs.devices.gamepads[0]

        # Refresh the ball position 100 times a second
        GLib.timeout_add(10, self.update_ball_pos)

    def update_ball_pos(self):
      # Current ball positions
      xl = self.lball.get_property('x')
      yl = self.lball.get_property('y')
      xr = self.rball.get_property('x')
      yr = self.rball.get_property('y')

      # Consume all pending events
      while True:
        events = self.gamepad._do_iter()
        if events is None or len(events)==0:
          break

        for event in events:
          # Here are the four joystick axes that we
          # map to the left and the right ball
          if event.code == 'ABS_X':
            self.dxl = (event.state-128)/50
          elif event.code == 'ABS_Y':
            self.dyl = (event.state-128)/50
          elif event.code == 'ABS_Z':
            self.dxr = (event.state-128)/50
          elif event.code == 'ABS_RZ':
            self.dyr = (event.state-128)/50

      # Update the ball positions
      self.lball.set_property('x', xl+self.dxl)
      self.lball.set_property('y', yl+self.dyl)
      self.rball.set_property('x', xr+self.dxr)
      self.rball.set_property('y', yr+self.dyr)

      return True

if __name__ == '__main__':
    mainwdw = MainWindow()
    Gtk.main()