Kivy with Python tutorial Part 8 - Simple Drawing Application

In this Kivy application development tutorial, we cover how to use the touch input from the user to create a simple drawing application, treating the presses from the user as a pencil.

Bitcoin donations: 1GV7srgR4NJx4vrk7avCmmVQQrqmv87ty6

[MiledRizk]

thanks again for these good tutorials:
i modified a little the script so i can click without dragging and create straight lines, and if i want i can start dragging
and i'll have a freeform shape, so i'll end up with a mixed shape. Of course it still lots of work to make it more useful, because now after finishing the dragging i cannot start a new independent shape. Anyway here's my code:
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.graphics import Line


class Drawapp(Widget):
def __init__(self, **kwargs):
super(Drawapp, self).__init__(**kwargs)
self.arr = []

def on_touch_down(self, touch):
with self.canvas:
touch.ud["polyline"] = Line(points=(touch.x, touch.y))
self.arr.append((touch.x, touch.y))
if len(self.arr) <= 2:
for idx in range(len(self.arr)):
touch.ud["polyline"].points += self.arr[idx]
else:
for idx in range(len(self.arr)):
touch.ud["polyline"].points += self.arr[-2]

def on_touch_move(self, touch):
touch.ud["polyline"].points += (touch.x, touch.y)


def on_touch_up(self, touch):
self.arr.append((touch.x, touch.y))

class SimpleApp5(App):
def build(self):
return Drawapp()

if __name__ == "__main__":
SimpleApp5().run()

[mushinart]

sentdex , you have a great channel and tutorials but i have a question ... how to access hardware api for phones (android and ios) to benefit from cervices like gps location and gyro ...???

[shivamsahil]

is there any way to alter line thickness and color?

[kphxmfi]

Everyone does the paint example, nobody demonstrates how to modify an existing application with working buttons for a touch screen.

Anyone know any good resources for accomplishing this?

[jeancarlosadrianza]

Hi, sentdex. Very interesting video... I would like to know how to make notifications for App's in kivy... Do you have information about that? Thanks in advance...

[unknownlifeform]

Quick question, can pyqt do something similar?

[TarekAlouiGeek]

Thanks for the tutorial, but what does touch.ud means ? and what is it exactly (variable : list )? a kivy keyword ? and what can I do else than writing ["Line"] ? Can I change Line to sth else ?
And your tutorials are awesome ! <3

[vijaykumarsamanthapudi]

how to add vertical scrollbar for the canvas in the paint application.Please help me out

[sumansharma]

Sir i just cand draw a line not the curves