kivy-reloader 0.2.2

Hot reload your Kivy app on multiple Android phones and computer in real-time.

Kivy Reloader

Hot reload your Kivy app on multiple phones and computer in real-time.

This tool allows you to instantly update your Kivy app on multiple devices simultaneously by pressing Ctrl+S, saving your precious development time and effort.

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I am too impatient to read the tutorial, I want to see it working RIGHT NOW!

Clone this project, open the folder on terminal and type:

1. poetry shell
2. poetry install
3. Update the kivy-reloader.toml file with your phone IP.
4. adb install bin/kivy_super_reloader-0.1-armeabi-v7a_arm64-v8a-debug.apk
5. python main.py
6. Keep calm and enjoy the Kivy Reloader! 😄

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How to use

Instead of importing from kivy.app, import from kivy_reloader.app. Start the app within an async event loop using trio.

On this tutorial we are going to show 3 possible different structures of your beautiful app.

Beautiful App structure 0:

Suppose your beautiful app has only one file:

├── main.py

import trio
from kivy.lang import Builder

from kivy_reloader.app import App

kv = """
Button:
    text: "Hello World"
"""


class MainApp(App):
    def build(self):
        return Builder.load_string(kv)


app = MainApp()
trio.run(app.async_run, "trio")

Start your app with python main.py.

Beautiful App structure 1:

Suppose your beautiful app has this tree structure:

.
├── main.py
└── screens
    ├── main_screen.kv
    └── main_screen.py

import trio

from kivy_reloader.app import App

class MainApp(App):
    def build(self):
        from screens.main_screen import MainScreen

        return MainScreen(name="Main Screen")

app = MainApp()
trio.run(app.async_run, "trio")

Start your app with python main.py.

Beautiful App structure 2:

Suppose your beautiful app has this tree structure (recommended):

.
├── beautifulapp
│ ├── __init__.py
│ └── screens
│ ├── main_screen.kv
│ └── main_screen.py
├── main.py

main.py:

import trio

from beautifulapp import app

trio.run(app.async_run, "trio")

beautifulapp/__init__.py:

from kivy_reloader.app import App


class MainApp(App):
    def build(self):
        from .screens.main_screen import MainScreen

        return MainScreen(name="Main Screen")


app = MainApp()

Start your app with python main.py.

Prerequisites

Install scrcpy on your operating system: Linux, Windows or macOS. You will be able to control your device from your computer.

Install kivy: choose your operating system on Kivy School Tutorial.

How to install:

I recommend you to use poetry to install kivy-reloader.

Option 1) Using poetry - recommended

poetry add kivy-reloader

Option 2) Using pip

pip install kivy-reloader

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Configure Kivy Reloader

After installing kivy-reloader, on the project folder, type on the terminal kivy-reloader init. This is going to create two files on your project folder: kivy-reloader.toml and buildozer.spec.

Configure the kivy-reloader.toml file:

The first time you run kivy-reloader init, you will see on the terminal:

This is the kivy-reloader.toml that has been created on your project folder.

Every line has an explanation above. The most important constants on this file are:

1. PHONE_IPS: Put the IP of your phone here. You can find the IP of your Android phone on: Settings > About phone > Status > IP Address.
2. HOT_RELOAD_ON_PHONE: Set it to True to hot heload on your phone when you press Ctrl+S
3. WATCHED_FOLDERS_RECURSIVELY: This is a list of folder names, for example ["screens", "components"]. If any file inside these folders change, your Kivy app will reload.
4. WATCHED_KV_FOLDERS_RECURSIVELY: This is a list of folder names, for example ["screens", "components"]. This is where the Reloader will find your .kv files to reload them every time you press Ctrl+S.

The kivy-reloader init also creates a file called buildozer.spec on your project folder. It has the minimal buildozer.spec that you can use to make your app work with Kivy Reloader.

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How to compile and hot reload on Android:

1. Connect your phone to the computer using a USB cable.
2. Enable developer options and enable USB debugging on your phone.
3. Create a script compile.py with the following code:

from kivy_reloader import compile_app

compile_app.start()

3. Run on the terminal python compile.py.

4. You can change the selected option by using UP ↑ / DOWN ↓ arrows and press ENTER. Choose the first option and Buildozer will compile the app and deploy on your phone. Once the app is on your phone, run python main.py and the hot reload will be already working. Just press Ctrl+S in any file inside screens folder or main.py and your app will be updated on computer and phone at the same time.

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Do you want to test directly from this repo?

Clone this project, open the folder on terminal and type:

1. poetry shell
2. poetry install
3. Update the kivy-reloader.toml file with your phone IP.
4. python main.py
5. python compile.py and press enter.
6. Wait the compilation to finish on your phone.
7. Enjoy the Kivy Reloader!