Building Cross-Platform Applications

As the demand for mobile applications continues to grow, developers face the challenge of building applications that work across different operating systems. One such solution is Kivy, a powerful Python framework that allows developers to create cross-platform applications with a single codebase. In this article, we will explore Kivy for iOS, a toolchain that enables developers to build and deploy Kivy applications on iOS devices. We will discuss the installation process, configuring your app, using recipes, reducing application size, and more. Let’s dive in!

Installation & Requirements

Before getting started with Kivy for iOS, it is recommended to use a Python virtual environment. This ensures a clean and isolated environment for installing the necessary packages.

To install Kivy for iOS, you can use pip, the package installer for Python. Open your terminal and run the following command:

python3 -m venv venv
. venv/bin/activate
pip3 install kivy-ios

In addition to Kivy for iOS, you will also need to install Xcode and its command line tools. Xcode is the integrated development environment for macOS and is necessary for building and running iOS applications. You can install Xcode and the command line tools by running the following command:

xcode-select --install

The installation process may take some time, so grab a coffee and let it complete.

Using the Toolchain

The toolchain is a set of commands that allows you to build and manage the necessary libraries for your Kivy application. It provides recipes that contain the compilation and packaging instructions for Python extensions and C/C++ libraries.

To list the available recipes and their versions, run the following command:

toolchain recipes

You can build a recipe by specifying its name, for example:

toolchain build python3 kivy

You can also build multiple recipes at once by adding them as parameters:

toolchain build python3 openssl kivy

To remove a recipe build, use the clean command followed by the recipe name:

toolchain clean openssl

For a complete list of available commands, you can run:

toolchain

Creating the Xcode Project

Once you have compiled the necessary libraries using the toolchain, you can create the Xcode project for your Kivy application. The toolchain.py script provides a command to generate the initial Xcode project for you. Specify the title and app directory for your project, for example:

toolchain create Touchtracer ~/code/kivy/examples/demo/touchtracer

This command will create a directory named <title>-ios with an Xcode project inside it. You can open the Xcode project using the following command:

open touchtracer-ios/touchtracer.xcodeproj

From here, you can customize your app by setting the icon and launch images in Xcode, configuring the environment variables in the main.m file, and modifying the orientation settings.

Using Recipes

Recipes are used to install and compile any additional libraries that you may need for your Kivy application. These recipes are similar to those used in the Python-for-Android project. You can refer to the recipe documentation for more details.

Reducing Application Size

To reduce the size of your distributed app, there are several techniques you can employ:

1. Minimize the build/pythonX/lib/pythonXX.zip file, which contains all the Python modules. You can remove any files that are not needed for your application.

2. Disable stripping options in the Xcode settings. Stripping can remove needed symbols from Python dynamic modules.

3. Consider removing the x86_64 architecture from the iOS package if you are not targeting the iOS emulator. This can significantly reduce the size of your app.

Please note that these steps may require some additional configuration and testing for your specific application.

Conclusion

Kivy for iOS provides a powerful toolchain for building cross-platform applications on iOS devices. With a single codebase written in Python, developers can create applications that run seamlessly on both Android and iOS platforms. By utilizing the installation process, configuring the app, using recipes, and reducing application size, developers can optimize their development workflow and deliver efficient and resource-friendly applications. Kivy for iOS opens up new possibilities for developers looking to reach a wider audience and deliver innovative mobile experiences. So, why wait? Start building your cross-platform Kivy application for iOS today!

Happy coding!