Jano

Jano is a rust library that provides useful integration tools for android. A list of android integrations provided by Jano:

• TcpStream connecting/reading/writing via java.net.Socket
• opening/closing keyboard overlay
• opening camera for a picture
• getting/setting clipboard content (text only)
• creating wgpu Surface (with wgpu feature flag enabled)
• touch to mouse event translations
• getting display insets (eg: the space the camera notch/island occupies)

Example

The most basic android app can be created with the following.

use jano::{FrameStats};
use jano::android_activity::{AndroidApp, MainEvent};

#[no_mangle]
fn android_main(android: AndroidApp) {
    jano::android_main(android, App::default());
}

#[derive(Default)]
struct App;
impl jano::AppState for App {
    fn on_main_event(&mut self, event: MainEvent, _draw_frames: &mut bool) -> bool {
    	match event {
            MainEvent::Destroy => return true,
            _ => {}
        }
        false
    }
    fn on_frame(&mut self, _stats: FrameStats) {}
}

And in the Cargo.toml file:

[package]
name = "simple-example"
version = "0.0.1"
edition = "2021"

[lib]
name = "main"
crate-type = ["cdylib"]

[dependencies]
jano = { git = "https://github.com/MasonFeurer/Jano.git" }

Running

To run a rust project that uses jano, you will need to use jano-cli (in this repository). If you have not already, you will have to build jano-cli from source. In the future, it will be available on https://crates.io, but that is not today.

Jano CLI

Building Jano CLI

• Download this repository:
• Go to Jano/jano-cli
• Use cargo build

git clone "https://github.com/MasonFeurer/Jano.git"
cd Jano/jano-cli
cargo b -r

Then, in order for the built jano-cli to be usable, you will have to add it to your PATH. On Linux Debian, this can be done by putting this line into your ~/.bashrc file:

export PATH="path_to_the_jano_binary:$PATH"

Examples

To build your project:

jano-cli b

To build, then run your app on a connected android device:

jano-cli r

To skip building, and run your app on a connected android device:

jano-cli r --no-build

App attributes

Jano-cli will read your projects Cargo.toml for some info before building your app. It will look at all members of the [jano] header in your TOML. Here are the recognized options and their meaning:

• icon : (string)

  A path to an image file to be used for the android application's icon image.

• name : (string)

  The android application name. This is what android will show as the name of the app on the home screen.

• app_id : (string)

  The android application ID. Should look like a namespace. This uniquely identifies the app on the android device.

  Example: "com.example.namespace"

• version : (string)

  The "version" value for the android APK. Used for versioning the android app on the android device.

  Example: "0.1.0"

• build_targets : [(string), ...]

  The target names to build native libraries for. cargo-ndk is executed for every target.

• no_strip : true|false,

  Wether to strip debug symbols from the generated native library. Passed to cargo-ndk.

• java_src_files : [(string), ...]

  Paths to Java files to be copied into the java source directory of the created Java Application. Can be used to override MainActivity.java.