add a URL link to an app

[guimath]

Hi all, I've been looking for a way to add a hyperlink that is clickable and will launch in the web browser.

Is there a built in way of doing that? Is it in the works?
If not, i understand how to make a clickable text widget but how can I then launch the browser? Do I need to do it in the rust code?

(I would like to have it run on android so that might complicate things a bit...)

[Vadoola]

You would need to do it in Rust code. In my app Tomotroid I have a Hyperlink object I created you can look at or use. I'm not sure if the Rust crate works on Android though, I never looked.

[Vadoola]

I was on mobile early when I wrote that, but coming back to give a bit more detailed answer.

The Hyperlink Slint object can be seen here.

The Rust code for it is:

tomotroid.window.global::<HLClick>().on_hl_clicked(|url| {
        open::that(url.as_str()).unwrap();
    });

utilizing the Rust crate Open, which opens a URL or file path in the default Application for the OS. The crate makes mention of Linux, Mac, and Windows. It makes no mention one way or the other about Android. Having never done Android development, I'm not really sure what would be involved to make it work on the Rust side for Android.

[guimath]

Thanks, I had a look and this seems like a good solution for PC but I am yet to test it on android and don't really expect it to work - will let you know if it does !

[guimath]

Ok so the open crate doesn't really have dedicated android code, which mean they basically attempt to run terminal commands like on linux but you need high permissions to do that from an app.

The proper way to do it on Android is to use what's called ACTION_VIEW intents that can trigger opening of other apps. The crate webbrowser uses those and thus manages to open links even in apps without any permissions. It is fully crossplatform and super useful!

On android and IOS it is restricted to http though (for safety and error handeling I guess) but using their code without the http validation allowed me to open mailto links as well.

// In Cargo.toml
// [target.'cfg(target_os = "android")'.dependencies]
// jni = "0.21"
// ndk-context = "0.1"

#[cfg(target_os = "android")]
fn start_android_action_view(
    url: String,
) -> Result<(), Box<dyn std::error::Error>> {
    use jni::objects::{JObject, JValue};
    // use ndk::native_activity::NativeActivity;
    // Create a VM for executing Java calls
    let ctx = ndk_context::android_context();
    let vm = unsafe { jni::JavaVM::from_raw(ctx.vm() as _) }?;
    let activity = unsafe { jni::objects::JObject::from_raw(ctx.context() as _) };
    // let context = unsafe { jni::objects::JObject::from_raw(ctx.context().cast()) };
    let mut env = vm.attach_current_thread()?;
    
    // activity 
    let intent_class = env.find_class("android/content/Intent")?;
    let action_view = env.get_static_field(&intent_class, "ACTION_VIEW", "Ljava/lang/String;")?;

    // Create Uri object
    let uri_class = env.find_class("android/net/Uri")?;
    let url = env.new_string(url)?;
    let uri = env.call_static_method(
        &uri_class,
        "parse",
        "(Ljava/lang/String;)Landroid/net/Uri;",
        &[JValue::Object(&JObject::from(url))],
    )?;
    // Create new ACTION_VIEW intent with the uri
    let intent = env.alloc_object(&intent_class)?;
    env.call_method(
        &intent,
        "<init>",
        "(Ljava/lang/String;Landroid/net/Uri;)V",
        &[action_view.borrow(), uri.borrow()],
    )?;

    // Start the intent activity.
    env.call_method(
        &activity,
        "startActivity",
        "(Landroid/content/Intent;)V",
        &[JValue::Object(&intent)],
    )?;

    Ok(())
}

[Vadoola]

Good to know, I found Open first and it did what I wanted. I started Tomotroid as a learning project and Slint didn't even support Android at that time. Back when they added Android support I thought maybe at some point I would try and get Tomotroid working it, but it's low on the priority list.