Keyboard not opening under Android

[SolidTux]

Describe the bug
When using a text edit field, the onscreen keyboard is not opened under Android. Also other things like long pressing to open a menu do not work.

To Reproduce
Steps to reproduce the behavior (also appears with the hello-android example):

1. Use eframe with NativeActivity
2. Add text_edit_singleline
3. Run with cargo apk
4. Switch focus to text field

Expected behavior
When moving the focus to the text field, the onscreen keyboard should pop up and long pressing to copy/paste etc. should work.

Smartphone (please complete the following information):

• Device: Pixel 7 Pro
• OS: LineageOS 22.1 (Android 15)

[SolidTux]

It looks like it might be related to this winit issue.

[podusowski]

For showing up the keyboard you can try this workaround.

rust-mobile/android-activity#178 (comment)

But be prepared for more issues with the IME on Android.

[wareya]

It's hacky and unsafe but I managed to get the virtual keyboard to pop up when focusing text fields, but only the backspace key does anything. In fact, in the android SDK emulator, the emulated physical keyboard connected to my actual physical keyboard also cannot do anything except for submit backspaces. I think the IME-related stuff isn't hooked up or something.

I want this to work so if anyone has anything they want me to try to see if it gets it working I'll be happy to give it a shot.

qemu-system-x86_64_2025-04-26_01-26-38.mp4

Code (some of it it was based on rust-mobile/android-activity#178 -- for me it's only for testing)

#[cfg(target_os = "android")]
static mut APP_CONTEXT : Option<egui_winit::winit::platform::android::activity::AndroidApp> = None;
// ^---- set on boot

#[cfg(target_os = "android")]
pub fn show_soft_input(show_implicit: bool)
{
    use std::borrow::Borrow;
    
    let ctx : egui_winit::winit::platform::android::activity::AndroidApp = unsafe { APP_CONTEXT.as_ref().unwrap().clone() };
    
    let jvm = unsafe { jni::JavaVM::from_raw(ctx.vm_as_ptr().cast()) }.unwrap();
    let mut env = jvm.attach_current_thread().unwrap();
    let na = unsafe { jni::objects::JObject::from_raw(ctx.activity_as_ptr().cast()) };
    
    let mut env = jvm.attach_current_thread().unwrap();
    let class_ctxt = env.find_class("android/content/Context").unwrap();
    let ims = env.get_static_field(class_ctxt, "INPUT_METHOD_SERVICE", "Ljava/lang/String;").unwrap();

    let im_manager = env.call_method(
        &na, "getSystemService", "(Ljava/lang/String;)Ljava/lang/Object;", &[(&ims).into()]
    ).unwrap().l().unwrap();

    let jni_window = env.call_method(&na, "getWindow", "()Landroid/view/Window;", &[]).unwrap().l().unwrap();
    let view = env.call_method(&jni_window, "getDecorView", "()Landroid/view/View;", &[]).unwrap().l().unwrap();

    env.call_method(
        im_manager,
        "showSoftInput",
        "(Landroid/view/View;I)Z",
        &[
            jni::objects::JValue::Object(&view),
            if show_implicit
            {
                (ndk_sys::ANATIVEACTIVITY_SHOW_SOFT_INPUT_IMPLICIT as i32).into()
            }
            else
            {
                0i32.into()
            },
        ],
    )
    .unwrap();
}

fn check_ui_keyboard_focus(ctx : &egui::Context) -> bool
{
    ctx.memory(|mem| mem.focused()).is_some()
}

in my app:

        #[cfg(target_os = "android")]
        {
            if check_ui_keyboard_focus(ctx)
            {
                show_soft_input(true);
            }
        }

[wareya]

Apparently android-activity just doesn't convey any IME events at all when compiled in NativeActivity mode. And I guess eframe on android only listens for IME events w/r/t text input, and ignores individual key events, even on the android-native-activity feature. Until android-activity finds a way to fix this, eframe on android in native activity mode should convey non-IME key events as egui text input events.

Here I have 1 and 2 set up to rotate my canvas, even if a text field is focused. That works. But they don't make it to the text field.

qemu-system-x86_64_2025-04-26_05-39-51.mp4

[wareya]

I tried again with the git version of egui, rather than the latest stable (0.31.1), and forcibly opening the virtual keyboard as shown above does actually work and result in working input, even on a NativeActivity app that's using android:hasCode="false". I can't change languages though, probably a problem with the technique being used to force the soft keyboard to open.

screen-20250430-062057.mp4

[poerlang]

I tried again with the git version of egui, rather than the latest stable (0.31.1), and forcibly opening the virtual keyboard as shown above does actually work and result in working input, even on a NativeActivity app that's using android:hasCode="false". I can't change languages though, probably a problem with the technique being used to force the soft keyboard to open.

screen-20250430-062057.mp4

try this in Android 8.1.0 and Android 14, not work ....

[target.'cfg(target_os = "android")'.dependencies.eframe]
git = "https://github.com/emilk/egui.git"
rev = "bdbe6558527899331440dd11024c07bcebb3c876"
default-features = false
features = [
    "glow",
    "android-native-activity",
    "default_fonts",
]