Struct OnCreateState 

pub struct OnCreateState<'a> { /* private fields */ }

The state passed to the optional android_on_create entry point if available.

This gives access to the Java VM, the Java Activity and any saved state from a previous instance of the Activity that was saved via the onSaveInstanceState callback.

Each time android_on_create is called it will receive a new Activity reference.

See the top-level android-activity documentation for more details on android_on_create.

Implementations

impl<'a> OnCreateState<'a>

pub fn vm_as_ptr(&self) -> *mut c_void

Returns a pointer to the Java Virtual Machine, for making JNI calls

If you use the jni crate, you can wrap this pointer as a JavaVM via:

let vm = unsafe { JavaVM::from_raw(on_create_state.vm_as_ptr().cast()) };

pub fn activity_as_ptr(&self) -> *mut c_void

Returns an (unowned) JNI global object reference for this Activity as a pointer

If you use the jni crate, you can cast this as a JObject reference via:

let vm = unsafe { JavaVM::from_raw(on_create_state.vm_as_ptr().cast()) };
let _res = vm.attach_current_thread(|env| -> jni::errors::Result<()> {
    let activity = on_create_state.activity_as_ptr() as jni::sys::jobject;
    // SAFETY: The reference / pointer is valid at least until we return from `android_on_create`
    let activity = unsafe { env.as_cast_raw::<JObject>(&activity)? };
    // Do something with `activity` here
    Ok(())
});

JNI Safety

It is not specified whether this will be a global or local reference and in any case you must treat is as a reference that you do not own and must not attempt to delete it.

• Don’t wrap the reference as a Global which would try to delete the reference when dropped.
• Don’t wrap the reference in an Auto which would treat the reference like a local reference and try to delete it when dropped.

pub fn saved_state(&self) -> &[u8]

Returns the saved state of the Activity as a byte slice, which may be empty if there is no saved state.