I want MotionEvent history, how to get ndk MotionEvent that has it?

[rnikander]

As the Android docs explain, a move event can have a batched history. I want to get this because I'm implementing a drawing app, and I want the fine-grain locations from the stylus. But I see comment in code here that it's not exposed.

It appears that this MotionEvent event from android-activity is just a wrapper around the MotionEvent from the ndk crate. That one does expose the history, but the conversion function into_ndk_event is pub(crate) so I don't think I can call it.

I'm calling poll_events on AndroidApp and I'm getting these various event types from android-activity. How do I get to the ndk event so I can get the history?

PollEvent::Main(MainEvent::InputAvailable) => {
    match app.android_app.input_events_iter() {
        Ok(mut iter) => {
            loop {
                let read_input = iter.next(|event| {
                    let handled = match event {
                        InputEvent::MotionEvent(e) => {
                             // want e's history here 

[rib]

Unfortunately the motion event history isn't currently exposed in the public API.

Technically if you can guarantee your code will only ever run against the native-activity backend you could get very, very unsafe and do a transmute of the MotionEvent because it's a repr(transparent) wrapper for the ndk::event::MotionEvent but this is definitely not intended to be part of the public API contract and would be a safety liability in case the type definition ever changes in the future.

android-activity aims to provide a consistent API across two notable Activity backends, NativeActivity and GameActivity and at the time that I wrote that commented-out code there was no support in GameActivity for historic axis events and at the time I didn't look at how expose them in some backend-specific way.

Now it looks like GameActivity does support motion event history and so we should be able revisit this.

Lets continue the discussion in issue #207 which you opened.