scrollController.animateTo Invoked Multiple Times Asyncronously - flutter

Question

I Have RawKeyboardListener that invoke _getIDCardInfo each time KeyDown is press and hold.
the problem is _getIDCardInfo is invoked multiple times. this make problem because scrollcontroller.animateTo is animated only in the last time _getIDCardInfo is invoked.
I want scrollcontroller.animateTo is animated each time _getIDCardInfo is invoked, not only in the last call of _getIDCardInfo.
how can i make _getIdCardInfo() is invoked syncronously. or there is any way scrollController can be animated properly without getting invoked multiple times.
_getIdCardInfo() async {
try {
final String result = await platform.invokeMethod('scanIDCard');
await _myItems.insert(0, {"id": result});
await _scrollController.animateTo(
_scrollController.position.maxScrollExtent,
curve: Curves.easeIn,
duration: Duration(milliseconds: 30));
await _scrollController.animateTo(0,
curve: Curves.easeIn, duration: Duration(milliseconds: 50));
} on PlatformException catch (e) {
print(e);
}
}
#override
Widget build(BuildContext context) {
FocusNode _focusNode = FocusNode();
return RawKeyboardListener(
focusNode: _focusNode,
autofocus: true,
onKey: (RawKeyEvent event) async {
if ((event.runtimeType == RawKeyDownEvent &&
event.logicalKey.keyId == 1108101562648)) {
await _getIdCardInfo();
}
},
);
}
}

Answer 1

I guess what you need is to run animation recursively like this:
final _scrollController = ScrollController();
final _focusNode = FocusNode();
int _animateTimes = 0; // How many times we need to run an animation
Future<void> _animateFuture; // Is animation currently running
Future<void> _getIdCardInfo() async {
await _scrollController.animateTo(
Random().nextInt(1000).toDouble(),
duration: Duration(milliseconds: 1000),
curve: Curves.linear
);
_runNext();
}
void _runAnimation() {
_animateTimes++;
if (_animateFuture == null) {
_animateFuture = _getIdCardInfo();
}
}
void _runNext() {
_animateTimes--;
_animateFuture = null;
if (_animateTimes > 0) {
_animateFuture = _getIdCardInfo();
}
}
#override
void dispose() {
_focusNode.dispose(); // Don't forget to dispose of focus node
super.dispose();
}
...
RawKeyboardListener(
focusNode: _focusNode,
autofocus: true,
onKey: (RawKeyEvent event) async {
if (event is RawKeyDownEvent && event.logicalKey.keyId == 1108101562648) {
_runAnimation();
}
},
child: Text('asd')
),
...