updateIMEComposionPosition method
Implementation
updateIMEComposionPosition(double x, double y, Offset offset) {
/// 1.It always displays at the last position, which should be a bug in the Flutter engine.
/// 2.If switch windows and switch back, this function can run well once.I think there must have a flush function called when switching windows
/// 3.Windows can run well, but Linux can't.
_textInputConnection?.setEditableSizeAndTransform(const Size(0, 0),
Matrix4.translationValues(offset.dx + x, offset.dy + y, 0));
}