Flutter PageView keep rebuilding the main widget on setState value - flutter

Question

currently flutter app structure
StackedHome has a pageview with 2 children
Pageview(parent):
HomeScreen(child#1)
Vertical PageView
bottom navigation bar
UserProfilePage(child#2)
HomeScreen should pass the index value to UserProfilePage, so when scrolling horizontally, we will get user profilescreen with id passed to that received from HomeScreen. based on the id passed i will display related user profile
Here is sample video showing the problem :
https://drive.google.com/file/d/1tIypNOHewcFSo2Pf-F97hsQGfDgNVqfW/view?usp=sharing
Problem:
i managed to do that and its working fine, but my problem on setState of that variable
setState(() {
_postIndex = postIndex;
});
on each HomeScreen > onPageChanged call i am updating the index value pass it to the parent (StackedHome) class, and since there is a setState to update profile index (UserProfilePage)...the whole app will be rebuild on each pageview change...
What i need is to disable that main widget to be rebuilt again and again on value update..
StackedHome
class StackedHome extends StatefulWidget {
final int data;
final Function(int) onDataChange;
const StackedHome({
this.data,
this.onDataChange,
Key key,
}) : super(key: key);
#override
_StackedHomeState createState() => _StackedHomeState();
}
class _StackedHomeState extends State<StackedHome>{
PageController pageController;
int _count = 0;
int _postIndex = 0;
void _postId(int postIndex) {
//This cuasing main screen to be rebuilt everytime on pageview scroll
//but getting the value correctly
setState(() {
_postIndex = postIndex;
});
}
#override
void initState() {
super.initState();
pageController = PageController();
}
#override
void dispose() {
pageController.dispose();
super.dispose();
}
int index = 0;
#override
Future<void> _refreshPosts() async {
PostApi postApi = PostApi();
setState(() {
postApi.fetchAllPosts();
});
}
Widget build(BuildContext context) {
PostApi postApi = PostApi();
return FutureBuilder(
future: postApi.fetchAllPosts(),
builder: (BuildContext context, AsyncSnapshot<List<Post>> snapshot) {
switch (snapshot.connectionState) {
case ConnectionState.none:
return apiError('No Connection Made');
break;
case ConnectionState.waiting:
case ConnectionState.active:
return ApiLoading(color:0xff000000);
break;
case ConnectionState.done:
if (snapshot.hasError) {
return apiError(snapshot.error.toString());
}
if (snapshot.hasData) {
return _drawPostsList(snapshot.data, context);
}
break;
}
return Container();
},
);
}
Widget _drawPostsList(List<Post> posts, BuildContext context) {
return PageView(
reverse: true,
children: <Widget>[
HomeScreen(
posts: posts,
index: index,
postId: _postId,//function Passed
),
UserProfilePage(
posts: posts,
index: _postIndex,
)
],
);
}
}
HomeScreen
class HomeScreen extends StatefulWidget {
#override
final List posts;
final int index;
final Function(int) postId;
int getPage() {
return value;
}
void setPage(int page) {
value = page;
}
HomeScreen({Key key, this.posts, this.index, this.postId}) : super(key: key);
HomeScreenState createState() => HomeScreenState();
}
class HomeScreenState extends State<HomeScreen>
with SingleTickerProviderStateMixin {
final PageController _controller = PageController();
PageController _pageController = PageController();
int index = 0;
#override
void initState() {
super.initState();
//Set pageview inital page
_pageController = PageController(
keepPage: true,
initialPage: widget.getPage(),
);
}
#override
Widget build(BuildContext context) {
return RefreshIndicator(
onRefresh: _refreshPosts,
child: Stack(children: <Widget>[
PageView.builder(
controller: _pageController,
onPageChanged: (index) => setState(() {
.
widget.postId(index);//I am calling parent class and updating the vlaue with new index value
.
}),
scrollDirection: Axis.vertical,
itemBuilder: (context, position) {
//Build image lists
return _homeList(widget.posts, position);
},
),
BottomNavigation("light"),
]),
);
}
}
i hope my problem is clear enough....i need to pass the value to parent so i can pass it to second child which is the profile screen so it will show user profile realted to that post

Answer 1

Ohh wow, managed to solve this problem using provider and consumer, by listening to any update on index id... this post helped me to solve it https://medium.com/flutter-nyc/a-closer-look-at-the-provider-package-993922d3a5a5