Flutter How to check if Sliver AppBar is expanded or collapsed?
1
I am using a SliverAppBar in Flutter, with a background widget.
The thing is When it's expanded, the title and icons (leading and actions) should be white in order to be seen correctly, and when it's collapsed, they should be changed to black.
Any ideas on how I can get a bool out of it? Or other ways of resolving this problem.
Thank you.
class SliverExample extends StatefulWidget {
final Widget backgroundWidget;
final Widget bodyWidgets;
SliverExample({
this.backgroundWidget,
this.body,
});
@override
_SliverExampleState createState() => _SliverExampleState();
}
class _SliverExampleState extends State<SliverExample> {
// I need something like this
// To determine if SliverAppBar is expanded or not.
bool isAppBarExpanded = false;
@override
Widget build(BuildContext context) {
// To change the item's color accordingly
// To be used in multiple places in code
Color itemColor = isAppBarExpanded ? Colors.white : Colors.black;
// In my case PrimaryColor is white,
// and the background widget is dark
return Scaffold(
body: CustomScrollView(
slivers: <Widget>[
SliverAppBar(
pinned: true,
leading: BackButton(
color: itemColor, // Here
),
actions: <Widget>[
IconButton(
icon: Icon(
Icons.shopping_cart,
color: itemColor, // Here
),
onPressed: () {},
),
],
expandedHeight: 200.0,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text(
'title',
style: TextStyle(
fontSize: 18.0,
color: itemColor, // Here
),
),
// Not affecting the question.
background: widget.backgroundWidget,
),
),
// Not affecting the question.
SliverToBoxAdapter(child: widget.body),
],
),
);
}
}
flutter flutter-sliver asked Nov 19 '18 at 10:05
Sina SeirafiSina Seirafi
143
add a comment |
1
I am using a SliverAppBar in Flutter, with a background widget.
The thing is When it's expanded, the title and icons (leading and actions) should be white in order to be seen correctly, and when it's collapsed, they should be changed to black.
Any ideas on how I can get a bool out of it? Or other ways of resolving this problem.
Thank you.
class SliverExample extends StatefulWidget {
final Widget backgroundWidget;
final Widget bodyWidgets;
SliverExample({
this.backgroundWidget,
this.body,
});
@override
_SliverExampleState createState() => _SliverExampleState();
}
class _SliverExampleState extends State<SliverExample> {
// I need something like this
// To determine if SliverAppBar is expanded or not.
bool isAppBarExpanded = false;
@override
Widget build(BuildContext context) {
// To change the item's color accordingly
// To be used in multiple places in code
Color itemColor = isAppBarExpanded ? Colors.white : Colors.black;
// In my case PrimaryColor is white,
// and the background widget is dark
return Scaffold(
body: CustomScrollView(
slivers: <Widget>[
SliverAppBar(
pinned: true,
leading: BackButton(
color: itemColor, // Here
),
actions: <Widget>[
IconButton(
icon: Icon(
Icons.shopping_cart,
color: itemColor, // Here
),
onPressed: () {},
),
],
expandedHeight: 200.0,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text(
'title',
style: TextStyle(
fontSize: 18.0,
color: itemColor, // Here
),
),
// Not affecting the question.
background: widget.backgroundWidget,
),
),
// Not affecting the question.
SliverToBoxAdapter(child: widget.body),
],
),
);
}
}
asked Nov 19 '18 at 10:05
Sina SeirafiSina Seirafi
143
Please Add Your Code also !
– anmol.majhail
Nov 19 '18 at 10:27
@anmol.majhail Thanks for the heads up.
– Sina Seirafi
Nov 19 '18 at 11:36
stackoverflow.com/a/51927031/10269042
– anmol.majhail
Nov 19 '18 at 11:48
add a comment |
1
1
1
I am using a SliverAppBar in Flutter, with a background widget.
The thing is When it's expanded, the title and icons (leading and actions) should be white in order to be seen correctly, and when it's collapsed, they should be changed to black.
Any ideas on how I can get a bool out of it? Or other ways of resolving this problem.
Thank you.
class SliverExample extends StatefulWidget {
final Widget backgroundWidget;
final Widget bodyWidgets;
SliverExample({
this.backgroundWidget,
this.body,
});
@override
_SliverExampleState createState() => _SliverExampleState();
}
class _SliverExampleState extends State<SliverExample> {
// I need something like this
// To determine if SliverAppBar is expanded or not.
bool isAppBarExpanded = false;
@override
Widget build(BuildContext context) {
// To change the item's color accordingly
// To be used in multiple places in code
Color itemColor = isAppBarExpanded ? Colors.white : Colors.black;
// In my case PrimaryColor is white,
// and the background widget is dark
return Scaffold(
body: CustomScrollView(
slivers: <Widget>[
SliverAppBar(
pinned: true,
leading: BackButton(
color: itemColor, // Here
),
actions: <Widget>[
IconButton(
icon: Icon(
Icons.shopping_cart,
color: itemColor, // Here
),
onPressed: () {},
),
],
expandedHeight: 200.0,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text(
'title',
style: TextStyle(
fontSize: 18.0,
color: itemColor, // Here
),
),
// Not affecting the question.
background: widget.backgroundWidget,
),
),
// Not affecting the question.
SliverToBoxAdapter(child: widget.body),
],
),
);
}
}
asked Nov 19 '18 at 10:05
Sina SeirafiSina Seirafi
143
I am using a SliverAppBar in Flutter, with a background widget.
The thing is When it's expanded, the title and icons (leading and actions) should be white in order to be seen correctly, and when it's collapsed, they should be changed to black.
Any ideas on how I can get a bool out of it? Or other ways of resolving this problem.
Thank you.
class SliverExample extends StatefulWidget {
final Widget backgroundWidget;
final Widget bodyWidgets;
SliverExample({
this.backgroundWidget,
this.body,
});
@override
_SliverExampleState createState() => _SliverExampleState();
}
class _SliverExampleState extends State<SliverExample> {
// I need something like this
// To determine if SliverAppBar is expanded or not.
bool isAppBarExpanded = false;
@override
Widget build(BuildContext context) {
// To change the item's color accordingly
// To be used in multiple places in code
Color itemColor = isAppBarExpanded ? Colors.white : Colors.black;
// In my case PrimaryColor is white,
// and the background widget is dark
return Scaffold(
body: CustomScrollView(
slivers: <Widget>[
SliverAppBar(
pinned: true,
leading: BackButton(
color: itemColor, // Here
),
actions: <Widget>[
IconButton(
icon: Icon(
Icons.shopping_cart,
color: itemColor, // Here
),
onPressed: () {},
),
],
expandedHeight: 200.0,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text(
'title',
style: TextStyle(
fontSize: 18.0,
color: itemColor, // Here
),
),
// Not affecting the question.
background: widget.backgroundWidget,
),
),
// Not affecting the question.
SliverToBoxAdapter(child: widget.body),
],
),
);
}
}
asked Nov 19 '18 at 10:05
Sina SeirafiSina Seirafi
143
asked Nov 19 '18 at 10:05
Sina SeirafiSina Seirafi
143
edited Nov 19 '18 at 11:26
Sina Seirafi
asked Nov 19 '18 at 10:05
Sina SeirafiSina Seirafi
143
asked Nov 19 '18 at 10:05
Sina SeirafiSina Seirafi
143
asked Nov 19 '18 at 10:05
Sina SeirafiSina Seirafi
143
143
Please Add Your Code also !
– anmol.majhail
Nov 19 '18 at 10:27
@anmol.majhail Thanks for the heads up.
– Sina Seirafi
Nov 19 '18 at 11:36
stackoverflow.com/a/51927031/10269042
– anmol.majhail
Nov 19 '18 at 11:48
add a comment |
Please Add Your Code also !
– anmol.majhail
Nov 19 '18 at 10:27
@anmol.majhail Thanks for the heads up.
– Sina Seirafi
Nov 19 '18 at 11:36
stackoverflow.com/a/51927031/10269042
– anmol.majhail
Nov 19 '18 at 11:48
Please Add Your Code also !
– anmol.majhail
Nov 19 '18 at 10:27
Please Add Your Code also !
– anmol.majhail
Nov 19 '18 at 10:27
@anmol.majhail Thanks for the heads up.
– Sina Seirafi
Nov 19 '18 at 11:36
@anmol.majhail Thanks for the heads up.
– Sina Seirafi
Nov 19 '18 at 11:36
stackoverflow.com/a/51927031/10269042
– anmol.majhail
Nov 19 '18 at 11:48
stackoverflow.com/a/51927031/10269042
– anmol.majhail
Nov 19 '18 at 11:48
add a comment |
2 Answers
2
active
oldest
votes
0
You can use LayoutBuilder to get sliver AppBar biggest height. When biggest.height = 80.0, it actually means sliver appbar is collapsed.
Here is a full example:
import 'package:flutter/material.dart';
void main() => runApp(MaterialApp(
home: MyApp(),
));
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
var top = 0.0;
@override
Widget build(BuildContext context) {
return Scaffold(
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
SliverAppBar(
expandedHeight: 200.0,
floating: false,
pinned: true,
flexibleSpace: LayoutBuilder(
builder: (BuildContext context, BoxConstraints constraints) {
// print('constraints=' + constraints.toString());
top = constraints.biggest.height;
return FlexibleSpaceBar(
centerTitle: true,
title: AnimatedOpacity(
duration: Duration(milliseconds: 300),
//opacity: top == 80.0 ? 1.0 : 0.0,
opacity: 1.0,
child: Text(
top.toString(),
style: TextStyle(fontSize: 12.0),
)),
background: Image.network(
"https://images.unsplash.com/photo-1542601098-3adb3baeb1ec?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=5bb9a9747954cdd6eabe54e3688a407e&auto=format&fit=crop&w=500&q=60",
fit: BoxFit.cover,
));
})),
];
},body: ListView.builder(
itemCount: 100,
itemBuilder: (context,index){
return Text("List Item: " + index.toString());
},
),
));
}
}
Final result:
answered Nov 19 '18 at 18:28
Jack SunJack Sun
506
add a comment |
1
You need to use ScrollController to achieve the desired effect
try this code
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: SliverExample(
bodyWidgets: Text('Hello Body gggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg'),
backgroundWidget: Text('Hello Background'),
),
);
}
}
class SliverExample extends StatefulWidget {
final Widget backgroundWidget;
final Widget bodyWidgets;
SliverExample({
this.backgroundWidget,
this.bodyWidgets,
});
@override
_SliverExampleState createState() => _SliverExampleState();
}
class _SliverExampleState extends State<SliverExample> {
// I need something like this
// To determine if SliverAppBar is expanded or not.
ScrollController _scrollController;
bool isAppBarExpanded = false;
@override
void initState() {
super.initState();
_scrollController = ScrollController()
..addListener(() => setState(() {
print('Scroll view Listener is called offset ${_scrollController.offset}');
}));
}
bool get _changecolor {
return _scrollController.hasClients
&& _scrollController.offset > (200-kToolbarHeight);
}
@override
Widget build(BuildContext context) {
// To change the item's color accordingly
// To be used in multiple places in code
//Color itemColor = isAppBarExpanded ? Colors.white : Colors.black;
// In my case PrimaryColor is white,
// and the background widget is dark
return Scaffold(
body: CustomScrollView(
controller: _scrollController,
slivers: <Widget>[
SliverAppBar(
pinned: true,
leading: BackButton(
color: _changecolor? Colors.white: Colors.black, // Here
),
actions: <Widget>[
IconButton(
icon: Icon(
Icons.shopping_cart,
color: _changecolor? Colors.white: Colors.black, // Here
),
onPressed: () {},
),
],
expandedHeight: 200.0,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text(
'title',
style: TextStyle(
fontSize: 18.0,
color: _changecolor? Colors.white: Colors.black, // Here
),
),
// Not affecting the question.
background: widget.backgroundWidget,
),
),
// Not affecting the question.
SliverToBoxAdapter(child: widget.bodyWidgets),
],
),
);
}
}
answered Nov 19 '18 at 13:50
Saed NabilSaed Nabil
1,17828
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
0
You can use LayoutBuilder to get sliver AppBar biggest height. When biggest.height = 80.0, it actually means sliver appbar is collapsed.
Here is a full example:
import 'package:flutter/material.dart';
void main() => runApp(MaterialApp(
home: MyApp(),
));
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
var top = 0.0;
@override
Widget build(BuildContext context) {
return Scaffold(
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
SliverAppBar(
expandedHeight: 200.0,
floating: false,
pinned: true,
flexibleSpace: LayoutBuilder(
builder: (BuildContext context, BoxConstraints constraints) {
// print('constraints=' + constraints.toString());
top = constraints.biggest.height;
return FlexibleSpaceBar(
centerTitle: true,
title: AnimatedOpacity(
duration: Duration(milliseconds: 300),
//opacity: top == 80.0 ? 1.0 : 0.0,
opacity: 1.0,
child: Text(
top.toString(),
style: TextStyle(fontSize: 12.0),
)),
background: Image.network(
"https://images.unsplash.com/photo-1542601098-3adb3baeb1ec?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=5bb9a9747954cdd6eabe54e3688a407e&auto=format&fit=crop&w=500&q=60",
fit: BoxFit.cover,
));
})),
];
},body: ListView.builder(
itemCount: 100,
itemBuilder: (context,index){
return Text("List Item: " + index.toString());
},
),
));
}
}
Final result:
answered Nov 19 '18 at 18:28
Jack SunJack Sun
506
add a comment |
0
You can use LayoutBuilder to get sliver AppBar biggest height. When biggest.height = 80.0, it actually means sliver appbar is collapsed.
Here is a full example:
import 'package:flutter/material.dart';
void main() => runApp(MaterialApp(
home: MyApp(),
));
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
var top = 0.0;
@override
Widget build(BuildContext context) {
return Scaffold(
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
SliverAppBar(
expandedHeight: 200.0,
floating: false,
pinned: true,
flexibleSpace: LayoutBuilder(
builder: (BuildContext context, BoxConstraints constraints) {
// print('constraints=' + constraints.toString());
top = constraints.biggest.height;
return FlexibleSpaceBar(
centerTitle: true,
title: AnimatedOpacity(
duration: Duration(milliseconds: 300),
//opacity: top == 80.0 ? 1.0 : 0.0,
opacity: 1.0,
child: Text(
top.toString(),
style: TextStyle(fontSize: 12.0),
)),
background: Image.network(
"https://images.unsplash.com/photo-1542601098-3adb3baeb1ec?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=5bb9a9747954cdd6eabe54e3688a407e&auto=format&fit=crop&w=500&q=60",
fit: BoxFit.cover,
));
})),
];
},body: ListView.builder(
itemCount: 100,
itemBuilder: (context,index){
return Text("List Item: " + index.toString());
},
),
));
}
}
Final result:
answered Nov 19 '18 at 18:28
Jack SunJack Sun
506
add a comment |
0
0
0
You can use LayoutBuilder to get sliver AppBar biggest height. When biggest.height = 80.0, it actually means sliver appbar is collapsed.
Here is a full example:
import 'package:flutter/material.dart';
void main() => runApp(MaterialApp(
home: MyApp(),
));
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
var top = 0.0;
@override
Widget build(BuildContext context) {
return Scaffold(
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
SliverAppBar(
expandedHeight: 200.0,
floating: false,
pinned: true,
flexibleSpace: LayoutBuilder(
builder: (BuildContext context, BoxConstraints constraints) {
// print('constraints=' + constraints.toString());
top = constraints.biggest.height;
return FlexibleSpaceBar(
centerTitle: true,
title: AnimatedOpacity(
duration: Duration(milliseconds: 300),
//opacity: top == 80.0 ? 1.0 : 0.0,
opacity: 1.0,
child: Text(
top.toString(),
style: TextStyle(fontSize: 12.0),
)),
background: Image.network(
"https://images.unsplash.com/photo-1542601098-3adb3baeb1ec?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=5bb9a9747954cdd6eabe54e3688a407e&auto=format&fit=crop&w=500&q=60",
fit: BoxFit.cover,
));
})),
];
},body: ListView.builder(
itemCount: 100,
itemBuilder: (context,index){
return Text("List Item: " + index.toString());
},
),
));
}
}
Final result:
answered Nov 19 '18 at 18:28
Jack SunJack Sun
506
You can use LayoutBuilder to get sliver AppBar biggest height. When biggest.height = 80.0, it actually means sliver appbar is collapsed.
Here is a full example:
import 'package:flutter/material.dart';
void main() => runApp(MaterialApp(
home: MyApp(),
));
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
var top = 0.0;
@override
Widget build(BuildContext context) {
return Scaffold(
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
SliverAppBar(
expandedHeight: 200.0,
floating: false,
pinned: true,
flexibleSpace: LayoutBuilder(
builder: (BuildContext context, BoxConstraints constraints) {
// print('constraints=' + constraints.toString());
top = constraints.biggest.height;
return FlexibleSpaceBar(
centerTitle: true,
title: AnimatedOpacity(
duration: Duration(milliseconds: 300),
//opacity: top == 80.0 ? 1.0 : 0.0,
opacity: 1.0,
child: Text(
top.toString(),
style: TextStyle(fontSize: 12.0),
)),
background: Image.network(
"https://images.unsplash.com/photo-1542601098-3adb3baeb1ec?ixlib=rb-0.3.5&ixid=eyJhcHBfaWQiOjEyMDd9&s=5bb9a9747954cdd6eabe54e3688a407e&auto=format&fit=crop&w=500&q=60",
fit: BoxFit.cover,
));
})),
];
},body: ListView.builder(
itemCount: 100,
itemBuilder: (context,index){
return Text("List Item: " + index.toString());
},
),
));
}
}
Final result:
answered Nov 19 '18 at 18:28
Jack SunJack Sun
506
answered Nov 19 '18 at 18:28
Jack SunJack Sun
506
answered Nov 19 '18 at 18:28
Jack SunJack Sun
506
answered Nov 19 '18 at 18:28
Jack SunJack Sun
506
506
add a comment |
add a comment |
1
You need to use ScrollController to achieve the desired effect
try this code
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: SliverExample(
bodyWidgets: Text('Hello Body gggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg'),
backgroundWidget: Text('Hello Background'),
),
);
}
}
class SliverExample extends StatefulWidget {
final Widget backgroundWidget;
final Widget bodyWidgets;
SliverExample({
this.backgroundWidget,
this.bodyWidgets,
});
@override
_SliverExampleState createState() => _SliverExampleState();
}
class _SliverExampleState extends State<SliverExample> {
// I need something like this
// To determine if SliverAppBar is expanded or not.
ScrollController _scrollController;
bool isAppBarExpanded = false;
@override
void initState() {
super.initState();
_scrollController = ScrollController()
..addListener(() => setState(() {
print('Scroll view Listener is called offset ${_scrollController.offset}');
}));
}
bool get _changecolor {
return _scrollController.hasClients
&& _scrollController.offset > (200-kToolbarHeight);
}
@override
Widget build(BuildContext context) {
// To change the item's color accordingly
// To be used in multiple places in code
//Color itemColor = isAppBarExpanded ? Colors.white : Colors.black;
// In my case PrimaryColor is white,
// and the background widget is dark
return Scaffold(
body: CustomScrollView(
controller: _scrollController,
slivers: <Widget>[
SliverAppBar(
pinned: true,
leading: BackButton(
color: _changecolor? Colors.white: Colors.black, // Here
),
actions: <Widget>[
IconButton(
icon: Icon(
Icons.shopping_cart,
color: _changecolor? Colors.white: Colors.black, // Here
),
onPressed: () {},
),
],
expandedHeight: 200.0,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text(
'title',
style: TextStyle(
fontSize: 18.0,
color: _changecolor? Colors.white: Colors.black, // Here
),
),
// Not affecting the question.
background: widget.backgroundWidget,
),
),
// Not affecting the question.
SliverToBoxAdapter(child: widget.bodyWidgets),
],
),
);
}
}
answered Nov 19 '18 at 13:50
Saed NabilSaed Nabil
1,17828
add a comment |
1
You need to use ScrollController to achieve the desired effect
try this code
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: SliverExample(
bodyWidgets: Text('Hello Body gggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg'),
backgroundWidget: Text('Hello Background'),
),
);
}
}
class SliverExample extends StatefulWidget {
final Widget backgroundWidget;
final Widget bodyWidgets;
SliverExample({
this.backgroundWidget,
this.bodyWidgets,
});
@override
_SliverExampleState createState() => _SliverExampleState();
}
class _SliverExampleState extends State<SliverExample> {
// I need something like this
// To determine if SliverAppBar is expanded or not.
ScrollController _scrollController;
bool isAppBarExpanded = false;
@override
void initState() {
super.initState();
_scrollController = ScrollController()
..addListener(() => setState(() {
print('Scroll view Listener is called offset ${_scrollController.offset}');
}));
}
bool get _changecolor {
return _scrollController.hasClients
&& _scrollController.offset > (200-kToolbarHeight);
}
@override
Widget build(BuildContext context) {
// To change the item's color accordingly
// To be used in multiple places in code
//Color itemColor = isAppBarExpanded ? Colors.white : Colors.black;
// In my case PrimaryColor is white,
// and the background widget is dark
return Scaffold(
body: CustomScrollView(
controller: _scrollController,
slivers: <Widget>[
SliverAppBar(
pinned: true,
leading: BackButton(
color: _changecolor? Colors.white: Colors.black, // Here
),
actions: <Widget>[
IconButton(
icon: Icon(
Icons.shopping_cart,
color: _changecolor? Colors.white: Colors.black, // Here
),
onPressed: () {},
),
],
expandedHeight: 200.0,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text(
'title',
style: TextStyle(
fontSize: 18.0,
color: _changecolor? Colors.white: Colors.black, // Here
),
),
// Not affecting the question.
background: widget.backgroundWidget,
),
),
// Not affecting the question.
SliverToBoxAdapter(child: widget.bodyWidgets),
],
),
);
}
}
answered Nov 19 '18 at 13:50
Saed NabilSaed Nabil
1,17828
add a comment |
1
1
1
You need to use ScrollController to achieve the desired effect
try this code
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: SliverExample(
bodyWidgets: Text('Hello Body gggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg'),
backgroundWidget: Text('Hello Background'),
),
);
}
}
class SliverExample extends StatefulWidget {
final Widget backgroundWidget;
final Widget bodyWidgets;
SliverExample({
this.backgroundWidget,
this.bodyWidgets,
});
@override
_SliverExampleState createState() => _SliverExampleState();
}
class _SliverExampleState extends State<SliverExample> {
// I need something like this
// To determine if SliverAppBar is expanded or not.
ScrollController _scrollController;
bool isAppBarExpanded = false;
@override
void initState() {
super.initState();
_scrollController = ScrollController()
..addListener(() => setState(() {
print('Scroll view Listener is called offset ${_scrollController.offset}');
}));
}
bool get _changecolor {
return _scrollController.hasClients
&& _scrollController.offset > (200-kToolbarHeight);
}
@override
Widget build(BuildContext context) {
// To change the item's color accordingly
// To be used in multiple places in code
//Color itemColor = isAppBarExpanded ? Colors.white : Colors.black;
// In my case PrimaryColor is white,
// and the background widget is dark
return Scaffold(
body: CustomScrollView(
controller: _scrollController,
slivers: <Widget>[
SliverAppBar(
pinned: true,
leading: BackButton(
color: _changecolor? Colors.white: Colors.black, // Here
),
actions: <Widget>[
IconButton(
icon: Icon(
Icons.shopping_cart,
color: _changecolor? Colors.white: Colors.black, // Here
),
onPressed: () {},
),
],
expandedHeight: 200.0,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text(
'title',
style: TextStyle(
fontSize: 18.0,
color: _changecolor? Colors.white: Colors.black, // Here
),
),
// Not affecting the question.
background: widget.backgroundWidget,
),
),
// Not affecting the question.
SliverToBoxAdapter(child: widget.bodyWidgets),
],
),
);
}
}
answered Nov 19 '18 at 13:50
Saed NabilSaed Nabil
1,17828
You need to use ScrollController to achieve the desired effect
try this code
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: SliverExample(
bodyWidgets: Text('Hello Body gggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg'),
backgroundWidget: Text('Hello Background'),
),
);
}
}
class SliverExample extends StatefulWidget {
final Widget backgroundWidget;
final Widget bodyWidgets;
SliverExample({
this.backgroundWidget,
this.bodyWidgets,
});
@override
_SliverExampleState createState() => _SliverExampleState();
}
class _SliverExampleState extends State<SliverExample> {
// I need something like this
// To determine if SliverAppBar is expanded or not.
ScrollController _scrollController;
bool isAppBarExpanded = false;
@override
void initState() {
super.initState();
_scrollController = ScrollController()
..addListener(() => setState(() {
print('Scroll view Listener is called offset ${_scrollController.offset}');
}));
}
bool get _changecolor {
return _scrollController.hasClients
&& _scrollController.offset > (200-kToolbarHeight);
}
@override
Widget build(BuildContext context) {
// To change the item's color accordingly
// To be used in multiple places in code
//Color itemColor = isAppBarExpanded ? Colors.white : Colors.black;
// In my case PrimaryColor is white,
// and the background widget is dark
return Scaffold(
body: CustomScrollView(
controller: _scrollController,
slivers: <Widget>[
SliverAppBar(
pinned: true,
leading: BackButton(
color: _changecolor? Colors.white: Colors.black, // Here
),
actions: <Widget>[
IconButton(
icon: Icon(
Icons.shopping_cart,
color: _changecolor? Colors.white: Colors.black, // Here
),
onPressed: () {},
),
],
expandedHeight: 200.0,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text(
'title',
style: TextStyle(
fontSize: 18.0,
color: _changecolor? Colors.white: Colors.black, // Here
),
),
// Not affecting the question.
background: widget.backgroundWidget,
),
),
// Not affecting the question.
SliverToBoxAdapter(child: widget.bodyWidgets),
],
),
);
}
}
answered Nov 19 '18 at 13:50
Saed NabilSaed Nabil
1,17828
answered Nov 19 '18 at 13:50
Saed NabilSaed Nabil
1,17828
answered Nov 19 '18 at 13:50
Saed NabilSaed Nabil
1,17828
answered Nov 19 '18 at 13:50
Saed NabilSaed Nabil
1,17828
1,17828
add a comment |
add a comment |
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Please Add Your Code also !
– anmol.majhail
Nov 19 '18 at 10:27
@anmol.majhail Thanks for the heads up.
– Sina Seirafi
Nov 19 '18 at 11:36
stackoverflow.com/a/51927031/10269042
– anmol.majhail
Nov 19 '18 at 11:48