Images dose not display on the screen instead it shows loading icon - flutter

I used a grid view list in order to show some items in another list that contain images
and doesn't show the items, instead it shows the loading icon
this is my code:
import 'package:flutter/material.dart';
import 'package:sct/list/list.dart';
class badriya2 extends StatefulWidget {
#override
State<badriya2> createState() => _badriya2State();
}
class _badriya2State extends State<badriya2> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
centerTitle: true,
title: Text(
"She codes",
),
),
body: FutureBuilder(builder: (context, AsyncSnapshot snapshot) {
height:
MediaQuery.of(context).size.height;
width:
MediaQuery.of(context).size.width;
if (snapshot.hasData) {
List resList = snapshot.data;
child:
Expanded(
child: GridView.builder(
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 5,
crossAxisSpacing: 5.0,
mainAxisSpacing: 5.0,
),
itemCount: resList.length,
itemBuilder: (context, index) {
primary:
true;
padding:
const EdgeInsets.all(20);
shrinkWrap:
true;
children:
<Widget>[
Card(
child: Center(
child: CircleAvatar(
child: ClipRRect(
borderRadius: BorderRadius.circular(20),
child: Image.asset(
list[0].image,
),
),
minRadius: 50,
maxRadius: 75,
),
),
elevation: 10,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(15),
),
),
];
return Center(child: CircularProgressIndicator());
}));
}
return Center(child: CircularProgressIndicator());
}));
}
}
and this is the list :
import 'package:flutter/cupertino.dart';
List list = [
{
Image.asset('assets/images/butterfly.jpg'),
},
{
Image.asset('assets/images/flower.jpg'),
},
{
Image.asset('assets/images/glass.jpg'),
},
{
Image.asset('assets/images/sun.jpg'),
},
{
Image.asset('assets/images/lighting.jpg'),
},
{
Image.asset('assets/images/phone.jpg'),
},
{
Image.asset('assets/images/eye.jpg'),
},
{
Image.asset('assets/images/photo1.jpg'),
},
];
the point of this code is not to duplicate the items in grid view, I want to write in one line

Add future method onfuture inside FutureBuilder.
return FutureBuilder(
future: yourFutureMethod(),
builder: (context, snapshot) {...},
);

You use the Future Builder but you didn't mention any future. Set the Future
import 'package:flutter/material.dart';
import 'package:sct/list/list.dart';
class badriya2 extends StatefulWidget {
#override
State<badriya2> createState() => _badriya2State();
}
class _badriya2State extends State<badriya2> {
var dummy;
#override
void initState() {
super.initState();
dummy = _getimages();
print("data ${dummy}");
}
_getimages() async {
var imagelist = await list;
print(imagelist);
return imagelist;
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
centerTitle: true,
title: Text(
"She codes",
),
),
body: FutureBuilder(
future: _getimages(),
builder: (context, AsyncSnapshot snapshot) {
if(snapshot.hasError) print(snapshot.error);
return snapshot.hasData
?GridView.builder(
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 3,
crossAxisSpacing: 5.0,
mainAxisSpacing: 5.0,
),
itemCount: snapshot.data.length,
itemBuilder: (context, index) {
List reslist = snapshot.data;
return Column(
children: [
Card(
child: Center(
child: Container(
width: 100,
height: 100,
child: CircleAvatar(
child: ClipRRect(
borderRadius: BorderRadius.circular(20),
child: Image.network(reslist[index].toString(),)
),
minRadius: 50,
maxRadius: 75,
),
),
),
elevation: 10,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(15),
),
),
],
);
}
):
Center(
child:CircularProgressIndicator()
);
}
)
);
}
}
And please assign proper list of data
import 'package:flutter/cupertino.dart';
List list= [
"https://dlanzer.com/flutter_api/assets/uploads/images/farm_2021-10-25%2005:09:48am.png",
"https://dlanzer.com/flutter_api/assets/uploads/images/farm_2021-10-25%2005:09:11am.png",
"https://dlanzer.com/flutter_api/assets/uploads/images/farm_2021-10-19%2002:51:18pm.png",
"https://dlanzer.com/flutter_api/assets/uploads/images/farm_2021_10_12_04_30_13_pm.png",
];
Here I use network images You change to asset images

Related

How to load more items to a list when reach the bottom of results flutter

I have the code below which feed a list with 10 results from firebase. In this case it shows only the 10 items, now I wanna, when user gets the bottom of results, it loads more 10 items and add it to the list. I already have the scrollController and it works.. I receive the log "LOAD HERE" when I get the bottom of the results.
My doubt is how to add the new 10 items in the list?
scrollListener() async {
if (scrollController.position.maxScrollExtent == scrollController.offset) {
print('LOAD HERE');
}
}
#override
void initState() {
scrollController.addListener(scrollListener);
super.initState();
}
#override
void dispose() {
scrollController.removeListener(scrollListener);
super.dispose();
}
loadList(submenu ,callback, context, deviceSize){
return FutureBuilder(
future: ctrlLab.loadList(submenu, 10),
builder: (ctx, snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return Center(child: CircularProgressIndicator());
} else if (snapshot.error != null) {
print(snapshot.error);
return Center(child: Text('ERROR!'));
}else {
return GridView.builder(
padding: EdgeInsets.all(10.0),
controller: scrollController,
itemCount: snapshot.data.length,
itemBuilder: (ctx, i) {
Item item = snapshot.data[i];
if (i < snapshot.data.length) {
return Dismissible(
key: UniqueKey(),
direction: DismissDirection.endToStart,
background: Container(
padding: EdgeInsets.all(10.0),
color: Colors.grey[800],
child: Align(
alignment: AlignmentDirectional.centerEnd,
child: Icon(
Icons.delete,
color: Colors.white,
size: 40,
),
),
),
onDismissed: (DismissDirection direction) {
ctrl.onDismissed(callback, item);
},
child: GestureDetector(
child: Card(
elevation: 5.0,
child: Padding(
padding: EdgeInsets.all(10.0),
child: GridTile(
child: Hero(
tag: "${item}",
child: item.imageUrl == null
? setIconLab(item)
: CachedNetworkImage(
fit: BoxFit.cover,
imageUrl: setIconLab(item),
placeholder: (ctx, url) =>
Center(child: CircularProgressIndicator()),
errorWidget: (context, url, error) =>
Image.asset('assets/images/noPhoto.jpg',
fit: BoxFit.cover),
),
),
footer: Container(
padding: EdgeInsets.all(8.0),
color: Colors.white70,
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Text(
item.name
),
),
],
),
),
),
),
),
),
);
}
},
gridDelegate: SliverGridDelegateWithFixedCrossAxisCountAndLoading(
itemCount: snapshot.data.length + 1,
crossAxisCount: deviceSize.width < 600 ? 2 : 3,
childAspectRatio: 0.7,
crossAxisSpacing: 10.0,
mainAxisSpacing: 10.0,
),
);
}
},
);
}
Infinite Scrolling in ListView
I have achieved this case by using the local field instead of getting data from firebase. Hope it will give you some idea.
import 'package:flutter/material.dart';
class ListViewDemo extends StatefulWidget {
ListViewDemo({Key key}) : super(key: key);
#override
_ListViewDemoState createState() => _ListViewDemoState();
}
class _ListViewDemoState extends State<ListViewDemo> {
ScrollController controller;
int count = 15;
#override
void initState() {
super.initState();
controller = ScrollController()..addListener(handleScrolling);
}
void handleScrolling() {
if (controller.offset >= controller.position.maxScrollExtent) {
setState(() {
count += 10;
});
}
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('List view'),
),
body: ListView.builder(
controller: controller,
itemCount: count,
itemBuilder: (BuildContext context, int index) {
return ListTile(
title: Text('Item $index'),
);
},
),
);
}
#override
void dispose() {
controller.removeListener(handleScrolling);
super.dispose();
}
}
You have to add another 10 data to the crtLap.loadList(subMenu, 20) and call setState inside the scrollListener to rebuild the widget about the changes.
var data = crtLap.loadList(subMenu, 10);
scrollListener() async {
if (scrollController.position.maxScrollExtent == scrollController.offset) {
setState((){
data = crtLap.loadList(subMenu, 20);
});
}
}
and use this data field to the FutureBuilder directly,
loadList(submenu ,callback, context, deviceSize){
return FutureBuilder(
future: data,
builder: (ctx, snapshot) {
.....
...
..
}

how to create an icon on image with inkwell after Click on the image in flutter

I made a grid view in the flutter app. But like the Pictures on the below link , I want to create an icon on the picture and change the background color After tap the picture,
I've been looking for ways, but I've finally got a question. I'd appreciate it from the bottom of my heart if you'd let me know.
Please enter img link(below)
https://firebasestorage.googleapis.com/v0/b/instaclone-2-fd9de.appspot.com/o/post%2F12344.png?alt=media&token=89d46c03-83ba-4d30-b716-e9b718c1340b
Widget _bodyBuilder() {
// TODO : 그 예시를 어떻해 stream View로 보여줄것인가
return StreamBuilder <QuerySnapshot>(
stream: _commentStream(),
builder: (BuildContext context, AsyncSnapshot snapshot){
if(!snapshot.hasData){
return Center(child: CircularProgressIndicator());
}
var items = snapshot.data?.documents ??[];
var fF = items.where((doc)=> doc['style'] == "오피스룩").toList();
var sF = items.where((doc)=> doc['style'] == "로맨틱").toList();
var tF = items.where((doc)=> doc['style'] == "캐주").toList();
fF.addAll(sF);
fF.addAll(tF);
fF.shuffle();
return GridView.builder(
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 3,
childAspectRatio: 0.6,
mainAxisSpacing: 2.0,
crossAxisSpacing: 2.0),
itemCount: fF.length,
itemBuilder: (BuildContext context, int index) {
return _buildListItem(context, fF[index]);
});
},
);
}
Widget _buildListItem(context, document) {
return Ink.image(
image : NetworkImage(document['thumbnail_img']),
fit : BoxFit.cover,
child: new InkWell(
//I think we need to get something in here....
onTap: (){},
),
);
}
You should create List of Image which have isSelected value and when the user clicks on item them set true/false base of the old value which have imageURL and isSelected variable. First, you should store value in List Of Image obj. which coming from Firebase/API then flow below step. I have created a demo and post here. Please take reference.
Example code
class Demo extends StatefulWidget {
#override
_DemoState createState() => _DemoState();
}
class _DemoState extends State<Demo> {
List<ImageData> imageList;
#override
void initState() {
super.initState();
imageList = ImageData.getImage();
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: GridView.builder(
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
childAspectRatio: 0.5,
crossAxisCount: 5,
crossAxisSpacing: 2.0,
mainAxisSpacing: 2.0),
itemCount: imageList.length,
itemBuilder: (builder, index) {
return InkWell(
onTap: () {
setState(() {
imageList[index].isSelected = !imageList[index].isSelected;
});
},
child: Stack(
children: [
_getImage(imageList[index].imageURL),
Opacity(
opacity: imageList[index].isSelected ? 1 : 0,
child: Stack(
children: [
Container(
width: double.infinity,
height: double.infinity,
color: Colors.black38,
),
Center(
child: CircleAvatar(
backgroundColor: Colors.greenAccent,
child: Icon(
Icons.check,
color: Colors.white,
),
),
)
],
),
)
],
));
},
),
);
}
_getImage(url) => Image.network(
url,
height: 500,
fit: BoxFit.fitHeight,
);
#override
void dispose() {
super.dispose();
}
}
class ImageData {
String imageURL;
bool isSelected;
int id;
ImageData(this.imageURL, this.isSelected, this.id);
static List<ImageData> getImage() {
return [
ImageData('https://picsum.photos/200', false, 1),
ImageData('https://picsum.photos/100', false, 2),
ImageData('https://picsum.photos/300', false, 3),
ImageData('https://picsum.photos/400', false, 4),
ImageData('https://picsum.photos/500', false, 5),
ImageData('https://picsum.photos/600', false, 6),
ImageData('https://picsum.photos/700', false, 7),
ImageData('https://picsum.photos/800', false, 8),
ImageData('https://picsum.photos/900', false, 9),
];
}
}
Output

Flutter page jumps to top after setState({})

I display many images in a Staggered Gridview in a Flutter application.
Everytime I call setState({}), for example after deleting an item, the page jumps to top. How could I remove this behavior?
This is my code:
final _scaffoldKey = new GlobalKey<ScaffoldState>();
.. outside the build function. And then...
return loadingScreen == true
? LoadingScreen()
: Scaffold(
key: _scaffoldKey,
body: CustomScrollView(
slivers: <Widget>[
_AppBar(
theme: theme,
index: index,
albumImagePath: albumImagePath,
albumID: albumID,
albumValue: albumValue,
addPictureToGallery: _addPictureToGallery,
),
SliverToBoxAdapter(
child: Column(
children: <Widget>[
InfoBar(
albumPicturesSum: albumPicturesSum,
getBilderString: _getBilderString,
theme: theme,
getVideoProgress: _getVideoProgress,
progress: progress,
),
albumID == 99999999
? // Demo Projekt
DemoImageGrid(
demoImageList: demoImageList,
getDemoImagesJson: _getDemoImagesJson,
)
: UserImageGrid(
picturesData: picturesData,
albumID: albumID,
showPictureActions: _showPictureActions)
],
),
)
],
),
);
}
The UserImageGrid looks like the following:
class UserImageGrid extends StatelessWidget {
final Pictures picturesData;
final int albumID;
final Function showPictureActions;
final _key = new UniqueKey();
UserImageGrid(
{#required this.picturesData,
#required this.albumID,
#required this.showPictureActions});
#override
Widget build(BuildContext context) {
return FutureBuilder(
key: _key,
future: picturesData.getPicturesFromAlbum(albumID),
builder: (BuildContext context, AsyncSnapshot snapshot) {
// Normale Projekte
if (snapshot.hasData && snapshot.data.length == 0) {
return Center(
child: Column(
children: <Widget>[
Lottie.asset('assets/lottie/drone.json',
width: 250,
options: LottieOptions(enableMergePaths: false)),
],
),
);
}
if (!snapshot.hasData ||
snapshot.connectionState == ConnectionState.waiting) {
return Center(
child: CircularProgressIndicator(),
);
} else {
return Container(
child: StaggeredGridView.countBuilder(
physics: NeverScrollableScrollPhysics(),
shrinkWrap: true,
padding: EdgeInsets.all(0),
crossAxisCount: 6,
itemCount: snapshot.data.length,
itemBuilder: (BuildContext context, int index) =>
GestureDetector(
onLongPress: () {
showPictureActions(snapshot.data[index]);
},
onTap: () async {
await showDialog(
context: context,
builder: (_) {
return Dialog(
child: Stack(
children: [
Container(
margin: const EdgeInsets.symmetric(
vertical: 10.0,
horizontal: 10.0,
),
height: 500.0,
child: ClipRect(
child: PhotoView(
maxScale:
PhotoViewComputedScale.covered * 2.0,
minScale:
PhotoViewComputedScale.contained *
0.8,
initialScale:
PhotoViewComputedScale.covered,
imageProvider: FileImage(
File(snapshot.data[index].path))),
),
),
Positioned(
bottom: 20,
left: 20,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text(
DateFormat(tr("date_format")).format(
snapshot.data[index].timestamp
.toDateTime()),
style: TextStyle(color: Colors.white),
),
),
)
],
));
});
},
child: Container(
child: Image.file(
File(snapshot.data[index].thumbPath),
fit: BoxFit.cover,
)),
),
staggeredTileBuilder: (int index) =>
new StaggeredTile.count(2, index.isEven ? 2 : 2),
mainAxisSpacing: 5.0,
crossAxisSpacing: 5.0,
),
);
}
});
}
}
What could be the issue?
I found a solution for this issue. The problem was not the setState({}). It was the return Widget of the FutureBuilder.
I changed
if (!snapshot.hasData || snapshot.connectionState == ConnectionState.waiting) {
return Center(child: CircularProgressIndicator());
}
to:
if (!snapshot.hasData || snapshot.connectionState == ConnectionState.waiting) {
return Container(
height: MediaQuery.of(context).size.height,
);
}
I don´t exactly know why, but with this change the page is not jumping to top anymore on setState({})

Adjust Z-Index in flutter

I try to place an element above another element in flutter. With transform: Matrix4.translationValues it worked to set a negative value, but the element above has a bigger z-index. How could I adjust that? To understand what I need:
This is what I have
This is what I need
My code
class _AlbumDetailState extends State<AlbumDetail> {
#override
Widget build(BuildContext context) {
final theme = Theme.of(context);
final routeArgs =
ModalRoute.of(context).settings.arguments as Map<String, int>;
final albumID = routeArgs['id'];
final index = routeArgs['index'];
final picturesData = Provider.of<Pictures>(context, listen: true);
Future<void> _addPictureToGallery() async {
final picker = ImagePicker();
final imageFile =
await picker.getImage(source: ImageSource.gallery, maxWidth: 600);
final appDir = await syspath.getApplicationDocumentsDirectory();
final fileName = path.basename(imageFile.path);
final savedImage =
await File(imageFile.path).copy('${appDir.path}/$fileName');
print(savedImage);
picturesData.add(Picture(
album: albumID, path: savedImage.path, timestamp: Timestamp.now()));
}
return Scaffold(
body: CustomScrollView(
slivers: <Widget>[
SliverAppBar(
title: Text("Album"),
flexibleSpace: FlexibleSpaceBar(
background: Container(
color: Colors.transparent,
child: Hero(
tag: "open_gallery" + index.toString(),
child: Image(
image: NetworkImage('https://placeimg.com/640/480/any'),
fit: BoxFit.cover,
),
),
)),
expandedHeight: 350,
backgroundColor: Colors.green,
pinned: true,
stretch: false,
),
SliverToBoxAdapter(
child: FutureBuilder(
future: picturesData.getPicturesFromAlbum(albumID),
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.hasData && snapshot.data.length == 0) {
return Center(
child: Text("Noch keine Bilder vorhanden"),
);
}
if (!snapshot.hasData ||
snapshot.connectionState == ConnectionState.waiting) {
return Center(
child: CircularProgressIndicator(),
);
} else {
return Column(
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Container(
alignment: Alignment.center,
transform: Matrix4.translationValues(0.0, -75.0, 0.0),
width: MediaQuery.of(context).size.width - 50,
height: 150,
color: Colors.black87,
margin: EdgeInsets.only(top: 50),
child: Text(
"Headline",
style: Theme.of(context)
.textTheme
.headline2
.copyWith(color: theme.colorScheme.onPrimary),
),
),
StaggeredGridView.countBuilder(
physics: NeverScrollableScrollPhysics(),
shrinkWrap: true,
crossAxisCount: 6,
itemCount: snapshot.data.length,
itemBuilder: (BuildContext context, int index) =>
Container(
child: Image.file(
File(snapshot.data[index].path),
fit: BoxFit.cover,
)),
staggeredTileBuilder: (int index) =>
new StaggeredTile.count(2, index.isEven ? 2 : 1),
mainAxisSpacing: 5.0,
crossAxisSpacing: 5.0,
),
],
);
}
}),
)
],
),
);
}
}
The problem: The z-index is not correct on my element. My header is above. How could I adjust the z-index? I know this from CSS. Is there a way to to this with flutter?
One way of achieving overlapping widgets is by using Stack widget. You can check the docs for more details.
try this package https://pub.dev/packages/indexed
https://raw.githubusercontent.com/physia/kflutter/main/indexed/doc/assets/demo.gif
This package allows you to order items inside stack using index like z-index in css
this is example how it works
Indexer(
children: [
Indexed(
index: 100,
child: Positioned(
//...
)
),
Indexed(
index: 1000,
child: Positioned(
//...
)
),
Indexed(
index: 3,
child: Positioned(
//...
)
),
],
);
if you are using bloc of some complex widget you can extands or implement the IndexedInterface class and override index getter:
class IndexedDemo extends IndexedInterface {
int index = 5;
}
or implements
class IndexedDemo extends AnimatedWidget implements IndexedInterface {
int index = 1000;
//...
//...
}
then use it just like Indexed class widget:
Indexer(
children: [
IndexedDemo(
index: 100,
child: Positioned(
//...
)
),
IndexedFoo(
index: 1000,
child: Positioned(
//...
)
),
],
);
Online demo
Video demo

A build function returned null,The offending widget is: StreamBuilder<QuerySnapshot>

Im new to flutter. Im trying to get items from firestore to be shown in Listview on the app but getting "build function returned null.The offending widget is: StreamBuilder,Build functions must never return null". I just want the list 'post' from firstore shown in listview
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:font_awesome_flutter/font_awesome_flutter.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Post App',
debugShowCheckedModeBanner: false,
theme: ThemeData(
primaryColor: Color(0xff543b7a),
),
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
leading: IconButton(
icon: Icon(FontAwesomeIcons.hamburger),
),
),
body: StreamBuilder(
stream: Firestore.instance.collection('post').snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) {
Text('Loading');
} else {
return ListView.builder(
itemCount: snapshot.data.document.length,
itemBuilder: (context, index) {
DocumentSnapshot myPost = snapshot.data.documents[index];
return Stack(
children: <Widget>[
Container(
width: MediaQuery.of(context).size.width,
height: 350.0,
child: Padding(
padding: EdgeInsets.only(top: 8.0, bottom: 8.0),
child: Material(
color: Colors.white,
elevation: 14.0,
shadowColor: Color(0x802196f3),
child: Column(
children: <Widget>[
Container(
width: MediaQuery.of(context).size.width,
height: 200.0,
child: Image.network(
'${myPost['image']}',
fit: BoxFit.fill,
),
),
SizedBox(
height: 10.0,
),
Text('${myPost['title']}'),
SizedBox(
height: 10.0,
),
Text('${myPost['subtitle']}'),
],
),
),
),
)
],
);
},
);
},
},
),
);
}
}
[enter image description here][1]
[1]: https://i.stack.imgur.com/QeSyi.png
A build function returned null.The offending widget is: StreamBuilder.Build functions must never return null.
You missed return:
builder: (context, snapshot) {
if (!snapshot.hasData) {
Text('Loading'); // <---- no return here
} else {
return ListView.builder(
itemCount: snapshot.data.documents.length, // <---- documents here
itemBuilder: (context, index) {
DocumentSnapshot myPost = snapshot.data.documents[index];