How do i create a gridview-layout with multi-select feature in Flutter, like android photo app? I was looking for an existing widget but couldn't find one.
What I have at the moment: a gridview-layout with n rows and 2 columns. The cells contain a GridTile-widget with some information and a header text. Now i want to have a functionality like in android photo app, after a long press on one of these tiles, a check-circle appears on the left top corner for all items.
Do i have to build this on my own, or is there an existing Flutter-widget which i didn't find so far?
I also don't know an existing widget, but perhaps this will help you:
import 'package:flutter/material.dart';
import 'package:flutter_staggered_grid_view/flutter_staggered_grid_view.dart';
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',
debugShowCheckedModeBanner: false,
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
List<String> _imageList = List();
List<int> _selectedIndexList = List();
bool _selectionMode = false;
@override
Widget build(BuildContext context) {
List<Widget> _buttons = List();
if (_selectionMode) {
_buttons.add(IconButton(
icon: Icon(Icons.delete),
onPressed: () {
_selectedIndexList.sort();
print('Delete ${_selectedIndexList.length} items! Index: ${_selectedIndexList.toString()}');
}));
}
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
actions: _buttons,
),
body: _createBody(),
);
}
@override
void initState() {
super.initState();
_imageList.add('https://picsum.photos/800/600/?image=280');
_imageList.add('https://picsum.photos/800/600/?image=281');
_imageList.add('https://picsum.photos/800/600/?image=282');
_imageList.add('https://picsum.photos/800/600/?image=283');
_imageList.add('https://picsum.photos/800/600/?image=284');
}
void _changeSelection({bool enable, int index}) {
_selectionMode = enable;
_selectedIndexList.add(index);
if (index == -1) {
_selectedIndexList.clear();
}
}
Widget _createBody() {
return StaggeredGridView.countBuilder(
crossAxisCount: 2,
mainAxisSpacing: 4.0,
crossAxisSpacing: 4.0,
primary: false,
itemCount: _imageList.length,
itemBuilder: (BuildContext context, int index) {
return getGridTile(index);
},
staggeredTileBuilder: (int index) => StaggeredTile.count(1, 1),
padding: const EdgeInsets.all(4.0),
);
}
GridTile getGridTile(int index) {
if (_selectionMode) {
return GridTile(
header: GridTileBar(
leading: Icon(
_selectedIndexList.contains(index) ? Icons.check_circle_outline : Icons.radio_button_unchecked,
color: _selectedIndexList.contains(index) ? Colors.green : Colors.black,
),
),
child: GestureDetector(
child: Container(
decoration: BoxDecoration(border: Border.all(color: Colors.blue[50], width: 30.0)),
child: Image.network(
_imageList[index],
fit: BoxFit.cover,
),
),
onLongPress: () {
setState(() {
_changeSelection(enable: false, index: -1);
});
},
onTap: () {
setState(() {
if (_selectedIndexList.contains(index)) {
_selectedIndexList.remove(index);
} else {
_selectedIndexList.add(index);
}
});
},
));
} else {
return GridTile(
child: InkResponse(
child: Image.network(
_imageList[index],
fit: BoxFit.cover,
),
onLongPress: () {
setState(() {
_changeSelection(enable: true, index: index);
});
},
),
);
}
}
}
I used staggered grid view to show a grid and grid tiles with a header to have a space for the selection icon. Hope that helps!
This is a plugin from flutter package You can use this
You can check on below link. In this video, it is step by step explained how to
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