How to link Flutter StaggeredGridView items individually?

Question

Following a tutorial on StaggeredGridView, I successfully built a page to display staggered grids of text and an icon. The tutorial stopped short on explaining how to link each grid item separately. I am aware of onTap, GestureDetector, OnPressed, but I can not figure out how to implement any of these in this grid layout so that each element can link to a different material page route (or _UrlLauncher, etc.)

child: Material(
child: StaggeredGridView.count(
    crossAxisCount: 2,
    crossAxisSpacing: 8,
    mainAxisSpacing: 16,
    shrinkWrap: true,
    padding: EdgeInsets.symmetric(horizontal: 6.0, vertical: 6.0),
    children: < Widget > [
        MyItems(Icons.shop, "Tecxt Here", 0xff42a5f5),
        MyItems(Icons.shop, "Text Here", 0xff42a5f5),
        MyItems(Icons.shop, "Text Here", 0xff42a5f5),
        MyItems(Icons.shop, "Text Here", 0xff42a5f5),
        MyItems(Icons.shop, "Text Here", 0xff42a5f5),
        MyItems(Icons.shop, "Text Here", 0xff42a5f5),
        MyItems(Icons.shop, "Text Here", 0xff42a5f5),

    ],
    staggeredTiles: [
        StaggeredTile.extent(2, 150.0),
        StaggeredTile.extent(1, 150.0),
        StaggeredTile.extent(1, 150.0),
        StaggeredTile.extent(2, 150.0),
        StaggeredTile.extent(1, 150.0),
        StaggeredTile.extent(1, 150.0),
        StaggeredTile.extent(2, 150.0),
    ],
),

), //material

For each "MyItems" we created a Method and parameters:

  Material MyItems(IconData icon, String heading, int color) {
    return Material(color: Colors.white,
      elevation: 12.0,
      shadowColor: Color(0xff2962ff),
      borderRadius: BorderRadius.circular(20.0),
      child: Center(
        child: Padding(
            padding: const EdgeInsets.all(16.0),
            child: Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: < Widget > [
                    Column(
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: < Widget > [

                            //Text here
                            Padding(
                                padding: const EdgeInsets.all(8.0),
                                child: Text(heading,
                                    style: TextStyle(
                                        color: new Color(color),
                                        fontSize: 20.0,
                                    ),
                                ),
                            ), //text

                            //icon
                            Material(
                                color: new Color(color),
                                borderRadius: BorderRadius.circular(24.0),
                                child: Padding(padding: const EdgeInsets.all(16.0),
                                    child: Icon(
                                        icon,
                                        color: Colors.white,
                                        size: 20.0,

                                    ),
                                ),
                            ),
                        ],
                    ),
                ]))),
    );

There doesn't appear to be any information on how to solve this. The only follow up I could find from the author was "There are couple of ways to tackle it":

Use Keys property of the widget

TagButton(onPressed: (k) => onPress(k)), void onPress(Key id) { print('pressed $id'); }

2.Assign a callback that calls a different method for each button

Or you can pass a parameter like shown below and use a switch to identify the parameter value and call the corresponding method.

onPressed: () => onButtonPressed('okButton'),

But after much struggle, I just can't comprehend this. Is it even possible to individually link each staggered grid to their own unique link (page route, UrlLauncher, etc.?

After countless hours trying to find an answer the only thing that came close to linking grids separately was to add click event above each grid item, but when I did that those grids disappeared. I guess there is no solution — Mark, Feb 09 '20 at 18:34

chunhunghan · Accepted Answer · 2020-02-11T00:22:53.797

You can copy paste run full code below
You can pass route name as String

code snippet

return MaterialApp(
  title: 'Flutter Demo',
  theme: ThemeData(
    primarySwatch: Colors.blue,
  ),
  initialRoute: '/',
  routes: {
    // When navigating to the "/" route, build the FirstScreen widget.
    '/': (context) => Example01(),
    '/first': (context) => FirstScreen(),
    '/second': (context) => SecondScreen(),
  },
);
...

List<Widget> _tiles = const <Widget>[
  const MyItems(Icons.shop, "Text1 Here", 0xff42a5f5, "/first"),
  const _Example01Tile(Colors.green, Icons.widgets),
  const _Example01Tile(Colors.amber, Icons.panorama_wide_angle),
  const MyItems(Icons.shop, "Text 2 Here", 0xff42a5f5, "/second"),
...

 class MyItems extends StatelessWidget {
    const MyItems(this.icon, this.heading, this.color, this.routeName);
 ...

 IconButton(
                          icon: Icon(icon),
                          iconSize: 20,
                          color: Colors.white,
                          onPressed: () {
                            Navigator.pushNamed(context, routeName);
                          },
                        )

working demo

full code

import 'package:flutter/material.dart';
import 'package:flutter_staggered_grid_view/flutter_staggered_grid_view.dart';

List<StaggeredTile> _staggeredTiles = const <StaggeredTile>[
  StaggeredTile.extent(2, 150.0),
  StaggeredTile.extent(1, 150.0),
  StaggeredTile.extent(1, 150.0),
  StaggeredTile.extent(2, 150.0),
  StaggeredTile.extent(1, 150.0),
  StaggeredTile.extent(1, 150.0),
  StaggeredTile.extent(2, 150.0),
];

List<Widget> _tiles = const <Widget>[
  const MyItems(Icons.shop, "Text1 Here", 0xff42a5f5, "/first"),
  const _Example01Tile(Colors.green, Icons.widgets),
  const _Example01Tile(Colors.amber, Icons.panorama_wide_angle),
  const MyItems(Icons.shop, "Text 2 Here", 0xff42a5f5, "/second"),
  const _Example01Tile(Colors.deepOrange, Icons.send),
  const _Example01Tile(Colors.indigo, Icons.airline_seat_flat),
  const _Example01Tile(Colors.red, Icons.bluetooth),
  const _Example01Tile(Colors.pink, Icons.battery_alert),
  const _Example01Tile(Colors.purple, Icons.desktop_windows),
  const _Example01Tile(Colors.blue, Icons.radio),
];

class Example01 extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text('Example 01'),
        ),
        body: Padding(
            padding: const EdgeInsets.only(top: 12.0),
            child: StaggeredGridView.count(
              crossAxisCount: 4,
              staggeredTiles: _staggeredTiles,
              children: _tiles,
              mainAxisSpacing: 4.0,
              crossAxisSpacing: 4.0,
              padding: const EdgeInsets.all(4.0),
            )));
  }
}

class _Example01Tile extends StatelessWidget {
  const _Example01Tile(this.backgroundColor, this.iconData);

  final Color backgroundColor;
  final IconData iconData;

  @override
  Widget build(BuildContext context) {
    return Card(
      color: backgroundColor,
      child: InkWell(
        onTap: () {},
        child: Center(
          child: Padding(
            padding: const EdgeInsets.all(4.0),
            child: Icon(
              iconData,
              color: Colors.white,
            ),
          ),
        ),
      ),
    );
  }
}

class MyItems extends StatelessWidget {
  const MyItems(this.icon, this.heading, this.color, this.routeName);

  final int color;
  final IconData icon;
  final String heading;
  final String routeName;

  @override
  Widget build(BuildContext context) {
    return Material(
      color: Colors.white,
      elevation: 12.0,
      shadowColor: Color(0xff2962ff),
      borderRadius: BorderRadius.circular(20.0),
      child: Center(
          child: Padding(
              padding: const EdgeInsets.all(16.0),
              child: Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: <Widget>[
                    Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: <Widget>[
                        //Text here
                        Padding(
                          padding: const EdgeInsets.all(8.0),
                          child: Text(
                            heading,
                            style: TextStyle(
                              color: new Color(color),
                              fontSize: 18.0,
                            ),
                          ),
                        ), //text

                        //icon
                        Material(
                          color: new Color(color),
                          borderRadius: BorderRadius.circular(24.0),
                          child: Padding(
                            padding: const EdgeInsets.all(16.0),
                            child: IconButton(
                              icon: Icon(icon),
                              iconSize: 20,
                              color: Colors.white,
                              onPressed: () {
                                Navigator.pushNamed(context, routeName);
                              },
                            ),
                          ),
                        ),
                      ],
                    ),
                  ]))),
    );
  }
}

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,
      ),
      initialRoute: '/',
      routes: {
        // When navigating to the "/" route, build the FirstScreen widget.
        '/': (context) => Example01(),
        '/first': (context) => FirstScreen(),
        '/second': (context) => SecondScreen(),
      },
    );
  }
}

class FirstScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Text("First Screen");
  }
}

class SecondScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Text("Second Screen");
  }
}

Thanks for the reply. So I guess there is no simple way just to add a link for each grid separately in my original code? Now, I still don't understand how I can link each individual tile separately (ie; to a different MaterialPageRoute, UrlLauncher..), since all the tiles are named the same - 'const _Example01Tile', or in my case, 'const MyItems'. Try to comprehend this, how can I add a different link to each grid item? — Mark, Feb 10 '20 at 19:34
please see my updated answer. You can pass route name as String — chunhunghan, Feb 11 '20 at 00:23
Thank you for the thorough reply, I really appreciate it. Constructors are hard for me to understand and I have a hard time comprehending how this works, and why so much code is need for such a seemingly simple task. — Mark, Feb 12 '20 at 17:28
please mark this as answer if it help you, thanks. if it did not help you, you can clarify your question again. thanks. — chunhunghan, Feb 13 '20 at 00:44
Although I still don't understand this and trying to comprehend, I see that it works. I did vote for an accepted answer although the code is entirely different from my original code, but yours works. Because I am a new poster I do not have a reputation here so this place doesn't count my votes, which is very peculiar. — Mark, Feb 19 '20 at 02:23
You can mark an answer as accepted by click on the check mark beside the answer to toggle it from greyed out to filled in. you can see https://meta.stackexchange.com/questions/5234/how-does-accepting-an-answer-work , thank you very much. — chunhunghan, Feb 19 '20 at 02:25
Because you are OP (Original Post), You can not click upvote mark under 15. But you can click "V" mark under downvote mark. — chunhunghan, Feb 19 '20 at 03:10

How to link Flutter StaggeredGridView items individually?

1 Answers1