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https://github.com/hcbpassos/drag_select_grid_view
A grid that supports both dragging and tapping to select its items.
https://github.com/hcbpassos/drag_select_grid_view
dart flutter grid ui widget
Last synced: 12 days ago
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A grid that supports both dragging and tapping to select its items.
- Host: GitHub
- URL: https://github.com/hcbpassos/drag_select_grid_view
- Owner: hcbpassos
- License: bsd-2-clause
- Created: 2019-06-19T14:19:05.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2023-08-29T03:42:13.000Z (about 1 year ago)
- Last Synced: 2024-10-13T21:01:32.484Z (28 days ago)
- Topics: dart, flutter, grid, ui, widget
- Language: Dart
- Homepage:
- Size: 3.32 MB
- Stars: 133
- Watchers: 1
- Forks: 35
- Open Issues: 11
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# drag_select_grid_view
[](https://pub.dartlang.org/packages/drag_select_grid_view)
[](https://github.com/hcbpassos/drag_select_grid_view/actions?workflow=CI)
[](https://github.com/Solido/awesome-flutter)
A grid that supports both dragging and tapping to select its items.
## Basic usage
`DragSelectGridView` constructor is very similar to [`GridView.builder`](https://api.flutter.dev/flutter/widgets/GridView/GridView.builder.html), so you should take your time to understand the latter before diving into this library.
Once you are familiar with [`GridView.builder`](https://api.flutter.dev/flutter/widgets/GridView/GridView.builder.html), probably the only additional piece of information you'll need is `DragSelectGridViewController`. With it, you're able to know which indexes are selected.
Check this example:
```dart
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State {
final controller = DragSelectGridViewController();
@override
void initState() {
super.initState();
controller.addListener(scheduleRebuild);
}
@override
void dispose() {
controller.removeListener(scheduleRebuild);
super.dispose();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: SelectionAppBar(
selection: controller.value,
),
body: DragSelectGridView(
gridController: controller,
itemCount: 20,
itemBuilder: (context, index, selected) {
return SelectableItem(
index: index,
selected: selected,
);
},
gridDelegate: SliverGridDelegateWithMaxCrossAxisExtent(
maxCrossAxisExtent: 80,
),
),
);
}
void scheduleRebuild() => setState(() {});
}
```
As you may have noticed in the code above, `DragSelectGridView` must be used along two other widgets in order to provide a proper user experience. In the example, they are:
* `SelectableItem`: A selectable widget, which is going to visually indicate whether the item is selected or not.
* `SelectionAppBar`: A custom `AppBar`, which shows the amount of selected items and an option to unselect them.
The [example project](https://github.com/hcbpassos/drag_select_grid_view/tree/master/example/lib) provides some samples of those widgets. I won't add them to the library, since they are unrelated to the grid itself, but feel free to copy them into your project, as long as you respect the license terms.
## Advanced usage
You can use the setter `DragSelectGridViewController.value` to directly change the selection (I'm not quite sure why you'd need this, but I don't ask questions).
It allows this sort of interaction:
You can check the code [here](https://github.com/hcbpassos/drag_select_grid_view/blob/master/example/lib/example_with_fab.dart).
There are some other minor settings you can do to make `DragSelectGridView` fit your needs, like `DragSelectGridView.autoScrollHotspotHeight` and `DragSelectGridView.unselectOnWillPop`. Those features are well documented, so I'll let you take your discovery time.
Hopefully, this is everything you need to know to use this library.
## Thanks ❤️
Once upon a time I asked at [Flutter Study Group](https://flutterstudygroup.com/) how to implement a specific feature that I intended to add to this library. [Simon Lightfoot](https://github.com/slightfoot) offered to help me and effortlessly implemented what eventually became part of this library ([check this gist](https://gist.github.com/slightfoot/a002dd1e031f5f012f810c6d5da14a11)). A big thanks to him.
I took a lot of inspiration from [Aidan Follestad](https://github.com/afollestad)'s Android implementation, [drag-select-recyclerview](https://github.com/afollestad/drag-select-recyclerview). Also a big thanks to him.