Multi Select Flutter

Multi Select Flutter is a package for creating multi-select widgets in a variety of ways.

Dialog	BottomSheet	ChoiceChip

Features

• Supports FormField features like validator.
• Neutral default design.
• Dialog, BottomSheet, or ChoiceChip style widgets.
• Make your multi select searchable for larger lists.

Usage

MultiSelectDialogField / MultiSelectBottomSheetField

These widgets provide an InkWell button which open the dialog or bottom sheet and are equipped with FormField features. You can customize it using the provided parameters.

To store the selected values, you can use the onConfirm parameter. You could also use onSelectionChanged for this.

By default these widgets render a MultiSelectChipDisplay below the field. This can be overridden with the chipDisplay parameter or removed completely by using chipDisplay: MultiSelectChipDisplay.none().

MultiSelectDialogField(
  items: _animals.map((e) => MultiSelectItem(e, e.name)).toList(),
  listType: MultiSelectListType.CHIP,
  onConfirm: (values) {
    _selectedAnimals = values;
  },
),

MultiSelectDialog / MultiSelectBottomSheet

           

If you prefer to create your own button for opening the dialog or bottom sheet, you may do so and then make a call to a function like this:

MultiSelectDialog can be used in the builder of showDialog().

void _showMultiSelect(BuildContext context) async {
  await showDialog(
    context: context,
    builder: (ctx) {
      return  MultiSelectDialog(
        items: _items,
        initialValue: _selectedAnimals,
        onConfirm: (values) {...},
      );
    },
  );
}

MultiSelectBottomSheet can be used in the builder of showModalBottomSheet().

void _showMultiSelect(BuildContext context) async {
  await showModalBottomSheet(
    isScrollControlled: true, // required for min/max child size
    context: context,
    builder: (ctx) {
      return  MultiSelectBottomSheet(
        items: _items,
        initialValue: _selectedAnimals,
        onConfirm: (values) {...},
        maxChildSize: 0.8,
      );
    },
  );
}

MultiSelectChipDisplay

To display the selected items, this widget can be used alongside your own button or it can be specified as a chipDisplay parameter of widgets like MultiSelectDialogField.

You can also remove items from the source list in the onTap function.

MultiSelectChipDisplay(
  items: _selectedAnimals.map((e) => MultiSelectItem(e, e)).toList(),
  onTap: (value) {
    setState(() {
      _selectedAnimals.remove(value);
    });
  },
),

A MultiSelectChipDisplay that is part of a MultiSelectDialogField still renders outside the BoxDecoration of the MultiSelectDialogField as seen here:

If you want to encapsulate the MultiSelectChipDisplay, wrap the MultiSelectDialogField in a Container and apply the decoration to that instead:

Container(
  decoration: BoxDecoration(...),
  child: MultiSelectDialogField(
    items: _items,
    chipDisplay: MultiSelectChipDisplay(...),
  ),
),

MultiSelectChipField

This widget is similar to MultiSelectChipDisplay, except these chips are the primary interface for selecting items.

MultiSelectChipField<Animal>(
  items: _items,
  icon: Icon(Icons.check),
  onTap: (values) {
    _selectedAnimals = values;
  },
),

Using itemBuilder to create custom items:

MultiSelectChipField<Animal>(
  items: _items,
  key: _multiSelectKey,
  validator: (values) {...}
  itemBuilder: (item, state) {
    // return your custom widget here
    return InkWell(
      onTap: () {
        _selectedAnimals.contains(item.value)
			      ? _selectedAnimals.remove(item.value)
			      : _selectedAnimals.add(item.value);
	      state.didChange(_selectedAnimals);
	      _multiSelectKey.currentState.validate();
	    },
	    child: Text(item.value.name),
    );
  },
),

The itemBuilder param takes a function that will create a widget for each of the provided items.

In order to use validator and other FormField features with custom widgets, you must call state.didChange(_updatedList) any time the list of selected items is updated.

Using scrollControl to auto scroll:

MultiSelectChipField(
  items: _items,
  scrollControl: (controller) {
    _startAnimation(controller);
  },
)

// waits 5 seconds, scrolls to end slow, then back fast
void _startAnimation(ScrollController controller) {
  // when using more than one animation, use async/await
  Future.delayed(const Duration(milliseconds: 5000), () async {
    await controller.animateTo(
      controller.position.maxScrollExtent,
      duration: Duration(milliseconds: 8000), 
      curve: Curves.linear);
      
    await controller.animateTo(
      controller.position.minScrollExtent,
      duration: Duration(milliseconds: 1250),
      curve: Curves.fastLinearToSlowEaseIn);
  });
}

Constructors

MultiSelectDialog

Parameter	Type	Description
backgroundColor	Color	Set the background color of the dialog.
cancelText	Text	Specifies the cancel button text.
checkColor	Color	Set the color of the check in the checkbox.
closeSearchIcon	Icon	Icon(Icons.close)
confirmText	Text	Specifies the confirm button text.
colorator	Color	Function(V) Set the selected color of individual items based on their value. Applies to both chips and checkboxes.
height	double	Give the dialog a fixed height.
initialValue	List<V>	List of selected values. Required to retain values when re-opening the dialog.
items	List<MultiSelectItem<V>>	The source list of options.
itemsTextStyle	TextStyle	Specifies the style of text on chips or list tiles.
listType	MultiSelectListType	Change the listType. Can be either  MultiSelectListType.LIST or MultiSelectListType.CHIP
onSelectionChanged	Function(List<V>)	Fires when an item is selected or unselected.
onConfirm	Function(List)	Fires when the confirm button is pressed.
searchable	bool	Enables search functionality within the dialog.
searchHintStyle	TextStyle	Style the text of the search hint.
searchIcon	Icon	The icon button that shows the search field.
searchHint	String	Set the placeholder text of the search field.
searchTextStyle	TextStyle	Style the search text.
selectedColor	Color	Set the color of the checkbox or chip items that are selected.
separateSelectedItems	bool	Moves the selected items to the top of the list.
title	Widget	The title that is displayed at the top of the dialog.
unselectedColor	Color	Set the color of the chip body or checkbox border while not selected.

MultiSelectDialogField

MultiSelectDialogField has all the parameters of MultiSelectDialog plus these extra parameters:

Parameter	Type	Description
autovalidateMode	AutovalidateMode	If enabled, form fields will validate and update their error text immediately after every change. Default is disabled.
barrierColor	Color	Set the color of the space outside the dialog.
buttonText	Text	Set text that is displayed on the button.
buttonIcon	Icon	Specify the button icon.
chipDisplay	MultiSelectChipDisplay	Override the default MultiSelectChipDisplay that belongs to this field.
decoration	BoxDecoration	Style the Container that makes up the field.
key	GlobalKey<FormFieldState>	Access FormFieldState methods.
onSaved	List<MultiSelectItem>	A callback that is called whenever we submit the field (usually by calling the save method on a form.
validator	FormFieldValidator<List>	Validation. See Flutter's documentation.

MultiSelectBottomSheet

Parameter	Type	Description
cancelText	Text	Specifies the cancel button text.
checkColor	Color	Set the color of the check in the checkbox.
confirmText	Text	Specifies the confirm button text.
closeSearchIcon	Icon	The icon button that hides the search field .
colorator	Color Function(V)	Set the selected color of individual items based on their value. Applies to both chips and checkboxes.
initialChildSize	double	The initial height of the BottomSheet. Default is 0.3
initialValue	List<V>	List of selected values. Required to retain values when re-opening the BottomSheet.
items	List<MultiSelectItem<V>>	The source list of options.
itemsTextStyle	TextStyle	Specifies the style of text on chips or list tiles.
listType	MultiSelectListType	MultiSelectListType.LIST
maxChildSize	double	Set the maximum height threshold of the BottomSheet. Default is 0.6
minChildSize	double	Set the minimum height threshold of the BottomSheet before it closes. Default is 0.3
onSelectionChanged	Function(List<V>)	Fires when an item is selected or unselected.
onConfirm	Function(List)	Fires when the confirm button is pressed.
searchable	bool	Toggle search functionality within the BottomSheet.
searchHint	String	Set the placeholder text of the search field.
searchHintStyle	TextStyle	Style the text of the search hint.
searchIcon	Icon	The icon button that shows the search field.
searchTextStyle	TextStyle	Style the search text.
selectedColor	Color	Set the color of the checkbox or chip items that are selected.
separateSelectedItems	bool	Moves the selected items to the top of the list.
title	Widget	The title that is displayed at the top of the BottomSheet.
unselectedColor	Color	Set the color of the chip body or checkbox border while not selected.

MultiSelectBottomSheetField

MultiSelectBottomSheetField has all the parameters of MultiSelectBottomSheet plus these extra parameters:

Parameter	Type	Description
autovalidateMode	AutovalidateMode	If enabled, form fields will validate and update their error text immediately after every change. Default is disabled.
backgroundColor	Color	Set the background color of the BottomSheet.
barrierColor	Color	Set the color of the space outside the BottomSheet.
buttonIcon	Icon	Specify the button icon.
buttonText	Text	Set text that is displayed on the button.
chipDisplay	MultiSelectChipDisplay	Override the default MultiSelectChipDisplay that belongs to this field.
decoration	BoxDecoration	Style the Container that makes up the field.
key	GlobalKey<FormFieldState>	Can be used to call methods like _multiSelectKey.currentState.validate().
onSaved	List<MultiSelectItem>	A callback that is called whenever we submit the field (usually by calling the save method on a form.
shape	ShapeBorder	Apply a ShapeBorder to alter the edges of the BottomSheet. Default is a RoundedRectangleBorder with top circular radius of 15.
validator	FormFieldValidator<List>	Validation. See Flutter's documentation.

MultiSelectChipField

Parameter	Type	Description
autovalidateMode	AutovalidateMode	If enabled, form fields will validate and update their error text immediately after every change. Default is disabled.
chipColor	Color	Set the chip color.
chipShape	ShapeBorde	Define a ShapeBorder for the chips.
closeSearchIcon	Icon	The icon button that hides the search field .
colorator	Color Function(V)	Set the selected chip color of individual items based on their value.
decoration	BoxDecoration	Style the surrounding Container.
headerColor	Color	Set the header color.
height	double	Set the height of the selectable area.
icon	Icon	The icon to display prior to the chip label.
initialValue	List<V>	List of selected values before any interaction.
itemBuilder	Function(MultiSelectItem<V>, FormFieldState<List<V>>)	Build a custom widget that gets created dynamically for each item.
items	List<MultiSelectItem<V>>	The source list of options.
key	GlobalKey<FormFieldState>	Can be used to call methods like _multiSelectKey.currentState.validate().
onSaved	List<MultiSelectItem>	A callback that is called whenever the field is submitted (usually by calling the save method on a form.
onTap	Function(V)	Fires when a chip is tapped.
scroll	bool	Enables horizontal scrolling.
scrollBar	HorizontalScrollBar	Define a scroll bar.
scrollControl	Function(ScrollController)	Make use of the ScrollController to automatically scroll through the list.
searchable	bool	Toggle search functionality.
searchHint	String	Set the placeholder text of the search field.
searchHintStyle	TextStyle	Style the text of the search hint.
searchIcon	Icon	The icon button that shows the search field.
searchTextStyle	TextStyle	Style the search text.
selectedChipColor	Color	Set the color of the chip items that are selected.
selectedTextStyle	TextStyle	Set the TextStyle on selected chips.
showHeader	bool	Determines whether to show the header.
textStyle	TextStyle	Style the text on the chips.
title	Widget	The title that is displayed in the header.
validator	FormFieldValidator<List>	Validation. See Flutter's documentation.

MultiSelectChipDisplay

Parameter	Type	Description
alignment	Alignment	Change the alignment of the chips. Default is Alignment.centerLeft.
chipColor	Color	Set the chip color.
colorator	Color Function(V)	Set the chip color of individual items based on their value.
decoration	BoxDecoration	Style the Container that makes up the chip display.
height	double	Set a fixed height.
icon	Icon	The icon to display prior to the chip label.
items	List<MultiSelectItem>	The source list of selected items.
onTap	Function(V)	Fires when a chip is tapped.
scroll	bool	Enables horizontal scroll instead of wrap.
scrollBar	HorizontalScrollBar	Enable the scroll bar.
shape	ShapeBorder	Define a ShapeBorder for the chips.
textStyle	TextStyle	Style the text on the chips.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.