accordion

An expandable Flutter widget list where each item can be expanded or collapsed simply by clicking on the header.

Simple to use accordion widget with lots of preset properties. Use the maxOpenSections property to automatically close sections when opening a new section. This is especially helpful if you always want your list to look clean -- just set this parameter to 1 and whenever you open a new section the previous one closes. scrollIntoView paramter can be set to fast, slow, or none and makes sure that just opened items will be fully visible. This parameter will only take affect if there are enough items in the list so scrolling is feasible.

Many parameters can be set globally on Accordion as well as individually on each AccordionSection (see list below).

The header consists of the left and right icons (right icon is preset to arrow down). Both can be set globally and individually. As of version 2.1: the headerText, headerTextStyle & headerTextAlign parameters have been removed and should be replaced with the header widget parameter.

The content area basically provides the container in which you drop whatever you want to display when AccordionSection opens. Background and borders can be set globally or individually per section.

Side note: it is possible to nest an Accordion within an AccordionSection

• see the example app (in the "Accordion within Accordion" section) for further info

Common mistakes

Please avoid wrapping the entire Accordion widget in your state management system since this might cause the opening animation to play each time your state changes. Instead, only wrap the content of an AccordionSection with your state management that actually requires updating. Better yet, extract the entire content part of an AccordionSection into its own widget and handle your state management needs there locally.

Enjoy!

The included example

Common Properties

The following properties can be set globally for all sections in Accordion or for each section individually in AccordionSection:

Property	Description	Type	Required	Default value
headerBackgroundColor	background color of the section header	Color	no	primaryColor (of theme)
headerBackgroundColorOpened	background color of the section when header is open	Color	no	headerBackgroundColor
headerBorderColor	border color of header when section is closed	Color	no	primaryColor (of theme)
headerBorderColorOpened	border color of header when section is open	Color	no	primaryColor (of theme)
headerBorderWidth	width of header border. Set to 0 if no header border is desired.	bool	no	0
headerPadding	padding of the title in the section header	EdgeInsets	no	EdgeInsets.symmetric(horizontal: 20, vertical: 10)
leftIcon	widget to the left of the title in the section header	Widget	no	null
rightIcon	widget to the right of the title in the section header	Widget	no	Icon(Icons.keyboard_arrow_down, color: Colors.white60, size: 20)
contentBackgroundColor	background color of the content part of the section	Color	no	Colors.white
contentBorderColor	border color of the content part of the section	Color	no	Colors.white
contentBorderWidth	border width of the content part of the section	double	no	0
contentBorderRadius	border radius of the content part of the section	double	no	20
contentHorizontalPadding	horizontal padding within the content part of the section	double	no	10
contentVerticalPadding	vertical padding within the content part of the section	double	no	10
paddingBetweenClosedSections	padding below closed sections	double	no	3
paddingBetweenOpenSections	padding below an open section to visually make it stand out more	double	no	10
scrollIntoViewOfItems	if a section should automatically be scrolled to the center of the list when opened	ScrollIntoViewOfItems	no	ScrollIntoViewOfItems.fast
initialOpeningSequenceDelay	the delay in milliseconds (when the entire accordion loads) before the individual sections open one after another. Helpful if you go to a new page in your app and then (after the delay) have a nice opening sequence.	int	no	0
sectionOpeningHapticFeedback	if to play a haptic feedback when opening a section	SectionHapticFeedback	no	SectionHapticFeedback.none
sectionClosingHapticFeedback	if to play a haptic feedback when closing a section	SectionHapticFeedback	no	SectionHapticFeedback.none

Properties for Accordion

Property	Description	Type	Required	Default value
maxOpenSections	maximum number of open sections at any given time. Opening a new section will close the "oldest" open section	int	no	1
children	the list of AccordionSection	List	YES	[]
flipLeftIconIfOpen	if the left icon in the header should be flipped when section is open	bool	no	false
flipRightIconIfOpen	if the right icon in the header should be flipped when section is open	bool	no	true
paddingListTop	padding of the Accordion list at the top	double	no	20.0
paddingListBottom	padding of the Accordion list at the bottom	double	no	40.0
paddingListHorizontal	horizontal padding of the Accordion list	double	no	10.0
disableScrolling	disables internal scrolling of the Accordion widget. Useful when the Accordion is used within a ListView or something else already scrollable	bool	no	false
openAndCloseAnimation	controls if sections should animate when opened or closed	bool	no	true
scaleWhenAnimating	controls if sections use a scale effectwhen opened or closed	bool	no	true

Properties for AccordionSection

Property	Description	Type	Required	Default value
isOpen	if this section should initially be displayed open or not	bool	no	false
header	the header widget located between leftIcon & rightIcon	Widget	no
content	the widget you want to display as the visible content when the section is open	Widget	YES
paddingListBottom	padding of the Accordion list at the bottom	double	no	40.0
paddingListHorizontal	horizontal padding of the Accordion list	double	no	10.0
onOpenSection	callback function when this section opens	Function	no
onCloseSection	callback function when this section closes	Function	no