material_floating_search_bar 0.1.0

A Flutter implementation of an expandable floating search bar similar to the ones used extensively by Google in their own apps.

Material Floating Search Bar

A Flutter implementation of an expandable floating search bar, also known as persistent search, similar to the ones used extensively by Google in their own apps.

Click here to view the full example.

Installing

Add it to your pubspec.yaml file:

dependencies:
  material_floating_search_bar: ^0.1.0

Install packages from the command line

flutter packages get

If you like this package, consider supporting it by giving it a star on GitHub and a like on pub.dev ❤️

Usage

A FloatingSearchBar should be placed above your main content in your widget tree and be allowed to fill all the available space.

@override
Widget build(BuildContext context) {
  return Scaffold(
    // This is handled by the search bar itself.
    resizeToAvoidBottomInset: false,
    body: Stack(
      fit: StackFit.expand,
      children: [
        buildMap(),
        buildBottomNavigationBar(),
        buildFloatingSearchBar(),
      ],
    ),
  );
}

Widget buildFloatingSearchBar() {
  final isPortrait = MediaQuery.of(context).orientation == Orientation.portrait;

  return FloatingSearchBar(
    hint: 'Search...',
    scrollPadding: const EdgeInsets.only(top: 16, bottom: 56),
    transitionDuration: const Duration(milliseconds: 800),
    transitionCurve: Curves.easeInOut,
    physics: const BouncingScrollPhysics(),
    axisAlignment: isPortrait ? 0.0 : -1.0,
    openAxisAlignment: 0.0,
    maxWidth: isPortrait ? 600 : 500,
    debounceDelay: const Duration(milliseconds: 500),
    onQueryChanged: (query) {
      // Call your model, bloc, controller here.
    },
    // Specify a custom transition to be used for
    // animating between opened and closed stated.
    transition: CircularFloatingSearchBarTransition(),
    actions: [
      FloatingSearchBarAction(
        showIfOpened: false,
        child: CircularButton(
          icon: const Icon(Icons.place),
          onPressed: () {},
        ),
      ),
      FloatingSearchBarAction.searchToClear(
        showIfClosed: false,
      ),
    ],
    bodyBuilder: (context, transition) {
      return ClipRRect(
        borderRadius: BorderRadius.circular(8),
        child: Material(
          color: Colors.white,
          elevation: 4.0,
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: Colors.accents.map((color) {
              return Container(height: 112, color: color);
            }).toList(),
          ),
        ),
      );
    },
  );
}

Usage with Scrollables

By default, the Widget returned by the builder is not allowed to have an unbounded (infinite) height. This is necessary in order for the search bar to be able to dismiss itself, when the user taps below the area of the child. (For example, when you have a list of items but there are not enough items to fill the whole screen, as shown in the gifs above, the user would expect to be able to close the search bar when tapping below the last item in the list).

Therefore, shrinkWrap should be set to true on all Scrollables and physics to NeverScrollableScrollPhysics. On Columns, the mainAxisSize should be set to MainAxisSize.min.

If you don't want this behavior, you can set the isScrollControlled flag to true. Then you are allowed to use expanding Widgets such as Scrollables with the caveat that the search bar may not be able to detect taps on the backdrop area.

Customizations

There are many customization options:

Field	Description
body	The widget displayed below the FloatingSearchBar. This is useful, if the FloatingSearchBar should react to scroll events (i.e. hide from view when a Scrollable is being scrolled down and show it again when scrolled up).
accentColor	The color used for elements such as the progress indicator. Defaults to the themes accent color if not specified.
backgroundColor	The color of the card. If not specified, defaults to theme.cardColor.
shadowColor	The color of the shadow drawn when elevation > 0. If not specified, defaults to Colors.black54.
iconColor	When specified, overrides the themes icon color for this FloatingSearchBar, for example to easily adjust the icon color for all actions and startActions.
backdropColor	The color that fills the available space when the FloatingSearchBar is opened. Typically a black-ish color. If not specified, defaults to Colors.black26.
margins	The insets from the edges of its parent. This can be used to position the FloatingSearchBar. If not specifed, the FloatingSearchBar will try to position itself at the top offsetted by MediaQuery.of(context).viewPadding.top to avoid the status bar.
padding	The padding of the card. Only the horizontal values will be honored.
insets	The padding between startActions, the input field and actions respectively. Only the horizontal values will be honored.
height	The height of the card. If not specified, defaults to 48.0 pixels.
elevation	The elevation of the card.
maxWidth	The max width of the FloatingSearchBar. By default the FloatingSearchBar will expand to fill all the available width. This value can be set to avoid this.
openMaxWidth	The max width of the FloatingSearchBar when opened. This can be used, when the max width when opened should be different from the one specified by maxWidth. When not specified, will use the value of maxWidth.
axisAlignment	How the FloatingSearchBar should be aligned when the available width is bigger than the width specified by maxWidth. When not specified, defaults to 0.0 which centers the FloatingSearchBar.
openAxisAlignment	How the FloatingSearchBar should be aligned when the available width is bigger than the width specified by openMaxWidth. When not specified, will use the value of axisAlignment.
border	The border of the card.
borderRadius	The BorderRadius of the card. When not specified, defaults to BorderRadius.circular(4).
hintStyle	The TextStyle for the hint in the TextField.
queryStyle	The TextStyle for the input in the TextField.
clearQueryOnClose	Whether the current query should be cleared when the FloatingSearchBar was closed. When not specifed, defaults to true.
showDrawerHamburger	Whether a hamburger menu should be shown when there is a Scaffold with a Drawer in the widget tree.
closeOnBackdropTap	Whether the FloatingSearchBar should be closed when the backdrop was tapped. When not specified, defaults to true.
progress	The progress of the LinearProgressIndicator inside the card. When set to a double between 0..1, will show show a determined LinearProgressIndicator. When set to true, the FloatingSearchBar will show an indetermined LinearProgressIndicator. When null or false, will hide the LinearProgressIndicator.
transitionDuration	The duration of the animation between opened and closed state.
transitionCurve	The curve for the animation between opened and closed state.
debounceDelay	The delay between the time the user stopped typing and the invocation of the onQueryChanged callback. This is useful for example if you want to avoid doing expensive tasks, such as making a network call, for every single character.
title	A widget that is shown in place of the TextField when the FloatingSearchBar is closed.
hint	The text value of the hint of the TextField.
actions	A list of widgets displayed in a row after the TextField. Consider using FloatingSearchBarActions for more advanced actions that can interact with the FloatingSearchBar. In LTR languages, they will be displayed to the left of the TextField.
startActions	A list of widgets displayed in a row before the TextField. Consider using FloatingSearchBarActions for more advanced actions that can interact with the FloatingSearchBar. In LTR languages, they will be displayed to the right of the TextField.
onQueryChanged	A callback that gets invoked when the input of the query inside the TextField changed.
onSubmitted	A callback that gets invoked when the user submitted their query (e.g. hit the search button).
onFocusChanged	A callback that gets invoked when the FloatingSearchBar receives or looses focus.
transition	The transition to be used for animating between closed and opened state. See below for a list of all available transitions.
builder	The builder for the body of this FloatingSearchBar. Usually, a list of items. Note that unless isScrollControlled is set to true, the body of a FloatingSearchBar must not have an unbounded height meaning that shrinkWrap should be set to true on all Scrollables.
controller	The controller for this FloatingSearchBar which can be used to programatically open, close, show or hide the FloatingSearchBar.
isScrollControlled	Whether the body of this FloatingSearchBar is using its own Scrollable. This will allow the body of the FloatingSearchBar to have an unbounded height. Note that when set to true, the FloatingSearchBar won't be able to dismiss itself when tapped below the height of child inside the Scrollable, when the child is smaller than the avaialble height.

Transitions

As of now there are three types of transitions that are exemplified above:

Transition	Description
CircularFloatingSearchBarTransition	Clips its child in an expanding circle.
ExpandingFloatingSearchBarTransition	Fills all the available space with the background of the FloatingSearchBar. Similar to the ones used in many Google apps like Gmail.
SlideFadeFloatingSearchBarTransition	Vertically slides and fades its child.

You can also easily create you own custom transition by extending FloatingSearchBarTransition.