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.

CircularFloatingSearchBarTransition ExpandingFloatingSearchBarTransition SlideFadeFloatingSearchBarTransition

Click here to view the full example.

Installing

Add it to your pubspec.yaml file:

dependencies:
  material_floating_search_bar: ^0.2.3

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 :heart:

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,
      ),
    ],
    builder: (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:

FieldDescription
bodyThe 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). See here for more info.
accentColorThe color used for elements such as the progress indicator.

Defaults to the themes accent color if not specified.
backgroundColorThe color of the card.

If not specified, defaults to theme.cardColor.
shadowColorThe color of the shadow drawn when elevation > 0.

If not specified, defaults to Colors.black54.
iconColorWhen specified, overrides the themes icon color for this FloatingSearchBar, for example to easily adjust the icon color for all actions and leadingActions.
backdropColorThe color that fills the available space when the FloatingSearchBar is opened.

Typically a black-ish color.

If not specified, defaults to Colors.black26.
marginsThe 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.
paddingThe padding of the card.

Only the horizontal values will be honored.
insetsThe padding between leadingActions, the input field and actions respectively.

Only the horizontal values will be honored.
heightThe height of the card.

If not specified, defaults to 48.0 pixels.
elevationThe elevation of the card.
maxWidthThe 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.
openMaxWidthThe 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.
axisAlignmentHow 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.
openAxisAlignmentHow 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.
borderThe border of the card.
borderRadiusThe BorderRadius of the card.

When not specified, defaults to BorderRadius.circular(4).
hintStyleThe TextStyle for the hint in the TextField.
queryStyleThe TextStyle for the input in the TextField.
clearQueryOnCloseWhether the current query should be cleared when the FloatingSearchBar was closed.

When not specifed, defaults to true.
automaticallyImplyDrawerHamburgerWhether a hamburger menu should be shown when there is a Scaffold with a Drawer in the widget tree.
closeOnBackdropTapWhether the FloatingSearchBar should be closed when the backdrop was tapped.

When not specified, defaults to true.
automaticallyImplyBackButtonWhether to automatically display a back button if the enclosing route can be popped.

When not specified, defaults to true.
progressThe 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.
transitionDurationThe duration of the animation between opened and closed state.
transitionCurveThe curve for the animation between opened and closed state.
debounceDelayThe 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.
titleA widget that is shown in place of the TextField when the FloatingSearchBar is closed.
hintThe text value of the hint of the TextField.
actionsA 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.
leadingActionsA 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.
onQueryChangedA callback that gets invoked when the input of the query inside the TextField changed.
onSubmittedA callback that gets invoked when the user submitted their query (e.g. hit the search button).
onFocusChangedA callback that gets invoked when the FloatingSearchBar receives or looses focus.
transitionThe transition to be used for animating between closed and opened state. See below for a list of all available transitions.
builderThe 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.
controllerThe controller for this FloatingSearchBar which can be used to programatically open, close, show or hide the FloatingSearchBar.
isScrollControlledWhether 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:

TransitionDescription
CircularFloatingSearchBarTransitionClips its child in an expanding circle.
ExpandingFloatingSearchBarTransitionFills all the available space with the background of the FloatingSearchBar. Similar to the ones used in many Google apps like Gmail.
SlideFadeFloatingSearchBarTransitionVertically slides and fades its child.

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

Scrolling

Scrolling

A common behavior for floating search bars is to disappear when the user scrolls a Scrollable down and appear again when scrolling up. This can be easily achieved by passing your Widget to the body field of FloatingSearchBar. This way FloatingSearchBar can listen for ScrollNotifications. In order that the FloatingSearchBar doesn't interact with every Scrollable below in the widget tree, you should wrap every Scrollable that should interact with the FloatingSearchBar inside a FloatingSearchBarScrollNotifier.

Example

class Home extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return FloatingSearchBar(
      // Your pages or just a simple Scaffold...
      body: IndexedStack(
        children: [
          MyAwesomePage(),
        ],
      ),
    );
  }
}

class MyAwesomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    /// Wrap your Scrollable in a FloatingSearchBarScrollNotifier
    /// to indicate that the FloatingSearchBar should react to
    /// scroll events from this Scrollable.
    return FloatingSearchBarScrollNotifier(
      child: ListView.builder(
        itemCount: 42,
        itemBuilder: (_, index) => Item('Item $index'),
      ),
    );
  }
}

Floating Search App Bar

Sometimes a FloatingSearchBar might not be the most appriopriate search method for your use case. For this reason there is also the FloatingSearchAppBar. It is a normal AppBar with easy search integration very similar to the normal FloatingSearchBar.

FloatingSearchAppBar example

Additional Customizations

In addition to most of the fields from the FloatingSearchBar, FloatingSearchAppBar has the following additional fields:

FieldDescription
colorOnScrollThe color of the bar when a Scrollable inside the body was scrolled (i.e. the Scrollable is not at the top)
liftOnScrollElevationThe elevation of the bar when a Scrollable inside the body was scrolled (i.e. the Scrollable is not at the top)
alwaysOpenedWhether the bar should be always in opened state.

This is useful for example, if you have a page dedicated only for search.
hideKeyboardOnDownScrollHides the keyboard a Scrollable inside the body was scrolled and shows it again when the user scrolls to the top.

Libraries