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: ^0.3.4

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,
    width: 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:

Transitions

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

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

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.

Additional Customizations

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

Download Material Floating Search Bar Widget source code on GitHub

https://github.com/bnxm/material_floating_search_bar

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