BookSearch.dart

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';


void main(){
  runApp(new MaterialApp(
    debugShowCheckedModeBanner: false,
    home: new BookSearch(),
  ));
}
class BookSearch extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
      title: Text("search App"),
      actions : <Widget>[
        IconButton(icon : Icon(Icons.search), onPressed : (){
          showSearch(context: context, delegate: DataSearch());
        })
        ]
      ),
      drawer: Drawer(),
    );
  }
}

class DataSearch extends SearchDelegate<String>{

  final books = [
    'The Alchemist',
    "Veronica Decides to Die",
    "Winner Stands Alone",
    "Eleven Minutes",
    "Brida",
    "By the River Piedra",
    "Manuscript",
    "Maktub",
    "The Zahir",
    "The Witch of Portobello",
    "Da vinci code",
    "Angels and demons"
    "Origin",
    "Digital Fortress"
  ];

  //hard coded searches
  final recentBooks = [ 
    "Brida",
    "By the River Piedra",
    "Manuscript",
    "Maktub",
    ];
  
  @override
  List<Widget> buildActions(BuildContext context) {
    // actions for AppBar
    return [
      IconButton(icon: Icon(Icons.clear), onPressed: () {
        query = " ";
      }),
    ];
  }

  @override
  Widget buildLeading(BuildContext context) {
    // leading icon on left of the Appbar
    return IconButton(
      icon: AnimatedIcon(
      icon: AnimatedIcons.menu_arrow,
      progress : transitionAnimation
      ), 
    
      onPressed: (){
        close(context, null);
      }
      );
  }

  @override
  Widget buildResults(BuildContext context) {
    // Tshow result based on search selection
    return Card(
      color: Colors.red,
      shape: StadiumBorder(),
      child : Center(child: Text(query),
      )
    );
  }

  @override
  Widget buildSuggestions(BuildContext context) {
    // show search
    final suggestionList = query.isEmpty ? recentBooks : books.where((p) => p.startsWith(query)).toList();

    return ListView.builder(
      itemBuilder: (context, index) => ListTile(
        onTap: (){
          showResults(context);
        },
        leading: Icon(Icons.location_city), 
        title: RichText(
          text: TextSpan(
            text: suggestionList[index].substring(0,query.length),
            style: TextStyle(color: Colors.black,fontWeight : FontWeight.bold), 
            children: [TextSpan(text: suggestionList[index].substring(query.length), 
            style : TextStyle(color : Colors.grey))
        ]
        )
        ),
        ),
        itemCount: suggestionList.length,
        );
    


  }

}