cake_wallet/lib/src/screens/exchange/widgets/currency_picker.dart

import 'dart:ui';
import 'package:cake_wallet/palette.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:cake_wallet/entities/crypto_currency.dart';
import 'package:cake_wallet/src/widgets/alert_background.dart';
import 'package:cake_wallet/src/widgets/alert_close_button.dart';

class CurrencyPicker extends StatelessWidget {
  CurrencyPicker({
    @required this.selectedAtIndex,
    @required this.items,
    @required this.title,
    @required this.onItemSelected,
  });

  final int selectedAtIndex;
  final List<CryptoCurrency> items;
  final String title;
  final Function(CryptoCurrency) onItemSelected;
  final closeButton = Image.asset('assets/images/close.png',
    color: Palette.darkBlueCraiola,
  );

  @override
  Widget build(BuildContext context) {
    return AlertBackground(
        child: Stack(
          alignment: Alignment.center,
          children: <Widget>[
            Column(
              mainAxisSize: MainAxisSize.min,
              children: <Widget>[
                Container(
                  padding: EdgeInsets.only(left: 24, right: 24),
                  child: Text(
                    title,
                    textAlign: TextAlign.center,
                    style: TextStyle(
                        fontSize: 18,
                        fontFamily: 'Poppins',
                        fontWeight: FontWeight.bold,
                        decoration: TextDecoration.none,
                        color: Colors.white
                    ),
                  ),
                ),
                Padding(
                  padding: EdgeInsets.only(top: 24),
                  child: GestureDetector(
                    onTap: () => null,
                    child: ClipRRect(
                      borderRadius: BorderRadius.all(Radius.circular(14)),
                      child: Container(
                        height: 400,
                        width: 300,
                        color: Theme.of(context).accentTextTheme.title.backgroundColor,
                        child: GridView.count(
                            shrinkWrap: true,
                            crossAxisCount: 3,
                            childAspectRatio: 1.25,
                            physics: const NeverScrollableScrollPhysics(),
                            crossAxisSpacing: 1,
                            mainAxisSpacing: 1,
                            children: List.generate(items.length, (index) {

                              final item = items[index];
                              final isItemSelected = index == selectedAtIndex;

                              final color = isItemSelected
                                  ? Theme.of(context).textTheme.body2.color
                                  : Theme.of(context).accentTextTheme.title.color;
                              final textColor = isItemSelected
                                  ? Palette.blueCraiola
                                  : Theme.of(context).primaryTextTheme.title.color;

                              return GestureDetector(
                                onTap: () {
                                  if (onItemSelected == null) {
                                    return;
                                  }
                                  Navigator.of(context).pop();
                                  onItemSelected(item);
                                },
                                child: Container(
                                  color: color,
                                  child: Center(
                                    child: Text(
                                      item.toString(),
                                      style: TextStyle(
                                          fontSize: 18,
                                          fontFamily: 'Poppins',
                                          fontWeight: FontWeight.w600,
                                          decoration: TextDecoration.none,
                                          color: textColor
                                      ),
                                    ),
                                  ),
                                ),
                              );
                            })
                        ),
                      ),
                    ),
                  ),
                )
              ],
            ),
            AlertCloseButton(image: closeButton)
          ],
        )
    );
  }
}