workouttest_app/lib/view/menu_page.dart

import 'package:aitrainer_app/localization/app_localization.dart';
import 'package:aitrainer_app/model/auth.dart';
import 'package:aitrainer_app/model/exercise_type.dart';
import 'package:aitrainer_app/model/workout_tree.dart';
import 'package:aitrainer_app/util/common.dart';
import 'package:aitrainer_app/util/menu_tests.dart';
import 'package:aitrainer_app/viewmodel/exercise_changing_view_model.dart';
import 'package:aitrainer_app/widgets/bottom_nav.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'dart:collection';
import 'package:provider/provider.dart';

// ignore: must_be_immutable
class MenuPage extends StatefulWidget {
  _MenuPageState _state;
  static const routeName = '/menu_page';
  int parent;

  MenuPage({this.parent});

  @override
  _MenuPageState createState() {
    _state = new _MenuPageState();
    return _state;
  }

}

class _MenuPageState extends State<MenuPage> {
  final BottomNavigator bottomNav = BottomNavigator();

  @override
  Widget build(BuildContext context) {
    final MenuTests menu = MenuTests(context);
    return Scaffold(
        appBar: AppBar(
          backgroundColor: Colors.transparent,
          title: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: <Widget>[
              Text(AppLocalizations.of(context).translate("Tests")),
              Image.asset(
                'asset/image/WT_long_logo.png',
                fit: BoxFit.cover,
                height: 65.0,
              ),
            ],
          ),
          leading: IconButton(
            icon: Icon(Icons.arrow_back, color: Colors.white),
            onPressed: () => {
                this.setState(() {
                  widget.parent = 0;
                },
              )},
          ),
        ),

        body: Container(
            decoration: BoxDecoration(
              image: DecorationImage(
                image: AssetImage('asset/image/WT_menu_dark.png'),
                fit: BoxFit.fill,
                alignment: Alignment.center,
              ),
            ),

          child: CustomScrollView(
              scrollDirection: Axis.vertical,
              slivers: <Widget>[
                buildMenuColumn(widget.parent, context, menu)
              ]
          )
        ),
    );
  }

  SliverList buildMenuColumn(int parent, BuildContext context, MenuTests menu)  {
    LinkedHashMap tree = menu.getMenuItems();
    List<Widget> _columnChildren = List();
    ExerciseType exerciseType;
    ExerciseChangingViewModel model = Provider.of<ExerciseChangingViewModel>(context, listen: false);

    tree.forEach((treeName, value) {
      WorkoutTree workoutTree = value as WorkoutTree;

      if ( workoutTree.parent == parent ) {
        _columnChildren.add(
          Container(
              padding: EdgeInsets.only(top: 16.0),
            child: Center(
              child: Stack(
                  alignment: Alignment.bottomLeft,
                  overflow: Overflow.visible,
                  children: [
                FlatButton(
                    child: _getButtonImage(workoutTree),
                    padding: EdgeInsets.all(0.0),
                    onPressed:() =>
                    {
                      print("Hi!, Menu clicked " + workoutTree.id.toString()),
                      if ( workoutTree.child == false ) {
                          this.setState(() {
                            widget.parent = workoutTree.id;
                          },
                        ),
                      } else {
                        exerciseType = Common.getExerciseType(workoutTree.exerciseTypeId),
                        model.setExerciseType(exerciseType),
                        model.setCustomer(Auth().userLoggedIn),
                        if ( Auth().userLoggedIn == null  ) {
                          Scaffold.of(context)
              .             showSnackBar(
                              SnackBar(
                                backgroundColor: Colors.orange,
                                content: Text(
                                    AppLocalizations.of(context).translate('Please log in'),
                                    style: TextStyle(color: Colors.white))
                              ))
                        } else {
                            Navigator.of(context).pushNamed('exerciseNewPage'),
                        }
                      }

                    }
                ),
                    InkWell(
                      child: Text(workoutTree.name, style: TextStyle(color: workoutTree.color, fontSize: workoutTree.fontSize, fontFamily: 'Arial', fontWeight: FontWeight.w900 ),),
                      highlightColor: workoutTree.color,
                    )]))));

      }
    });
    //_columnChildren.add(Spacer(flex: 3));
    SliverList sliverList =
        SliverList(
          delegate: SliverChildListDelegate(
              _columnChildren
          )
        );

    return sliverList;
  }

  dynamic _getButtonImage(WorkoutTree workoutTree) {
    dynamic image;
    if ( workoutTree.imageName.startsWith("http") ) {
      image = FadeInImage.assetNetwork(
        image: workoutTree.imageName,
        placeholder: 'asset/image/dots.gif',
        //imageScale: 0.1,
        height: 180,
        placeholderScale: 0.1,
      );
    } else {
      image = Image.asset(workoutTree.imageName, height: 180,);
    }
    return image;
  }

}