calorimeter/lib/perdate/perdate_pageview.dart

77 lines
2.2 KiB
Dart

import 'package:calorimeter/perdate/perdate_widget.dart';
import 'package:flutter/material.dart';
class PerDatePageview extends StatefulWidget {
// this is the date for which the PerDate widget will be shown on screen
// left of it will be yesterday's PerDate widget
// right of it will be tomorrow's PerDate widget
final DateTime initalDate;
const PerDatePageview({required this.initalDate, super.key});
@override
State<PerDatePageview> createState() => _PerDatePageviewState();
}
class _PerDatePageviewState extends State<PerDatePageview> {
late PageController pageController;
late DateTime displayedDate;
late List<int> visitedIndexes = [];
final int initialOffset = 36500000;
//TODO: that is just ugly
bool backButtonWasPressed = false;
@override
void initState() {
super.initState();
pageController = PageController(initialPage: initialOffset);
displayedDate = widget.initalDate;
visitedIndexes.add(initialOffset);
}
@override
Widget build(BuildContext context) {
return BackButtonListener(
onBackButtonPressed: () async {
if (visitedIndexes.length == 1) {
return false;
}
visitedIndexes.removeLast();
backButtonWasPressed = true;
pageController.jumpToPage(visitedIndexes.last);
return true;
},
child: PageView.builder(
reverse: true,
controller: pageController,
onPageChanged: (value) {
if (backButtonWasPressed) {
backButtonWasPressed = false;
return;
}
visitedIndexes.add(value);
},
itemBuilder: (context, index) {
var dateToBuildWidgetFor =
displayedDate.subtract(Duration(days: index - initialOffset));
return PerDateWidget(
key: ValueKey(dateToBuildWidgetFor.toString()),
date: dateToBuildWidgetFor.copyWith(isUtc: true),
onDateSelected: (dateSelected) {
if (dateSelected == null) return;
var diff = dateSelected.difference(dateToBuildWidgetFor);
var newIndex = index - diff.inDays;
pageController.jumpToPage(newIndex);
});
}),
);
}
}