calorimeter/lib/perdate/perdate_pageview.dart

import 'dart:developer';

import 'package:calorimeter/perdate/perdate_pageview_controller.dart';
import 'package:calorimeter/perdate/perdate_widget.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

class PerDatePageView extends StatelessWidget {
  // 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 initialDate;
  final PageController pageController;

  const PerDatePageView({
    required this.initialDate,
    required this.pageController,
    super.key,
  });

  @override
  Widget build(BuildContext context) {
    log("PerDatePageView's build()");
    return PageView.builder(
        reverse: true,
        controller: pageController,
        onPageChanged: (value) {
          log("onPageChanged() with value $value");

          var diff = value - pageController.initialPage;
          var newDate = initialDate.subtract(Duration(days: diff));
          log("newDate = $newDate");

          context
              .read<PageViewStateProvider>()
              .addVisitedindexIfNotVisitedByBackButton(value);
          context.read<PageViewStateProvider>().setDisplayedDate(newDate);
        },
        itemBuilder: (context, index) {
          log("itemBuilder() called with index $index");
          var dateToBuildWidgetFor = initialDate
              .subtract(Duration(days: index - pageController.initialPage));

          return PerDateWidget(
            key: ValueKey(dateToBuildWidgetFor.toString()),
            date: dateToBuildWidgetFor,
          );
        });
  }
}