simple graph view with sorted data

2025-01-25 02:06:25 +01:00
parent dfb9b59560
commit 85e3471c87
4 changed files with 104 additions and 10 deletions
--- a/lib/Widgets/reading_graph.dart
+++ b/lib/Widgets/reading_graph.dart
@@ -0,0 +1,88 @@
+import 'package:fl_chart/fl_chart.dart';
+import 'package:flutter/material.dart';
+import 'package:intl/intl.dart' as intl;
+import 'dart:math';
+
+import '../model/reading.dart';
+
+class ReadingGraph extends StatelessWidget {
+  const ReadingGraph({super.key, required List<Reading> readings})
+      : _readings = readings;
+  final List<Reading> _readings;
+
+  @override
+  Widget build(BuildContext context) {
+    if (_readings.isEmpty) {
+      return Text('No readings on record.');
+    }
+
+    final spots = _readings
+        .map<FlSpot>(
+          (e) => FlSpot(
+              e.dateTime.millisecondsSinceEpoch.toDouble() / 1000 / 60,
+              e.value),
+        )
+        .toList();
+
+    return LineChart(
+      LineChartData(
+        maxY: _readings.map<double>((e) => e.value).reduce(max) + 0.05,
+        minY: _readings.map<double>((e) => e.value).reduce(min) - 0.05,
+        lineBarsData: [
+          LineChartBarData(
+            isCurved: true,
+            color: Colors.cyan,
+            barWidth: 2,
+            isStrokeCapRound: true,
+            dotData: const FlDotData(show: false),
+            spots: _readings
+                .map<FlSpot>(
+                  (e) => FlSpot(
+                      e.dateTime.millisecondsSinceEpoch.toDouble() / 1000 / 60,
+                      e.value),
+                )
+                .toList(),
+          )
+        ],
+        titlesData: FlTitlesData(
+          bottomTitles: getBottomTitles(spots),
+          topTitles: const AxisTitles(sideTitles: SideTitles()),
+          rightTitles: const AxisTitles(sideTitles: SideTitles()),
+        ),
+      ),
+    );
+  }
+
+  AxisTitles getBottomTitles(List<FlSpot> spots) {
+    final maxX = double.parse(
+        spots.map<double>((e) => (e.x)).reduce(max).toStringAsFixed(0));
+    final minX = double.parse(
+        spots.map<double>((e) => e.x).reduce(min).toStringAsFixed(0));
+    final middle =
+        double.parse(spots[spots.length ~/ 2].x.toStringAsFixed(0)) + 4;
+
+    return AxisTitles(
+      sideTitles: SideTitles(
+        interval: 1,
+        showTitles: true,
+        getTitlesWidget: (value, meta) {
+          String text = '';
+          if (value == maxX) {
+            text = getDate(spots.first.x);
+          } else if (double.parse(value.toStringAsFixed(0)) == minX) {
+            text = getDate(spots.last.x);
+          } else if (value == middle) {
+            text = getDate(middle);
+          }
+          return Text(text);
+        },
+      ),
+    );
+  }
+
+  String getDate(double value) {
+    intl.DateFormat hmFormat = intl.DateFormat('Hm');
+    return hmFormat.format(
+        DateTime.fromMillisecondsSinceEpoch((value * 1000 * 60).toInt()));
+  }
+}