WIP: Feature/error indicator

.gitignore

@@ -18,3 +18,6 @@ example/android/app/.settings/org.eclipse.buildship.core.prefs
 example/macos/Flutter/ephemeral/
 coverage/
 .fvm/
+
+# Files generated by dart tools
+.dart_tool

CHANGELOG.md

@@ -1,3 +1,6 @@
+## newVersion
+* **FEATURE** (by @imaNNeo) Add error range feature in our axis-based charts. You can set `xError` and `yError` in the [FlSpot](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/base_chart.md#flspot) or `toYErrorRange` in [BarChartRodData](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/bar_chart.md#barchartroddata). Also we have `errorIndicatorData` property in our [LineChartData](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/line_chart.md#linechartdata), [BarChartData](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/bar_chart.md#barchartdata) and [ScatterChartData](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/scatter_chart.md#scatterchartdata) that is responsible to render the error bars. You can take a look at the [LineChartSample 13](https://github.com/imaNNeo/fl_chart/blob/main/example/lib/presentation/samples/line/line_chart_sample13.dart) and [BarChartSample 8](https://github.com/imaNNeo/fl_chart/blob/main/example/lib/presentation/samples/bar/bar_chart_sample8.dart) in our [sample app](https://app.flchart.dev), #1483 
+
 ## 0.70.1
 * **FEATURE** (by @Peetee06) Add `panEnabled` and `scaleEnabled` properties in the TransformationController, #1818
 * **FEATURE** (by @mitulagr2) Add `renderPriority` feature in our [ScatterSpot](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/scatter_chart.md#scatterspot), #1545

Makefile

@@ -1,14 +1,20 @@
+ifeq ($(OS),Windows_NT)
+  FIND_CMD=dir /S /B lib\*.dart test\*.dart | findstr /V .mocks.dart
+else
+  FIND_CMD=find lib test -name '*.dart' -not -name '*.mocks.dart'
+endif
+
 analyze:
 	flutter analyze
 
 checkFormat:
-	dart format -o none --set-exit-if-changed .
+	dart format -o none --set-exit-if-changed $$( $(FIND_CMD) )
 
 checkstyle:
 	make analyze && make checkFormat
 
 format:
-	dart format .
+	dart format $$( $(FIND_CMD) )
 
 runTests:
 	flutter test
@@ -27,7 +33,7 @@ sure:
 
 # To create generated files (for example mock files in unit_tests)
 codeGen:
-	flutter pub run build_runner build --delete-conflicting-outputs
+	dart run build_runner build --delete-conflicting-outputs
 
 showTestCoverage:
 	flutter test --coverage

example/lib/presentation/samples/bar/bar_chart_sample8.dart

@@ -61,12 +61,14 @@ class BarChartSample1State extends State<BarChartSample8> {
   BarChartGroupData makeGroupData(
     int x,
     double y,
+    FlErrorRange errorRange,
   ) {
     return BarChartGroupData(
       x: x,
       barRods: [
         BarChartRodData(
           toY: y,
+          toYErrorRange: errorRange,
           color: x >= 4 ? Colors.transparent : widget.barColor,
           borderRadius: BorderRadius.zero,
           borderDashArray: x >= 4 ? [4, 4] : null,
@@ -134,12 +136,39 @@ class BarChartSample1State extends State<BarChartSample8> {
       ),
       barGroups: List.generate(
         7,
-        (i) => makeGroupData(
-          i,
-          Random().nextInt(290).toDouble() + 10,
-        ),
+        (i) {
+          final y = Random().nextInt(290).toDouble() + 10;
+          final lowerBy = y < 50
+              ? Random().nextDouble() * 10
+              : Random().nextDouble() * 30 + 5;
+          final upperBy = y > 290
+              ? Random().nextDouble() * 10
+              : Random().nextDouble() * 30 + 5;
+          return makeGroupData(
+            i,
+            y,
+            FlErrorRange(
+              lowerBy: lowerBy,
+              upperBy: upperBy,
+            ),
+          );
+        },
       ),
       gridData: const FlGridData(show: false),
+      errorIndicatorData: FlErrorIndicatorData(
+        painter: _errorPainter,
+      ),
     );
   }
+
+  FlSpotErrorRangePainter _errorPainter(
+    BarChartSpotErrorRangeCallbackInput input,
+  ) =>
+      FlSimpleErrorPainter(
+        lineWidth: 2.0,
+        capLength: 14,
+        lineColor: input.groupIndex < 4
+            ? AppColors.contentColorOrange
+            : AppColors.primary.withValues(alpha: 0.5),
+      );
 }

example/lib/presentation/samples/chart_samples.dart

@@ -13,6 +13,7 @@ import 'line/line_chart_sample1.dart';
 import 'line/line_chart_sample10.dart';
 import 'line/line_chart_sample11.dart';
 import 'line/line_chart_sample12.dart';
+import 'line/line_chart_sample13.dart';
 import 'line/line_chart_sample2.dart';
 import 'line/line_chart_sample3.dart';
 import 'line/line_chart_sample4.dart';
@@ -43,6 +44,7 @@ class ChartSamples {
       LineChartSample(10, (context) => const LineChartSample10()),
       LineChartSample(11, (context) => const LineChartSample11()),
       LineChartSample(12, (context) => const LineChartSample12()),
+      LineChartSample(13, (context) => const LineChartSample13()),
     ],
     ChartType.bar: [
       BarChartSample(1, (context) => BarChartSample1()),