Bugfix/chart memory leak

CHANGELOG.md

@@ -1,3 +1,6 @@
+## newVersion
+* **BUGFIX** Fix a memory leak issue in the axis-based charts, there was a logic to calculate and cache the minX, maxX, minY and maxY properties to reduce the computation cost. But it caused some memory issues, as we don't have a quick solution for this, we disabled the caching logic for now, later we can move the calculation logic to the render objects to keep and update them only when the data is changed, #1106, #1693
+
 ## 0.68.0
 * **Improvement** (by @imaNNeo) Update LineChartSample6 to implement a way to show a tooltip on a single spot, #1620
 * **Feature** (by @herna) Add `titleSunbeamLayout` inside the [BarChartData](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/bar_chart.md#barchartdata) to allow the user to customize the layout of the title sunbeam

lib/src/chart/bar_chart/bar_chart.dart

@@ -86,10 +86,11 @@ class _BarChartState extends AnimatedWidgetBaseState<BarChart> {
   BarChartData _getData() {
     var newData = widget.data;
     if (newData.minY.isNaN || newData.maxY.isNaN) {
-      final values = _barChartHelper.calculateMaxAxisValues(newData.barGroups);
+      final (minY, maxY) =
+          _barChartHelper.calculateMaxAxisValues(newData.barGroups);
       newData = newData.copyWith(
-        minY: newData.minY.isNaN ? values.minY : newData.minY,
-        maxY: newData.maxY.isNaN ? values.maxY : newData.maxY,
+        minY: newData.minY.isNaN ? minY : newData.minY,
+        maxY: newData.maxY.isNaN ? maxY : newData.maxY,
       );
     }
 

lib/src/chart/bar_chart/bar_chart_helper.dart

@@ -1,38 +1,24 @@
 import 'dart:math';
 
-import 'package:equatable/equatable.dart';
 import 'package:fl_chart/src/chart/bar_chart/bar_chart_data.dart';
-import 'package:fl_chart/src/utils/list_wrapper.dart';
 
 /// Contains anything that helps BarChart works
 class BarChartHelper {
-  /// Contains List of cached results, base on [List<BarChartGroupData>]
-  ///
-  /// We use it to prevent redundant calculations
-  final Map<ListWrapper<BarChartGroupData>, BarChartMinMaxAxisValues>
-      _cachedResults = {};
-
   /// Calculates minY, and maxY based on [barGroups],
   /// returns cached values, to prevent redundant calculations.
-  BarChartMinMaxAxisValues calculateMaxAxisValues(
+  (double minY, double maxY) calculateMaxAxisValues(
     List<BarChartGroupData> barGroups,
   ) {
     if (barGroups.isEmpty) {
-      return BarChartMinMaxAxisValues(0, 0);
-    }
-
-    final listWrapper = barGroups.toWrapperClass();
-
-    if (_cachedResults.containsKey(listWrapper)) {
-      return _cachedResults[listWrapper]!.copyWith(readFromCache: true);
+      return (0, 0);
     }
 
     final BarChartGroupData barGroup;
     try {
       barGroup = barGroups.firstWhere((element) => element.barRods.isNotEmpty);
     } catch (e) {
       // There is no barChartGroupData with at least one barRod
-      return BarChartMinMaxAxisValues(0, 0);
+      return (0, 0);
     }
 
     var maxY = max(barGroup.barRods[0].fromY, barGroup.barRods[0].toY);
@@ -57,33 +43,6 @@ class BarChartHelper {
         }
       }
     }
-
-    final result = BarChartMinMaxAxisValues(minY, maxY);
-    _cachedResults[listWrapper] = result;
-    return result;
-  }
-}
-
-/// Holds minY, and maxY for use in [BarChartData]
-class BarChartMinMaxAxisValues with EquatableMixin {
-  BarChartMinMaxAxisValues(this.minY, this.maxY, {this.readFromCache = false});
-
-  final double minY;
-  final double maxY;
-  final bool readFromCache;
-
-  @override
-  List<Object?> get props => [minY, maxY, readFromCache];
-
-  BarChartMinMaxAxisValues copyWith({
-    double? minY,
-    double? maxY,
-    bool? readFromCache,
-  }) {
-    return BarChartMinMaxAxisValues(
-      minY ?? this.minY,
-      maxY ?? this.maxY,
-      readFromCache: readFromCache ?? this.readFromCache,
-    );
+    return (minY, maxY);
   }
 }

lib/src/chart/line_chart/line_chart.dart

@@ -87,14 +87,14 @@ class _LineChartState extends AnimatedWidgetBaseState<LineChart> {
         newData.maxX.isNaN ||
         newData.minY.isNaN ||
         newData.maxY.isNaN) {
-      final values = _lineChartHelper.calculateMaxAxisValues(
+      final (minX, maxX, minY, maxY) = _lineChartHelper.calculateMaxAxisValues(
         newData.lineBarsData,
       );
       newData = newData.copyWith(
-        minX: newData.minX.isNaN ? values.minX : newData.minX,
-        maxX: newData.maxX.isNaN ? values.maxX : newData.maxX,
-        minY: newData.minY.isNaN ? values.minY : newData.minY,
-        maxY: newData.maxY.isNaN ? values.maxY : newData.maxY,
+        minX: newData.minX.isNaN ? minX : newData.minX,
+        maxX: newData.maxX.isNaN ? maxX : newData.maxX,
+        minY: newData.minY.isNaN ? minY : newData.minY,
+        maxY: newData.maxY.isNaN ? maxY : newData.maxY,
       );
     }
 

lib/src/chart/line_chart/line_chart_helper.dart

@@ -1,26 +1,14 @@
-import 'package:equatable/equatable.dart';
 import 'package:fl_chart/fl_chart.dart';
-import 'package:fl_chart/src/utils/list_wrapper.dart';
 
 /// Contains anything that helps LineChart works
 class LineChartHelper {
-  /// Contains List of cached results, base on [List<LineChartBarData>]
-  ///
-  /// We use it to prevent redundant calculations
-  final Map<ListWrapper<LineChartBarData>, LineChartMinMaxAxisValues>
-      _cachedResults = {};
-
-  LineChartMinMaxAxisValues calculateMaxAxisValues(
+  /// Calculates the [minX], [maxX], [minY], and [maxY] values of
+  /// the provided [lineBarsData].
+  (double minX, double maxX, double minY, double maxY) calculateMaxAxisValues(
     List<LineChartBarData> lineBarsData,
   ) {
     if (lineBarsData.isEmpty) {
-      return const LineChartMinMaxAxisValues(0, 0, 0, 0);
-    }
-
-    final listWrapper = lineBarsData.toWrapperClass();
-
-    if (_cachedResults.containsKey(listWrapper)) {
-      return _cachedResults[listWrapper]!.copyWith(readFromCache: true);
+      return (0, 0, 0, 0);
     }
 
     final LineChartBarData lineBarData;
@@ -29,7 +17,7 @@ class LineChartHelper {
           lineBarsData.firstWhere((element) => element.spots.isNotEmpty);
     } catch (e) {
       // There is no lineBarData with at least one spot
-      return const LineChartMinMaxAxisValues(0, 0, 0, 0);
+      return (0, 0, 0, 0);
     }
 
     final FlSpot firstValidSpot;
@@ -38,7 +26,7 @@ class LineChartHelper {
           lineBarData.spots.firstWhere((element) => element != FlSpot.nullSpot);
     } catch (e) {
       // There is no valid spot
-      return const LineChartMinMaxAxisValues(0, 0, 0, 0);
+      return (0, 0, 0, 0);
     }
 
     var minX = firstValidSpot.x;
@@ -68,43 +56,6 @@ class LineChartHelper {
       }
     }
 
-    final result = LineChartMinMaxAxisValues(minX, maxX, minY, maxY);
-    _cachedResults[listWrapper] = result;
-    return result;
-  }
-}
-
-/// Holds minX, maxX, minY, and maxY for use in [LineChartData]
-class LineChartMinMaxAxisValues with EquatableMixin {
-  const LineChartMinMaxAxisValues(
-    this.minX,
-    this.maxX,
-    this.minY,
-    this.maxY, {
-    this.readFromCache = false,
-  });
-  final double minX;
-  final double maxX;
-  final double minY;
-  final double maxY;
-  final bool readFromCache;
-
-  @override
-  List<Object?> get props => [minX, maxX, minY, maxY, readFromCache];
-
-  LineChartMinMaxAxisValues copyWith({
-    double? minX,
-    double? maxX,
-    double? minY,
-    double? maxY,
-    bool? readFromCache,
-  }) {
-    return LineChartMinMaxAxisValues(
-      minX ?? this.minX,
-      maxX ?? this.maxX,
-      minY ?? this.minY,
-      maxY ?? this.maxY,
-      readFromCache: readFromCache ?? this.readFromCache,
-    );
+    return (minX, maxX, minY, maxY);
   }
 }

lib/src/chart/scatter_chart/scatter_chart_data.dart

@@ -61,19 +61,19 @@ class ScatterChartData extends AxisChartData with EquatableMixin {
           minX: minX ??
               ScatterChartHelper.calculateMaxAxisValues(
                 scatterSpots ?? const [],
-              ).minX,
+              ).$1,
           maxX: maxX ??
               ScatterChartHelper.calculateMaxAxisValues(
                 scatterSpots ?? const [],
-              ).maxX,
+              ).$2,
           minY: minY ??
               ScatterChartHelper.calculateMaxAxisValues(
                 scatterSpots ?? const [],
-              ).minY,
+              ).$3,
           maxY: maxY ??
               ScatterChartHelper.calculateMaxAxisValues(
                 scatterSpots ?? const [],
-              ).maxY,
+              ).$4,
         );
   final List<ScatterSpot> scatterSpots;
   final ScatterTouchData scatterTouchData;

lib/src/chart/scatter_chart/scatter_chart_helper.dart

@@ -1,28 +1,19 @@
-import 'package:equatable/equatable.dart';
 import 'package:fl_chart/src/chart/scatter_chart/scatter_chart_data.dart';
-import 'package:fl_chart/src/utils/list_wrapper.dart';
 
 /// Contains anything that helps ScatterChart works
 class ScatterChartHelper {
-  /// Contains List of cached results, base on [List<ScatterSpot>]
-  ///
-  /// We use it to prevent redundant calculations
-  static final Map<ListWrapper<ScatterSpot>, ScatterChartMinMaxAxisValues>
-      _cachedResults = {};
-
   /// Calculates minX, maxX, minY, and maxY based on [scatterSpots],
   /// returns cached values, to prevent redundant calculations.
-  static ScatterChartMinMaxAxisValues calculateMaxAxisValues(
+  static (
+    double minX,
+    double maxX,
+    double minY,
+    double maxY,
+  ) calculateMaxAxisValues(
     List<ScatterSpot> scatterSpots,
   ) {
     if (scatterSpots.isEmpty) {
-      return ScatterChartMinMaxAxisValues(0, 0, 0, 0);
-    }
-
-    final listWrapper = scatterSpots.toWrapperClass();
-
-    if (_cachedResults.containsKey(listWrapper)) {
-      return _cachedResults[listWrapper]!.copyWith(readFromCache: true);
+      return (0, 0, 0, 0);
     }
 
     var minX = scatterSpots[0].x;
@@ -47,44 +38,6 @@ class ScatterChartHelper {
         minY = spot.y;
       }
     }
-
-    final result = ScatterChartMinMaxAxisValues(minX, maxX, minY, maxY);
-    _cachedResults[listWrapper] = result;
-    return result;
-  }
-}
-
-/// Holds minX, maxX, minY, and maxY for use in [ScatterChartData]
-class ScatterChartMinMaxAxisValues with EquatableMixin {
-  ScatterChartMinMaxAxisValues(
-    this.minX,
-    this.maxX,
-    this.minY,
-    this.maxY, {
-    this.readFromCache = false,
-  });
-  final double minX;
-  final double maxX;
-  final double minY;
-  final double maxY;
-  final bool readFromCache;
-
-  @override
-  List<Object?> get props => [minX, maxX, minY, maxY, readFromCache];
-
-  ScatterChartMinMaxAxisValues copyWith({
-    double? minX,
-    double? maxX,
-    double? minY,
-    double? maxY,
-    bool? readFromCache,
-  }) {
-    return ScatterChartMinMaxAxisValues(
-      minX ?? this.minX,
-      maxX ?? this.maxX,
-      minY ?? this.minY,
-      maxY ?? this.maxY,
-      readFromCache: readFromCache ?? this.readFromCache,
-    );
+    return (minX, maxX, minY, maxY);
   }
 }

repo_files/documentations/bar_chart.md

@@ -27,8 +27,8 @@ When you change the chart's state, it animates to the new state internally (usin
 |barTouchData| [BarTouchData](#bartouchdata-read-about-touch-handling) holds the touch interactivity details|BarTouchData()|
 |gridData| check the [FlGridData](base_chart.md#FlGridData)|FlGridData()|
 |borderData| check the [FlBorderData](base_chart.md#FlBorderData)|FlBorderData()|
-|maxY| gets maximum y of y axis, if null, value will be read from the input barGroups | null|
-|minY| gets minimum y of y axis, if null, value will be read from the input barGroups | null|
+|maxY| gets maximum y of y axis, if null, value will be read from the input barGroups (But it is more performant if you provide them) | null|
+|minY| gets minimum y of y axis, if null, value will be read from the input barGroups (But it is more performant if you provide them) | null|
 |baselineY| defines the baseline of y-axis | 0|
 |extraLinesData| allows extra horizontal lines to be drawn on the chart. Vertical lines are ignored when used with BarChartData, please see [#1149](https://github.com/imaNNeo/fl_chart/issues/1149), check [ExtraLinesData](base_chart.md#ExtraLinesData)|ExtraLinesData()|
 

repo_files/documentations/line_chart.md

@@ -26,11 +26,11 @@ When you change the chart's state, it animates to the new state internally (usin
 |showingTooltipIndicators| show the tooltip based on provided list of [LineBarSpot](#LineBarSpot), The point is that you need to disable touches to show these tooltips manually| [] |
 |gridData| check the [FlGridData](base_chart.md#FlGridData)|FlGridData()|
 |borderData| check the [FlBorderData](base_chart.md#FlBorderData)|FlBorderData()|
-|minX| gets minimum x of x axis, if null, value will read from the input lineBars |null|
-|maxX| gets maximum x of x axis, if null, value will read from the input lineBars | null|
+|minX| gets minimum x of x axis, if null, value will read from the input lineBars (But it is more performant if you provide them)|null|
+|maxX| gets maximum x of x axis, if null, value will read from the input lineBars (But it is more performant if you provide them)| null|
 |baselineX| defines the baseline of x-axis | 0|
-|minY| gets minimum y of y axis, if null, value will read from the input lineBars | null|
-|maxY| gets maximum y of y axis, if null, value will read from the input lineBars | null|
+|minY| gets minimum y of y axis, if null, value will read from the input lineBars (But it is more performant if you provide them)| null|
+|maxY| gets maximum y of y axis, if null, value will read from the input lineBars (But it is more performant if you provide them)| null|
 |baselineY| defines the baseline of y-axis | 0|
 |clipData| clip the chart to the border (prevent drawing outside the border) | FlClipData.none()|
 |backgroundColor| a background color which is drawn behind th chart| null |