Move fitInside offset calculation to AxisChartHelper

Author: dhiyaaulauliyaa

lib/src/chart/base/axis_chart/axis_chart_helper.dart

@@ -1,4 +1,6 @@
+import 'package:fl_chart/fl_chart.dart';
 import 'package:fl_chart/src/utils/utils.dart';
+import 'package:flutter/material.dart';
 
 class AxisChartHelper {
  factory AxisChartHelper() {
@@ -51,4 +53,52 @@ class AxisChartHelper {
  yield max;
  }
  }
+
+ /// Calculate translate offset to keep [SideTitle] child
+ /// placed inside its corresponding axis.
+ /// The offset will translate the child to the closest edge inside
+ /// of the corresponding axis bounding box
+ Offset calcFitInsideOffset({
+ required AxisSide axisSide,
+ required double? childSize,
+ required double parentAxisSize,
+ required double axisPosition,
+ required double distanceFromEdge,
+ }) {
+ if (childSize == null) return Offset.zero;
+
+ // Find title alignment along its axis
+ final axisMid = parentAxisSize / 2;
+ final mainAxisAligment = (axisPosition - axisMid).isNegative
+ ? MainAxisAlignment.start
+ : MainAxisAlignment.end;
+
+ // Find if child widget overflowed outside the chart
+ late bool isOverflowed;
+ if (mainAxisAligment == MainAxisAlignment.start) {
+ isOverflowed = (axisPosition - (childSize / 2)).isNegative;
+ } else {
+ isOverflowed = (axisPosition + (childSize / 2)) > parentAxisSize;
+ }
+
+ if (isOverflowed == false) return Offset.zero;
+
+ // Calc offset if child overflowed
+ late double offset;
+ if (mainAxisAligment == MainAxisAlignment.start) {
+ offset = (childSize / 2) - axisPosition + distanceFromEdge;
+ } else {
+ offset =
+ -(childSize / 2) + (parentAxisSize - axisPosition) - distanceFromEdge;
+ }
+
+ switch (axisSide) {
+ case AxisSide.left:
+ case AxisSide.right:
+ return Offset(0, offset);
+ case AxisSide.top:
+ case AxisSide.bottom:
+ return Offset(offset, 0);
+ }
+ }
 }

lib/src/chart/base/axis_chart/axis_chart_widgets.dart

@@ -1,4 +1,5 @@
 import 'package:fl_chart/fl_chart.dart';
+import 'package:fl_chart/src/chart/base/axis_chart/axis_chart_helper.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
 
@@ -62,8 +63,6 @@ class _SideTitleWidgetState extends State<SideTitleWidget> {
  return Alignment.centerLeft;
  case AxisSide.bottom:
  return Alignment.topCenter;
- default:
- throw StateError('Invalid side');
  }
  }
 
@@ -77,64 +76,12 @@ class _SideTitleWidgetState extends State<SideTitleWidget> {
  return EdgeInsets.only(left: widget.space);
  case AxisSide.bottom:
  return EdgeInsets.only(top: widget.space);
- default:
- throw StateError('Invalid side');
- }
- }
-
- /// Calculate translate offset to keep child
- /// placed inside its corresponding axis.
- /// The offset will translate the child to the closest edge inside
- /// of the parent
- Offset _getOffset() {
- if (!widget.fitInside.enabled || _childSize == null) return Offset.zero;
-
- final parentAxisSize = widget.fitInside.parentAxisSize;
- final axisPosition = widget.fitInside.axisPosition;
-
- // Find title alignment along its axis
- final axisMid = parentAxisSize / 2;
- final mainAxisAligment = (axisPosition - axisMid).isNegative
- ? MainAxisAlignment.start
- : MainAxisAlignment.end;
-
- // Find if child widget overflowed outside the chart
- final childSize = _childSize!;
- late bool isOverflowed;
- if (mainAxisAligment == MainAxisAlignment.start) {
- isOverflowed = (axisPosition - (childSize / 2)).isNegative;
- } else {
- isOverflowed = (axisPosition + (childSize / 2)) > parentAxisSize;
- }
-
- if (isOverflowed == false) return Offset.zero;
-
- // Calc offset if child overflowed
- late double offset;
- if (mainAxisAligment == MainAxisAlignment.start) {
- offset =
- (childSize / 2) - axisPosition + widget.fitInside.distanceFromEdge;
- } else {
- offset = -(childSize / 2) +
- (parentAxisSize - axisPosition) -
- widget.fitInside.distanceFromEdge;
- }
-
- switch (widget.axisSide) {
- case AxisSide.left:
- case AxisSide.right:
- return Offset(0, offset);
- case AxisSide.top:
- case AxisSide.bottom:
- return Offset(offset, 0);
  }
  }
 
  /// Calculate child width/height
  final GlobalKey widgetKey = GlobalKey();
-
  double? _childSize;
-
  void _getChildSize(_) {
  // If fitInside is false, no need to find child size
  if (!widget.fitInside.enabled) return;
@@ -179,7 +126,15 @@ class _SideTitleWidgetState extends State<SideTitleWidget> {
  @override
  Widget build(BuildContext context) {
  return Transform.translate(
- offset: _getOffset(),
+ offset: !widget.fitInside.enabled
+ ? Offset.zero
+ : AxisChartHelper().calcFitInsideOffset(
+ axisSide: widget.axisSide,
+ childSize: _childSize,
+ parentAxisSize: widget.fitInside.parentAxisSize,
+ axisPosition: widget.fitInside.axisPosition,
+ distanceFromEdge: widget.fitInside.distanceFromEdge,
+ ),
  child: Transform.rotate(
  angle: widget.angle,
  child: Container(