update documents

Author: huanghui1998hhh

CHANGELOG.md

@@ -1,5 +1,51 @@
-## newVersion
+## 1.2.0
 * **BUGFIX** (by @imaNNeo) Consider the `enabled` property in [LineTouchData](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/line_chart.md#linetouchdata-read-about-touch-handling), [BarTouchData](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/bar_chart.md#bartouchdata-read-about-touch-handling), [PieTouchData](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/pie_chart.md#pietouchdata-read-about-touch-handling), [ScatterTouchData](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/scatter_chart.md#scattertouchdata-read-about-touch-handling), [RadarTouchData](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/radar_chart.md#radartouchdata-read-about-touch-handling) and [CandlestickTouchData](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/candlestick_chart.md#candlesticktouchdata-read-about-touch-handling), #1676
+* **BREAKING** ⚠️ (by @huanghui1998hhh) Enhanced line chart curve function with a new extensible curve system. Introduced `LineChartCurve` abstract class. You can implement your own curve or use built-in curve: `LineChartCubicTensionCurve`(old curve implementation), and `LineChartCubicMonotoneCurve`.
+**Migration Guide:**
+
+Old API (deprecated):
+```dart
+LineChartBarData(
+  spots: spots,
+  isCurved: true,
+  curveSmoothness: 0.35,
+  preventCurveOverShooting: true,
+  preventCurveOvershootingThreshold: 10.0,
+)
+```
+
+New API:
+```dart
+LineChartBarData(
+  spots: spots,
+  curve: LineChartCurve.cubicTension( // or use LineChartCubicTensionCurve()
+    smoothness: 0.35,
+    preventCurveOverShooting: true,
+    preventCurveOvershootingThreshold: 10.0,
+  ),
+)
+```
+
+Or use the new monotone curve:
+```dart
+LineChartBarData(
+  spots: spots,
+  curve: LineChartCurve.cubicMonotone( // or use LineChartCubicMonotoneCurve()
+    smooth: 0.5,
+    monotone: SmoothMonotone.x,  // Prevents overshooting along X-axis
+  ),
+)
+```
+
+For straight lines (isCurved: false):
+```dart
+LineChartBarData(
+  spots: spots,
+  curve: LineChartCurve.noCurve,  // or omit the curve parameter (default)
+)
+```
+
+Check the updated [LineChart documentation](https://github.com/imaNNeo/fl_chart/blob/main/repo_files/documentations/line_chart.md#linechartcurve) for more details.
 
 ## 1.1.1
 * **IMPROVEMENT** (by @imaNNeo) Upgrade `vector_math` dependency to `2.2.0`, #1985

repo_files/documentations/line_chart.md

@@ -47,10 +47,7 @@ When you change the chart's state, it animates to the new state internally (usin
 |gradient| You can use any [Gradient](https://api.flutter.dev/flutter/dart-ui/Gradient-class.html) here. such as [LinearGradient](https://api.flutter.dev/flutter/painting/LinearGradient-class.html) or [RadialGradient](https://api.flutter.dev/flutter/painting/RadialGradient-class.html)|null|
 |gradientArea| determines the area where the gradient is applied |null|
 |barWidth| gets the stroke width of the line bar|2.0|
-|isCurved| curves the corners of the line on the spot's positions| false|
-|curveSmoothness| smoothness radius of the curve corners (works when isCurved is true) | 0.35|
-|preventCurveOverShooting|prevent overshooting when draw curve line on linear sequence spots, check this [issue](https://github.com/imaNNeo/fl_chart/issues/25)| false|
-|preventCurveOvershootingThreshold|threshold for applying prevent overshooting algorithm | 10.0|
+|curve| determines the curve style for drawing segments between spots (use [LineChartCurve](#LineChartCurve) types)| LineChartCurve.noCurve (straight lines)|
 |isStrokeCapRound| determines whether start and end of the bar line is Qubic or Round | false|
 |isStrokeJoinRound| determines whether stroke joins have a round shape or a sharp edge | false|
 |belowBarData| check the [BarAreaData](#BarAreaData) |BarAreaData|
@@ -63,6 +60,21 @@ When you change the chart's state, it animates to the new state internally (usin
 |lineChartStepData|Holds data for representing a Step Line Chart, and works only if [isStepChart] is true.|[LineChartStepData](#LineChartStepData)()|
 |errorIndicatorData|Holds data for representing an error indicator (you see the error indicators if you provide the `xError` or `yError` in the [FlSpot](base_chart.md#FlSpot)).|[ErrorIndicatorData()](base_chart.md#FlErrorIndicatorData)|
 
+### LineChartCurve
+#### LineChartCubicTensionCurve
+|PropName|Description|default value|
+|:-------|:----------|:------------|
+|smoothness| smoothness radius of the curve corners | 0.35|
+|preventCurveOverShooting|prevent overshooting when draw curve line on linear sequence spots, check this [issue](https://github.com/imaNNeo/fl_chart/issues/25)| false|
+|preventCurveOvershootingThreshold|threshold for applying prevent overshooting algorithm | 10.0|
+
+#### LineChartCubicMonotoneCurve
+|PropName|Description|default value|
+|:-------|:----------|:------------|
+|smooth| determines smoothness of the curve (0.0 = straight, 1.0 = roundest) | 0.5|
+|monotone| monotonicity constraint (none, x, or y) to prevent overshooting along the specified axis | SmoothMonotone.none|
+|tinyThresholdSquared| squared distance threshold to draw straight line when points are too close (avoids jitter) | 0.5|
+
 ### LineChartStepData
 |PropName|Description|default value|
 |:-------|:----------|:------------|