Fix pieChart drawing single section on iPhone, #1515

CHANGELOG.md

@@ -24,6 +24,7 @@ ScatterSpot(
 ),
 ```
 * **BUGFIX** (by @imaNNeo) Fix barChart tooltip for values below or above the 0 point, #1462
+* **BUGFIX** (by @imaNNeo) Fix pieChart drawing single section on iPhone, #1515
 
 ## 0.65.0
 * **FEATURE** (by @Dartek12) Added gradient to [FlLine](https://github.com/imaNNeo/fl_chart/blob/master/repo_files/documentations/base_chart.md#FlLine), #1197

lib/src/chart/pie_chart/pie_chart_painter.dart

@@ -21,11 +21,15 @@ class PieChartPainter extends BaseChartPainter<PieChartData> {
   PieChartPainter() : super() {
     _sectionPaint = Paint()..style = PaintingStyle.stroke;
 
+    _sectionSaveLayerPaint = Paint();
+
     _sectionStrokePaint = Paint()..style = PaintingStyle.stroke;
 
     _centerSpacePaint = Paint()..style = PaintingStyle.fill;
   }
+
   late Paint _sectionPaint;
+  late Paint _sectionSaveLayerPaint;
   late Paint _sectionStrokePaint;
   late Paint _centerSpacePaint;
 
@@ -100,13 +104,24 @@ class PieChartPainter extends BaseChartPainter<PieChartData> {
       if (sectionDegree == 360) {
         _sectionPaint
           ..color = section.color
-          ..strokeWidth = section.radius
-          ..style = PaintingStyle.stroke;
-        canvasWrapper.drawCircle(
-          center,
-          centerRadius + section.radius / 2,
-          _sectionPaint,
+          ..style = PaintingStyle.fill;
+        final bounds = Rect.fromCircle(
+          center: center,
+          radius: centerRadius + section.radius,
         );
+        canvasWrapper
+          ..saveLayer(bounds, _sectionSaveLayerPaint)
+          ..drawCircle(
+            center,
+            centerRadius + section.radius,
+            _sectionPaint..blendMode = BlendMode.srcOver,
+          )
+          ..drawCircle(
+            center,
+            centerRadius,
+            _sectionPaint..blendMode = BlendMode.srcOut,
+          )
+          ..restore();
         if (section.borderSide.width != 0.0 &&
             section.borderSide.color.opacity != 0.0) {
           _sectionStrokePaint

test/chart/pie_chart/pie_chart_painter_test.dart

@@ -117,10 +117,12 @@ void main() {
     test('test 1', () {
       const viewSize = Size(200, 200);
 
+      const radius = 30.0;
+      const centerSpace = 10.0;
       final sections = [
         PieChartSectionData(
           color: MockData.color2,
-          radius: 30,
+          radius: radius,
           value: 10,
           borderSide: const BorderSide(
             color: MockData.color3,
@@ -141,17 +143,31 @@ void main() {
       when(mockCanvasWrapper.canvas).thenReturn(MockCanvas());
       barChartPainter.drawSections(mockCanvasWrapper, [360], 10, holder);
 
-      final result = verify(
+      final rect = Rect.fromCircle(
+        center: viewSize.center(Offset.zero),
+        radius: radius + centerSpace,
+      );
+      final results = verifyInOrder([
+        mockCanvasWrapper.saveLayer(
+          rect,
+          any,
+        ),
         mockCanvasWrapper.drawCircle(
           const Offset(100, 100),
-          10 + 15,
+          10 + 30,
           captureAny,
         ),
-      );
+        mockCanvasWrapper.drawCircle(
+          const Offset(100, 100),
+          10,
+          captureAny,
+        ),
+        mockCanvasWrapper.restore(),
+      ]);
+      final result = results[1];
       expect(result.callCount, 1);
       expect((result.captured.single as Paint).color, MockData.color2);
-      expect((result.captured.single as Paint).strokeWidth, 30);
-      expect((result.captured.single as Paint).style, PaintingStyle.stroke);
+      expect((result.captured.single as Paint).style, PaintingStyle.fill);
 
       final result2 = verify(
         mockCanvasWrapper.drawCircle(