Implement lerp method for FlDotPainter

imaNNeo · Dec 3, 2023 · 59e58a8 · 59e58a8
1 parent 711824c
commit 59e58a8
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Showing 3 changed files with 121 additions and 14 deletions.
diff --git a/lib/src/chart/line_chart/line_chart_data.dart b/lib/src/chart/line_chart/line_chart_data.dart
@@ -808,6 +808,8 @@ abstract class FlDotPainter with EquatableMixin {
 
   /// Used to show default UIs, for example [defaultScatterTooltipItem]
   Color get mainColor;
+
+  FlDotPainter lerp(FlDotPainter a, FlDotPainter b, double t);
 }
 
 /// This class is an implementation of a [FlDotPainter] that draws
@@ -876,6 +878,27 @@ class FlDotCirclePainter extends FlDotPainter {
         strokeColor,
         strokeWidth,
       ];
+
+  FlDotCirclePainter _lerp(
+    FlDotCirclePainter a,
+    FlDotCirclePainter b,
+    double t,
+  ) {
+    return FlDotCirclePainter(
+      color: Color.lerp(a.color, b.color, t)!,
+      radius: lerpDouble(a.radius, b.radius, t),
+      strokeColor: Color.lerp(a.strokeColor, b.strokeColor, t)!,
+      strokeWidth: lerpDouble(a.strokeWidth, b.strokeWidth, t)!,
+    );
+  }
+
+  @override
+  FlDotPainter lerp(FlDotPainter a, FlDotPainter b, double t) {
+    if (a is! FlDotCirclePainter || b is! FlDotCirclePainter) {
+      return b;
+    }
+    return _lerp(a, b, t);
+  }
 }
 
 /// This class is an implementation of a [FlDotPainter] that draws
@@ -948,6 +971,27 @@ class FlDotSquarePainter extends FlDotPainter {
         strokeColor,
         strokeWidth,
       ];
+
+  FlDotSquarePainter _lerp(
+    FlDotSquarePainter a,
+    FlDotSquarePainter b,
+    double t,
+  ) {
+    return FlDotSquarePainter(
+      color: Color.lerp(a.color, b.color, t)!,
+      size: lerpDouble(a.size, b.size, t)!,
+      strokeColor: Color.lerp(a.strokeColor, b.strokeColor, t)!,
+      strokeWidth: lerpDouble(a.strokeWidth, b.strokeWidth, t)!,
+    );
+  }
+
+  @override
+  FlDotPainter lerp(FlDotPainter a, FlDotPainter b, double t) {
+    if (a is! FlDotSquarePainter || b is! FlDotSquarePainter) {
+      return b;
+    }
+    return _lerp(a, b, t);
+  }
 }
 
 /// This class is an implementation of a [FlDotPainter] that draws
@@ -998,6 +1042,26 @@ class FlDotCrossPainter extends FlDotPainter {
   @override
   Color get mainColor => color;
 
+  FlDotCrossPainter _lerp(
+    FlDotCrossPainter a,
+    FlDotCrossPainter b,
+    double t,
+  ) {
+    return FlDotCrossPainter(
+      color: Color.lerp(a.color, b.color, t)!,
+      size: lerpDouble(a.size, b.size, t)!,
+      width: lerpDouble(a.width, b.width, t)!,
+    );
+  }
+
+  @override
+  FlDotPainter lerp(FlDotPainter a, FlDotPainter b, double t) {
+    if (a is! FlDotCrossPainter || b is! FlDotCrossPainter) {
+      return b;
+    }
+    return _lerp(a, b, t);
+  }
+
   /// Used for equality check, see [EquatableMixin].
   @override
   List<Object?> get props => [

diff --git a/lib/src/chart/scatter_chart/scatter_chart_data.dart b/lib/src/chart/scatter_chart/scatter_chart_data.dart
@@ -232,7 +232,7 @@ class ScatterSpot extends FlSpot with EquatableMixin {
       lerpDouble(a.x, b.x, t)!,
       lerpDouble(a.y, b.y, t)!,
       show: b.show,
-      dotPainter: t == 0 ? a.dotPainter : b.dotPainter,
+      dotPainter: a.dotPainter.lerp(a.dotPainter, b.dotPainter, t),
     );
   }
 

diff --git a/test/chart/scatter_chart/scatter_chart_painter_test.dart b/test/chart/scatter_chart/scatter_chart_painter_test.dart
@@ -106,9 +106,27 @@ void main() {
         holder,
       );
 
-      verify(mockCanvasWrapper.drawDot(dotPainter1, spot1, const Offset(10, 90))).called(1);
-      verify(mockCanvasWrapper.drawDot(dotPainter3, spot3, const Offset(80, 80))).called(1);
-      verify(mockCanvasWrapper.drawDot(dotPainter4, spot4, const Offset(70, 50))).called(1);
+      verify(
+        mockCanvasWrapper.drawDot(
+          dotPainter1,
+          spot1,
+          const Offset(10, 90),
+        ),
+      ).called(1);
+      verify(
+        mockCanvasWrapper.drawDot(
+          dotPainter3,
+          spot3,
+          const Offset(80, 80),
+        ),
+      ).called(1);
+      verify(
+        mockCanvasWrapper.drawDot(
+          dotPainter4,
+          spot4,
+          const Offset(70, 50),
+        ),
+      ).called(1);
 
       verifyNever(mockCanvasWrapper.drawText(any, any));
       verify(mockCanvasWrapper.clipRect(any)).called(1);
@@ -210,16 +228,41 @@ void main() {
         holder,
       );
 
-      verify(mockCanvasWrapper.drawDot(any, data.scatterSpots[0], const Offset(10, 90)))
-          .called(1);
-      verify(mockCanvasWrapper.drawDot(any, data.scatterSpots[1], const Offset(20, 80)))
-          .called(1);
-      verify(mockCanvasWrapper.drawDot(any, data.scatterSpots[3], const Offset(80, 20)))
-          .called(1);
-      verify(mockCanvasWrapper.drawDot(any, data.scatterSpots[4], const Offset(70, 50)))
-          .called(1);
-      verify(mockCanvasWrapper.drawDot(any, data.scatterSpots[5], const Offset(40, 40)))
-          .called(1);
+      verify(
+        mockCanvasWrapper.drawDot(
+          any,
+          data.scatterSpots[0],
+          const Offset(10, 90),
+        ),
+      ).called(1);
+      verify(
+        mockCanvasWrapper.drawDot(
+          any,
+          data.scatterSpots[1],
+          const Offset(20, 80),
+        ),
+      ).called(1);
+      verify(
+        mockCanvasWrapper.drawDot(
+          any,
+          data.scatterSpots[3],
+          const Offset(80, 20),
+        ),
+      ).called(1);
+      verify(
+        mockCanvasWrapper.drawDot(
+          any,
+          data.scatterSpots[4],
+          const Offset(70, 50),
+        ),
+      ).called(1);
+      verify(
+        mockCanvasWrapper.drawDot(
+          any,
+          data.scatterSpots[5],
+          const Offset(40, 40),
+        ),
+      ).called(1);
 
       verify(mockCanvasWrapper.drawText(any, any)).called(4);