CHORE: refractor code

lib/flutter_highlight.dart

@@ -1,20 +1,38 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 
-@immutable
+part 'src/flutter_highlight_filter.dart';
+part 'src/flutter_highlight_render.dart';
+
 class FlutterHighlight extends StatefulWidget {
+  /// Duration of the animation.
   final Duration duration;
+
+  /// Number of times the animation goes forward and reverse.
   final int blinkNumber;
+
+  /// Color of the highlight.
   final Color? color;
+
+  /// Minimum highlight opacity.
+  final double minOpacity;
+
+  /// Maximum highlight opacity.
+  final double maxOpacity;
+
   final Widget child;
 
   const FlutterHighlight({
     super.key,
     required this.duration,
     this.blinkNumber = 3,
+    this.minOpacity = 0.0,
+    this.maxOpacity = 0.6,
     this.color,
     required this.child,
-  });
+  }) : assert(blinkNumber >= 1),
+       assert(minOpacity >= 0.0),
+       assert(maxOpacity <= 1.0);
 
   @override
   State<FlutterHighlight> createState() => _FlutterHighlightState();
@@ -27,9 +45,9 @@ class _FlutterHighlightState extends State<FlutterHighlight>
   Future<void> _runAnimation() async {
     int count = 0;
     while (count < widget.blinkNumber) {
+      count++;
       await _animationController.forward();
       await _animationController.reverse();
-      count++;
     }
   }
 
@@ -39,7 +57,8 @@ class _FlutterHighlightState extends State<FlutterHighlight>
     _animationController = AnimationController(
       vsync: this,
       duration: widget.duration,
-      upperBound: 0.6,
+      lowerBound: widget.minOpacity,
+      upperBound: widget.maxOpacity,
     );
     _runAnimation();
   }
@@ -65,93 +84,3 @@ class _FlutterHighlightState extends State<FlutterHighlight>
     );
   }
 }
-
-/// ----------------------------------------------------------------------------
-
-@immutable
-class _FlutterHighlightRender extends SingleChildRenderObjectWidget {
-  final double percent;
-  final Color color;
-
-  const _FlutterHighlightRender({
-    required this.percent,
-    required this.color,
-    required super.child,
-  });
-
-  @override
-  _FlutterHighlightFilter createRenderObject(BuildContext context) {
-    return _FlutterHighlightFilter(percent, color);
-  }
-
-  @override
-  void updateRenderObject(
-    BuildContext context,
-    _FlutterHighlightFilter filter,
-  ) {
-    filter.percent = percent;
-    filter.color = color;
-  }
-}
-
-/// ----------------------------------------------------------------------------
-
-class _FlutterHighlightFilter extends RenderProxyBox {
-  double _percent;
-  Color _color;
-
-  _FlutterHighlightFilter(this._percent, this._color);
-
-  @override
-  ShaderMaskLayer? get layer => super.layer as ShaderMaskLayer?;
-
-  @override
-  bool get alwaysNeedsCompositing => child != null;
-
-  set percent(double newValue) {
-    if (newValue == _percent) return;
-    _percent = newValue;
-    markNeedsPaint();
-  }
-
-  set color(Color newValue) {
-    if (newValue == _color) return;
-    _color = newValue;
-    markNeedsPaint();
-  }
-
-  double _offset(double start, double end, double percent) {
-    return start + (end - start) * percent;
-  }
-
-  @override
-  void paint(PaintingContext context, Offset offset) {
-    if (child != null) {
-      final double width = child!.size.width;
-      final double height = child!.size.height;
-
-      Rect rect;
-      double dx, dy;
-
-      dx = _offset(-width, width, 1);
-      dy = 0.0;
-      rect = Rect.fromLTWH(dx - width, dy, 3 * width, height);
-
-      layer ??= ShaderMaskLayer();
-      layer!
-        ..shader = LinearGradient(
-          begin: Alignment.centerLeft,
-          end: Alignment.centerRight,
-          colors: [
-            _color.withValues(alpha: _percent),
-            _color.withValues(alpha: _percent),
-          ],
-        ).createShader(rect)
-        ..maskRect = offset & size
-        ..blendMode = BlendMode.srcATop;
-      context.pushLayer(layer!, super.paint, offset);
-    } else {
-      layer = null;
-    }
-  }
-}

lib/src/flutter_highlight_filter.dart

@@ -0,0 +1,61 @@
+part of '../flutter_highlight.dart';
+
+class _FlutterHighlightFilter extends RenderProxyBox {
+  double _percent;
+  Color _color;
+
+  _FlutterHighlightFilter(this._percent, this._color);
+
+  @override
+  ShaderMaskLayer? get layer => super.layer as ShaderMaskLayer?;
+
+  @override
+  bool get alwaysNeedsCompositing => child != null;
+
+  set percent(double newValue) {
+    if (newValue == _percent) return;
+    _percent = newValue;
+    markNeedsPaint();
+  }
+
+  set color(Color newValue) {
+    if (newValue == _color) return;
+    _color = newValue;
+    markNeedsPaint();
+  }
+
+  double _offset(double start, double end, double percent) {
+    return start + (end - start) * percent;
+  }
+
+  @override
+  void paint(PaintingContext context, Offset offset) {
+    if (child != null) {
+      final double width = child!.size.width;
+      final double height = child!.size.height;
+
+      Rect rect;
+      double dx, dy;
+
+      dx = _offset(-width, width, 1);
+      dy = 0.0;
+      rect = Rect.fromLTWH(dx - width, dy, 3 * width, height);
+
+      layer ??= ShaderMaskLayer();
+      layer!
+        ..shader = LinearGradient(
+          begin: Alignment.centerLeft,
+          end: Alignment.centerRight,
+          colors: [
+            _color.withValues(alpha: _percent),
+            _color.withValues(alpha: _percent),
+          ],
+        ).createShader(rect)
+        ..maskRect = offset & size
+        ..blendMode = BlendMode.srcATop;
+      context.pushLayer(layer!, super.paint, offset);
+    } else {
+      layer = null;
+    }
+  }
+}

lib/src/flutter_highlight_render.dart

@@ -0,0 +1,26 @@
+part of '../flutter_highlight.dart';
+
+class _FlutterHighlightRender extends SingleChildRenderObjectWidget {
+  final double percent;
+  final Color color;
+
+  const _FlutterHighlightRender({
+    required this.percent,
+    required this.color,
+    required super.child,
+  });
+
+  @override
+  _FlutterHighlightFilter createRenderObject(BuildContext context) {
+    return _FlutterHighlightFilter(percent, color);
+  }
+
+  @override
+  void updateRenderObject(
+    BuildContext context,
+    _FlutterHighlightFilter filter,
+  ) {
+    filter.percent = percent;
+    filter.color = color;
+  }
+}

pubspec.yaml

@@ -1,10 +1,9 @@
 name: flutter_highlight
 description: "A new Flutter project."
 version: 0.0.1
-homepage:
 
 environment:
-  sdk: ^3.7.2
+  sdk: ">=3.7.0"
   flutter: ">=1.17.0"
 
 dependencies: