ref: Divider config (#26)

* Add ResizableDivider config class

* Move divider config into new model

* Fix alignment of line within space

* Add indent and endIndent back to DividerPainter

* Clean up helper methods

* Rename height to size

* Add ResizableDivider tests

example/lib/main.dart

@@ -101,10 +101,13 @@ class _ExampleAppState extends State<ExampleApp> {
           child: ResizableContainer(
             controller: controller1,
             direction: direction,
-            dividerWidth: 3.0,
-            dividerColor: Colors.blue,
-            dividerIndent: 12,
-            dividerEndIndent: 12,
+            divider: const ResizableDivider(
+              thickness: 3.0,
+              size: 5.0,
+              color: Colors.blue,
+              indent: 12,
+              endIndent: 12,
+            ),
             children: [
               LayoutBuilder(
                 builder: (context, constraints) => Center(
@@ -121,7 +124,9 @@ class _ExampleAppState extends State<ExampleApp> {
               ),
               ResizableContainer(
                 controller: controller2,
-                dividerColor: Colors.green,
+                divider: const ResizableDivider(
+                  color: Colors.green,
+                ),
                 direction: direction == Axis.horizontal
                     ? Axis.vertical
                     : Axis.horizontal,

lib/flutter_resizable_container.dart

@@ -3,3 +3,4 @@ library flutter_resizable_container;
 export 'src/resizable_container.dart';
 export 'src/resizable_controller.dart';
 export 'src/resizable_child_data.dart';
+export 'src/resizable_divider.dart';

lib/src/divider_painter.dart

@@ -6,13 +6,13 @@ class DividerPainter extends CustomPainter {
   const DividerPainter({
     required this.color,
     required this.direction,
-    required this.width,
+    required this.thickness,
     this.indent,
     this.endIndent,
   });
 
   final Axis direction;
-  final double width;
+  final double thickness;
   final Color color;
   final double? indent;
   final double? endIndent;
@@ -34,7 +34,7 @@ class DividerPainter extends CustomPainter {
     return Paint()
       ..color = color
       ..style = PaintingStyle.stroke
-      ..strokeWidth = width;
+      ..strokeWidth = thickness;
   }
 
   Path _getPath(Size size) {
@@ -55,7 +55,7 @@ class DividerPainter extends CustomPainter {
       // The indent should be the lesser of the available height, the specified
       // indent, or 0.
       final indentAmount = min(size.height, indent ?? 0.0);
-      return Point(width / 2, indentAmount);
+      return Point(size.width / 2, indentAmount);
     }
 
     // If the direction is vertical, the divider is a horizontal line and the
@@ -64,7 +64,7 @@ class DividerPainter extends CustomPainter {
     // The indent should be the lesser of the available width, the specified
     // indent, or 0.
     final indentAmount = min(size.width, indent ?? 0.0);
-    return Point(indentAmount, width / 2);
+    return Point(indentAmount, size.height / 2);
   }
 
   Point<double> _getEndingPoint(Size size) {
@@ -75,7 +75,7 @@ class DividerPainter extends CustomPainter {
       // The indent should be the available height minus the indent amount,
       // capped at a minimum of 0.
       final indentAmount = max(0.0, size.height - (endIndent ?? 0));
-      return Point(width / 2, indentAmount);
+      return Point(size.width / 2, indentAmount);
     }
 
     // If the direction is vertical, the divider is a horizontal line and the
@@ -84,6 +84,6 @@ class DividerPainter extends CustomPainter {
     // The indent should be the available width minus the indent amount, capped
     // at a minimum of 0.
     final indentAmount = max(0.0, size.width - (endIndent ?? 0));
-    return Point(indentAmount, width / 2);
+    return Point(indentAmount, size.height / 2);
   }
 }

lib/src/resizable_container.dart

@@ -1,7 +1,7 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_resizable_container/flutter_resizable_container.dart';
 import 'package:flutter_resizable_container/src/extensions/box_constraints_ext.dart';
 import 'package:flutter_resizable_container/src/resizable_container_divider.dart';
-import 'package:flutter_resizable_container/src/resizable_controller.dart';
 
 /// A container that holds multiple child [Widget]s that can be resized.
 ///
@@ -17,11 +17,9 @@ class ResizableContainer extends StatelessWidget {
     required this.children,
     required this.controller,
     required this.direction,
-    this.dividerColor,
-    this.dividerWidth = 2.0,
-    this.dividerIndent,
-    this.dividerEndIndent,
-  }) : assert(
+    ResizableDivider? divider,
+  })  : divider = divider ?? const ResizableDivider(),
+        assert(
           children.length == controller.data.length,
           'Controller must have as many data items as there are children.',
         );
@@ -35,25 +33,8 @@ class ResizableContainer extends StatelessWidget {
   /// The direction along which the child widgets will be laid and resized.
   final Axis direction;
 
-  /// The width of the dividers between the children.
-  final double dividerWidth;
-
-  /// The color of the dividers between the children.
-  ///
-  /// If not provided, Theme.of(context).dividerColor will be used.
-  final Color? dividerColor;
-
-  /// The indent of the divider at its start.
-  ///
-  /// For dividers running from top-to-bottom, this indents the top.
-  /// For dividers running from left-to-right, this indents the left.
-  final double? dividerIndent;
-
-  /// The indent of the divider at its end.
-  ///
-  /// For dividers running from top-to-bottom, this indents the bottom.
-  /// For dividers running from left-to-right, this indents the right.
-  final double? dividerEndIndent;
+  /// Configuration values for the dividing space/line between this container's [children].
+  final ResizableDivider divider;
 
   @override
   Widget build(BuildContext context) {
@@ -93,11 +74,7 @@ class ResizableContainer extends StatelessWidget {
                   ),
                   if (i < children.length - 1) ...[
                     ResizableContainerDivider(
-                      dividerColor:
-                          dividerColor ?? Theme.of(context).dividerColor,
-                      dividerWidth: dividerWidth,
-                      indent: dividerIndent,
-                      endIndent: dividerEndIndent,
+                      config: divider,
                       direction: direction,
                       onResizeUpdate: (delta) => controller.adjustChildSize(
                         index: i,
@@ -116,7 +93,7 @@ class ResizableContainer extends StatelessWidget {
 
   double _getAvailableSpace(BoxConstraints constraints) {
     final totalSpace = constraints.maxForDirection(direction);
-    final dividerSpace = (children.length - 1) * dividerWidth;
+    final dividerSpace = (children.length - 1) * divider.size;
     return totalSpace - dividerSpace;
   }
 

lib/src/resizable_container_divider.dart

@@ -1,26 +1,24 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_resizable_container/src/divider_painter.dart';
+import 'package:flutter_resizable_container/src/resizable_divider.dart';
 
 class ResizableContainerDivider extends StatelessWidget {
   const ResizableContainerDivider({
     super.key,
     required this.direction,
     required this.onResizeUpdate,
-    required this.dividerWidth,
-    required this.dividerColor,
-    this.indent,
-    this.endIndent,
+    required this.config,
   });
 
   final Axis direction;
   final void Function(double) onResizeUpdate;
-  final double dividerWidth;
-  final Color dividerColor;
-  final double? indent;
-  final double? endIndent;
+  final ResizableDivider config;
 
   @override
   Widget build(BuildContext context) {
+    final width = _getWidth();
+    final height = _getHeight();
+
     return MouseRegion(
       cursor: _getCursor(),
       child: GestureDetector(
@@ -31,15 +29,18 @@ class ResizableContainerDivider extends StatelessWidget {
             ? (details) => onResizeUpdate(details.delta.dx)
             : null,
         child: SizedBox(
-          height: direction == Axis.horizontal ? double.infinity : dividerWidth,
-          width: direction == Axis.horizontal ? dividerWidth : double.infinity,
-          child: CustomPaint(
-            painter: DividerPainter(
-              direction: direction,
-              width: dividerWidth,
-              color: dividerColor,
-              indent: indent,
-              endIndent: endIndent,
+          height: height,
+          width: width,
+          child: Center(
+            child: CustomPaint(
+              size: Size(width, height),
+              painter: DividerPainter(
+                direction: direction,
+                color: config.color ?? Theme.of(context).dividerColor,
+                thickness: config.thickness,
+                indent: config.indent,
+                endIndent: config.endIndent,
+              ),
             ),
           ),
         ),
@@ -48,11 +49,23 @@ class ResizableContainerDivider extends StatelessWidget {
   }
 
   MouseCursor _getCursor() {
-    switch (direction) {
-      case Axis.horizontal:
-        return SystemMouseCursors.resizeLeftRight;
-      case Axis.vertical:
-        return SystemMouseCursors.resizeUpDown;
-    }
+    return switch (direction) {
+      Axis.horizontal => SystemMouseCursors.resizeLeftRight,
+      Axis.vertical => SystemMouseCursors.resizeUpDown,
+    };
+  }
+
+  double _getHeight() {
+    return switch (direction) {
+      Axis.horizontal => double.infinity,
+      Axis.vertical => config.size,
+    };
+  }
+
+  double _getWidth() {
+    return switch (direction) {
+      Axis.horizontal => config.size,
+      Axis.vertical => double.infinity,
+    };
   }
 }

lib/src/resizable_divider.dart

@@ -0,0 +1,40 @@
+import 'package:flutter/material.dart';
+
+class ResizableDivider {
+  const ResizableDivider({
+    this.thickness = 1.0,
+    this.size = 2.0,
+    this.color,
+    this.indent,
+    this.endIndent,
+  })  : assert(size >= thickness, '[size] must be >= [thickness].'),
+        assert(thickness > 0, '[thickness] must be > 0.');
+
+  /// The thickness of the line drawn within the divider.
+  ///
+  /// Defaults to 1.0.
+  final double thickness;
+
+  /// The divider's size (height/width) extent.
+  /// The divider line will be drawn in the center of this space.
+  ///
+  /// Defaults to 2.0.
+  final double size;
+
+  /// The color of the dividers between children.
+  ///
+  /// Defaults to [ThemeData.dividerColor].
+  final Color? color;
+
+  /// The amount of empty space to the leading edge of the divider.
+  ///
+  /// For dividers running from top-to-bottom, this adds empty space at the top.
+  /// For dividers running from left-to-right, this adds empty space to the left.
+  final double? indent;
+
+  /// The amount of empty space to the trailing edge of the divider.
+  ///
+  /// For dividers running from top-to-bottom, this adds empty space at the bottom.
+  /// For dividers running from left-to-right, this adds empty space to the right.
+  final double? endIndent;
+}

test/resizable_container_test.dart

@@ -89,7 +89,9 @@ void main() {
             body: ResizableContainer(
               controller: controller,
               direction: Axis.horizontal,
-              dividerWidth: dividerWidth,
+              divider: const ResizableDivider(
+                size: dividerWidth,
+              ),
               children: const [
                 SizedBox.expand(
                   key: Key('BoxA'),
@@ -143,7 +145,9 @@ void main() {
             body: ResizableContainer(
               controller: controller,
               direction: Axis.horizontal,
-              dividerWidth: dividerWidth,
+              divider: const ResizableDivider(
+                size: dividerWidth,
+              ),
               children: const [
                 SizedBox.expand(
                   key: Key('BoxA'),
@@ -231,7 +235,9 @@ void main() {
                   ),
                 ],
               ),
-              dividerWidth: dividerWidth,
+              divider: const ResizableDivider(
+                size: dividerWidth,
+              ),
               direction: Axis.horizontal,
               children: const [
                 SizedBox.expand(
@@ -277,7 +283,9 @@ void main() {
                   ),
                 ],
               ),
-              dividerWidth: dividerWidth,
+              divider: const ResizableDivider(
+                size: dividerWidth,
+              ),
               direction: Axis.horizontal,
               children: const [
                 SizedBox.expand(
@@ -325,7 +333,9 @@ void main() {
         final container = ResizableContainer(
           controller: controller,
           direction: Axis.horizontal,
-          dividerWidth: 2.0,
+          divider: const ResizableDivider(
+            size: 2.0,
+          ),
           children: const [
             SizedBox.expand(
               key: Key('Box A'),

test/resizable_divider_test.dart

@@ -0,0 +1,42 @@
+import 'package:flutter_resizable_container/flutter_resizable_container.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group(ResizableDivider, () {
+    group('thickness', () {
+      test('must be greater than 0', () {
+        expect(() => ResizableDivider(thickness: 0), throwsAssertionError);
+      });
+
+      test('accepts greater than 0', () {
+        expect(
+          () => const ResizableDivider(thickness: 1),
+          isNot(throwsAssertionError),
+        );
+      });
+    });
+
+    group('size', () {
+      test('throws if less than thickness', () {
+        expect(
+          () => ResizableDivider(thickness: 1, size: 0.5),
+          throwsAssertionError,
+        );
+      });
+
+      test('does not throw if the same as thickness', () {
+        expect(
+          () => const ResizableDivider(thickness: 1, size: 1),
+          isNot(throwsAssertionError),
+        );
+      });
+
+      test('does not throw if greater than thickness', () {
+        expect(
+          () => const ResizableDivider(thickness: 1, size: 2),
+          isNot(throwsAssertionError),
+        );
+      });
+    });
+  });
+}