Add Checkbox checkIcon color parameter #26808

The new parameter defines the color of the checkbox's check mark. Default is (still) white.

packages/flutter/lib/src/material/checkbox.dart

@@ -59,6 +59,7 @@ class Checkbox extends StatefulWidget {
     this.tristate = false,
     @required this.onChanged,
     this.activeColor,
+    this.checkColor,
     this.materialTapTargetSize,
   }) : assert(tristate != null),
        assert(tristate || value != null),
@@ -103,6 +104,11 @@ class Checkbox extends StatefulWidget {
   /// Defaults to [ThemeData.toggleableActiveColor].
   final Color activeColor;
 
+  /// The color to use for the check icon when this checkbox is checked
+  ///
+  /// Defaults to Color(0xFFFFFFFF)
+  final Color checkColor;
+
   /// If true the checkbox's [value] can be true, false, or null.
   ///
   /// Checkbox displays a dash when its value is null.
@@ -150,6 +156,7 @@ class _CheckboxState extends State<Checkbox> with TickerProviderStateMixin {
       value: widget.value,
       tristate: widget.tristate,
       activeColor: widget.activeColor ?? themeData.toggleableActiveColor,
+      checkColor: widget.checkColor ?? const Color(0xFFFFFFFF),
       inactiveColor: widget.onChanged != null ? themeData.unselectedWidgetColor : themeData.disabledColor,
       onChanged: widget.onChanged,
       additionalConstraints: additionalConstraints,
@@ -164,6 +171,7 @@ class _CheckboxRenderObjectWidget extends LeafRenderObjectWidget {
     @required this.value,
     @required this.tristate,
     @required this.activeColor,
+    @required this.checkColor,
     @required this.inactiveColor,
     @required this.onChanged,
     @required this.vsync,
@@ -178,6 +186,7 @@ class _CheckboxRenderObjectWidget extends LeafRenderObjectWidget {
   final bool value;
   final bool tristate;
   final Color activeColor;
+  final Color checkColor;
   final Color inactiveColor;
   final ValueChanged<bool> onChanged;
   final TickerProvider vsync;
@@ -188,6 +197,7 @@ class _CheckboxRenderObjectWidget extends LeafRenderObjectWidget {
     value: value,
     tristate: tristate,
     activeColor: activeColor,
+    checkColor: checkColor,
     inactiveColor: inactiveColor,
     onChanged: onChanged,
     vsync: vsync,
@@ -200,6 +210,7 @@ class _CheckboxRenderObjectWidget extends LeafRenderObjectWidget {
       ..value = value
       ..tristate = tristate
       ..activeColor = activeColor
+      ..checkColor = checkColor
       ..inactiveColor = inactiveColor
       ..onChanged = onChanged
       ..additionalConstraints = additionalConstraints
@@ -216,6 +227,7 @@ class _RenderCheckbox extends RenderToggleable {
     bool value,
     bool tristate,
     Color activeColor,
+    this.checkColor,
     Color inactiveColor,
     BoxConstraints additionalConstraints,
     ValueChanged<bool> onChanged,
@@ -232,6 +244,7 @@ class _RenderCheckbox extends RenderToggleable {
        );
 
   bool _oldValue;
+  Color checkColor;
 
   @override
   set value(bool newValue) {
@@ -270,7 +283,7 @@ class _RenderCheckbox extends RenderToggleable {
   // White stroke used to paint the check and dash.
   void _initStrokePaint(Paint paint) {
     paint
-      ..color = const Color(0xFFFFFFFF)
+      ..color = checkColor
       ..style = PaintingStyle.stroke
       ..strokeWidth = _kStrokeWidth;
   }

packages/flutter/test/material/checkbox_test.dart

@@ -336,4 +336,32 @@ void main() {
     expect(getCheckboxRenderer(), paints..line()); // null is rendered as a line (a "dash")
   });
 
+  testWidgets('CheckBox color rendering', (WidgetTester tester) async {
+    Widget buildFrame(Color color) {
+      return Material(
+        child: StatefulBuilder(
+          builder: (BuildContext context, StateSetter setState) {
+            return Checkbox(
+              value: true,
+              checkColor: color,
+              onChanged: (bool value) { },
+            );
+          },
+        ),
+      );
+    }
+
+    RenderToggleable getCheckboxRenderer() {
+      return tester.renderObject<RenderToggleable>(find.byType(Checkbox));
+    }
+
+    await tester.pumpWidget(buildFrame(null));
+    await tester.pumpAndSettle();
+    expect(getCheckboxRenderer(), paints..path(color: const Color(0xFFFFFFFF))); // paints's color is 0xFFFFFFFF (default color)
+
+    await tester.pumpWidget(buildFrame(const Color(0xFF000000)));
+    await tester.pumpAndSettle();
+    expect(getCheckboxRenderer(), paints..path(color: const Color(0xFF000000))); // paints's color is 0xFF000000 (params)
+  });
+
 }