add checkbox border side state (#2973)

Author: 50Bytes-dev

packages/flet/lib/src/controls/checkbox.dart

@@ -1,9 +1,12 @@
+import 'dart:convert';
+
 import 'package:flutter/material.dart';
 
 import '../flet_control_backend.dart';
 import '../models/control.dart';
 import '../utils/borders.dart';
 import '../utils/colors.dart';
+import '../utils/material_state.dart';
 import '../utils/mouse.dart';
 import '../utils/text.dart';
 import '../utils/theme.dart';
@@ -117,15 +120,17 @@ class _CheckboxControlState extends State<CheckboxControl> with FletStoreMixin {
         labelStyle = labelStyle.apply(color: Theme.of(context).disabledColor);
       }
 
+      MaterialStateBorderSide? side = parseMaterialStateBorderSide(
+          Theme.of(context), widget.control, "borderSide");
+
       var checkbox = Checkbox(
           autofocus: autofocus,
           focusNode: _focusNode,
           value: _value,
           isError: widget.control.attrBool("isError", false)!,
           semanticLabel: widget.control.attrString("semanticsLabel"),
           shape: parseOutlinedBorder(widget.control, "shape"),
-          side:
-              parseBorderSide(Theme.of(context), widget.control, "borderSide"),
+          side: side,
           splashRadius: widget.control.attrDouble("splashRadius"),
           activeColor: widget.control.attrColor("activeColor", context),
           focusColor: widget.control.attrColor("focusColor", context),

packages/flet/lib/src/utils/borders.dart

@@ -120,3 +120,56 @@ OutlinedBorder? outlinedBorderFromJSON(Map<String, dynamic> json) {
   }
   return null;
 }
+
+MaterialStateBorderSide? parseMaterialStateBorderSide(
+    ThemeData theme, Control control, String propName) {
+  var v = control.attrString(propName, null);
+  if (v == null) {
+    return null;
+  }
+
+  var j = json.decode(v);
+  if (j is Map<String, dynamic> && (j.containsKey("w") || j.containsKey("c"))) {
+    j = {"": j};
+  }
+
+  return MaterialStateBorderSideFromJSON(
+      j, (jv) => borderSideFromJSON(theme, jv, null), BorderSide.none);
+}
+
+class MaterialStateBorderSideFromJSON extends MaterialStateBorderSide {
+  late final Map<String, BorderSide?> _states;
+  late final BorderSide _defaultValue;
+
+  MaterialStateBorderSideFromJSON(
+      Map<String, dynamic>? jsonDictValue,
+      BorderSide? Function(dynamic) converterFromJson,
+      BorderSide defaultValue) {
+    _defaultValue = defaultValue;
+    _states = {};
+    if (jsonDictValue != null) {
+      jsonDictValue.forEach((stateStr, jv) {
+        stateStr.split(",").map((s) => s.trim().toLowerCase()).forEach((state) {
+          _states[state] = converterFromJson(jv);
+        });
+      });
+    }
+  }
+
+  @override
+  BorderSide? resolve(Set<MaterialState> states) {
+    // find specific state
+    for (var state in states) {
+      if (_states.containsKey(state.name)) {
+        return _states[state.name];
+      }
+    }
+
+    // catch-all value
+    if (_states.containsKey("")) {
+      return _states[""];
+    }
+
+    return _defaultValue;
+  }
+}

sdk/python/packages/flet-core/src/flet_core/checkbox.py

@@ -71,7 +71,7 @@ def __init__(
         semantics_label: Optional[str] = None,
         shape: Optional[OutlinedBorder] = None,
         splash_radius: OptionalNumber = None,
-        border_side: Optional[BorderSide] = None,
+        border_side: Union[None, BorderSide, Dict[MaterialState, BorderSide]] = None,
         is_error: Optional[bool] = None,
         visual_density: Optional[ThemeVisualDensity] = None,
         mouse_cursor: Optional[MouseCursor] = None,
@@ -174,10 +174,9 @@ def before_update(self):
         self._set_attr_json("fillColor", self.__fill_color)
         self._set_attr_json("overlayColor", self.__overlay_color)
         self._set_attr_json("shape", self.__shape)
+        self._set_attr_json("borderSide", self.__border_side)
         if isinstance(self.__label_style, TextStyle):
             self._set_attr_json("labelStyle", self.__label_style)
-        if isinstance(self.__border_side, BorderSide):
-            self._set_attr_json("borderSide", self.__border_side)
 
     # value
     @property
@@ -356,11 +355,13 @@ def is_error(self, value: Optional[bool]):
 
     # border_side
     @property
-    def border_side(self) -> Optional[BorderSide]:
+    def border_side(self) -> Union[None, BorderSide, Dict[MaterialState, BorderSide]]:
         return self.__border_side
 
     @border_side.setter
-    def border_side(self, value: Optional[BorderSide]):
+    def border_side(
+        self, value: Union[None, BorderSide, Dict[MaterialState, BorderSide]]
+    ):
         self.__border_side = value
 
     # on_change