feat: introduce _SpacingWidget for conditional spacing in SDUIFormWidget, enhance visibility handling with reactive updates, and improve error handling for child widgets

packages/chicken/lib/presentation/widget/sdui/form/sdui_form_widget.dart

@@ -30,6 +30,101 @@ class _StepperInfo {
   });
 }
 
+// Helper widget that adds spacing only if previous widget is visible
+class _SpacingWidget extends StatelessWidget {
+  final double spacing;
+  final String? previousVisibleCondition;
+  final RxMap<String, dynamic>? state;
+
+  const _SpacingWidget({
+    required this.spacing,
+    required this.previousVisibleCondition,
+    required this.state,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    // If previous widget has no visible condition, it's always visible
+    if (previousVisibleCondition == null || previousVisibleCondition!.isEmpty) {
+      return SizedBox(height: spacing);
+    }
+
+    // Use Obx to reactively check if previous widget is visible
+    return Obx(() {
+      final isPreviousVisible = _evaluateVisibleConditionStatic(
+        previousVisibleCondition!,
+        state,
+      );
+
+      if (isPreviousVisible) {
+        return SizedBox(height: spacing);
+      } else {
+        return const SizedBox.shrink();
+      }
+    });
+  }
+
+  // Static version of _evaluateVisibleCondition for use in helper widget
+  bool _evaluateVisibleConditionStatic(
+    String condition,
+    RxMap<String, dynamic>? state,
+  ) {
+    if (state == null) {
+      if (condition.contains('activeStepperIndex == 0')) {
+        return true;
+      }
+      return false;
+    }
+
+    try {
+      // Simple condition evaluation
+      // Supports: variable == value
+
+      if (condition.contains(' == ')) {
+        final parts = condition.split(' == ');
+        if (parts.length == 2) {
+          final variable = parts[0].trim();
+          var value = parts[1].trim();
+
+          // Remove quotes if present
+          if ((value.startsWith("'") && value.endsWith("'")) ||
+              (value.startsWith('"') && value.endsWith('"'))) {
+            value = value.substring(1, value.length - 1);
+          }
+
+          final stateValue = state[variable];
+          if (stateValue == null) {
+            // If variable doesn't exist in state, default to showing first step (0)
+            if (variable == 'activeStepperIndex' && value == '0') {
+              return true;
+            }
+            return false;
+          }
+
+          // Handle int comparison
+          final intValue = int.tryParse(value);
+          if (intValue != null) {
+            if (stateValue is int) {
+              return stateValue == intValue;
+            }
+            if (stateValue is num) {
+              return stateValue.toInt() == intValue;
+            }
+          }
+
+          // Handle string comparison
+          return stateValue.toString() == value;
+        }
+      }
+
+      // If condition format is not recognized, return false
+      return false;
+    } catch (e) {
+      return false;
+    }
+  }
+}
+
 class SDUIFormWidget extends StatelessWidget {
   final SDUIWidgetModel model;
   final Map<String, TextEditingController>? controllers;
@@ -187,15 +282,25 @@ class SDUIFormWidget extends StatelessWidget {
       if (visibleCondition.contains('activeStepperIndex == 0')) {
         return builder();
       }
-      return const SizedBox.shrink();
+      return Visibility(
+        visible: false,
+        maintainSize: false,
+        maintainState: false,
+        maintainAnimation: false,
+        child: builder(),
+      );
     }
 
     // Use Obx for reactive updates
     return Obx(() {
-      if (!_evaluateVisibleCondition(visibleCondition)) {
-        return const SizedBox.shrink();
-      }
-      return builder();
+      final isVisible = _evaluateVisibleCondition(visibleCondition);
+      return Visibility(
+        visible: isVisible,
+        maintainSize: false,
+        maintainState: false,
+        maintainAnimation: false,
+        child: builder(),
+      );
     });
   }
 
@@ -316,7 +421,6 @@ class SDUIFormWidget extends StatelessWidget {
     double paddingVertical,
   ) {
     if (children.isEmpty) {
-      iLog('Column has no children');
       return const SizedBox.shrink();
     }
 
@@ -328,31 +432,84 @@ class SDUIFormWidget extends StatelessWidget {
         crossAxisAlignment,
       );
 
-      final builtChildren = children.map((child) {
+      // Build all children first and extract their visible conditions
+      final builtChildren = <Widget>[];
+      final visibleConditions = <String?>[];
+
+      for (final child in children) {
         try {
-          return _buildWidget(child);
+          // Extract visible_condition from child model
+          final visibleCondition = child.maybeWhen(
+            column:
+                (
+                  children,
+                  spacing,
+                  mainAxisSize,
+                  crossAxisAlignment,
+                  paddingHorizontal,
+                  paddingVertical,
+                  visible,
+                  visibleCondition,
+                ) => visibleCondition,
+            row:
+                (
+                  children,
+                  spacing,
+                  mainAxisAlignment,
+                  visible,
+                  visibleCondition,
+                ) => visibleCondition,
+            cardLabelItem: (data, child, children, visible, visibleCondition) =>
+                visibleCondition,
+            stepper: (data, children, visible, visibleCondition) =>
+                visibleCondition,
+            textFormField: (data, visible, visibleCondition) =>
+                visibleCondition,
+            chipSelection: (data, visible, visibleCondition) =>
+                visibleCondition,
+            dropdown: (data, visible, visibleCondition) => visibleCondition,
+            imagePicker: (data, visible, visibleCondition) => visibleCondition,
+            pageView: (data, children, visible, visibleCondition) =>
+                visibleCondition,
+            sizedBox: (width, height, visible, visibleCondition) =>
+                visibleCondition,
+            orElse: () => null,
+          );
+
+          visibleConditions.add(visibleCondition);
+          builtChildren.add(_buildWidget(child));
         } catch (e) {
           iLog('Error building column child: $e');
-          return Container(
-            padding: EdgeInsets.all(8),
-            color: Colors.yellow.withAlpha(10),
-            child: Text('Child Error'),
+          visibleConditions.add(null);
+          builtChildren.add(
+            Container(
+              padding: EdgeInsets.all(8),
+              color: Colors.yellow.withAlpha(10),
+              child: Text('Child Error'),
+            ),
           );
         }
-      }).toList();
+      }
 
       // Add spacing between children
-      final columnChildren = spacing > 0 && builtChildren.length > 1
-          ? <Widget>[]
-          : builtChildren;
+      // Wrap each child (except first) with spacing that only shows if previous child is visible
+      final columnChildren = <Widget>[];
 
-      if (spacing > 0 && builtChildren.length > 1) {
-        for (int i = 0; i < builtChildren.length; i++) {
-          columnChildren.add(builtChildren[i]);
-          if (i < builtChildren.length - 1) {
-            columnChildren.add(SizedBox(height: spacing));
-          }
+      for (int i = 0; i < builtChildren.length; i++) {
+        final widget = builtChildren[i];
+
+        if (i > 0 && spacing > 0) {
+          // Add spacing that will be removed if previous widget is invisible
+          // Use the visible_condition of the previous widget
+          columnChildren.add(
+            _SpacingWidget(
+              spacing: spacing,
+              previousVisibleCondition: visibleConditions[i - 1],
+              state: state,
+            ),
+          );
         }
+        columnChildren.add(widget);
       }
 
       final column = Column(
@@ -849,6 +1006,8 @@ class SDUIFormWidget extends StatelessWidget {
         'sdui_form_stepper_${stepperInfo.stepperData.key ?? 'default'}';
     SDUIFormWidgetController formController;
 
+    fLog('mj ==>build With Stepper Layout');
+
     try {
       formController = Get.find<SDUIFormWidgetController>(tag: controllerTag);
     } catch (_) {
@@ -931,6 +1090,7 @@ class SDUIFormWidget extends StatelessWidget {
               child: Column(
                 mainAxisSize: MainAxisSize.min,
                 crossAxisAlignment: CrossAxisAlignment.stretch,
+                spacing: 30.h,
                 children: contentWidgets,
               ),
             ),