first commit

app/lib/presentation/widgets/error_view.dart

@@ -0,0 +1,141 @@
+import 'package:flutter/material.dart';
+
+class ErrorView extends StatelessWidget {
+  final String message;
+  final VoidCallback? onRetry;
+  final String? retryText;
+  final IconData? icon;
+
+  const ErrorView({
+    super.key,
+    required this.message,
+    this.onRetry,
+    this.retryText,
+    this.icon,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Center(
+      child: Padding(
+        padding: const EdgeInsets.all(32),
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: [
+            Container(
+              width: 100,
+              height: 100,
+              decoration: BoxDecoration(
+                color: theme.colorScheme.error.withValues(alpha: 26),
+                shape: BoxShape.circle,
+              ),
+              child: Icon(
+                icon ?? Icons.error_outline,
+                size: 48,
+                color: theme.colorScheme.error,
+              ),
+            ),
+            const SizedBox(height: 24),
+            Text(
+              'Oops!',
+              style: theme.textTheme.headlineMedium?.copyWith(
+                fontWeight: FontWeight.bold,
+                color: theme.colorScheme.onSurface,
+              ),
+            ),
+            const SizedBox(height: 12),
+            Text(
+              message,
+              style: theme.textTheme.bodyMedium?.copyWith(
+                color: theme.colorScheme.onSurface.withValues(alpha: 179),
+              ),
+              textAlign: TextAlign.center,
+            ),
+            if (onRetry != null) ...[
+              const SizedBox(height: 32),
+              ElevatedButton.icon(
+                onPressed: onRetry,
+                icon: const Icon(Icons.refresh),
+                label: Text(retryText ?? 'Erneut versuchen'),
+              ),
+            ],
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class EmptyStateView extends StatelessWidget {
+  final String title;
+  final String? subtitle;
+  final IconData icon;
+  final VoidCallback? onAction;
+  final String? actionText;
+
+  const EmptyStateView({
+    super.key,
+    required this.title,
+    this.subtitle,
+    this.icon = Icons.inbox,
+    this.onAction,
+    this.actionText,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Center(
+      child: Padding(
+        padding: const EdgeInsets.all(32),
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: [
+            Container(
+              width: 100,
+              height: 100,
+              decoration: BoxDecoration(
+                color: Colors.grey.shade200,
+                shape: BoxShape.circle,
+              ),
+              child: Icon(
+                icon,
+                size: 48,
+                color: Colors.grey.shade500,
+              ),
+            ),
+            const SizedBox(height: 24),
+            Text(
+              title,
+              style: theme.textTheme.titleLarge?.copyWith(
+                fontWeight: FontWeight.w600,
+                color: theme.colorScheme.onSurface,
+              ),
+              textAlign: TextAlign.center,
+            ),
+            if (subtitle != null) ...[
+              const SizedBox(height: 8),
+              Text(
+                subtitle!,
+                style: theme.textTheme.bodyMedium?.copyWith(
+                  color: theme.colorScheme.onSurface.withValues(alpha: 153),
+                ),
+                textAlign: TextAlign.center,
+              ),
+            ],
+            if (onAction != null && actionText != null) ...[
+              const SizedBox(height: 24),
+              ElevatedButton(
+                onPressed: onAction,
+                child: Text(actionText!),
+              ),
+            ],
+          ],
+        ),
+      ),
+    );
+  }
+}