update text diff

lib/src/features/diff/json_diff_view.dart

@@ -0,0 +1,175 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import '../widgets/text_diff_view.dart';
+
+class TextComparePage extends StatelessWidget {
+  const TextComparePage({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('文本对比'),
+        backgroundColor: Theme.of(context).colorScheme.surfaceVariant,
+      ),
+      body: const TextCompareBody(),
+    );
+  }
+}
+
+class TextCompareBody extends StatefulWidget {
+  const TextCompareBody({super.key});
+
+  @override
+  State<TextCompareBody> createState() => _TextCompareBodyState();
+}
+
+class _TextCompareBodyState extends State<TextCompareBody> {
+  final TextEditingController _controller1 = TextEditingController();
+  final TextEditingController _controller2 = TextEditingController();
+  List<TextDiff>? _diffs;
+
+  @override
+  void dispose() {
+    _controller1.dispose();
+    _controller2.dispose();
+    super.dispose();
+  }
+
+  void _compareTexts() {
+    final text1 = _controller1.text;
+    final text2 = _controller2.text;
+    if (text1.isEmpty || text2.isEmpty) {
+      setState(() {
+        _diffs = null;
+      });
+      return;
+    }
+
+    setState(() {
+      _diffs = TextDiffView.computeDiffs(text1, text2);
+    });
+  }
+
+  void _clearTexts() {
+    setState(() {
+      _controller1.clear();
+      _controller2.clear();
+      _diffs = null;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return LayoutBuilder(
+      builder: (context, constraints) {
+        return Padding(
+          padding: const EdgeInsets.all(16.0),
+          child: Column(
+            children: [
+              // 输入区域
+              SizedBox(
+                height: _diffs == null
+                    ? constraints.maxHeight * 0.8
+                    : constraints.maxHeight * 0.4,
+                child: Row(
+                  children: [
+                    Expanded(
+                      child: _buildInputCard(
+                        controller: _controller1,
+                        hintText: '原文本',
+                      ),
+                    ),
+                    const SizedBox(width: 16),
+                    Expanded(
+                      child: _buildInputCard(
+                        controller: _controller2,
+                        hintText: '对比文本',
+                      ),
+                    ),
+                  ],
+                ),
+              ),
+
+              const SizedBox(height: 16),
+
+              // 操作按钮
+              Row(
+                mainAxisAlignment: MainAxisAlignment.center,
+                children: [
+                  FilledButton.icon(
+                    onPressed: _compareTexts,
+                    icon: const Icon(Icons.compare_arrows),
+                    label: const Text('对比'),
+                  ),
+                  const SizedBox(width: 16),
+                  FilledButton.icon(
+                    onPressed: _clearTexts,
+                    icon: const Icon(Icons.clear_all),
+                    label: const Text('清空'),
+                  ),
+                  const SizedBox(width: 16),
+                  FilledButton.icon(
+                    onPressed: () {
+                      Clipboard.setData(ClipboardData(
+                        text: '${_controller1.text}\n---\n${_controller2.text}',
+                      ));
+                      ScaffoldMessenger.of(context).showSnackBar(
+                        const SnackBar(content: Text('已复制到剪贴板')),
+                      );
+                    },
+                    icon: const Icon(Icons.copy),
+                    label: const Text('复制'),
+                  ),
+                ],
+              ),
+
+              // 对比结果
+              if (_diffs != null) ...[
+                const SizedBox(height: 16),
+                Expanded(
+                  child: Card(
+                    elevation: 2,
+                    child: ClipRRect(
+                      borderRadius: BorderRadius.circular(12),
+                      child: TextDiffView(
+                        diffs: _diffs!,
+                        background: Theme.of(context).colorScheme.surface,
+                      ),
+                    ),
+                  ),
+                ),
+              ],
+            ],
+          ),
+        );
+      },
+    );
+  }
+
+  Widget _buildInputCard({
+    required TextEditingController controller,
+    required String hintText,
+  }) {
+    return Card(
+      elevation: 2,
+      child: Padding(
+        padding: const EdgeInsets.all(16.0),
+        child: TextField(
+          controller: controller,
+          maxLines: null,
+          expands: true,
+          decoration: InputDecoration(
+            hintText: hintText,
+            border: OutlineInputBorder(
+              borderRadius: BorderRadius.circular(12),
+            ),
+            filled: true,
+            fillColor: Theme.of(context).colorScheme.surface,
+          ),
+          style: Theme.of(context).textTheme.bodyMedium,
+        ),
+      ),
+    );
+  }
+}