优化人物列表页

lib/widgets/person_avatar.dart

@@ -0,0 +1,72 @@
+import 'package:flutter/material.dart';
+import 'fade_in_local_image.dart';
+
+/// 人物头像。
+///
+/// 有照片时显示照片；无照片时根据名字哈希从调色板取色，
+/// 显示首字占位（同一人物始终同色）。
+class PersonAvatar extends StatelessWidget {
+  final String? photoPath;
+  final String name;
+  final double size;
+  final double fontSize;
+
+  const PersonAvatar({
+    super.key,
+    required this.photoPath,
+    required this.name,
+    required this.size,
+    required this.fontSize,
+  });
+
+  // 固定调色板：背景为该色的低透明度，文字为该色本身。
+  static const _palette = <Color>[
+    Color(0xFF4A90D9), // 蓝
+    Color(0xFF009688), // 青
+    Color(0xFFE91E63), // 粉
+    Color(0xFF7E57C2), // 紫
+    Color(0xFFFF7043), // 橙
+    Color(0xFF4CAF50), // 绿
+    Color(0xFFFF9800), // 琥珀
+    Color(0xFF795548), // 棕
+    Color(0xFF5C6BC0), // 靛
+    Color(0xFFEC407A), // 玫红
+  ];
+
+  Color _colorFor(String name) {
+    var hash = 0;
+    for (final c in name.codeUnits) {
+      hash = (hash * 31 + c) & 0x7fffffff;
+    }
+    return _palette[hash % _palette.length];
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final hasPhoto = photoPath != null && photoPath!.isNotEmpty;
+    final color = _colorFor(name);
+    final initial = name.isNotEmpty ? name[0] : '?';
+
+    return Container(
+      width: size,
+      height: size,
+      decoration: BoxDecoration(
+        color: hasPhoto ? null : color.withValues(alpha: 0.15),
+        shape: BoxShape.circle,
+      ),
+      clipBehavior: Clip.antiAlias,
+      child: hasPhoto
+          ? FadeInLocalImage(path: photoPath, fit: BoxFit.cover)
+          : Center(
+              child: Text(
+                initial,
+                style: TextStyle(
+                  fontSize: fontSize,
+                  fontWeight: FontWeight.w600,
+                  color: color,
+                ),
+              ),
+            ),
+    );
+  }
+}