refactor: implement UI code optimization and refactoring

This commit implements the comprehensive UI code refactoring plan to improve
code quality, reduce duplication, and enhance maintainability.

Phase 1: High Priority Improvements
- Create BaseDialog class to eliminate window centering code duplication
  across ProgressDialog, DeleteProgressWindow, LoginDialog, and
  UserSelectionDialog (~30 lines of duplicate code removed)
- Unify log color configuration with LogTheme class in gui/log_config.py
- Create permission check decorators (@require_admin, @require_permission,
  @require_user_type, @handle_errors)
- Update all dialog classes to use unified patterns

Phase 2: Architecture Improvements
- Create input validation framework (ValidationResult, Validator,
  ValidatedWidget classes)
- Implement StateManager with observer pattern for component state sharing
- Create unified ErrorHandler for consistent error handling
- Extract CheckboxTreeview into reusable component

New Modules:
- gui/widgets/base_dialog.py - Base dialog class with modal setup and centering
- gui/utils/decorators.py - Permission and error handling decorators
- gui/utils/error_handler.py - Unified error handling with user-friendly messages
- gui/utils/state_manager.py - State management with observer pattern
- gui/utils/validators.py - Input validation framework
- gui/material_validation/checkbox_treeview.py - Reusable checkbox table

Modified Files:
- gui/log_config.py - Added LogTheme class for centralized styling
- gui/widgets/log_text.py - Use LogTheme.COLORS
- gui/widgets/progress_dialog.py - Inherit from BaseDialog
- gui/widgets/delete_progress_window.py - Inherit from BaseDialog, use LogTheme
- gui/widgets/__init__.py - Add new exports, optional imports
- gui/login_dialog.py - Use unified centering pattern
- gui/user_selection_dialog.py - Use unified centering pattern
- gui/material_validation_tab.py - Import CheckboxTreeview from new module

Benefits:
- Reduced code duplication by ~200 lines
- Improved maintainability through centralized configuration
- Better abstraction with 5 new reusable base classes
- Enhanced type safety with type hints
- Future-proof theming support via LogTheme

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

gui/utils/decorators.py

@@ -0,0 +1,159 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""
+Decorators - GUI 装饰器集合
+
+提供常用的 GUI 相关装饰器，用于权限检查、异常处理等
+"""
+from functools import wraps
+from typing import Callable, Optional
+
+try:
+    from auth.session_manager import SessionManager
+except ImportError:
+    SessionManager = None
+
+from tkinter import messagebox
+
+
+def require_admin(func: Callable) -> Callable:
+    """
+    装饰器：要求管理员权限
+
+    如果当前用户不是管理员，显示警告消息并阻止函数执行
+
+    Usage:
+        @require_admin
+        def _open_admin_panel(self):
+            # 只有管理员可以执行
+            pass
+
+    Args:
+        func: 被装饰的函数
+
+    Returns:
+        包装后的函数
+    """
+    @wraps(func)
+    def wrapper(self, *args, **kwargs):
+        if SessionManager is None:
+            # 如果没有 SessionManager，直接执行（向后兼容）
+            return func(self, *args, **kwargs)
+
+        session = SessionManager.get_instance()
+        if not session.is_admin():
+            messagebox.showwarning("权限不足", "此功能需要管理员权限")
+            return
+        return func(self, *args, **kwargs)
+    return wrapper
+
+
+def require_permission(permission: str):
+    """
+    装饰器：要求特定权限
+
+    如果当前用户缺少指定权限，显示警告消息并阻止函数执行
+
+    Usage:
+        @require_permission("delete_materials")
+        def _delete_materials(self):
+            # 只有具有 delete_materials 权限的用户可以执行
+            pass
+
+    Args:
+        permission: 所需的权限名称
+
+    Returns:
+        装饰器函数
+    """
+    def decorator(func: Callable) -> Callable:
+        @wraps(func)
+        def wrapper(self, *args, **kwargs):
+            if SessionManager is None:
+                # 如果没有 SessionManager，直接执行（向后兼容）
+                return func(self, *args, **kwargs)
+
+            session = SessionManager.get_instance()
+            if not session.has_permission(permission):
+                messagebox.showwarning("权限不足", f"缺少权限: {permission}")
+                return
+            return func(self, *args, **kwargs)
+        return wrapper
+    return decorator
+
+
+def require_user_type(user_type: str):
+    """
+    装饰器：要求特定用户类型
+
+    如果当前用户不是指定类型，显示警告消息并阻止函数执行
+
+    Usage:
+        @require_user_type("Admin")
+        def _admin_function(self):
+            # 只有 Admin 类型用户可以执行
+            pass
+
+    Args:
+        user_type: 所需的用户类型
+
+    Returns:
+        装饰器函数
+    """
+    def decorator(func: Callable) -> Callable:
+        @wraps(func)
+        def wrapper(self, *args, **kwargs):
+            if SessionManager is None:
+                # 如果没有 SessionManager，直接执行（向后兼容）
+                return func(self, *args, **kwargs)
+
+            session = SessionManager.get_instance()
+            current_user_type = session.get_current_user_type()
+
+            if current_user_type != user_type:
+                messagebox.showwarning(
+                    "权限不足",
+                    f"此功能仅限 {user_type} 用户使用"
+                )
+                return
+            return func(self, *args, **kwargs)
+        return wrapper
+    return decorator
+
+
+def handle_errors(
+    show_user: bool = True,
+    default_return=None,
+    log_context: str = ""
+):
+    """
+    装饰器：统一错误处理
+
+    捕获函数中的异常并使用 ErrorHandler 进行处理
+
+    Usage:
+        @handle_errors(show_user=True, log_context="Deleting materials")
+        def _delete_materials(self):
+            # 可能抛出异常的操作
+            pass
+
+    Args:
+        show_user: 是否向用户显示错误消息
+        default_return: 发生异常时的默认返回值
+        log_context: 日志上下文信息
+
+    Returns:
+        装饰器函数
+    """
+    def decorator(func: Callable) -> Callable:
+        @wraps(func)
+        def wrapper(self, *args, **kwargs):
+            try:
+                return func(self, *args, **kwargs)
+            except Exception as e:
+                from gui.utils.error_handler import ErrorHandler
+                context = log_context or f"{func.__name__}"
+                ErrorHandler.handle(e, context, show_user)
+                return default_return
+        return wrapper
+    return decorator