feat: multitab and basic file saving

tabwidget.h

@@ -0,0 +1,57 @@
+#pragma once
+
+#include <QTabWidget>
+#include <QHash>
+
+class SciEdit;
+class DocumentManager;
+
+class TabWidget : public QTabWidget
+{
+    Q_OBJECT
+
+public:
+    explicit TabWidget(DocumentManager *documentManager, QWidget *parent = nullptr);
+    ~TabWidget();
+
+    // 标签页管理
+    int newDocument();
+    int openDocument(const QString &filePath);
+    bool saveCurrentDocument();
+    bool saveCurrentDocumentAs();
+    void closeCurrentTab();
+    bool closeTab(int index);
+    void closeAllTabs();
+
+    // 获取当前编辑器和文档信息
+    SciEdit *currentEditor() const;
+    SciEdit *editorAt(int index) const;
+    int currentDocumentId() const;
+    int documentIdAt(int index) const;
+
+    // 标签页操作
+    void setCurrentTab(int index);
+    int findTabByDocumentId(int docId) const;
+
+signals:
+    void currentEditorChanged(SciEdit *editor);
+    void tabCloseRequested(int index);
+
+private slots:
+    void onCurrentChanged(int index);
+    void onTabCloseRequested(int index);
+    void onDocumentModified(int docId, bool modified);
+    void onDocumentTitleChanged(int docId, const QString &title);
+    void onEditorTextChanged();
+
+private:
+    DocumentManager *m_documentManager;
+    QHash<int, int> m_tabToDocumentId;  // tab index -> document id
+    QHash<int, int> m_documentIdToTab;  // document id -> tab index
+    QHash<int, SciEdit*> m_editors;     // document id -> editor
+
+    SciEdit *createEditor();
+    void updateTabTitle(int tabIndex);
+    void connectEditorSignals(SciEdit *editor);
+    void disconnectEditorSignals(SciEdit *editor);
+};