UI Component

class MainWindow : public QMainWindow
{
public:
    explicit MainWindow(Core::Application *app, QWidget *parent = nullptr);
    
    void search(const Registry::SearchQuery &query);
    void bringToFront();
    BrowserTab *createTab();
    
public slots:
    void toggleWindow();
    
signals:
    void currentTabChanged();
    
protected:
    void changeEvent(QEvent *event) override;
    void closeEvent(QCloseEvent *event) override;
    bool eventFilter(QObject *object, QEvent *event) override;
    void keyPressEvent(QKeyEvent *keyEvent) override;
};

Core::Application *m_application = nullptr;
Core::Settings *m_settings = nullptr;
Browser::WebBridge *m_webBridge = nullptr;

QxtGlobalShortcut *m_globalShortcut = nullptr;

QMenuBar *m_menuBar = nullptr;
QTabBar *m_tabBar = nullptr;

QSplitter *m_splitter = nullptr;
QStackedWidget *m_webViewStack = nullptr;

// Actions
QAction *m_quitAction = nullptr;
QAction *m_showDocsetManagerAction = nullptr;
QAction *m_showPreferencesAction = nullptr;
#ifndef Q_OS_MACOS
QAction *m_showMenuBarAction = nullptr;
#endif

QSystemTrayIcon *m_trayIcon = nullptr;

private slots:
    void closeTab(int index = -1);
    void moveTab(int from, int to);
    void duplicateTab(int index);
    
private:
    void addTab(BrowserTab *tab, int index = -1);
    BrowserTab *currentTab() const;
    BrowserTab *tabAt(int index) const;

// From Core::Settings
QByteArray windowGeometry;
QByteArray verticalSplitterGeometry;
QByteArray tocSplitterState;

QxtGlobalShortcut *m_globalShortcut = nullptr;

void createTrayIcon();
void removeTrayIcon();
QSystemTrayIcon *m_trayIcon = nullptr;

class SearchSidebar final : public Sidebar::View
{
public:
    explicit SearchSidebar(QWidget *parent = nullptr);
    SearchSidebar *clone(QWidget *parent = nullptr) const;
    
    Registry::SearchModel *pageTocModel() const;
    
signals:
    void activated();
    void navigationRequested(const QUrl &url);
    
public slots:
    void focusSearchEdit(bool clear = false);
    void search(const Registry::SearchQuery &query);
};

SearchEdit *m_searchEdit = nullptr;
bool m_pendingSearchEditFocus = false;

// Index and search results tree view
QTreeView *m_treeView = nullptr;
QModelIndexList m_expandedIndexList;
int m_pendingVerticalPosition = 0;
Registry::SearchModel *m_searchModel = nullptr;

// TOC list view
QListView *m_pageTocView = nullptr;
Registry::SearchModel *m_pageTocModel = nullptr;

QSplitter *m_splitter = nullptr;
QTimer *m_delayedNavigationTimer = nullptr;

┌─────────────────────────┐
│   [Search Input]        │
├─────────────────────────┤
│                         │
│   QTreeView             │
│   (Search Results)      │
│                         │
├─────────────────────────┤ ← QSplitter
│   QListView             │
│   (Page TOC)            │
└─────────────────────────┘

QTimer *m_delayedNavigationTimer = nullptr;

class SettingsDialog : public QDialog
{
public:
    explicit SettingsDialog(QWidget *parent = nullptr);
    
public slots:
    void chooseCustomCssFile();
    void chooseDocsetStoragePath();
    
private:
    void loadSettings();
    void saveSettings();
    
private:
    Ui::SettingsDialog *ui = nullptr;
};

class DocsetsDialog : public QDialog
{
public:
    explicit DocsetsDialog(Core::Application *app, QWidget *parent = nullptr);
    
private slots:
    void addDashFeed();
    void updateSelectedDocsets();
    void updateAllDocsets();
    void removeSelectedDocsets();
    void updateDocsetFilter(const QString &filterString);
    void downloadSelectedDocsets();
    void downloadCompleted();
    void downloadProgress(qint64 received, qint64 total);
    void extractionCompleted(const QString &filePath);
    void extractionError(const QString &filePath, const QString &errorString);
    void extractionProgress(const QString &filePath, qint64 extracted, qint64 total);
    void loadDocsetList();
};

Util::CaseInsensitiveMap<Registry::DocsetMetadata> m_availableDocsets;
QMap<QString, Registry::DocsetMetadata> m_userFeeds;
QHash<QString, QTemporaryFile *> m_tmpFiles;

QList<QNetworkReply *> m_replies;
void cancelDownloads();
QNetworkReply *download(const QUrl &url);

class BrowserTab final : public QWidget
{
public:
    explicit BrowserTab(Browser::WebBridge *webBridge, QWidget *parent = nullptr);
    
    Browser::WebView *webView() const;
    // Additional tab-specific functionality
};

class SidebarViewProvider : public QObject
{
public:
    explicit SidebarViewProvider(MainWindow *mainWindow, QObject *parent = nullptr);
    // Creates and manages sidebar views per tab
};