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# Special-Purpose Global Functions Exported by Qt

Qt provides a few low-level global functions for fine-tuning applications. Most of these perform very specific tasks and are platform-specific. In general, we recommend that you try using Qt's public API before resorting to using any functions mentioned here.

These functions are exported by QtCore and QtGui, but most of them aren't declared in Qt's header files. To use them in your application, you must declare them before calling them. For example:

        #ifdef Q_WS_X11
        void qt_x11_wait_for_window_manager(QWidget *widget);
        #endif

        int main(int argc, char *argv[])
        {
            QApplication app(argc, argv);
            ...
            window.show();
        #ifdef Q_WS_X11
            qt_x11_wait_for_window_manager(&window);
        #endif
            ...
            return app.exec();
        }

These functions will remain as part of Qt for the lifetime of Qt 4.

Functions:

- void qt_set_library_config_file(const QString &fileName)
- void qt_set_sequence_auto_mnemonic(bool enable)
- HDC qt_win_display_dc()
- void qt_x11_set_fallback_font_family(int script, const QString &family)
- void qt_x11_wait_for_window_manager(QWidget *widget)
- void qt_mac_secure_keyboard(bool enable)
- void qt_mac_set_dock_menu(QMenu *menu)
- void qt_mac_set_menubar_icons(bool enable)
- void qt_mac_set_menubar_merge(bool enable)
- void qt_mac_set_native_menubar(bool enable)
- void qt_mac_set_press_and_hold_context(bool enable)

## void qt_set_library_config_file(const QString &fileName)

Specifies the location of the Qt configuration file. You must call this function before constructing a QApplication or QCoreApplication object. If no location is specified, Qt automatically finds an appropriate location.

## void qt_set_sequence_auto_mnemonic(bool enable)

Specifies whether mnemonics for menu items, labels, etc., should be honored or not. On Windows and X11, this feature is on by default; on Mac OS X, it is off. When this feature is off, the QKeySequence::mnemonic() function always returns an empty string.

## HDC qt_win_display_dc()

Returns the Windows device context for the display. Use this at your own risks and perils.

## void qt_x11_set_fallback_font_family(int script, const QString &family)

Sets the font family to be used for a given script as the fallback when the current font doesn't contain a character. The values for the script parameter are defined by the `Script` enum, located in `<private/qunicodetable_p.h>`.

## void qt_x11_wait_for_window_manager(QWidget *widget)

Blocks until the X11 window manager has shown the widget after a call to QWidget::show().

## void qt_mac_secure_keyboard(bool enable)

Turns the Mac OS X secure keyboard feature on or off. QLineEdit uses this when the echo mode is QLineEdit::Password or QLineEdit::NoEcho to guard the editor against keyboard sniffing. If you implement your own password editor, you might want to turn on this feature in your editor's focusInEvent() and turn it off in focusOutEvent().

## void qt_mac_set_dock_menu(QMenu *menu)

Sets the menu to display in the Mac OS X Dock for the application. This menu is shown when the user Ctrl-clicks on the application's icon while it is running.

## void qt_mac_set_menubar_icons(bool enable)

Specifies whether icons associated to menu items for the application's menu bar should be shown on Mac OS X. By default, icons are shown on Mac OS X just like on the other platforms.

## void qt_mac_set_menubar_merge(bool enable)

Specifies whether Qt should attempt to relocate standard menu items (such as Quit, Preferences, and About) to the application menu on Mac OS X. This feature is on by default. See Qt/Mac-Specific Issues for the list of menu items for which this applies.

## void qt_mac_set_native_menubar(bool enable)

Specifies whether the application should use the native menu bar on Mac OS X or be part of the main window. This feature is on by default.

## void qt_mac_set_press_and_hold_context(bool enable)

Turns emulation of the right mouse button by clicking and holding the left mouse button on or off. This feature is off by default.