source: trunk/doc/src/qdesktopwidget.qdoc@ 357

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/*!
    \class QDesktopWidget
    \brief The QDesktopWidget class provides access to screen information on multi-head systems.

    \ingroup advanced
    \ingroup desktop
    \ingroup environment
    \mainclass

    QApplication::desktop() function should be used to get an instance
    of the QDesktopWidget.

    Systems with more than one graphics card and monitor can manage the
    physical screen space available either as multiple desktops, or as a
    large virtual desktop, which usually has the size of the bounding
    rectangle of all the screens (see isVirtualDesktop()). For an
    application, one of the available screens is the primary screen, i.e.
    the screen where the main widget resides (see primaryScreen()). All
    windows opened in the context of the application should be
    constrained to the boundaries of the primary screen; for example,
    it would be inconvenient if a dialog box popped up on a different
    screen, or split over two screens.

    The QDesktopWidget provides information about the geometry of the
    available screens with screenGeometry(). The number of screens
    available is returned by numScreens(). The screen number that a
    particular point or widget is located in is returned by
    screenNumber().

    Widgets provided by Qt use this class, for example, to place
    tooltips, menus and dialog boxes according to the parent or
    application widget.

    Applications can use this class to save window positions, or to place
    child widgets on one screen.

    \img qdesktopwidget.png Managing Multiple Screens

    In the illustration above, Application One's primary screen is
    screen 0, and App Two's primary screen is screen 1.

    \target multiple screens note
    \note QDesktopWidget inherits the QWidget properties, width() and
    height(), which specify the size of the desktop. However, for
    desktops with multiple screens, the size of the desktop is the union
    of all the screen sizes, so width() and height() should \e not be
    used for computing the size of a widget to be placed on one of the
    screens. The correct width and height values are obtained using
    availableGeometry() or screenGeometry() for a particular screen.

    \sa QApplication, QApplication::desktop(), QX11Info::appRootWindow()
*/

/*!
    \fn QDesktopWidget::QDesktopWidget()

    \internal