source: trunk/doc/src/howtos/restoring-geometry.qdoc@ 603

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/*!
    \page restoring-geometry.html
    \title Restoring a Window's Geometry

    \ingroup best-practices

    This document describes how to save and restore a \l{Window
    Geometry}{window's geometry} using the geometry properties. On
    Windows, this is basically storing the result of
    QWidget::geometry() and calling QWidget::setGeometry() in the next
    session before calling \l{QWidget::show()}{show()}.

    On X11, this might not work because an invisible window does not
    have a frame yet. The window manager will decorate the window
    later.  When this happens, the window shifts towards the
    bottom/right corner of the screen depending on the size of the
    decoration frame.  Although X provides a way to avoid this shift,
    some window managers fail to implement this feature.

    Since version 4.2, Qt provides functions that saves and restores a
    window's geometry and state for you. QWidget::saveGeometry()
    saves the window geometry and maximized/fullscreen state, while
    QWidget::restoreGeometry() restores it. The restore function also
    checks if the restored geometry is outside the available screen
    geometry, and modifies it as appropriate if it is:

    \snippet doc/src/snippets/code/src_gui_widgets_qmainwindow.cpp 0
    \snippet doc/src/snippets/code/src_gui_widgets_qmainwindow.cpp 1

    If those functions are not available or cannot be used, then a
    workaround is to call \l{QWidget::setGeometry()}{setGeometry()}
    after \l{QWidget::show()}{show()}. This has the two disadvantages
    that the widget appears at a wrong place for a millisecond
    (results in flashing) and that currently only every second window
    manager gets it right. A safer solution is to store both
    \l{QWidget::pos()}{pos()} and \l{QWidget::size()}{size()} and to
    restore the geometry using \l{QWidget::resize()} and
    \l{QWidget::move()}{move()} before calling
    \l{QWidget::show()}{show()}, as demonstrated in the
    \l{mainwindows/application}{Application} example.
*/