/**************************************************************************** ** ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). ** All rights reserved. ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the documentation of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:FDL$ ** GNU Free Documentation License ** Alternatively, this file may be used under the terms of the GNU Free ** Documentation License version 1.3 as published by the Free Software ** Foundation and appearing in the file included in the packaging of ** this file. ** ** Other Usage ** Alternatively, this file may be used in accordance with the terms ** and conditions contained in a signed written agreement between you ** and Nokia. ** ** ** ** ** $QT_END_LICENSE$ ** ****************************************************************************/ /*! \page restoring-geometry.html \title Restoring a Window's Geometry \brief How to save & restore window 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. */