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/****************************************************************************
**
** Copyright (C) 2010 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.
**
** $QT_BEGIN_LICENSE:FDL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in a
** written agreement between you and Nokia.
**
** 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.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/
/*!
\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.
*/
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