Restoring a Window's GeometryThis document describes how to save and restore a 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 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: void MyMainWindow::closeEvent(QCloseEvent *event) { QSettings settings("MyCompany", "MyApp"); settings.setValue("geometry", saveGeometry()); settings.setValue("windowState", saveState()); QMainWindow::closeEvent(event); } void MainWindow::readSettings() { QSettings settings("MyCompany", "MyApp"); restoreGeometry(settings.value("myWidget/geometry").toByteArray()); restoreState(settings.value("myWidget/windowState").toByteArray()); } If those functions are not available or cannot be used, then a workaround is to call setGeometry() after 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 pos() and size() and to restore the geometry using QWidget::resize() and move() before calling show(), as demonstrated in the Application example. © 2008-2011 Nokia Corporation and/or its subsidiaries. Nokia, Qt and their respective logos are trademarks of Nokia Corporation in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. Privacy Policy Licensees holding valid Qt Commercial licenses may use this document 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. Alternatively, this document may be used under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. |