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Diffstat (limited to 'src/widgets/kernel/qdesktopwidget.qdoc')
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diff --git a/src/widgets/kernel/qdesktopwidget.qdoc b/src/widgets/kernel/qdesktopwidget.qdoc new file mode 100644 index 0000000000..f71155e117 --- /dev/null +++ b/src/widgets/kernel/qdesktopwidget.qdoc @@ -0,0 +1,269 @@ +/**************************************************************************** +** +** 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. +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \class QDesktopWidget + \brief The QDesktopWidget class provides access to screen information on multi-head systems. + + \ingroup advanced + \ingroup desktop + + 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. + + This class provides information about the user's desktop, such as its + total size, number of screens, the geometry of each screen, and whether + they are configured as separate desktops or a single virtual desktop. + + Widgets provided by Qt use this class to place tooltips, menus and + dialog boxes on the correct screen for their parent or application + widgets. Applications can use this class to obtain information that + can be used to save window positions, or to place child widgets and + dialogs on one particular screen. + + \section1 Obtaining a Desktop Widget + + The QApplication::desktop() function is used to get an instance of + QDesktopWidget. + + The widget's screenGeometry() function provides information about the + geometry of the available screens with. The number of screens + available is returned by screenCount, and the screenCountChanged() + signal is emitted when screens are added or removed. + The screen number that a particular point or widget is located in + is returned by screenNumber(). + + \section1 Screen Geometry + + To obtain the dimensions of a particular screen, call the screenGeometry() + function. On some desktop environments, not all of the screen is + available for applications to use; for example, an application dock or + menu bar may take up some space. Use the availableGeometry() function + to obtain the available area for applications. + + QDesktopWidget also 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. + + On systems that are configured to use the available screens as a + single, large virtual desktop, the virtualDesktop property will be + set to true. In this case, the widget's size is usually the size of + the bounding rectangle of all the screens. + + \section1 Use of the Primary Screen + + For an application, the screen where the main widget resides is the + primary screen. This is stored in the primaryScreen property. + 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. + + \image 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. + + \sa QApplication, QApplication::desktop(), QX11Info::appRootWindow() +*/ + +/*! + \fn QDesktopWidget::QDesktopWidget() + + \internal + + Creates the desktop widget. + + If the system supports a virtual desktop, this widget will have + the size of the virtual desktop; otherwise this widget will have + the size of the primary screen. + + Instead of using QDesktopWidget directly, use QApplication::desktop(). +*/ + +/*! + \fn QDesktopWidget::~QDesktopWidget() + + \internal + + Destroys the desktop widget and frees any allocated resources. +*/ + +/*! + \fn int QDesktopWidget::numScreens() const + + Returns the number of available screens. + + \obsolete + + This function is deprecated. Use screenCount instead. + + \sa primaryScreen +*/ + +/*! + \fn QWidget *QDesktopWidget::screen(int screen) + + Returns a widget that represents the screen with index \a screen + (a value of -1 means the default screen). + + If the system uses a virtual desktop, the returned widget will + have the geometry of the entire virtual desktop; i.e., bounding + every \a screen. + + \sa primaryScreen, screenCount, virtualDesktop +*/ + +/*! + \fn const QRect QDesktopWidget::availableGeometry(int screen) const + + Returns the available geometry of the screen with index \a screen. What + is available will be subrect of screenGeometry() based on what the + platform decides is available (for example excludes the dock and menu bar + on Mac OS X, or the task bar on Windows). The default screen is used if + \a screen is -1. + + \sa screenNumber(), screenGeometry() +*/ + +/*! + \fn const QRect QDesktopWidget::availableGeometry(const QWidget *widget) const + \overload + + Returns the available geometry of the screen which contains \a widget. + + \sa screenGeometry() +*/ + +/*! + \fn const QRect QDesktopWidget::availableGeometry(const QPoint &p) const + \overload + + Returns the available geometry of the screen which contains \a p. + + \sa screenGeometry() +*/ + + +/*! + \fn const QRect QDesktopWidget::screenGeometry(int screen) const + + Returns the geometry of the screen with index \a screen. The default + screen is used if \a screen is -1. + + \sa screenNumber() +*/ + +/*! + \fn const QRect QDesktopWidget::screenGeometry(const QWidget *widget) const + \overload + + Returns the geometry of the screen which contains \a widget. +*/ + +/*! + \fn const QRect QDesktopWidget::screenGeometry(const QPoint &p) const + \overload + + Returns the geometry of the screen which contains \a p. +*/ + + +/*! + \fn int QDesktopWidget::screenNumber(const QWidget *widget) const + + Returns the index of the screen that contains the largest + part of \a widget, or -1 if the widget not on a screen. + + \sa primaryScreen +*/ + +/*! + \fn int QDesktopWidget::screenNumber(const QPoint &point) const + + \overload + Returns the index of the screen that contains the \a point, or the + screen which is the shortest distance from the \a point. + + \sa primaryScreen +*/ + +/*! + \fn void QDesktopWidget::resizeEvent(QResizeEvent *event) + \reimp +*/ + +/*! + \fn void QDesktopWidget::resized(int screen) + + This signal is emitted when the size of \a screen changes. +*/ + +/*! + \fn void QDesktopWidget::workAreaResized(int screen) + + This signal is emitted when the work area available on \a screen changes. +*/ + +/*! + \property QDesktopWidget::screenCount + \brief the number of screens currently available on the system. + + \since 4.6 + + \sa screenCountChanged() +*/ + +/*! + \property QDesktopWidget::primaryScreen + \brief the index of the screen that is configured to be the primary screen + on the system. +*/ + +/*! + \property QDesktopWidget::virtualDesktop + + \brief if the system manages the available screens in a virtual desktop. + + For virtual desktops, screen() will always return the same widget. + The size of the virtual desktop is the size of this desktop + widget. +*/ + +/*! + \fn void QDesktopWidget::screenCountChanged(int newCount) + + \since 4.6 + + This signal is emitted when the number of screens changes to \a newCount. + + \sa screenCount +*/ |