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<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QDesktopWidget Class Reference</h1>
<p>The QDesktopWidget class provides access to screen information on multi-head systems.
<a href="#details">More...</a>
<p><tt>#include <<a href="qdesktopwidget-h.html">qdesktopwidget.h</a>></tt>
<p>Inherits <a href="qwidget.html">QWidget</a>.
<p><a href="qdesktopwidget-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li><div class=fn><a href="#QDesktopWidget"><b>QDesktopWidget</b></a> ()</div></li>
<li><div class=fn><a href="#~QDesktopWidget"><b>~QDesktopWidget</b></a> ()</div></li>
<li><div class=fn>bool <a href="#isVirtualDesktop"><b>isVirtualDesktop</b></a> () const</div></li>
<li><div class=fn>int <a href="#numScreens"><b>numScreens</b></a> () const</div></li>
<li><div class=fn>int <a href="#primaryScreen"><b>primaryScreen</b></a> () const</div></li>
<li><div class=fn>int <a href="#screenNumber"><b>screenNumber</b></a> ( QWidget * widget = 0 ) const</div></li>
<li><div class=fn>int <a href="#screenNumber-2"><b>screenNumber</b></a> ( const QPoint & point ) const</div></li>
<li><div class=fn>QWidget * <a href="#screen"><b>screen</b></a> ( int screen = -1 )</div></li>
<li><div class=fn>const QRect & <a href="#screenGeometry"><b>screenGeometry</b></a> ( int screen = -1 ) const</div></li>
<li><div class=fn>GDHandle <b>handle</b> ( int screen ) const</div></li>
</ul>
<hr><a name="details"></a><h2>Detailed Description</h2>
The QDesktopWidget class provides access to screen information on multi-head systems.
<p>
<p> 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, which usually has the size of the bounding
rectangle of all the screens (see <a href="#isVirtualDesktop">isVirtualDesktop</a>()). For an
application, one of the available screens is the primary screen, i.e.
the screen where the main widget resides (see <a href="#primaryScreen">primaryScreen</a>()). All
windows opened in the context of the application have to 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.
<p> The QDesktopWidget provides information about the geometry of the
available screens with <a href="#screenGeometry">screenGeometry</a>(). The number of screens
available is returned by <a href="#numScreens">numScreens</a>(). The screen number that a
particular point or widget is located in is returned by
<a href="#screenNumber">screenNumber</a>().
<p> Widgets provided by Qt use this class, for example, to place
tooltips, menus and dialog boxes according to the parent or
application widget.
<p> Applications can use this class to save window positions, or to place
child widgets on one screen.
<p> <center><img src="qdesktopwidget.png" alt="Managing Multiple Screens"></center> In the illustration above, Application One's primary screen is
screen 0, and App Two's primary screen is screen 1.
<p>See also <a href="advanced.html">Advanced Widgets</a> and <a href="environment.html">Environment Classes</a>.
<hr><h2>Member Function Documentation</h2>
<h3 class=fn><a name="QDesktopWidget"></a>QDesktopWidget::QDesktopWidget ()
</h3>
Creates the desktop widget.
<p> 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.
<p> Instead of using QDesktopWidget directly, use QAppliation::desktop().
<h3 class=fn><a name="~QDesktopWidget"></a>QDesktopWidget::~QDesktopWidget ()
</h3>
Destroy the object and free allocated resources.
<h3 class=fn>bool <a name="isVirtualDesktop"></a>QDesktopWidget::isVirtualDesktop () const
</h3>
Returns TRUE if the system manages the available screens in a virtual
desktop; otherwise returns FALSE.
<p> For virtual desktops, <a href="#screen">screen</a>() will always return the same widget.
The size of the virtual desktop is the size of this desktop widget.
<h3 class=fn>int <a name="numScreens"></a>QDesktopWidget::numScreens () const
</h3>
Returns the number of available screens.
<p> <p>See also <a href="#primaryScreen">primaryScreen</a>().
<h3 class=fn>int <a name="primaryScreen"></a>QDesktopWidget::primaryScreen () const
</h3>
Returns the index of the primary screen.
<p> <p>See also <a href="#numScreens">numScreens</a>().
<h3 class=fn><a href="qwidget.html">QWidget</a> * <a name="screen"></a>QDesktopWidget::screen ( int screen = -1 )
</h3>
Returns a widget that represents the screen with index <em>screen</em>.
This widget can be used to draw directly on the desktop, using an
unclipped painter like this:
<p> <pre>
<a href="qpainter.html">QPainter</a> paint( QApplication::<a href="qapplication.html#desktop">desktop</a>()->screen( 0 ), TRUE );
paint.draw...
...
paint.<a href="qpainter.html#end">end</a>();
</pre>
<p> If the system uses a virtual desktop, the returned widget will have
the geometry of the entire virtual desktop i.e. bounding every <em>screen</em>.
<p> <p>See also <a href="#primaryScreen">primaryScreen</a>(), <a href="#numScreens">numScreens</a>() and <a href="#isVirtualDesktop">isVirtualDesktop</a>().
<h3 class=fn>const <a href="qrect.html">QRect</a> & <a name="screenGeometry"></a>QDesktopWidget::screenGeometry ( int screen = -1 ) const
</h3>
Returns the geometry of the screen with index <em>screen</em>.
<p> <p>See also <a href="#screenNumber">screenNumber</a>().
<h3 class=fn>int <a name="screenNumber"></a>QDesktopWidget::screenNumber ( <a href="qwidget.html">QWidget</a> * widget = 0 ) const
</h3>
Returns the index of the screen that contains the largest
part of <em>widget</em>, or -1 if the widget not on a screen.
<p> <p>See also <a href="#primaryScreen">primaryScreen</a>().
<h3 class=fn>int <a name="screenNumber-2"></a>QDesktopWidget::screenNumber ( const <a href="qpoint.html">QPoint</a> & point ) const
</h3>
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Returns the index of the screen that contains <em>point</em>, or -1 if no
screen contains the point.
<p> <p>See also <a href="#primaryScreen">primaryScreen</a>().
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