You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
120 lines
4.6 KiB
120 lines
4.6 KiB
13 years ago
|
/****************************************************************************
|
||
|
|
**
|
||
|
|
** Qt/Embedded Virtual Framebuffer
|
||
|
|
**
|
||
|
|
** Copyright (C) 1992-2008 Trolltech ASA. All rights reserved.
|
||
|
|
**
|
||
|
|
** This file is part of the Qt GUI Toolkit.
|
||
|
|
**
|
||
|
|
** This file may be used under the terms of the GNU General
|
||
|
|
** Public License versions 2.0 or 3.0 as published by the Free
|
||
|
|
** Software Foundation and appearing in the files LICENSE.GPL2
|
||
|
|
** and LICENSE.GPL3 included in the packaging of this file.
|
||
|
|
** Alternatively you may (at your option) use any later version
|
||
|
|
** of the GNU General Public License if such license has been
|
||
|
|
** publicly approved by Trolltech ASA (or its successors, if any)
|
||
|
|
** and the KDE Free Qt Foundation.
|
||
|
|
**
|
||
|
|
** Please review the following information to ensure GNU General
|
||
|
|
** Public Licensing retquirements will be met:
|
||
|
|
** http://trolltech.com/products/qt/licenses/licensing/opensource/.
|
||
|
|
** If you are unsure which license is appropriate for your use, please
|
||
|
|
** review the following information:
|
||
|
|
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
|
||
|
|
** or contact the sales department at sales@trolltech.com.
|
||
|
|
**
|
||
|
|
** This file may be used under the terms of the Q Public License as
|
||
|
|
** defined by Trolltech ASA and appearing in the file LICENSE.QPL
|
||
|
|
** included in the packaging of this file. Licensees holding valid Qt
|
||
|
|
** Commercial licenses may use this file in accordance with the Qt
|
||
|
|
** Commercial License Agreement provided with the Software.
|
||
|
|
**
|
||
|
|
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
|
||
|
|
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
|
||
|
|
** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
|
||
|
|
** herein.
|
||
|
|
**
|
||
|
|
**********************************************************************/
|
||
|
|
|
||
|
|
/*! \page emb-qvfb.html
|
||
|
|
|
||
|
|
\title Qt/Embedded Virtual Framebuffer
|
||
|
|
|
||
|
|
The virtual framebuffer allows Qt/Embedded programs to be developed on
|
||
|
|
a desktop machine, without switching between consoles and X11.
|
||
|
|
|
||
|
|
The virtual framebuffer is located in \c $QTDIR/tools/qvfb.
|
||
|
|
|
||
|
|
\section1 Using the Virtual Framebuffer
|
||
|
|
|
||
|
|
\list 1
|
||
|
|
\i Configure Qt/Embedded with the \c -qvfb argument and compile the library:
|
||
|
|
\code
|
||
|
|
./configure -qvfb
|
||
|
|
make
|
||
|
|
\endcode
|
||
|
|
\i Compile \c qvfb as a normal Qt/X11 application and run it. Do \e not
|
||
|
|
compile it as a Qt/Embedded application.
|
||
|
|
\i Start a Qt/Embedded master application (i.e., construct
|
||
|
|
QApplication with the QApplication::GuiServer flag or use the \c
|
||
|
|
-qws command line parameter). You can specify to the server that
|
||
|
|
you wish to use the virtual framebuffer driver, e.g.:
|
||
|
|
\code
|
||
|
|
masterapp -qws -display QVFb:0
|
||
|
|
\endcode
|
||
|
|
\i Qt/Embedded will autodetect qvfb, so you can omit the \c -display
|
||
|
|
command line parameter if you know that qvfb is running, and that
|
||
|
|
the Qt/Embedded library supports qvfb. (If this is not the case,
|
||
|
|
Qt/Embedded will write to the real framebuffer, and your X11
|
||
|
|
display will be corrupted.)
|
||
|
|
|
||
|
|
\endlist
|
||
|
|
|
||
|
|
\c qvfb supports the following command line options:
|
||
|
|
|
||
|
|
\table
|
||
|
|
\header \i Option \i Meaning
|
||
|
|
\row
|
||
|
|
\i \c -width \e width
|
||
|
|
\i the width of the virtual framebuffer (default: 240).
|
||
|
|
\row
|
||
|
|
\i \c -height \e height
|
||
|
|
\i the height of the virtual framebuffer (default: 320).
|
||
|
|
\row
|
||
|
|
\i \c -depth \e depth
|
||
|
|
\i the depth of the virtual framebuffer (1, 8 or 32; default: 8).
|
||
|
|
\row
|
||
|
|
\i \c -nocursor
|
||
|
|
\i do not display the X11 cursor in the framebuffer window.
|
||
|
|
\row
|
||
|
|
\i \c -qwsdisplay \e :id
|
||
|
|
\i the Qt/Embedded display id to provide (default: :0).
|
||
|
|
\endtable
|
||
|
|
|
||
|
|
\section1 Virtual Framebuffer Design
|
||
|
|
|
||
|
|
The virtual framebuffer emulates a framebuffer using a shared memory region
|
||
|
|
(the virtual frame buffer) and a utility to display the framebuffer in a
|
||
|
|
window (\c qvfb). The regions of the display that have changed are updated
|
||
|
|
periodically, so you will see discrete snapshots of the framebuffer rather
|
||
|
|
than each individual drawing operation. For this reason drawing problems
|
||
|
|
such as flickering may not be apparent until the program is run using a real
|
||
|
|
framebuffer.
|
||
|
|
|
||
|
|
The target refresh rate can be set via the <b>View|Refresh Rate</b>
|
||
|
|
menu item. This will cause \c qvfb to check for updated regions more
|
||
|
|
frequently. The rate is a target only. If little drawing is being
|
||
|
|
done, the framebuffer will not show any updates between drawing
|
||
|
|
events. If an application is displaying an animation the updates will
|
||
|
|
be frequent, then the application and \c qvfb will compete for
|
||
|
|
processor time.
|
||
|
|
|
||
|
|
Mouse and keyboard events are passed to the Qt/Embedded master process via
|
||
|
|
named pipes.
|
||
|
|
|
||
|
|
The virtual framebuffer is a development tool only. No security issues have
|
||
|
|
been considered in the virtual framebuffer design. It should be avoided
|
||
|
|
in a production environment; do not configure production libraries with \c -qvfb.
|
||
|
|
|
||
|
|
*/
|