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671 lines
22 KiB
671 lines
22 KiB
/****************************************************************************
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**
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** Qt/Embedded (Qt on QWS) documentation
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**
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** Copyright (C) 2000-2008 Trolltech ASA. All rights reserved.
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**
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** This file is part of the TQt GUI Toolkit.
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**
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** This file may be used under the terms of the GNU General
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** Public License versions 2.0 or 3.0 as published by the Free
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** Software Foundation and appearing in the files LICENSE.GPL2
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** and LICENSE.GPL3 included in the packaging of this file.
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** Alternatively you may (at your option) use any later version
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** of the GNU General Public License if such license has been
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** publicly approved by Trolltech ASA (or its successors, if any)
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** and the KDE Free TQt Foundation.
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**
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** Please review the following information to ensure GNU General
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** Public Licensing requirements will be met:
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** http://trolltech.com/products/qt/licenses/licensing/opensource/.
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** If you are unsure which license is appropriate for your use, please
|
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** review the following information:
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** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
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** or contact the sales department at sales@trolltech.com.
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**
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** This file may be used under the terms of the Q Public License as
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** defined by Trolltech ASA and appearing in the file LICENSE.QPL
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** included in the packaging of this file. Licensees holding valid Qt
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** Commercial licenses may use this file in accordance with the Qt
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** Commercial License Agreement provided with the Software.
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**
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** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
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** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
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** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
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** herein.
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**
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**********************************************************************/
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/*!
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\page emb-install.html
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\title Installing Qt/Embedded
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This installation procedure is written for Linux. It may need
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to be modified for other platforms.
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\list 1
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\i Unpack the archive if you have not done so already
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\code
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cd <anywhere>
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gunzip qt-embedded-commercial-VERSION.tar.gz # uncompress the archive
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tar xf qt-embedded-commercial-VERSION.tar # unpack it
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\endcode
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Replace \c VERSION with the Qt/Embedded version number throughout.
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This document assumes that the archive is installed as \c{~/qt-embedded-commercial-VERSION}.
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\i Compile the Qt/Embedded library and examples.
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\code
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cd ~/qt-embedded-commercial-VERSION
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export TQTDIR=~/qt-embedded-commercial-VERSION
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./configure
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make
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\endcode
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The configuration system is designed to allow platform-specific options
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to be added, but in general all Linux systems which have framebuffer
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support can use the "linux-generic-g++" platform.
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The configuration system also supports cross-compilers:
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to build on Linux/x86 for the Linux/MIPSEL target, you would use:
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\code
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./configure -embedded mips
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\endcode
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Only a small number of configurations are predefined.
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You can create your own custom configuration by adding new files
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to the \c mkspecs/qws/ directory. Use existing similar configurations
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as a starting point.
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<b>Note</b>: Due to a bug in the configure script, cross-compiling on
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a little-endian machine (e.g. x86) for a big-endian processor
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(e.g. PowerPC) will use the host's endianness instead of the
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target's. Workaround: after running configure, and before running
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make, edit \c $TQTDIR/include/ntqconfig.h and change the definition of
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\c TQ_BYTE_ORDER.
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\i Enable framebuffer support.
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You may need to recompile your kernel to enable the framebuffer.
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This document does not describe how to do this; the
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\link emb-framebuffer-howto.html Framebuffer HOWTO page \endlink
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contains a short description. (You should see
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a penguin logo at boot time when the frame buffer is enabled.)
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For Matrox G100/G200/G400 use the matrox frame buffer driver.
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For NVidia TNT cards use the nvidia frame buffer driver.
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For Mach64 and most other cards, use the vesafb driver.
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Note that some cards are only supported in VGA16 mode, this will
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not work with the current version of Qt/Embedded, since VGA/16 is
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not yet supported. You may need to upgrade your kernel, or even
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switch to an experimental kernel.
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The frame buffer must also be enabled with a boot parameter. See
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\c /usr/src/linux/Documentation/fb for details.
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The \c fbset program, which should be included in Linux distributions,
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may be used to switch video modes without rebooting the system. The
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video mode active when the server is started will be used. (8-bit
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modes are still experimental.) <b>Note</b>: \c fbset does not work
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with the vesafb driver.
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\i Change permissions.
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To run Qt/Embedded, you need write access to the framebuffer device
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\c /dev/fb0.
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You also need read access to the mouse device. (Note that
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\c /dev/mouse is normally a symbolic link; the actual mouse device
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must be readable.)
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\i How to run the demonstration program.
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Log into a virtual console and do this:
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\code
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cd ~/qt-embedded-commercial-VERSION/examples/launcher
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./start-demo
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\endcode
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\i Miscellaneous troubleshooting and known bugs.
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To kill gpm, run the following command as root:
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\code
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gpm -k
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\endcode
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In some cases, if the server does not work, it will work when run as root.
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Show processes using the framebuffer:
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\code
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fuser -v /dev/fb0
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\endcode
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Kill such processes:
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\code
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fuser -vk /dev/fb0
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\endcode
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or harsher:
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\code
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fuser -k -KILL /dev/fb0
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\endcode
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Show existing semaphores:
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\code
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ipcs
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\endcode
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Remove semaphores:
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\code
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ipcrm
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\endcode
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The communication between client and server is done through the
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named pipe \c /tmp/qtembedded-username/QtEmbedded-0; sometimes it may need to be deleted
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(e.g. if you run Qt/Embedded with root privileges then later as an unprivileged user).
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\i Customization.
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The Qt/Embedded library can be reduced in size by
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\link emb-features.html removing unnecessary features \endlink.
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\i This document shows how to use Qt/Embedded with the Linux framebuffer. For
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development and debugging purposes it is often easier to use the \link
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emb-tqvfb.html Qt/Embedded virtual framebuffer\endlink instead.
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\endlist
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*/
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/*! \page emb-fonts.html
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\title Fonts in Qt/Embedded
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\section1 Supported Formats
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Qt/Embedded supports four font formats:
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\table
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\row
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\i <b>TrueType (TTF)</b>
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\i The scalable font technology now standard on MS-Windows and Apple
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Macintosh, and becoming popular on X11.
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\row
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\i <b>Postscript Type1 (PFA/PFB)</b>
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\i Scalable fonts often used by printers, also popular on X11. These
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are similar in functionality to TTF fonts and are not discussed
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further in this document.
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\row
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\i <b>Bitmap Distribution Format<br>fonts (BDF)</b>
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\i A standard format for non-scalable fonts. A large number of BDF
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fonts are supplied as part of standard X11 distributions - most of
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these can be used with Qt/Embedded. You should \e not use these in a
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production system: they are very slow to load and take up a \e lot of
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storage space. Instead, render the BDF to a QPF.
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\row
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\i <b>TQt Prerendered Font (QPF)</b>
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\i A light-weight non-scalable font format specific to Qt/Embedded.
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\endtable
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Support for each of these font formats (except QPF which is always
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enabled) can be enabled or disabled independently by using the \link
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emb-features.html Qt/Embedded Features Definition\endlink. There is
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support in Qt/Embedded for writing a QPF font file from any font, so
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you can initially enable TTF and BDF formats, save QPF files for the
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fonts and sizes you need, then remove TTF and BDF support.
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See \link maketqpf.html tools/maketqpf\endlink for a tool that helps
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produce QPF files from the TTF and BDF, or just run your application
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with the \c -savefonts option.
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\section1 Memory Requirements
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With TTF fonts, each character in the font at a given point size is
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only rendered when first used in a drawing or metrics operation. With
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BDF fonts all characters are rendered when the font is used.
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With QPF fonts, the characters are stored in the same format that Qt
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uses for drawing.
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For example, a 10-point Times font containing the ASCII characters uses
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around 1300 bytes when stored in QPF format.
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Taking advantage of the way the QPF format is structured, Qt/Embedded
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memory-maps the data rather than reading and parsing it.
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This reduces RAM consumption even further.
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Scalable fonts use a larger amount of memory per font, but
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these fonts provide a memory saving if many different sizes of each
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font are needed.
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\section1 Smooth Fonts
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TTF, PFA, and QPF fonts can be rendered as \e{smooth} anti-aliased
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fonts to give superior readability, especially on low-resolution
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devices. The difference between smooth and non-smooth fonts is
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illustrated below (you may need to change your display to low
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resolution to see the difference):
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\img unsmooth.png unsmooth
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\img smooth.png smooth
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\section1 Unicode
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All fonts used by Qt/Embedded use the Unicode character encoding.
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Most fonts available today use this encoding, but they usually don't
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contain all the Unicode characters. A \e complete 16-point Unicode
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font uses over 1 MB of memory.
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\section1 The font definition file
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When Qt/Embedded applications run, they look for a file called
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\c $TQTDIR/lib/fonts/fontdir or
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\c /usr/local/qt-embedded/lib/fonts/fontdir. This file defines the
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fonts available to the application. It has the following format:
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\quote
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\e name \e file \e renderer \e italic \e weight \e size \e flags
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\endquote
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where
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\table
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\header \i Field \i Value
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\row \i \e name \i \c Helvetica, \c Times, etc.
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\row \i \e file \i \c helvR0810.bdf, \c verdana.ttf, etc.
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\row \i \e renderer \i \c BDF or \c FT
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\row \i \e italic \i \c y or \c n
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\row \i \e weight \i \c 50 is normal, \c 75 is bold, etc.
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\row \i \e size \i \c 0 for scalable or point size * 10 (i.e. \c 120
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for 12pt)
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\row \i \e flags \i \list
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\i \c s: smooth (anti-aliased)
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\i \c u: Unicode range when saving (default is Latin-1)
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\i \c a: ASCII range when saving (default is Latin-1)
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\endlist
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\endtable
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The font definition file does not specify QPF fonts; these are loaded
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directly from the directory containing the \c fontdir file, and must
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be named \e {name}_\e {size}_\e {weight}\e {italicflag}.qpf, where
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\table
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\header \i Field \i Value
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\row \i \e name \i \c helvetica, \c times, etc. (in lowercase)
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\row \i \e size \i point size * 10 (i.e. \c 120 for 12pt)
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\row \i \e italicflag \i \c i for italic, otherwise nothing.
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\row \i \e weight \i \c 50 is normal, \c 75 is bold, etc.
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\endtable
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If an application is run with the \c -savefonts command-line option,
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then whenever a font other than a QPF font is used, a corresponding QPF file
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is saved. This allows you to easily find the font usage of your applications
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and to generate QPF files so that you can eventually reduce the memory
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usage of your applications by disabling TTF and BDF support from Qt/Embedded,
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or by modifying the initialization of \c qws_savefonts in
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\c kernel/qapplication_qws.cpp of the Qt/Embedded library source code.
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In extreme cases of memory-saving, it is possible to save partially-rendered
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fonts (i.e. only the characters in "Product Name<sup>TM</sup>") if you are
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certain that these are the only characters you will need from the font.
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See QMemoryManager::savePrerenderedFont() for this functionality.
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\section1 Notes
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The font definition file, naming conventions for font files, and the format
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of QPF files may change in versions of Qt/Embedded after 3.
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<p>
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To generate QPF files of different rotations, the program must be re-run with
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an orientation that matches the desired rotation of the QPF output. An example to
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generate all 4 rotations of fonts would be to run the following at a real framebuffer:
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<pre>
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for dpy in LinuxFb Transformed:Rot90 Transformed:Rot180 Transformed:Rot270
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do
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QWS_DISPLAY=$dpy ./maketqpf "$@"
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done
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</pre>
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If programs are only ever run in one orientation on a device, only the one
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appropriate set of fonts is needed.
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<p>
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When enabled, Qt/Embedded uses the powerful FreeType2 library to implement
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TrueType and Type1 support.
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*/
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/*! \page emb-running.html
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\title Running Qt/Embedded applications
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A Qt/Embedded application requires a master application to be running
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or to be a master application itself. The master application is
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primarily responsible for managing top-level window regions, and
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pointer and keyboard input.
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Any Qt/Embedded application can be a master application by
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constructing the QApplication object with the
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\e{QApplication::GuiServer} type, or by being run with the \e{-qws}
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command line option.
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This document assumes you have the Linux framebuffer configured correctly
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and no master process is running. If you do not have a working Linux
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framebuffer you can use the
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\link emb-tqvfb.html Qt/Embedded virtual framebuffer\endlink, or you can
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run Qt/Embedded as a \link emb-vnc.html VNC server\endlink.
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Change to a Linux console and select an example to run, e.g. \c
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examples/widgets. Make sure $TQTDIR is set to the directory where you
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installed Qt/Embedded and add the $TQTDIR/lib directory to
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$LD_LIBRARY_PATH, e.g.:
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\code
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export TQTDIR=$HOME/qt-VERSION
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export LD_LIBRARY_PATH=$TQTDIR/lib:$LD_LIBRARY_PATH
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\endcode
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Run the application with the \e{-qws} option:
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|
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\code
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cd $TQTDIR/examples/widgets
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./widgets -qws
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\endcode
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You should see the \c widgets example appear. If your mouse doesn't
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work correctly you must specify the type of mouse to use. You can
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exit the master application at any time using
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<b>Ctrl+Alt+Backspace</b>.
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|
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If you wish to run additional applications you should run them as clients
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i.e. without the \e{-qws} option.
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|
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\section1 Displays
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Qt/Embedded allows multiple displays to be used simultaneously by running
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multiple Qt/Embedded master processes. This is achieved using the -display
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command line parameter or the $QWS_DISPLAY environment variable.
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|
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The -display parameter's syntax is:
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\code
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[gfx driver][:driver specific options][:display number]
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\endcode
|
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For example, if you want to use the mach64 driver on fb1 as display 2:
|
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\code
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$ ./launcher -display Mach64:/dev/fb1:2
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\endcode
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|
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To try this functionality you can do the following:
|
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\list 1
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\i Change to VC 1 (virtual console one) and run the launcher:
|
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|
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\code
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$ cd examples/launcher
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$ ./launcher
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\endcode
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|
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\i Switch to VC 2 and run another one:
|
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|
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\code
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$ cd examples/launcher
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$ ./launcher -display :1
|
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\endcode
|
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|
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Another launcher will be started. Start an application in this launcher.
|
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|
|
\i Press <b>Ctrl+Alt+F1</b> - back to display 0. You can also start
|
|
additional applications on a particular display by specifying the
|
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display id. Change to VC 3:
|
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|
|
\code
|
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$ cd examples/widgets
|
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$ ./widgets -display :1
|
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\endcode
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|
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will display the widgets example on dislpay :1 (VC 2).
|
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\endlist
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|
|
Only the master process needs to specify the driver/device part
|
|
explicitly. The clients get the information they need from the master
|
|
when they connect. So once you have a master server running using a
|
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particular driver, you can just use "client -display :n" to use
|
|
display n.
|
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|
|
\section1 Mouse Input
|
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|
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Qt/Embedded attempts to autodetect a mouse by default. The supported
|
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protocols are MouseMan, Microsoft, IntelliMouse and
|
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some other devices specific to certain hardware (e.g. Vr touch panel).
|
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To specify the mouse to use set the \c $QWS_MOUSE_PROTO environment
|
|
variable, e.g.:
|
|
\code
|
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export QWS_MOUSE_PROTO=IntelliMouse
|
|
\endcode
|
|
|
|
The mouse autodetection opens the serial devices and psaux which
|
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may cause conflicts with other programs using those devices. If
|
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this is the case then specify the mouse driver protocol and device
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explicitly.
|
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|
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\sa \link emb-pointer.html Qt/Embedded Pointer Handling \endlink
|
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|
|
*/
|
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|
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/*! \page emb-porting.html
|
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|
|
\title Porting your applications to Qt/Embedded
|
|
|
|
Existing TQt applications should require no porting provided there is no
|
|
platform dependent code. Platform dependent code includes system calls,
|
|
calls to the underlying window system (Windows or X11), and TQt platform
|
|
specific methods such as QApplication::x11EventFilter().
|
|
|
|
For cases where it is necessary to use platform dependent code there are
|
|
macros defined that can be used to enable/disable code for each platform
|
|
using \c #ifdef directives:
|
|
|
|
\table
|
|
\header \i Platform \i Macro
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|
\row \i Qt/X11 \i Q_WS_X11
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\row \i Qt/Windows \i Q_WS_WIN
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\row \i Qt/Embedded \i Q_WS_QWS
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\endtable
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|
|
|
Qt/Embedded also requires the following flags to be defined when compiling
|
|
applications:
|
|
\code
|
|
-DQWS -fno-exceptions -fno-rtti
|
|
\endcode
|
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|
|
Exceptions and RTTI are disabled in Qt/Embedded because they incur a large
|
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overhead in both size and speed.
|
|
*/
|
|
|
|
|
|
/*! \page emb-pointer.html
|
|
\title Qt/Embedded Pointer Handling
|
|
|
|
Pointer handling in Qt/Embedded works for any mouse or mouse-like
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|
device such as touchpanels and trackballs.
|
|
|
|
Usually only one pointer device is supported in an embedded device,
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|
but for demonstration purposes, Qt/Embedded includes a large number of
|
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supported devices.
|
|
|
|
\section1 Mouse Protocols
|
|
|
|
Mouse drivers can be enabled/disabled via the configure script. Running
|
|
./configure -help lists the available mouse drivers. Only the
|
|
"pc" mouse driver is enabled in the default configuration.
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|
|
Provided the "pc" mouse driver is enabled, Qt/Embedded auto-detects the
|
|
mouse type and device if it is one of
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|
the supported types on \c /dev/psaux or one of the \c /dev/ttyS?
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|
serial lines. If multiple mice are detected, all may be used simultaneously.
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|
|
Alternatively, you may set the environment variable \c QWS_MOUSE_PROTO
|
|
to determine which mouse to use. This environment variable may be set
|
|
to:
|
|
\quote
|
|
\e{\<protocol\>}\c{:}\e{\<device\>}
|
|
\endquote
|
|
where \e{\<protocol\>} is one of:
|
|
\list
|
|
\i MouseMan
|
|
\i IntelliMouse
|
|
\i Microsoft
|
|
\endlist
|
|
and \e{\<device\>} is the mouse device, often \c /dev/mouse. If no
|
|
such variable is specified, the built-in default is \c Auto, which
|
|
enables auto-detection of the mouse protocol and device.
|
|
|
|
To add another protocol, new subclasses of QWSMouseHandler and
|
|
QMouseDriverPlugin can be written and installed as plugins.
|
|
|
|
\section1 Touch Panels
|
|
|
|
Qt/Embedded ships with support for the NEC Vr41XX touchpanel and the
|
|
emerging linux touchpanel standard used by the iPAQ and Zaurus. These
|
|
are subclasses of QWSCalibratedMouseHandler which is in turn a subclass
|
|
of QWSMouseHandler in \c embedded/qmouse_qws.cpp.
|
|
*/
|
|
|
|
|
|
/*! \page emb-performance.html
|
|
\title Qt/Embedded Performance Tuning
|
|
|
|
When building embedded applications on low-powered devices, a number
|
|
of options are available that would not be considered in a desktop
|
|
application environment. These options reduce the memory and/or CPU
|
|
requirements at the cost of other factors.
|
|
|
|
\list
|
|
\i \link emb-features.html <b>Tuning the functionality of Qt\endlink
|
|
\i \link #general General programming style\endlink
|
|
\i \link #static Static vs. Dynamic linking\endlink
|
|
\i \link #alloc Alternative memory allocation\endlink
|
|
\endlist
|
|
|
|
\target general
|
|
\section1 General programming style
|
|
|
|
The following guidelines will improve CPU performance:
|
|
\list
|
|
\i Create dialogs and widgets once, then TQWidget::hide() and
|
|
TQWidget::show() them, rather than creating them and deleting
|
|
them every time they are needed.
|
|
This will use a little more memory, but will be much faster.
|
|
Try to create them the first time "lazily" to avoid slow
|
|
startup (e.g. only create a Find dialog the first time the
|
|
user invokes it).
|
|
\endlist
|
|
|
|
\target static
|
|
\section1 Static vs. Dynamic linking
|
|
|
|
A lot of CPU and memory is used by the ELF linking process. You can
|
|
make significant savings by using a static build of your application
|
|
suite. This means that rather than having a dynamic library (\c
|
|
libtqte.so) and a collection of executables which link dynamically to
|
|
that library, you build all the applications into a single executable
|
|
and statically link that with a static library (\c libtqt.a). This
|
|
improves start-up time, and reduces memory usage, at the expense of
|
|
flexibility (to add a new application, you must recompile the single
|
|
executable) and robustness (if one application has a bug, it might
|
|
harm other applications). If you need to install end-user
|
|
applications, this may not be an option, but if you are building a
|
|
single application suite for a device with limited CPU power and
|
|
memory, this option could be very beneficial.
|
|
|
|
To compile TQt as a static library, add the \c -static options when
|
|
you run configure.
|
|
|
|
To build your application suite as an all-in-one application, design each
|
|
application as a stand-alone widget or set of widgets, with only minimal
|
|
code in the main() function. Then, write an application that gives
|
|
some way to switch between the applications (e.g. a QIconView).
|
|
\link http://www.trolltech.com/products/qtopia/index.html Qtopia
|
|
\endlink is an example of this. It can be built either as a set of
|
|
dynamically linked executables, or as a single static application.
|
|
|
|
Note that you should generally still link dynamically against the
|
|
standard C library and any other libraries which might be used by
|
|
other applications on your device.
|
|
|
|
\target alloc
|
|
\section1 Alternative memory allocation
|
|
|
|
We have found that the libraries shipped with some C++ compilers on
|
|
some platforms have poor performance in the built-in "new" and "delete"
|
|
operators. You might gain performance by re-implementing these
|
|
functions. For example, you can switch to the plain C allocators
|
|
by adding the following to your code:
|
|
|
|
\code
|
|
void* operator new[]( size_t size )
|
|
{
|
|
return malloc( size );
|
|
}
|
|
|
|
void* operator new( size_t size )
|
|
{
|
|
return malloc( size );
|
|
}
|
|
|
|
void operator delete[]( void *p )
|
|
{
|
|
free( p );
|
|
}
|
|
|
|
void operator delete[]( void *p, size_t size )
|
|
{
|
|
free( p );
|
|
}
|
|
|
|
void operator delete( void *p )
|
|
{
|
|
free( p );
|
|
}
|
|
|
|
void operator delete( void *p, size_t size )
|
|
{
|
|
free( p );
|
|
}
|
|
\endcode
|
|
*/
|
|
|
|
/*! \page emb-vnc.html
|
|
|
|
\title Qt/Embedded as a VNC Server
|
|
|
|
The \link http://www.uk.research.att.com/vnc/ VNC \endlink protocol
|
|
allows you to view and interact with the computer's display from
|
|
anywhere on the network.
|
|
|
|
To use Qt/Embedded in this way, \c configure TQt with the \c -qt-gfx-vnc
|
|
option, and ensure that you also enable 16-bit display support. Run
|
|
your application via:
|
|
\code
|
|
application -display VNC:0
|
|
\endcode
|
|
then, run a VNC client pointing at the machine that is running your
|
|
application. For example, using the X11 VNC client to view the
|
|
application from the same machine:
|
|
\code
|
|
vncviewer localhost:0
|
|
\endcode
|
|
|
|
By default, Qt/Embedded will create a 640 by 480 pixel display. You
|
|
can change this by setting the \c QWS_SIZE environment variable to
|
|
another size, e.g. \c QWS_SIZE=240x320.
|
|
|
|
VNC clients are available for a vast array of display systems: X11,
|
|
Windows, Amiga, DOS, VMS, and dozens of others.
|
|
|
|
The \link emb-tqvfb.html TQt Virtual Framebuffer \endlink is an alternative
|
|
technique. It uses shared memory and thus is much faster and smoother, but
|
|
it does not operate over a network.
|
|
|
|
*/
|