/****************************************************************************
**
** 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.
**
** $QT_BEGIN_LICENSE:FDL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** 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.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/

/*!
    \page qt-embedded-envvars.html

    \title Qt for Embedded Linux Environment Variables
    \ingroup qt-embedded-linux

    These environment variables are relevant to \l{Qt for Embedded Linux}
    users.

    \table
    \header \o Variable \o Description

    \row
    \o \bold POINTERCAL_FILE \target POINTERCAL_FILE

    \o Specifies the file containing the data used to calibrate the
    pointer device.

    See also QWSCalibratedMouseHandler and \l{Qt for Embedded Linux Pointer
    Handling}.

    \row
    \o \bold QT_ONSCREEN_PAINT \target QT_ONSCREEN_PAINT

    \o If defined, the application will render its widgets directly on
    screen. The affected regions of the screen will not be modified by
    the screen driver unless another window with a higher focus
    requests (parts of) the same region.

    Setting this environment variable is equivalent to setting the
    Qt::WA_PaintOnScreen attribute for all the widgets in the
    application.

    See also the Qt for Embedded Linux \l{Qt for Embedded Linux Architecture#Graphics
    Rendering}{graphics rendering} documentation.

    \row
    \o \bold QWS_SW_CURSOR \target QWS_SW_CURSOR
    \o If defined, the software mouse cursor is always used (even when using an
    accelerated driver that supports a hardware cursor).

    \row
    \o \bold QWS_DISPLAY \target QWS_DISPLAY
    \o

    Specifies the display type and framebuffer. For example, if the
    current shell is bash, ksh, zsh or sh:

    \snippet doc/src/snippets/code/doc_src_emb-envvars.qdoc 0

    The valid values for the \c <driver> argument are \c LinuxFb, \c
    QVFb, \c VNC, \c Transformed, \c Multi and \l
    {QScreenDriverPlugin::keys()}{keys} identifying custom drivers,
    and the \c {<display num>} argument is used to separate screens
    that are using the same screen driver and to enable multiple
    displays (see the \l {Running Qt for Embedded Linux Applications}
    documentation for more details).

    The driver specific options are described in the \l{Qt for Embedded Linux
    Display Management}{display management} documentation.

    \row
    \o \bold QWS_SIZE \target QWS_SIZE
    \o

    Specifies the size of the \l{Qt for Embedded Linux} window which is centered
    within the screen. For example, if the current shell is bash, ksh,
    zsh or sh:

    \snippet doc/src/snippets/code/doc_src_emb-envvars.qdoc 1

    \row
    \o \bold QWS_MOUSE_PROTO \target QWS_MOUSE_PROTO
    \o

    Specifies the driver for pointer handling. For example, if the
    current shell is bash, ksh, zsh or sh:

    \snippet doc/src/snippets/code/doc_src_emb-envvars.qdoc 2

    The valid values for the \c <driver> argument are \c MouseMan, \c
    IntelliMouse, \c Microsoft, \c VR41xx, \c LinuxTP, \c Yopy. \c
    Tslib and \l {QMouseDriverPlugin::keys()}{keys} identifying
    custom drivers, and the driver specific options are typically a
    device, e.g., \c /dev/mouse for mouse devices and \c /dev/ts for
    touch panels.

    Multiple mouse drivers can be specified in one go:

    \snippet doc/src/snippets/code/doc_src_emb-envvars.qdoc 3

    Input will be read from all specified drivers.
    Note that the \c Vr41xx driver also accepts two optional
    arguments: \c press=<value> defining a mouseclick (the default
    value is 750) and \c filter=<value> specifying the length of the
    filter used to eliminate noise (the default length is 3). For
    example:

    \snippet doc/src/snippets/code/doc_src_emb-envvars.qdoc 4

    See also \l {Qt for Embedded Linux Pointer Handling}.

    \row
    \o \bold QWS_KEYBOARD \target QWS_KEYBOARD
    \o

    Specifies the driver and device for character input. For example, if the
    current shell is bash, ksh, zsh or sh:

    \snippet doc/src/snippets/code/doc_src_emb-envvars.qdoc 5

    The valid values for the \c <driver> argument are \c SL5000, \c
    Yopy, \c VR41xx, \c TTY, \c USB and \l
    {QKbdDriverPlugin::keys()}{keys} identifying custom drivers,
    and the driver specific options are typically a device, e.g., \c
    /dev/tty0.

    Multiple keyboard drivers can be specified in one go:

    \snippet doc/src/snippets/code/doc_src_emb-envvars.qdoc 6

    Input will be read from all specified drivers.

    See also \l {Qt for Embedded Linux Character Input}.

    \endtable
*/