Gypsy plugin: add documentation

This patch adds a separate documentation page for the Gypsy plugin.

Task-number: QTBUG-74995
Change-Id: Id07d9ebee60de98ad780cb015a7278d74e68f0d9
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>
(cherry picked from commit 289bd144e0916cd2a643214874005c40285dce97)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

3 files changed, 122 insertions, 1 deletions

diff --git a/src/positioning/doc/src/external-resources.qdoc b/src/positioning/doc/src/external-resources.qdoc
index 41da9bb1..948249d9 100644
--- a/src/positioning/doc/src/external-resources.qdoc
+++ b/src/positioning/doc/src/external-resources.qdoc
@@ -54,3 +54,8 @@
 \externalpage https://www.freedesktop.org/software/geoclue/docs/gdbus-org.freedesktop.GeoClue2.Client.html#gdbus-property-org-freedesktop-GeoClue2-Client.DesktopId
 \title GeoClue DesktopId property
 */
+
+/*!
+\externalpage https://gypsy.freedesktop.org/wiki/
+\title Gypsy daemon
+*/
diff --git a/src/positioning/doc/src/plugins/gypsy.qdoc b/src/positioning/doc/src/plugins/gypsy.qdoc
new file mode 100644
index 00000000..9b59314a
--- /dev/null
+++ b/src/positioning/doc/src/plugins/gypsy.qdoc
@@ -0,0 +1,115 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:FDL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Free Documentation License Usage
+** 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. Please review the following information to ensure
+** the GNU Free Documentation License version 1.3 requirements
+** will be met: https://www.gnu.org/licenses/fdl-1.3.html.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+\page position-plugin-gypsy.html
+\title Qt Positioning Gypsy plugin
+\ingroup QtPositioning-plugins
+
+\brief Uses the Gypsy daemon to provide satellite information
+
+\section1 Overview
+
+The plugin is an interface to the \l {Gypsy daemon}. It requires the daemon
+to be installed and running on the system to function.
+
+The plugin uses D-Bus and GLib to connect to GPS device and provide satellite
+information.
+
+Currently the plugin \e {does not} provide positioning information.
+
+The plugin can be loaded using provider name \b gypsy.
+
+\section1 Parameters
+
+The following table lists parameters that \e can be passed to the gypsy
+plugin.
+
+\table
+\header
+    \li Parameter
+    \li Description
+\row
+    \li deviceName
+    \li The name of the device (or path to the device file) that will be used
+        to provide satellite information. The typical values can be
+        \c {/dev/ttyUSB0} or \c {/dev/ttyACM0}.
+\row
+    \li gconfKey
+    \li The key that will be used to extract device name from the GConf
+        configuration system.
+\endtable
+
+The plugin supports two ways of specifying the device name:
+\list
+    \li Specify the device name directly with the \e deviceName plugin
+        parameter.
+    \li Specify the configuration key using \e gconfKey plugin parameter and
+        extract the device name from the GConf configuration system. This
+        approach is useful when the device name is already specified for some
+        other GConf-based application.
+\endlist
+
+By default, when none of the parameters is specified, the plugin will try to
+extract the device name from the GConf configuration system using the following
+hardcoded key:
+
+\badcode
+/apps/geoclue/master/org.freedesktop.Geoclue.GPSDevice
+\endcode
+
+\section2 Using GConf to set parameters
+
+To specify a value for a key in the GConf configuration system, use
+\e {gconftool-2} as follows:
+
+\badcode
+gconftool-2 -t string -s /apps/geoclue/master/org.freedesktop.Geoclue.GPSDevice /dev/ttyUSB0
+\endcode
+
+\section1 Usage example
+
+The following examples show how to create a \b gypsy satellite info source
+from C++.
+
+Specifying device name directly:
+
+\code
+QVariantMap parameters;
+parameters["deviceName"] = "/dev/ttyACM0";
+QGeoSatelliteInfoSource *source = QGeoSatelliteInfoSource::createSource("gypsy", parameters, this);
+\endcode
+
+Using GConf key:
+
+\code
+QVariantMap parameters;
+parameters["gconfKey"] = "/apps/myapp/mykey";
+QGeoSatelliteInfoSource *source = QGeoSatelliteInfoSource::createSource("gypsy", parameters, this);
+\endcode
+
+*/
diff --git a/src/positioning/doc/src/qtpositioning-plugins.qdoc b/src/positioning/doc/src/qtpositioning-plugins.qdoc
index c87a6d01..c75896f4 100644
--- a/src/positioning/doc/src/qtpositioning-plugins.qdoc
+++ b/src/positioning/doc/src/qtpositioning-plugins.qdoc
@@ -49,7 +49,8 @@ Some plugins already ship with Qt. These are:
         provides an interface to the GeoClue v2 D-Bus service.
     \row
         \li \b gypsy
-        \li Interfaces with \l{https://gypsy.freedesktop.org/wiki/}{Gypsy} daemon. Requires Gypsy to be present to function.
+        \li A \l {Qt Positioning Gypsy plugin}{Gypsy} backend that provides
+        an interface to the Gypsy daemon.
     \row
         \li \b winrt
         \li Wraps WinRT positioning subsystem. Available only on WinRT and Windows10.