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Diffstat (limited to 'src/location/doc/src/examples/weatherinfo.qdoc')
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diff --git a/src/location/doc/src/examples/weatherinfo.qdoc b/src/location/doc/src/examples/weatherinfo.qdoc new file mode 100644 index 00000000..ad5ad5d5 --- /dev/null +++ b/src/location/doc/src/examples/weatherinfo.qdoc @@ -0,0 +1,109 @@ +/**************************************************************************** +** +** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/legal +** +** 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 Digia. For licensing terms and +** conditions see http://qt.digia.com/licensing. For further information +** use the contact form at http://qt.digia.com/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: http://www.gnu.org/copyleft/fdl.html. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \example weatherinfo + \title Weather Info (C++/QML) + + \brief The Weather Info example shows how to use the user's current position + to retrieve local content from a web service in a C++ plugin for QML. + + \ingroup qtlocation-examples + + Key Qt Location classes used in this example: + + \list + \li \l{QGeoPositionInfo} + \li \l{QGeoPositionInfoSource} + \endlist + + \image ../images/example-weatherinfo.png + + The key part of this example is the application's data model, contained + in the WeatherData and AppModel classes. WeatherData represents the weather + information taken from the HTTP service. It is a simple data class, but we + give it Q_PROPERTies to expose it nicely to QML, later. + + \snippet weatherinfo/appmodel.h 0 + \snippet weatherinfo/appmodel.h 1 + + AppModel models the state of the entire application. At startup, the + application first begins by waiting for network connectivity. We do + this using the QNetworkConfigurationManager and QNetworkSession family + of C++ APIs. + + \snippet weatherinfo/appmodel.cpp 0 + \snippet weatherinfo/appmodel.cpp 1 + + Once the network session is open, we proceed to get the platform's + default position source using QGeoPositionInfo::createDefaultSource() + + \snippet weatherinfo/appmodel.cpp 2 + + If no default source is available, we take a static location and fetch + weather for that. If, however, we do have a position source, we connect + its positionUpdated() signal to a slot on the AppModel and call + startUpdates(), which begins regular updates of device position. + + When a position update is received, we use the longitude and latitude + of the returned coordinate to retrieve the current "city" name for use + in the weather lookup. + + \snippet weatherinfo/appmodel.cpp 3 + + To inform the UI about this process, the cityChanged() signal is emitted + when a new city is used, and the weatherChanged() signal whenever a + weather update occurs. + + \snippet weatherinfo/appmodel.h 2 + \snippet weatherinfo/appmodel.h 3 + \snippet weatherinfo/appmodel.h 4 + + We use a QQmlListProperty for the weather forecast information, + which contains the next 4 days of forecast weather. This makes it + easy to access from QML. + + To expose these to the QML UI layer, we use the qmlRegisterType() + function. We call this once for each type we wish to register, before + loading the actual QML file. + + \snippet weatherinfo/main.cpp 0 + \snippet weatherinfo/main.cpp 1 + + Finally, in the actual QML, we instantiate the AppModel. + + \snippet weatherinfo/weatherinfo.qml 0 + \snippet weatherinfo/weatherinfo.qml 1 + \snippet weatherinfo/weatherinfo.qml 2 + + Once instantiated like this, we can use its properties elsewhere in the + QML document: + + \snippet weatherinfo/weatherinfo.qml 3 + \snippet weatherinfo/weatherinfo.qml 4 + +*/ |