// Copyright (C) 2017 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only

/*!
    \example mapviewer
    \title Map Viewer (QML)
    \ingroup qtlocation-examples
    \examplecategory {Mobile}
    \examplecategory {Positioning & Location}

    \brief The Map Viewer example shows how to display and interact with a map,
           search for an address, and find driving directions.

    \image mapviewer.png

    This is a large example covering many basic uses of maps, positioning, and
    navigation services in Qt Location. This page is divided into sections
    covering each of these areas of functionality with snippets from the code.

    \include examples-run.qdocinc

    \include example-parameters.qdocinc

    \section1 Overview

    QML types shown in this example:

    \list
    \li Displaying a map
        \list
        \li \l{QtLocation::Map}{Map}
        \li \l{QtLocation::MapView}{MapView}
        \li \l[QtPositioning]{geoCoordinate}
        \endlist
    \li Finding an address
        \list
        \li \l{QtLocation::GeocodeModel}{GeocodeModel}
        \li \l{QtLocation::MapItemView}{MapItemView}
        \li \l{QtLocation::MapCircle}{MapCircle}
        \endlist
    \li Directions and travel routes
        \list
        \li \l{QtLocation::RouteModel}{RouteModel}
        \li \l{QtLocation::MapRoute}{MapRoute}
        \endlist
    \endlist

    \section1 Displaying a Map

    Drawing a map on-screen is accomplished using the MapView type, as shown
    below.

    \snippet mapviewer/map/MapComponent.qml top
    \snippet mapviewer/map/MapComponent.qml coord
    \snippet mapviewer/map/MapComponent.qml end

    The MapView consists of a \l {MapView::map}{map} and extends it for basic navigation
    capabilities.
    In this example, we give the map an initial center \l [QtPositioning]{geoCoordinate}
    with a set latitude and longitude. We also set the initial zoom level to 50% (halfway between
    the maximum and minimum).

    \section1 Finding an Address (Geocoding)

    To locate a certain address or place on the map uses a process called
    geocoding. In order to perform a geocode operation, we first need to adjust
    our Map object to be able to receive the result.

    Receiving results of geocoding is done through a GeocodeModel:

    \snippet mapviewer/map/MapComponent.qml geocodemodel0

    To display the contents of the GeocodeModel we use a MapItemView:

    \snippet mapviewer/map/MapComponent.qml geocodeview

    MapItemView uses an object called a \c{delegate} to act as a template for the
    items it creates. This can contain any map object desired, but in this case
    we show a MapQuickItem that contains an image of a marker:

    \snippet mapviewer/map/MapComponent.qml pointdel0
    \snippet mapviewer/map/MapComponent.qml pointdel1

    With these three objects, we have enough to receive Geocode responses and
    display them on our Map. The final piece is to send the actual Geocode
    request.

    To send a geocode request, first we create an \l [QML]{Address} object, and fill it
    in with the desired parameters.

    \snippet mapviewer/Main.qml geocode0

    Then we set \c{geocodeModel.query} to the filled in \l [QML]{Address},
    and call update() on the GeocodeModel.

    \snippet mapviewer/map/MapComponent.qml geocode1

    \section1 Directions and Travel Routes

    Similar to the GeocodeModel, Qt Location also features the RouteModel type,
    which allows information about routes (for example driving directions) between two
    or more points, to be received and used with a \l{Map}.

    Here again, we instantiate the RouteModel as a property of our Map:

    \snippet mapviewer/map/MapComponent.qml routemodel0

    To display the contents of a model to the user, we need a view. Once again
    we will use a MapItemView, to display the Routes as objects on the Map:

    \snippet mapviewer/map/MapComponent.qml routeview0

    To act as a template for the objects we wish the view to create, we create
    a delegate component:

    \snippet mapviewer/map/MapComponent.qml routedelegate0

    With the model, view and delegate now complete, the only missing component
    is some kind of control over the model to begin the Route request process.
    In the simplest case, we can fill out a Route request using two already
    available \l [QtPositioning]{geoCoordinate}{coordinates}:

    \snippet mapviewer/Main.qml routecoordinate

    In the next snippet, we show how to set up the request object and instruct
    the model to update. We also instruct the map to center on the start
    coordinate for our routing request.

    \snippet mapviewer/map/MapComponent.qml routerequest0
    \snippet mapviewer/map/MapComponent.qml routerequest1
    \snippet mapviewer/map/MapComponent.qml routerequest2

    This is all that is required to display a Route on the Map. However, it is
    also useful to be able to retrieve the written directions and explanation
    of the travel route. In the example, these are displayed in a \l {ListView} element.
    To create this content, we use a standard \l {Models and Views in Qt Quick#Models}{ListModel} and
    \l {ListView} pair. The data in the \l {Models and Views in Qt Quick#Models}{ListModel} is
    built from the routeModel's output:

    \snippet mapviewer/forms/RouteList.qml routeinfomodel0
    \snippet mapviewer/forms/RouteList.qml routeinfomodel1
    \snippet mapviewer/forms/RouteList.qml routeinfomodel3

    Inside the RouteModel, as you can see above, we add an
    \l{QtLocation::RouteModel::status}{onStatusChanged} handler, which
    calls the \c{showRouteList()} which updates the \c{routeInfoModel}:

    \snippet mapviewer/forms/RouteList.qml routeinfomodel2
*/
