How to pass double from Qt c++ code to QML code? - c++

Question

I have this code in Qt
int main(int argc, char *argv[]) {
QGuiApplication app(argc,argv);
QQuickView view;
QUrl q(QStringLiteral("QML:///places_map.qml"));
view.setSource(QUrl(QStringLiteral("qrc:///places_map.qml")));
//I've tried this to init qml properties
QObject *object = view.rootObject();
object->setProperty("latitude", 48.4656371);
object->setProperty("longitude", 31.04900455);
QQuickItem *item = view.rootObject();
item->setProperty("device_latitude", 48.4656371);
item->setProperty("device_longitude", 35.04900455);
}
And my qml file:
import QtQuick 2.0
import QtPositioning 5.5
import QtLocation 5.6
Rectangle {
width: 720
height: 480
property double latitude: 0
property double longitude: 0
property double device_latitude: 0 //48.4656371
property double device_longitude: 0 //35.54900455
property variant location: QtPositioning.coordinate(latitude, longitude)
property variant deviceLocation: QtPositioning.coordinate(device_latitude, device_longitude)
Plugin {
id: myPlugin
name: "osm"
}
PlaceSearchModel {
id: searchModel
plugin: myPlugin
searchTerm: "Pizza"
searchArea: QtPositioning.circle(deviceLocation)
Component.onCompleted: update()
}
Map {
id: map
anchors.fill: parent
plugin: myPlugin;
center: location
zoomLevel: 13
MapItemView {
model: searchModel
delegate: MapQuickItem {
coordinate: deviceLocation //QtPositioning.coordinate(device_latitude, device_longitude)
anchorPoint.x: image.width * 0.5
anchorPoint.y: image.height
sourceItem: Column {
Image { id: image; source: "marker.png" }
Text { text: title; font.bold: true }
}
}
}
}
}
In qml code properties double latitude and longitude set the view on map
but map shows place with latitude = 0 and longtitude = 0
If I set the correct coordinates in qml code everything works
How can I init this value from c++ code so that map will show my city ?

Answer 1

Using Q_PROPERTY would be better. Exposing Attributes of C++
I have it working like this:
main.cpp
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQuickItem>
#include <QQuickView>
int main(int argc, char *argv[])
{
QGuiApplication app(argc, argv);
QQuickView view;
view.setSource(QUrl(QStringLiteral("qrc:/main.qml")));
QQuickItem *item = view.rootObject();
item->setProperty("number", 22.002);
view.show();
return app.exec();
}
main.qml
import QtQuick 2.4
import QtQuick.Window 2.2
Rectangle{
visible: true
width: 640
height: 480
property double number : 0
Text {
id: textEdit
text: number
verticalAlignment: Text.AlignVCenter
anchors.top: parent.top
anchors.horizontalCenter: parent.horizontalCenter
anchors.topMargin: 20
}
}