MapItemGroup QML Type▲
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Import Statement: import QtLocation 6.5
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Since:: QtLocation 5.9
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Group: MapItemGroup is part of QML Maps Plugin
I. Detailed Description▲
Its purpose is to enable code modularization by allowing the usage of qml files containing map elements related to each other, and the associated bindings.
The release of this API with Qt 5.9 is a Technology Preview.
I-1. Example Usage▲
The following snippet shows how to use a MapItemGroup to create a MapCircle, centered at the coordinate (63, -18) with a radius of 100km, filled in red, surrounded by an ondulated green border, both contained in a semitransparent blue circle with a MouseArea that moves the whole group. This group is defined in a separate file named PolygonGroup.qml:
import QtQuick
import QtPositioning
import QtLocation
MapItemGroup {
id: itemGroup
property alias position: mainCircle.center
property var radius: 100 * 1000
property var borderHeightPct : 0.3
MapCircle {
id: mainCircle
center : QtPositioning.coordinate(40, 0)
radius: itemGroup.radius * (1.0 + borderHeightPct)
opacity: 0.05
visible: true
color: 'blue'
MouseArea{
anchors.fill: parent
drag.target: parent
id: maItemGroup
}
}
MapCircle {
id: groupCircle
center: itemGroup.position
radius: itemGroup.radius
color: 'crimson'
onCenterChanged: {
groupPolyline.populateBorder();
}
}
MapPolyline {
id: groupPolyline
line.color: 'green'
line.width: 3
function populateBorder() {
groupPolyline.path = [] // clearing the path
var waveLength = 8.0;
var waveAmplitude = groupCircle.radius * borderHeightPct;
for (var i=0; i <= 360; i++) {
var wavePhase = (i/360.0 * 2.0 * Math.PI )* waveLength
var waveHeight = (Math.cos(wavePhase) + 1.0) / 2.0
groupPolyline.addCoordinate(groupCircle.center.atDistanceAndAzimuth(groupCircle.radius + waveAmplitude * waveHeight , i))
}
}
Component.onCompleted: {
populateBorder()
}
}
}PolygonGroup.qml is now a reusable component that can then be used in a Map as:
Map {
id: map
PolygonGroup {
id: polygonGroup
position: QtPositioning.coordinate(63,-18)
}
}