MapPolyline

The MapPolyline type displays a polyline on a map. More...

Import Statement:	import QtLocation 5.11
Since:	QtLocation 5.0

List of all members, including inherited members

Properties

line
- line.width : int
- line.color : color
path : list<coordinate>

Methods

void addCoordinate(coordinate)
coordinate containsCoordinate(coordinate)
coordinate coordinateAt(index)
void insertCoordinate(index, coordinate)
int pathLength()
void removeCoordinate(index)
void removeCoordinate(coordinate)
void replaceCoordinate(index, coordinate)
int setPath(geopath path)

Detailed Description

The MapPolyline type displays a polyline on a map, specified in terms of an ordered list of coordinates. The coordinates on the path cannot be directly changed after being added to the Polyline. Instead, copy the path into a var, modify the copy and reassign the copy back to the path.

var path = mapPolyline.path;
path[0].latitude = 5;
mapPolyline.path = path;

Coordinates can also be added and removed at any time using the addCoordinate and removeCoordinate methods.

By default, the polyline is displayed as a 1-pixel thick black line. This can be changed using the line.width and line.color properties.

Performance

MapPolylines have a rendering cost that is O(n) with respect to the number of vertices. This means that the per frame cost of having a polyline on the Map grows in direct proportion to the number of points in the polyline.

Like the other map objects, MapPolyline is normally drawn without a smooth appearance. Setting the opacity property will force the object to be blended, which decreases performance considerably depending on the hardware in use.

Example Usage

The following snippet shows a MapPolyline with 4 points, making a shape like the top part of a "question mark" (?), near Brisbane, Australia. The line drawn is 3 pixels in width and green in color.

Map {
    MapPolyline {
        line.width: 3
        line.color: 'green'
        path: [
            { latitude: -27, longitude: 153.0 },
            { latitude: -27, longitude: 154.1 },
            { latitude: -28, longitude: 153.5 },
            { latitude: -29, longitude: 153.5 }
        ]
    }
}