ST QML Type

Spatial Type singleton. More...

• List of all members, including inherited members

Properties

• projectionDataPaths : QStringList
• spatialReferenceDatabase : SqlDatabase

Signals

• srsDatabaseChanged()

Methods

• clearProjectionCache()
• object geometry(var data)
• ST_Point point(string text)
• ST_Point point(qgeocoordinate coordinate)
• ST_Point point(double x, double y)
• ST_Point point(double x, double y, int srid)
• ST_Projection projection(int srid)
• var spatialReference(int srid)

Detailed Description

The ST (Spatial Type) component contains methods for geometry construction and projection. This is a singleton component, meaning it does not need to be instantiated.

This code sample imports a spatial reference system from SqlDatabase into ST, by writing it into the spatialReferenceDatabase property. A specific record is then printed into the console log using the spatialReference method.

Item {
        SqlDatabase {
                id: db

                databaseName: ":memory:"
        }

        Component.onCompleted: {
                db.open();

                db.query( [
                        "CREATE TABLE SPATIAL_REF_SYS ( ",
                        "    SRID INTEGER NOT NULL PRIMARY KEY,",
                        "    AUTH_NAME VARCHAR(256),",
                        "    AUTH_SRID INTEGER,",
                        "    SRTEXT VARCHAR(2048),",
                        "    PROJ4TEXT VARCHAR(2048)",
                        ");" ].join("\n")
                        );

                db.query( [
                        "INSERT into spatial_ref_sys ",
                        "(srid, auth_name, auth_srid, proj4text, srtext) ",
                        "values ( ",
                        "94326, ",
                        "'epsg', ",
                        "4326, ",
                        "'+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs ', ",
                        "'GEOGCS[\"WGS 84\",DATUM[\"WGS_1984\",SPHEROID[\"WGS 84\",6378137,298.257223563,AUTHORITY[\"EPSG\",\"7030\"]],AUTHORITY[\"EPSG\",\"6326\"]],PRIMEM[\"Greenwich\",0,AUTHORITY[\"EPSG\",\"8901\"]],UNIT[\"degree\",0.01745329251994328,AUTHORITY[\"EPSG\",\"9122\"]],AUTHORITY[\"EPSG\",\"4326\"]]');",
                ].join("\n") );

                ST.spatialReferenceDatabase = db;

                console.log(JSON.stringify(ST.spatialReference(94326), undefined, 2));

                // The expected console output from this code sample:
                // {
                //   "AUTH_NAME": "epsg",
                //   "AUTH_SRID": 4326,
                //   "PROJ4TEXT": "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs ",
                //   "SRID": 94326,
                //   "SRTEXT": "GEOGCS[\"WGS 84\",DATUM[\"WGS_1984\",SPHEROID[\"WGS 84\",6378137,298.257223563,AUTHORITY[\"EPSG\",\"7030\"]],AUTHORITY[\"EPSG\",\"6326\"]],PRIMEM[\"Greenwich\",0,AUTHORITY[\"EPSG\",\"8901\"]],UNIT[\"degree\",0.01745329251994328,AUTHORITY[\"EPSG\",\"9122\"]],AUTHORITY[\"EPSG\",\"4326\"]]"
                // }

                db.close();
        }
}

Property Documentation

Signal Documentation

Method Documentation