Thanks to Terry Haimann to bring Mapview to my attention. I have some questions about the component.
I saw the component can read gpx-tracks. Can it read the extensions (TrackPointExtension) ? Like in this :
<trkpt lat="51.0034615" lon="3.8245881">
<ele>48.89</ele>
<time>2026-03-09T09:02:39.353Z</time>
<extensions>
<TrackPointExtension
xmlns="http://www.garmin.com/xmlschemas/TrackPointExtension/v2"> <hr>151</hr>
<cad>81</cad>
<speed>5.90185754985755</speed>
<bearing>260.0</bearing>
</TrackPointExtension>
</extensions>
</trkpt>
The hr, cad, and speed items ?
Can I access the individual trackpoints-data (more specific those extensions) ?
Mailing lists / lazarus / 2026-03
Mapview component questions
2 messages · 2 people ·
- Koenraad Lelong 1
- Werner Pamler 1
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Koenraad Lelong wrote 18 lines
I saw the component can read gpx-tracks. Can it read the extensions
(TrackPointExtension) ? Like in this :
????? <trkpt lat="51.0034615" lon="3.8245881">
??????? <ele>48.89</ele>
??????? <time>2026-03-09T09:02:39.353Z</time>
??????? <extensions>
????????? <TrackPointExtension
xmlns="http://www.garmin.com/xmlschemas/TrackPointExtension/v2">
??????????? <hr>151</hr>
??????????? <cad>81</cad>
??????????? <speed>5.90185754985755</speed>
??????????? <bearing>260.0</bearing>
????????? </TrackPointExtension>
??????? </extensions>
????? </trkpt>
The hr, cad, and speed items ?
Can I access the individual trackpoints-data (more specific those
extensions) ?
The TGpxReader class (in unit mvGPX) reads only the minimum amount of data needed by the MapView: latitude, longitude, date/time, elevation, visible, line colors, etc. The method ReadExtensions, however, has been declared as virtual so that you can simply subclass the TGpxReader to override this method. It has the "extensions" DOMNode and the current gpstrack or gpspoint as parameters. TGPSTrack contains a list Points of TGPSPoints to store the information of the track points. TGPSPoint itself contains a field ExtraData (TObject) which is meant to store additional custom data, in this case the data read by your dedicated reader (hr, cad, speed).