GoogleMaps GPX Import / displaying labels

FNC TMS FNC Maps
1

Hello!

I'm using the TMSFNCGoogleMaps component (latest release TMS FNC Maps v3.6.0.2 | Friday, March 24, 2023).

I use the .LoadGPXFromFile function which works, the polylines are loaded properly.

So far I see, there is still no support for displaying labels in TMSFNCGoogleMaps or am I overlooking something?

I've tried to use the event OnCreateGPXTrack to access the data from the GPX import and get the required values for each "trk"-part .

Basically it works, I can access the nodes and the NodeName "name" is found as expected.

Example:
procedure TForm4.TMSFNCGoogleMaps1CreateGPXTrack(Sender: TObject; AEventData: TTMSFNCMapsGPXTrackEventData);
var i:Integer;
c:IDOMNodeList;
_name:String;
begin
if AEventData.Node.hasChildNodes then
begin
c:=AEventData.Node.childNodes;
for I := 0 to c.length-1 do
begin
if LowerCase(c.Item[i].nodeName)='name' then _name:=c.Item[i].nodeValue;
end;
end;

// Do something with _name
end;

In the GPX data looks like this:

...
trk>
name>Nauru FIR
type>FIR
extensions>
ogr:designator>ANAU</ogr:designator>
ogr:lower>0.0</ogr:lower>
/extensions>
trkseg>
trkpt lat="0.000090000089997" lon="160.000180000180023">
/trkpt>
trkpt lat="3.500013500013495" lon="160.000180000180023">
...
(had to remove the "<")

The problem is, c.Item[i].nodeValue is empty and not "Nauru FIR" as I expected.

Do you have any suggestion? Or do I have to parse the GPX File on my own to get the values?

By the way: a Centroid Property for Polylines/Polygones would be very nice.

Thanks in advance and kind regards
Andreas

2

Hi,

In TTMSFNCGoogleMaps you can connect an OverlayViews with a Marker to make it function like a label. This is explained in the following blog post:

Labels in general for TTMSFNCMaps were added recently and are explained here:
https://download.tmssoftware.com/doc/tmsfncmaps/components/ttmsfncmaps/#labels

Extra data from GPX files should be parsed manually. This is explained in the online doc:
https://download.tmssoftware.com/doc/tmsfncmaps/components/ttmsfncmaps/#loading-gpxgeojson

1 Like
3

Hi,
You refered to "Extra data from GPX files should be parsed manually. This is explained in the online doc:"

In the example is the following line:
HeartRate := StrToInt(NodeToString(FindNode(FindNode(AEventData.Node,
'extensions'), 'hr')));

Please be so kind and tell me, where to find the functions "NodeToString" and "FindNode".
Well, I found them in VCL.TMSFNCMaps, but I can't access them as they are not declared in the interface part.

Thanks and kind regards
Andreas

4

Hi,

We'll look into making these functions available publicly in a future version.
You can add both functions directly in your code like this:

function FindNode(const ANode: TTMSFNCMapsXMLDOMNode; const ANodeName: string): TTMSFNCMapsXMLDOMNode;
var
  I: Integer;
  rNode: TTMSFNCMapsXMLDOMNode;
begin
  Result := nil;
  for I := 0 to ANode.childNodes.length - 1 do
  begin
    rNode := ANode.childNodes[I];
    if rNode.NodeName = ANodeName then
      Result := rNode;
  end;
end;

function NodeToString(ANode: TTMSFNCMapsXMLDOMNode): string;
begin
  Result := '';
  if not Assigned(ANode) then
    Exit;

  Result := ANode.firstChild.nodeValue;
end