Caching mechanisms on GPX layers

[Niklas B]

Hi,

no the patch attached to the ticket is not related to this issue. There the
waypoints are just put in a list and sorted by time, it is intentional that
no new instance is created.

Here however I thought that the (maybe expensive) copying of the instances
was not necessary if I removed the cached values (dir), because the old
layer was going to be removed in the process anyway. But now with new
instances it works, so thanks for mentioning this :)

For some reason now some lines between waypoints in the old layer (that are
not even touched when adding a new one) disappear... but I haven't had a
closer look at that yet.

Cheers
Niklas


Michael Zangl <openstreetmap at michaelzangl.de> schrieb am So., 16. Sep.
2018, 8:22 AM:

> Hi,
>
> I just had a short look at the patch that is attached to the ticket,
> assuming it contains the code you used to split things.
>
> I did not have a deep look at it, but from what I can tell, you copy
> over the waypoints to a new layer.
>
> Mind that this should not be done. New WayPoints always need to be
> created for the new layer. So you need to call the WayPoint copy
> constructor for every waypoint you add to the new layer.
>
> The connectivity is cached using those waypoint objects.
>
> Michael
>
> On 15.09.2018 03:48, Niklas B wrote:
> > (maybe this time..?)
> >
> > Hi,
> >
> > I'm currently implementing an option to cut overlapping GPX tracks when
> > merging them into one layer (followup of #16681
> > <https://josm.openstreetmap.de/ticket/16681> "*allow multiple tracks to
> be
> > processed and prioritized (from different sources, e.g. GPS + phone +
> > Google Timeline)*", but when merging layers because this is not
> > specifically related to geotagging / geoimage layers).
> >
> > Everything works fine, but the resulting GPX layer is not displayed
> > correctly: Some lines are displayed between tracks that are not connected
> > anymore (because another track was on top of it, so the underlying track
> > needed to be split) and also some weird lines connecting points that were
> > never connected appear - haven't figured them out yet.
> >
> > Before I debug that any further: What caching mechanisms are there in
> > place, what do I have to reset? I'm already calling invalidate() (in
> > GpxData, which calls the appropriate listeners) and tried removing the
> > cached "dir" values from all of the waypoints, but it didn't help.
> > The layer will however be displayed perfectly fine if it's converted to a
> > data layer (and back) or saved as GPX and reloaded.
> >
> > Any ideas on what might be the reason for that?
> >
> > Thanks,
> > Niklas (Bjoeni)
> >
>
>