[QGIS-Developer] Labelling misplaced

Tue Nov 12 07:52:02 PST 2019

Cool!

Le mar. 12 nov. 2019 à 15:37, Luís Miguel Royo Pérez
<luis.miguel.royo at gmail.com> a écrit :
>
> Hi Régis,
>
> thanks a lot for your insights. Finally I caught the issue. It's easy, since the labelling layer is a view, everytime this view was updated, the id, changed, and then the messy thing happened. I fixed already.
> Again, thanks ^^
>
> El lun., 11 nov. 2019 a las 18:43, Régis Haubourg (<regis.haubourg at gmail.com>) escribió:
>>
>> Oh ok, expression taken from label connector plugin :)
>>
>> Be aware that it can be slow with big geometries and that it is a
>> temporary approach before having a native one in core (which I'd be
>> pleased to have implemented if anyone supports it).
>>
>> So it seems you have something messing the unique id's that auxiliary
>> storage database uses to link your data and qgis projected data when
>> you add a new feature. Are you sure your ID's and foreign keys beahve
>> like expected on the database side? For the auxiliary storage, a new
>> feature shouldn't have any x-y value and thus the label should fall
>> back to the automatic labeling options. In your case, it seems the
>> newly created feature inherits from the id of another feature. This is
>> a common case in labeling, and I remember the famous Mapinfo label
>> callout mix ups that occured when compressing datasets, just because
>> it didn't use real id's, but line number to identify features.
>>
>>
>> Régis
>>
>> Le lun. 11 nov. 2019 à 17:33, Luís Miguel Royo Pérez
>> <luis.miguel.royo at gmail.com> a écrit :
>> >
>> > Of course, here is:
>> >
>> > case when "auxiliary_storage_labeling_positionx" < $x and "auxiliary_storage_labeling_positiony" > $y and abs("auxiliary_storage_labeling_positiony"-$y) < abs("auxiliary_storage_labeling_positionx"-$x) THEN
>> >  make_line($geometry, make_point($x-abs("auxiliary_storage_labeling_positiony"-$y),"auxiliary_storage_labeling_positiony"),make_point("auxiliary_storage_labeling_positionx", "auxiliary_storage_labeling_positiony"))
>> > when  "auxiliary_storage_labeling_positionx" < $x and "auxiliary_storage_labeling_positiony" > $y and abs("auxiliary_storage_labeling_positiony"-$y) >= abs("auxiliary_storage_labeling_positionx"-$x) then
>> >   make_line($geometry, make_point($x,abs("auxiliary_storage_labeling_positionx"-$x)+$y),make_point("auxiliary_storage_labeling_positionx", "auxiliary_storage_labeling_positiony"))
>> > when "auxiliary_storage_labeling_positionx" < $x and "auxiliary_storage_labeling_positiony" < $y and abs("auxiliary_storage_labeling_positiony"-$y) < abs("auxiliary_storage_labeling_positionx"-$x) THEN
>> >   make_line($geometry, make_point($x-abs("auxiliary_storage_labeling_positiony"-$y),"auxiliary_storage_labeling_positiony"),make_point("auxiliary_storage_labeling_positionx", "auxiliary_storage_labeling_positiony"))
>> > when  "auxiliary_storage_labeling_positionx" < $x and "auxiliary_storage_labeling_positiony" < $y and abs("auxiliary_storage_labeling_positiony"-$y) >= abs("auxiliary_storage_labeling_positionx"-$x) then
>> >   make_line($geometry, make_point($x,$y-abs("auxiliary_storage_labeling_positionx"-$x)),make_point("auxiliary_storage_labeling_positionx", "auxiliary_storage_labeling_positiony"))
>> > when "auxiliary_storage_labeling_positionx" >= $x and "auxiliary_storage_labeling_positiony" > $y and abs("auxiliary_storage_labeling_positiony"-$y) > abs("auxiliary_storage_labeling_positionx"-$x) then --quadrant ur alternatif
>> >   make_line($geometry, make_point($x,"auxiliary_storage_labeling_positiony"-abs("auxiliary_storage_labeling_positionx"-$x)),make_point("auxiliary_storage_labeling_positionx", "auxiliary_storage_labeling_positiony"))
>> > when "auxiliary_storage_labeling_positionx" >= $x and "auxiliary_storage_labeling_positiony" > $y and abs("auxiliary_storage_labeling_positiony"-$y) < abs("auxiliary_storage_labeling_positionx"-$x) then
>> >    make_line($geometry, make_point($x+abs("auxiliary_storage_labeling_positiony"-$y),"auxiliary_storage_labeling_positiony"),make_point("auxiliary_storage_labeling_positionx", "auxiliary_storage_labeling_positiony"))
>> > when "auxiliary_storage_labeling_positionx" >= $x and "auxiliary_storage_labeling_positiony" <= $y and abs("auxiliary_storage_labeling_positiony"-$y) > abs("auxiliary_storage_labeling_positionx"-$x) THEN
>> >   make_line($geometry, make_point($x,$y-abs("auxiliary_storage_labeling_positionx"-$x)),make_point("auxiliary_storage_labeling_positionx", "auxiliary_storage_labeling_positiony"))
>> > when "auxiliary_storage_labeling_positionx" >= $x and "auxiliary_storage_labeling_positiony" <= $y and abs("auxiliary_storage_labeling_positiony"-$y) < abs("auxiliary_storage_labeling_positionx"-$x) THEN
>> >  make_line($geometry, make_point($x+abs("auxiliary_storage_labeling_positiony"-$y),"auxiliary_storage_labeling_positiony"),make_point("auxiliary_storage_labeling_positionx", "auxiliary_storage_labeling_positiony"))
>> >    END
>> >
>> >
>> >
>> >
>> > El lun., 11 nov. 2019 17:15, Régis Haubourg <regis.haubourg at gmail.com> escribió:
>> >>
>> >> Hi Luis, can you share your geometry generator expression please?
>> >> regards
>> >> Régis
>> >>
>> >> Le lun. 11 nov. 2019 à 09:04, Luís Miguel Royo Pérez
>> >> <luis.miguel.royo at gmail.com> a écrit :
>> >> >
>> >> > Hello everyone,
>> >> >
>> >> > I'm developing a QGIS plugin along with PostGIS and I'm facing some problems with labeling. This plugin creates several layers and tables. Some of these layers are views  (labeling layers), so if I edit the one fo the source layer the view changes and then the label. I explain more detailed:
>> >> >
>> >> > I have the following:
>> >> >
>> >> > One layer. Let's call it layer1.
>> >> > One none spatial table. Let's call it table1.
>> >> > One spatial view from these other two layers layer1 and table1 meant for labeling. Let's call it labelView1.
>> >> >
>> >> > The point is this, when I edit table1 adding a new element linked by a foreign key with layer1. The label position in labelView1 changes into a messy thing. The Style of labelView1 is the following:
>> >> >
>> >> > Symbol is a geometry generator. Since I want to create callouts from label to the geometry, wich is a point.
>> >> > The position of the label is saved on project. In the qgd file.
>> >> >
>> >> > I have seen this behaviour in Windows10 and in Ubuntu. The QGIS version is 3.4, but I tried to move to the new 3.10 version of QGIS, with the callouts new feature, but is the same result.
>> >> >
>> >> > As well I tried to reproduce it in a much simple way, but without succed, that's why I want to share a link with a GIF file showing this issue:
>> >> >
>> >> > https://gifyu.com/image/vMY7
>> >> >
>> >> > I've done the same but without fixed position,and the labels don't move, but the geometry_generator does.
>> >> >
>> >> > Is this a bug? Is there any way to prevent it?
>> >> >
>> >> > Thanks.
>> >> > --
>> >> > Luís Miguel Royo Pérez.
>> >> > Analista-Programador GIS
>> >> > C/ Antic Regne de Valencia nº 4. Manises (Valencia)
>> >> > Teléfono:+34  679846103
>> >> > webs:
>> >> > inisig.com
>> >> > geofibra.com
>> >> >
>> >> >
>> >> > _______________________________________________
>> >> > QGIS-Developer mailing list
>> >> > QGIS-Developer at lists.osgeo.org
>> >> > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer
>> >> > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
>
>
>
> --
> Luís Miguel Royo Pérez.
> Analista-Programador GIS
> C/ Antic Regne de Valencia nº 4. Manises (Valencia)
> Teléfono:+34  679846103
> webs:
> inisig.com
> geofibra.com
>
>