[Qgis-user] S57 map files

[Martin Dobias]

On Sun, Jan 18, 2009 at 6:52 PM, Chris h <chris123 at magma.ca> wrote:
> On Sunday 18 January 2009 11:04:13 Florian El Ahdab wrote:
>> - I believe Qgis doesn't use the S57 sublayers and that's why nothing gets
>> displayed. Is there any chance that I am right? If I am right,
>
> Your most likely correct.

Yes, QGIS always opens first sublayers and doesn't care about the rest.


>> I would like
>> to help with the implementation for this kind of problem. Can anyone in the
>> dev team give me directions on where to begin (I have spent some time in
>> the source and API of both Qgis and GDAL and feel I can contribute here...)
>
> Perhaps a good start would be reviewing the submitted material above and then
> following the directions and advice of the qgis development team.

First of all, a small change in OGR provider in QGIS will be needed to
allow sublayers. This provider awaits a file as input string - let's
add an optional parameter that would specify the layer inside the
file, e.g.:
/data/gis/s-57/ca49995b.000&layer=4
(note the added "&layer=4")

Then in GUI: when an input file for OGR provider is selected, check
whether there's more than one sublayer - if so, open a dialog and let
user select which sublayers he would like to see. Create input strings
for OGR provider from the chosen sublayers and load them.

Patches are always welcome :-)

Martin