[Qgis-developer] how to add crs to a new memory provider layer?

[Václav Řehák]

2010/8/9 Ricardo Filipe Soares Garcia da <ricardo.garcia.silva at gmail.com>:
> Hi Martin
>
> could you please elaborate a bit more on that? How can I get a pointer
> to this "QSettings" instance that you mention? I couldn't find any
> reference to it in the online API docs. Maybe you are talking about
> QgsProject class? If so, how can I get a pointer to it? I am coding in
> Python.

QSettings is part of PyQT4, not QGIS, so you find the doc in PyQT4
documentation [1] not in the QGIS API doc.

In my plugin I use it like this:

settings = QSettings()
dirName = settings.value("/UI/lastShapefileDir").toString()

Vaclav

[1] http://www.riverbankcomputing.co.uk/static/Docs/PyQt4/html/qsettings.html

>
> Thank you
>
> On Sat, Aug 7, 2010 at 4:23 PM, Martin Dobias <wonder.sk at gmail.com> wrote:
>> On Sat, Aug 7, 2010 at 12:00 AM, Ricardo Filipe Soares Garcia da
>> <ricardo.garcia.silva at gmail.com> wrote:
>>> Hi list
>>> I'm trying to create a plugin that creates a new layer using the
>>> memory provider. I'd like this new layer to have the same crs as
>>> another layer ('linesLayer' in my code below). All is going well,
>>> except that when I add the new layer to the mapLayerRegistry I always
>>> get prompted for selecting the new layer's crs. So, how do I go about
>>> defining it programatically? What I want is to not be bothered with
>>> the dialog to select my layer's crs during the execution of the
>>> plugin. Currently I am doing:
>>>
>>> # python code
>>> pointLayer = QgsVectorLayer("Point", "temporary_points", "memory")
>>> pointLayer.setCrs(linesLayer.crs())
>>> # rest of the code
>>> self.layerRegistry.addMapLayer(pointLayer)
>>
>> Hi Ricardo
>>
>> The dialog actually pops up when you construct the vector layer (not
>> when it is being added to layer registry). Currently I am not aware of
>> a nice solution. CRS dialog is shown if the key
>> "/Projections/defaultBehaviour" in QSettings is set to value "prompt".
>> So you could use a quick and dirty trick to change this setting to
>> e.g. "useGlobal" before loading the layer, so by default it will get
>> WGS84 crs, then change the setting back to original value and call
>> layer's setCrs() to force it to use the correct crs.
>>
>> Regards
>> Martin
>>
>
>
>
> --
> ___________________________ ___ __
> Ricardo Garcia Silva
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