[Qgis-developer] Re: [Qgis-user] vector editing in QGIS - questions and issues (PostGIS biased)

[Carlos Dávila]

Marco Hugentobler escribió:
> Hi,
>
> I changed the behaviour now such that the snapping settings is only changed if 
> the user really opened the project snapping dialog and clicked 'ok'.
>
> I'm quite open to suggestions about what reasonable defaults should be (this 
> was the main point of our discussion below). Possibilities are:
>
> - snap to editing layer with default tolerance but not to background layers. 
> This is the current default and the suggestion of Micha. 
> And it's the same as the behaviour prior to the merge of the advanced editing 
> branch (it was not possible then to snap to background layers)
>
> - snap to all vector layers using default snapping tolerance. This was what 
> Maciej suggested below.
>   
I think there could be three excluding options:
* No snapping (default)
* Snap all layers in the same way, with the following tolerance: X
* Snap to individual layers: opens snapping options dialog
Regards
Carlos
>
>   
>> I'd be also in favor
>> of enabling the QGIS "topological editing" feature by default.
>>     
>
> +1
>
> cheers,
> Marco
>
>
>
> Am Dienstag 04 März 2008 12:08:26 schrieb Micha Silver:
>   
>> Maciej Sieczka wrote:
>>     
>>> Marco Hugentobler pisze:
>>>       
>>>> Maciek wrote:
>>>>         
>>>>> Marco wrote:
>>>>>           
>>> Before you read on: NOTICE - I'm assuming that snapping = 0 is no
>>> different than snapping "disabled". Is this correct? If it is, maybe
>>> it would be better to remove the snapping checkbox for layers and use
>>> spinbox with numbers only to simplify the dialog?
>>>
>>>       
>>>> Ok, I see what you mean. In the snapping dialog of the project should
>>>> be inserted the default snapping settings (which is snapping to the
>>>> active layer with the default snapping tolerance) in case the
>>>> snapping dialog was not changed already.
>>>>         
>>> Yes.
>>>
>>>       
>>>> Otherwise, if a user changes any project property and clicks ok, the
>>>> snapping will be off for all layers.
>>>>         
>>> I think differently. As long as default QGIS-wide snapping is !=0, all
>>> layers which don't have inddividual setting set by the user, should
>>> have snapping set on equal to default setting - unless the user
>>> manually disables snapping for the given layer.
>>>
>>>       
>>>> I don't think that unchecked layers should automatically have the
>>>> default snapping tolerance.
>>>>         
>>> Then what is the point of default snapping setting at all? Look - as
>>> long as you don't enter project properties and click OK, the default
>>> QGIS snapping is on for all layers in the project. Once you go to
>>> project props. and click OK, all snapping is suddenly disabled,
>>> although you did not modify any setting related to snapping. Imagine a
>>> user trying to guess what happened.
>>>       
>> In the kind of jobs I do, and what I can imagine others do, I would NOT
>> want snapping automatically to all layers, but only the one layer I have
>> set to snap. Maybe, as you suggest, there should not be any default
>> project snapping setting at all, now that we have snapping for
>> individual layers.
>>
>>     
>>> Note also that this was different in QGIS before introducing
>>> individual snapping setting per layer. You only had the QGIS-wide
>>> snapping setting, which was always active, for all layers. Now as soon
>>> as you go to project settings for whatever reason and press OK that
>>> snapping is disabled. This should be avoided.
>>>
>>>       
>>>> Because it is possible that a user don't want to snap to some layers
>>>> at all.
>>>>         
>>> The user can disable snapping for a certain layer, if he needs to.
>>>
>>> Another thing - IMO users more often need snapping than they don't.
>>> Help users not to digitize overlapping features by default, eg.
>>> promote using snapping rather than not using it. I'd be also in favor
>>> of enabling the QGIS "topological editing" feature by default.
>>>
>>> What I hate most in GIS are all those overlapping polygons and lines
>>> which I have to tediously correct topology for, re-calculate their
>>> area and length, explain the vendor what is wrong about his data.
>>> Please promote topological practices.
>>>
>>> Maciek
>>> _______________________________________________
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>>> Qgis-user at lists.osgeo.org
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>>>
>>>
>>>
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>>>       
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