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

[Maciej Sieczka]

Micha Silver pisze:
> Maciej Sieczka wrote:

>> Thinking it all over again, I imagine the whole thing this way now:
>>
>> In Options > Digitizing > Default Snapping give it a "mode" selector 
>> and a checkbox (alike Project Properties > Snapping Options). These 
>> settings are stored in QGIS preferences file. Until Default Snapping 
>> *is checked*, it takes precedence over individual layer's settings, 
>> thus it's enabled for *all* layers, in any project.

> In what situation do you want snapping to all layers?

You mean 'snapping *for* all layers', right? I'm assuming you do.

> Now that it's 
> possible in 0.9.2 to set snapping for indivual layers, I think the 
> global snapping option is confusing and unnecessary.

When I load dozen layers I don't want to have to set it individually for 
each one I'm going to edit. Furthermore, I often use the same digitising 
snapping settings. I would love to not to have to set them up for each 
new added layer, but set it only once as a global default and "forget 
it" until I really need to use a custom snapping setting for a 
particular layer.

>> Modifying individual snapping of a layer, through Project Properties > 
>> Snapping Options, is not possible then - layers are greyed-out in the 
>> dialog. The latter is also a signal for the user that global snapping 
>> setting is enabled, and he should turn it off to be able to tweak 
>> snapping per layer.

> This "greyed-out" business might again be confusing. How would a user 
> know that the greyed out state means that global snapping is set?

Now it's even worse. The user can change global snapping like if it is 
supposed to do some something, but it does not have any effect (not 
mentioning this is a regression from QGIS before the advanced editing 
branch was merged). When a feature is greyed-out he can at least suspect 
something's fishy and search around. Besides, there could be an info in 
the Project Properties > Snapping Options like: "Per-layer snapping 
settings disabled until global snapping settings enabled. Please go to 
Options > Digitizing to modify default snapping."

>> If Options > Digitizing > Default Snapping *is not checked*, modifying 
>> individual snapping Project Properties > Snapping Options for any 
>> layer becomes possible, and this setting takes precedence over the 
>> default.

> In my opinion an individual setting for each layer, and no global 
> snapping at all, best solves all situations with no complications for 
> the user.

Per-layer snapping is a great new feature in QGIS. For some users that 
would propably be good enough alone. However there are also users who 
deal with tones of data at the same time. They would appreciate sane 
mechanism for default settings which would save them manual tweaking 
when feasible. Note also that global snapping setting was the only 
option in QGIS not so long time ago.

Maciek