[Qgis-user] data defined labelling field details?

[Marco Hugentobler]

Hi William

> - As I noted, data-driven offsets as an alternative to absolute position.

Data driven offset is available in the new labeling (first entry in data defined 
properties->position)

> - I see that the data-driven buffer settings are inconsistent between the
> old and new.  The old can set transparency from data but not color, and
> the new can set color from data but not transparency.  How about both?

Agreed, it would be useful to have dd transparency also in new.

> - data-driven scale dependent rendering values.  And same for the general
> feature rendering.  I've been designing my data with this in mind and was
> disappointed that it isn't possible yet - scale dependent rendering is
> only per layer.

True, that would be usefull. Also nice would be the possibility to have 
different label settings for different scale ranges. That's probably more a 
long-term project.

>- some way to specify in any data-driven setting to use the non-data driven
> setting, like an invalid or null value.  That is, say for placement, if
> the data value is NULL or empty use the around/over setting in the
> Advanced tab.  That way you can let the engine calculate fixed/dynamic
> settings and override them to fine-tune labelling of specific features.

This is how it already works. If you add two columns for x/y to your table 
(with NULL entries), the positions for all labels will be calculated automatic 
by the PAL label engine. As soon as you start dragging labels around, the 
position will be insterted to the columns and those entries are treated as 
data defined position.

However, it is currently not possible to mix automatic label placement with 
data defined rotation values (I think that was the start of the whole e-mail 
thread). 

Regards,
Marco

 

Am Mittwoch, 12. Januar 2011, um 02.54:13 schrieb William Kyngesburye:
> On Jan 11, 2011, at 2:17 PM, Paolo Cavallini wrote:
> > Il giorno mar, 11/01/2011 alle 11.24 -0600, William Kyngesburye ha
> > 
> > scritto:
> >> So, when you say new and old engines, will the new engine replace the
> >> old one someday?
> > 
> > I hope it will happen soon: the current situation is rather confusing.
> > Could you please note the missing features you need in new symbology, so
> > we'll know when it is ready to replace the old one?
> > Thanks.
> 
> I would say make sure all capabilities from the old are available in the
> new, unless there was some very specific reason to not include them.
> 
> specifically:
> 
> - As I noted, data-driven offsets as an alternative to absolute position.
> 
> - I see that the data-driven buffer settings are inconsistent between the
> old and new.  The old can set transparency from data but not color, and
> the new can set color from data but not transparency.  How about both?
> 
> Additional options to consider:
> 
> - data-driven scale dependent rendering values.  And same for the general
> feature rendering.  I've been designing my data with this in mind and was
> disappointed that it isn't possible yet - scale dependent rendering is
> only per layer.
> 
> - some way to specify in any data-driven setting to use the non-data driven
> setting, like an invalid or null value.  That is, say for placement, if
> the data value is NULL or empty use the around/over setting in the
> Advanced tab.  That way you can let the engine calculate fixed/dynamic
> settings and override them to fine-tune labelling of specific features.
> 
> -----
> William Kyngesburye <kyngchaos*at*kyngchaos*dot*com>
> http://www.kyngchaos.com/
> 
> The equator is so long, it could encircle the earth completely once.


-- 
Dr. Marco Hugentobler
Sourcepole -  Linux & Open Source Solutions
Churerstrasse 22, CH-8808 Pfäffikon SZ, Switzerland
marco.hugentobler at sourcepole.ch http://www.sourcepole.ch
Technical Advisor QGIS Project Steering Committee