[Qgis-developer] Thoughts on newly added "min-max map unit scale" feature

[Marco Hugentobler]

Hi Nyall

The use-case behind that function was to stop the symbols getting too 
big at some point if zooming in. Now if there is a complex symbol with 
several symbol layers and a lot of properties, you may just set minimum 
/ maximum scale on symbol level.

In case min/max size in mm has to be given, you need to set that for 
each property of each symbol layer again. Because each property is 
likely to be different in size  (e.g. line width, marker line distance, 
marker line marker size, marker line marker outline width, pattern 
distance, .....). The notation with the scale is more generic and can 
cover everything in one go.

I wonder if it would just be enough to set more descriptive 
labels/tooltips to the min/max scale dialog?

Regards,
Marco

On 09.05.2014 00:13, Nyall Dawson wrote:
> Hi all,
>
> I've been playing with the newly added "min-max map unit scale"
> feature. While this is a great feature to have, I think in it's
> current form it's rather confusing for users.
>
> Currently, when clicking the little settings icon next to a size in
> map units, a dialog with "maximum scale" and "minimum scale" appears.
> It's not immediately obvious as to what these settings actually do -
> do they prevent the style showing outside these scale ranges? does the
> symbol size reset to some default value outside these ranges? or is
> the size clamped to the size it would take at these max/min scale
> ranges? It took a bit of experimenting for me to work out that this
> last behavior is what occurs.
>
> I think it would make a lot more sense if these max/min sizes were
> instead given in "mm", and the labels renamed to "Maximum size" /
> "Minimum size". To me this is much more intuitive - it would be
> immediately obvious that the size is set in map units, but limited so
> that it never become larger or smaller than these set size limits.
>
> This would take this feature from being an advanced feature which
> takes a lot of experimenting to tweak correctly to something I'd use
> on a regular basis!
>
> What's everyone else's thoughts on this?
>
> Nyall
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-- 
Dr. Marco Hugentobler
Sourcepole -  Linux & Open Source Solutions
Weberstrasse 5, CH-8004 Zürich, Switzerland
marco.hugentobler at sourcepole.ch http://www.sourcepole.ch
Technical Advisor QGIS Project Steering Committee