[Qgis-developer] New adv labeling freeze-thaw tools

[Larry Shaffer]

I've updated and extensively tested this new tool (not all platforms)
and it works very well. I have sent in a pull request:

https://github.com/qgis/Quantum-GIS/pull/193

Again, here's the intro video:
http://vimeo.com/dakotacarto/freezethawlabels
(Note: I haven't had much sleep, so the video is a bit rough.)

As an unexpected added bonus (well, unexpected to me), the tool helps
greatly with slow label rendering options, like a polygon layer's
'free' and 'horizontal' modes. After the PAL labeling engine finishes
with those modes during a canvas refresh (sometimes taking several
minutes), just use the freeze label tool on the result. The subsequent
canvas refreshes are magnitudes faster.

Marco H., thank you for your help on this, and thanks to sourcepole
and Martin for doing such a great job of coding the advanced labeling
engine. I would have never been able to produce this tool had it not
been for the excellent existing and flexible code.

Regards,

Larry Shaffer
Dakota Cartography
Black Hills, South Dakota


On Mon, Jul 16, 2012 at 9:45 AM, Marco Hugentobler
<marco.hugentobler at sourcepole.ch> wrote:
> Hi Larry
>
>> If you have the time to look at the constructor for
>> QgsMapToolFreezeLabels (the FIXME), you'll notice I could not find a
>> way to make the signal/slot connections from there. Currently they are
>> in qgisapp.cpp, but I would prefer to not pollute that core file with
>> any more of my tool's code than necessary. What's the simplest way to
>> create the connections from inside my QObject-inherited tool instead?
>
>
> The slot methods need to be declared as slots in the header file, like this:
>
> public slots:
>
>     //! Update frozen label highlights on canvas render finished
>     void updateFrozenLabels();
>     //! Render rectangles around frozen labels
>     void highlightFrozenLabels();
>
> Currently, they are just normal public methods.
>
> Regards,
> Marco
>
> Am 16.07.2012 11:35, schrieb Larry Shaffer:
>>
>> On Mon, Jul 16, 2012 at 2:18 AM, Marco Hugentobler
>> <marco.hugentobler at sourcepole.ch> wrote:
>>>
>>> Hi Larry
>>>
>>> Excellent work, thank you!
>>> The freeze/thaw tool will be a great addition to the label tool bar.
>>>
>>> I wonder if the tool could also be active if x/y is data defined and
>>> rotation not (currently, x/y/rotation need to be data defined to use the
>>> tool).
>>
>> Yes, that is an unnecessary restriction. I'll make the rotation field
>> optional.
>>
>>> On a detail level, in QgsMapToolFreezeLabels::highlightLabel you could
>>> probably use QgsMapRenderer::mapToLayerCoordinates to transform the
>>> rectangle (instead of mCoordTransform ).
>>
>> Will make the change. Thanks.
>>
>> If you have the time to look at the constructor for
>> QgsMapToolFreezeLabels (the FIXME), you'll notice I could not find a
>> way to make the signal/slot connections from there. Currently they are
>> in qgisapp.cpp, but I would prefer to not pollute that core file with
>> any more of my tool's code than necessary. What's the simplest way to
>> create the connections from inside my QObject-inherited tool instead?
>>
>> Regards,
>> Larry
>>
>>
>>
>>> Am 16.07.2012 05:31, schrieb Larry Shaffer:
>>>
>>> Hi,
>>>
>>> The current large-format project I'm working on requires me to layout,
>>> for print, thousands of labels. So I spent the last couple of days
>>> making two new tools for the advanced labeling toolbar that allow the
>>> user to interactively 'freeze' (write coords and rotation info to
>>> attribute table) and 'thaw' (revert from data-defined to dynamic) any
>>> rendered labels.
>>>
>>> *Show Frozen Labels*
>>>
>>> This tool highlights frozen labels for all visible layers. Blue
>>> highlighted labels are frozen, green are frozen and editable (parent
>>> layer's in edit mode).
>>>
>>> *Freeze/Thaw Labels*
>>>
>>> This tool allows the user to interactively choose, by single or
>>> marquee selection, labels to freeze or thaw. The in-memory attribute
>>> table is immediately updated and results shown to user. This tool
>>> allows the user to interactively manipulate the PAL labeling engine to
>>> find the best solutions for their frozen labels.
>>>
>>> Since the topic and how the tool interacts with the labeling engine is
>>> more complicated, I made an intro video. (Note: I haven't had much
>>> sleep recently, so it's a bit rough.)
>>>
>>> http://vimeo.com/dakotacarto/freezethawlabels
>>>
>>>
>>> This is my first C++ project, so I'd be really happy if someone
>>> audited the code before I squash the commits and send a pull request:
>>>
>>> https://github.com/dakcarto/Quantum-GIS/tree/feature_freeze-thaw-labels
>>>
>>> Only tested on Mac, as of now. Nothing platform-specific about it though.
>>>
>>> Regards,
>>>
>>> Larry Shaffer
>>> Dakota Cartography
>>> Black Hills, South Dakota
>>>
>>>
>>>
>>> _______________________________________________
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>>> Qgis-developer at lists.osgeo.org
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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
>>>
>>>
>>> _______________________________________________
>>> Qgis-developer mailing list
>>> Qgis-developer at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/qgis-developer
>>>
>
>
> --
> 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
>