This commit implements the improvements described at:
https://lists.osgeo.org/pipermail/qgis-developer/2016-September/044393.html
The QgsRasterMinMaxWidget now offers a seetting to specify that the statistics
should be computed each time the canvas extent changes.
Other changes:
- the content of the QgsRasterMinMaxWidget is now persistant.
- there is no longer any Load button. The global Apply / OK button of the raster
properties dialog has this effect.
- the default "limits" for single band raster is now MinMax and not CumulativeCut
- the default "limits" can be configured for single band, multi band single byte and
multi band multi byte
- "Strech using current extent" honours the "limits" instead of forcing min/max.
Moved all temporary projector members to a private class,
so even recursive block() calls will not affect each other
(there is no new performance penalty as block() call always
recomputes the temporary control point matrix anyway)
The improvement allows immediate cancellation of raster rendering
in progress. Until now, even when map rendering got cancelled
(e.g. by zooming of panning canvas), the GUI got blocked while waiting
for raster layers to finish their rendering (only vector layers have
had support for cancellation). This should allow for much smoother
user experience while browsing maps including rasters.
The cancellation is supported currently by WMS/WMTS and WCS providers.
GDAL provider may also get support thanks to improvements in GDAL 2.
Funded by Land Information New Zealand.
- rename methods with XML to Xml, CRS to Crs, WMS to Wms, ID to Id
- rename methods with SRS to Crs
- rename methods with abbreviations like "dest" to "destination"
- rename methods with abbreviations like "src" to "source"
The current approach of testing !vl || vl->geometryType() != NoGeometry
is not intuitive and has been the source of 2 recent bugs.
Replacing these tests with the new isSpatial() function makes it
immediately obvious what is being tested. It also allows for
non-spatial plugin layers to be correctly handled by overriding
this method.
copy/= operators or making them private
This revealed (and fixes) some issues, including a potential crash
using server access control (refs #13919), and a potential crash with
diagrams
