Reworks the QgsLayoutItem API for handling multi-layered exports
to work as an iterator. The advantage with this is that it avoids
items needing to calculate in advance how many layers they require
in the output file.
This map renderer job subclass is designed for step-by-step rendering
of a map to different QPainters.
It exposes an API which lets callers iterate over parts of a map
(e.g. individual map layers, labels), specifying a destination
QPainter for each step in the iteration.
This is designed to improve the existing print layout export to
layered output map rendering, where currently the maps are rendered
by multiple renderer jobs, each only rendering one layer at a time.
This current approach of rendering individual layers are separate
jobs is fundamentally broken (and cannot be fixed), because it
prevents any handling of interactions between map layers (e.g. shifting
colliding labels).
exporting to a multi-layer format
Now, items are either
- placed onto the same layer as other items (simple items like labels, lines, pictures)
- placed onto the same layer as only other items of equal types (semi-complex items like scalebars or pages)
- placed onto their own unique layers (complex items like legends, maps)
Plus lots of tests covering this, where previously there was few
from project labeling settings
This is an unnecessary setting, resulting in 1000's of extra, very complex
and untested lines of code. Furthermore, the differences are almost non-existant
and it's extremely unlikely end users would (or should) need to change this
setting.
Adds an interface for classes which provider custom
handlers for features rendered as part of a map render job.
QgsRenderedFeatureHandlerInterface objects are registered
in the QgsMapSettings objects used to construct map render
jobs. During the rendering operation, the handleRenderedFeature()
method will be called once for every rendered feature, allowing
the handler to perform some custom task based on the provided
information.
They can be used for custom tasks which operate on a set of
rendered features, such as creating spatial indexes of the
location and rendered symbology bounding box of all features
rendered on a map.
This new setting, "Simplify geometries to reduce output file size",
is exposed in the SVG or PDF export settings dialogs shown when
exporting a layout/atlas/report to PDF or SVG.
If checked (the new default), geometries will be simplified while exporting
layouts in order to remove any redundant vertices which are not
discernably different at the export DPI. (e.g. if export DPI is 300 dpi,
vertices less then 1/600 inch different from each other will be removed).
This avoids exporting ALL geometry vertices during PDF/SVG export,
which can result in a ridiculously complex and large export file size.
Aside from the file size issues, it also causes problems when trying
to load these outputs into other applications, e.g. Inkscape, which
chokes on the huge number of vertices and grinds to a crawl.
Sponsored by the GeoPDF export group
QgsMapSettings object
If specified (they default to off), these simplification settings
will override any layer-specific simplification settings, and
provide a way for specifying a global simplication to apply
to vector layers while exporting maps.
