Populating the style library from the database can be a time
consuming process, especially if a user has many symbols
present in their library.
But for many standalone scripts, and for qgis_process, the
style database may not be required.
Let's defer initialization of it until it's actually required,
saving the startup cost in qgis_process and 3rd party scripts.
On my system with a style database containing ~700 items this
cuts down qgis_process startup times by around 25%
- Add enums to qgis.h instead of qgscoreenums, so that they belong to
a Qgis namespace
- Split up the various symbol headers into multiple files so that we
can fine-tune their inclusion and forward declare more readily, speeding
up recompilation
- Move QgsSymbol enums to qgis
use this as the text format for newly created layer labels
Instead of defaulting to a random font, this gives us a mechanism
to supply a better default label font to users via the default
style database. And users can always modify this "default" text
format if they'd like to change the default font!
For now this is the underlying code logic changes only -- we
don't yet include a 'Default' text format in the default style database
to take advantage of this functionality.
Adds a new visitor pattern API for creation of visitors which visit
all the style entities (symbols, color ramps, text formats, and
label styles) associated with different objects. Can be used on a
renderer, map layer, or project wide level.
E.g. on a project wide level, allows collection of ALL the style
symbols/color ramps/text settings inside a project, including those
in layouts or annotations!
Just like the earlier change which allows for text formats to
be managed in style manager, this change allows for layer-wide
label settings to be stored and managed in styles.
So while a text format includes just the font settings and other
appearance related settings, Label Settings also includes layer-type
specific settings such as label placement, priority, rendering
settings.
