This allows us a chance to correctly call start/stopRender on all
symbols which are used as part of the labels and ensure they are
nicely prepared and cleaned up.
Also adapt labeling engine to add calls to startRender/stopRender where
appropriate.
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.
Allows users to override the line placement settings (e.g.
above/below/on line options) on a per-feature basis. Somehow
this one was the only(?) setting from labeling which
was missing a data defined control...
For the c++ api dox this expands to "\c nullptr" (the
\c directive indicates a code literal value), and for sipify/Python
it expands to ``None`` (`` is sphinx annotation for literal values)
Makes for nicer dox for both c++ and Python!
Fixes an issue identified in the upcoming QGIS Map Design 2nd ed
(spoiler alert!) where it's impossible to utilise label text
substitutions if you also want to use word wrapping.
This isn't possible to directly fix, because we need to evaluate
the full label expression (including the word wrapping component)
in order to actually HAVE text to substitute into.
So, a new setting has been added to the label formatting tab
allowing users to directly set an auto-wrapping line ideal
line size. This is applied AFTER label text evaluation, substitutions,
and the 'wrap text on' character, so it can play correctly well with
all these other settings. This also has the nice side-effect
of making auto label text wrapping more accessible to new
users/those unfamiliar with the wordwrap expression function.
Fixes#20007, and cleans up a chapter of QMD 2ed ;)
