Run clang-tidy modernize-use-override to remove all the redundant
virtual keywords from overridden methods, and add some missing
overrides.
Another benefit is that this has also added the overrides
on destructors, which will cause a build failure if a base
class is missing a virtual destructor.
Rationale:
- there was a lot of large objects passed by value, so potentially
there's a speed bump from this
- even for implicitly shared classes like QString/QList there's still
a (small) cost for copying the objects when there's no reason to
- it's the right thing to do!
QToolButton. Features:
- context menu items have been moved to the attached menu button
- new gui widget QgsColorSwatchGrid, which displays a grid of colors
- new class for QgsColorScheme, which generates colors to show in a
color swatch grid
- new class QgsColorSchemeRegistry, with a global instance containing
default color schemes. QgsColorButtonV2 accepts a color scheme
registry, to control which schemes to show in the popup menu as
color swatch grids.
- color button can have a default color
- color button can also be quickly set to a totally transparent color
- c++ and python unit tests for all core components
