Moving empty destructors out of the .cpp files and into headers
allows them to be devirtualized in certain cases.
(When the compiler can't "see" a function in a header, it must largely
assume it's some black box that the linker will resolve.)
While we're at it, use C++11's `= default` to define empty virtual
desturctors for us.
For some classes (e.g., Piano), nothing is derived from it, so we can
mark the class as final and remove any explicit virtual dtor.
There are many other places where this can be done, but this is a large
enough patch as-is.
* Render the mixer levels in a dB FS scale
Adds the option to render the mixer levels in dB FS. By default this
option is disabled so that classes which inherit from Fader are not
affected by this change. However, in the code of the FxMixerView this
feature is enabled so that the mixer shows the levels in dB FS.
The ability to render in dB FS is exported as a property so that it can
also be set in a style sheet (not used as of now). The new property is
called "levelsDisplayedInDBFS".
There are now setters and getters for the min and max level.
Showing the levels in dB FS (which is a logarithmic scale) gives a less
"fidgety" impression when the levels are moving.
* Introduction of an init method in Fader
An init method was added to unify the initialization of the two Fader
constructors.
This commit addresses a lot of issues, namely:
1. When the "Move left/right" action was selected on a mixer channel
menu sometimes it would segfault due to the fxline object being
deleted before it returned to a method inside itself
2. The Fader was declaring a new variable for the model whereas it
should used the inherited model from FloatModelView < AutomatableModelView
3. Some methods were doing more things than they should be and
performing unnecessary actions. A little cleanup/refactor was made
Please notice that a bug of the same class as the one referred at point 1
still exists: clicking on "Remove channel". This commit does not
addresses this issue.
Fixes#1584
Lukas W