Allows reports to derive from other reports and then change the option
default values to suit. If they change only the values and not the defaults
then it's possible to create saved report configs that don't include the
options whose values are changed to the base report's default value. See
https://bugs.gnucash.org/show_bug.cgi?id=642292.
So that one can't instantiate an invalid constructor.
Unfortunately Swig doesn't understand SFINAE and will try to create the
invalid constructors anyway but at least this generates a compile-time
error when it tries to.
To support a variation available in dialog-options. Even though it's not
used in any GnuCash code nor documented anywhere it might be in some
custom reports.
After getting a better understanding of how it interacts with dialog-options and
finding some additional scheme API needing implementation (exposed only in
hello-world.scm, but possibly used in user-written reports).
Creates a new file-pair, gnc-options-date.[ch]pp to separate the creation of
the static structs with the type info and strings for the various
RelativeDatePeriod values from the already too large gnc-option-impl.
Although the result is a rather C-ish design the alternative with classes
or template specializations would be more complicated and offer no
benefit.
Implements the permissible_values functions of GncOptionMultichoiceValue
for GncDateValue and provides for absolute, relative, and both
UI values for the three widget configs afforded by dialog-options.
From std::string. The consumer is a GtkWidget so we might as well do the conversion
inside the class and this will simplify adding these functions to GncOptionDateValue
in the next commit.
Separating the UI from the data model. Note that the GncOptionVariant
classes still have a GncOptionUIType member to ensure that a
GncOptionUIItem of the right type is attached.
So only GncOption and the GncOptionDB free-function interface are public.
We don't want to expose template headers widely, it would blow up compilation
times and might lead to one definition rule violations.
These add or parse the textual noise needed to replicate the Scheme options'
serialization technique of saving scheme forms for saving report options
and then evaluating those forms to restore the option values. Required for
backward saved-reports compatibility.
Added advantage that it handles (not correctly, but in the same way as
the old code) the ambiguity between a period starting or ending with
the stored value "relative . today".