The rewrite of macro_nesting done at 0f15dcc6 was faulty, in
particular since the information should be available also at draw
time. To this end, we revert the patch of the said commit that removes
macro nesting information from MathRow::Element. In the next commit,
we will change the marker code so that MathRow::draw does not need the
nesting information.
Actually the code is now cleaner since the macro nesting stack of
MathRow::metrics can be removed.
Tweak the algorithm so that a BOX math row element can have some
spacing. To this end, MathRow::before/after do not look at the type of
an element for deciding when to skip it, but rather to its math class.
In the new setting, the spacing algorithm works on all elements, but
skips the MC_UNKNOWN elements as if they were not present. As a
consequence, the two element types BEGIN and END have been replaced by
a single DUMMY (they can be recognized from their class).
To simply the code, add a new `mclass' argument to the
MathRow::Element constructor (default is MC_UNKNOWN).
Macro nesting is now recorded into the macro inset itself. This allows
the ArgumentProxy inset to determine whether it is editable or not by
looking at its macro.
Remove code in the metrics and draw methods of ArgumentProxy: this
code is AFAICS not active anymore, since arguments are linearized into
math rows.
Use Changer idiom to change locally the values of MecticsInfo::base.macro_nesting.
Empty insets should use a minimal amount of space, especially when
they are part of a built-in macro in lib/symbols.
With this change, blue rectangles signal actually editable places.
Empty macros in editable data are shown as grey boxes, but they do not
appear when further nested.
This is done by adding a new type BOX of MathRow::Element object and a
MetricsInfo::macro_nesting that keeps track of macros (and is reset to
0 in editable macro arguments).
* new MathRow class which contains the description of a MathData
object in terms of math class and spacing
+ macros and their arguments used in the MathData object are
linearized (replaced with their contents) so that all math insets
are typeset as a string together. To this end, we introduce a
method addToMathRow to InsetMath and MathData. This method allows
to linearize recursively a MathData object.
+ It is then necessary to set manually the dimension and position of
the macros and arguments.
+ the class class and spacing are computed using the MathClass helpers.
The MathRow data is cached in the MathData object in a bufferview-dependent
way (different dpi for different screens).
* delegate most of the work MathData::metrics/draw to MathRow metrics/draw.
The case of draw is trickier, since many draw() methods rely on their
metrics without any spacing added.
