Re: Thoughts on LibreOffice Math

On Fri, Jul 5, 2013 at 1:34 AM, Frédéric WANG <fred.wang@free.fr> wrote:
> > 5. Can't easily remove parentheses around some text - have to cut the
> > text, delete the parentheses box, then re-paste text.
>
> The fenced construction have a special node type with the open fence,
> content and close fence. Perhaps you want a command to automatically remove
> the fences? Or that when you delete one fence character, the node is
> automatically converted to a non-fenced construction.
Well you currently can't delete any of these chars. If you could and
the matching one would be deleted automatically that'd be good enough.
Though, this leaves problem of non-matching braces. This would be
needed e.g. to write simultaneous equations. Currently only source
editing can achieve this.
> > (Ideally, I'd like to have Mathematica style shortcuts to enter formulas
> > in WYSIWYG editor, but I didn't have enough time to hack LOMath to address
> > this idea)
>
> That would be at least helpful if you could give the list of Mathematica
> shortcuts.
Here're some of the most common ones (some possible rationale given i for some):
Ctrl+2: square root (2 reminds 'square' :) )
Ctrl+4: enter text below char
Ctrl+5: add a root power to sqrt construct - to produce n-root
Ctrl+6: superscript (the 6 key has a ^ on it, meaning power)
Ctrl+7: enter text above char
Ctrl+'-': subscript (_ in LaTeX and LOMath means subscript)
Ctrl+/: fraction
Ctrl+',': new column - automatically creates a matrix if needed (comma
is a known delimiter in text)
Ctrl+<Enter>: new row - automatically creates a matrix if needed
(<Enter> is known to produce new line)
<ESC>some_keyword<ESC> produce special symbol defined by some_keyword.
These include integrals, sums, partial derivatives, Greek and Hebrew
letters, etc.Some of these can be seen e.g. here:
http://reference.wolfram.com/mathematica/tutorial/EnteringFormulas.html
\[LetterName]: letter defined by LetterName, e.g. \[Aleph]. See more
here (not all have to be implemented of course):
http://reference.wolfram.com/mathematica/guide/ListingOfNamedCharacters.html

Some notes:
When a fraction is created, two placeholders are created if nothing
precedes them, and cursor is placed in the numerator. If something is
to the left of cursor, the nearest variable is moved inside numerator.
If something is selected, it moves into numerator.
If a subscript, abovescript or belowscript is not preceeded by
anything, it makes two placeholders. Otherwise behavior is like with
fraction.
Pressing <ESC> makes a special char appear until entry is finished by
closing <ESC> — after this all the construct is changed to its
meaning. E.g. you enter "<ESC>del", it appears as you see (with <ESC>
denoted by special char), then you press <ESC> to finish entry, and
all this changes to a nabla.
Of course <ESC> could be changed to something without such strange
semantic like "escape", e.g. ` (backtick key) or \ (backslash).

> It seems that you want to preserve the frame to enter the StarMath source. I
> don't know if that it just because of the limitations of the current visual
> editor but personally, I imagine that in the future we could have only the
> visual rendering of the formula ; but one could type StarMath code directly
> in the placeholder and it would immediately be converted to the internal
> representation and inserted at the specified position. This would
> essentially address your issues 3 and 4 and remove the need for 1 and 2.

I want to preserve this only until everything could be entered via
keyboard in WYSIWYG editor. If one is forced to point&click to enter a
formula, this is lame and counter-productive.
> Thanks,
>
> --
> Frédéric Wang
> maths-informatique-jeux.com/blog/frederic