strikethrough text in gvim

[Jeroen Budts]

I have a feature request for gvim, I'm not sure if I should ask it here
or on the dev list?
Would it be possible to add support for strikethrough text in Gvim?
Since gvim can already display bold, italic, underline and undercurl
text I guess it can't be too difficult to add this to gvim?

Strikethrough text would be useful in multiple occasions imho. For
example in Vimwiki you can add ~~some text~~ which will be rendered to
html as strikethrough, so it would be nice if gvim could actually show
it as strikethrough (exactly the same as currently for *bold* and
_italic_ text in vimwiki).
Or for example to clearly indicate removed text when viewing a diff.

Jeroen

[Christian Brabandt]

This sounds like an interesting idea and I thought, it would be fun, to
check how easy it would be to implement it.

Attached is a patch to try out. It seems to work for me with GTK and
Motif Gui. I am a Unix gui and can't say for sure the code for Windows
and Mac is actually correct and works, though.

Secondly, I am unsure about the changes to term.c and term.h
I don't know, if these changes are actually needed, so I simply took the
undercurl code as an example and changed it so it would fit for
strikethrough.

regards,
Christian

[Ken Takata]

Hi Christian,

2013/07/31 Wed 4:56:39 UTC+9 Christian Brabandt wrote:
> Attached is a patch to try out. It seems to work for me with GTK and
> Motif Gui. I am a Unix gui and can't say for sure the code for Windows
> and Mac is actually correct and works, though.

I checked your patch on Windows. It works fine.
I checked it with the following process:

> gvim -N foo.html
:syn enable
:syn region htmlStrike start="<del\>" end="</del>"me=e-6 contains=@htmlTop
:hi def htmlStrike term=strikethrough cterm=strikethrough gui=strikethrough
i<del>foo</del>

> Secondly, I am unsure about the changes to term.c and term.h
> I don't know, if these changes are actually needed, so I simply took the
> undercurl code as an example and changed it so it would fit for
> strikethrough.

I think it is better to add term cap entries. Currently, termcap doesn't
support strikethrough attributes, so we have to use our own attribute names.
(E.g. 't_Ts'/'t_Te' or 't_SS'/'t_SE')
I also think that a new flag (e.g. 't' or 'S') should be added in the
'highlight' option.

I and Hayaki Saito updated your patch to add them. After applying this patch
and setting escape sequences properly,

let &t_Ts="\e[9m"
let &t_Te="\e[29m"

some terminals (*) will show strikethrough lines.

(*)
RLogin: http://nanno.dip.jp/softlib/man/rlogin/ (Japanese)
pangoterm: https://launchpad.net/pangoterm/

Regards,
Ken Takata

[Christian Brabandt]

Hi Ken!

Very nice, thanks!

regards,
Christian
--
Wie man sein Kind nicht nennen sollte:
Rod Ation

[Ken Takata]

Hi,

I found that this patch cannot be used for GTK3, but I don't know how to fix it.
I hope someone can fix this.


Regards,
Ken Takata

[Christian Brabandt]

Hi Ken!

Seems like you did fix this with the latest version here:
https://bitbucket.org/k_takata/vim-ktakata-mq/src/9e19c0c57c4812557e7750629de02986249a5246/strikethrough.diff?fileviewer=file-view-default

Seems to work fine for me. Bram, I think this might be a nice addition
for vim 8.


Best,
Christian
--
Um sich von einer zu großen Liebe oder Duldsamkeit für etwas zu
heilen, muß man nicht die Feinde davon lesen, sondern die Freunde.
Lavater
-- Jean Paul

[Ken Takata]

Hi Christian,

I made a fix but I haven't tested it yet.

> Seems to work fine for me. Bram, I think this might be a nice addition
> for vim 8.

Thank you for checking. Does it work both with GTK2 and GTK3?

Regards,
Ken Takata

[Christian Brabandt]

Hi Ken!

,----
| :syn region htmlStrike start="<del>"ms=s+5 end="</del>"me=e-6
| :hi def htmlStrike gui=strikethrough term=strikethrough
| i<del>foobar</del>
`----

This works in GTK2 and GTK3 gui but I couldn't check the terminal, since
I don't have a terminal that has this capability


Best,
Christian
--
Frauen sind das beste in dieser Art.
-- Curt Goetz

[Ken Takata]

Hi,

Thank you for checking.
Now I check with Win32 GUI and also with terminal (mintty). Both works fine.
As I wrote before, I have to set the following esc sequences:

let &t_Ts="\e[9m"
let &t_Te="\e[29m"

Hayaki Saito told me that xterm (with patch#305) also supported these sequences.
Is it better to set these sequences as default when $TERM is xterm?


Regards,
Ken Takata