\RequirePackage{xparse}
\ProvidesExplPackage {returntogrid} {2018/08/21} {0.2}
{return to a grid position}
% \debug_on:n { check-expressions,deprecation } % needs enable-debug
\RequirePackage{eso-pic}
\RequirePackage{zref-savepos,zref-abspage}
\msg_new:nnn {ufgrid} {tikz-needed} { the~showdebugpagegrid~command~needs~the~tikz~package }
\msg_new:nnn {ufgrid} {tab-list-unknown} { the~tab~list~"#1"~has~not~been~declared}
\sys_if_engine_luatex:T
{
\directlua{require ("returntogrid.lua")}
}
\int_new:N \l__ufgrid_vskip_int %vskip in sp
\int_new:N \g__ufgrid_vpoint_int %for the v-labels
\int_new:N \g__ufgrid_hpoint_int %for the h-labels of tabs
\int_new:N \l__ufgrid_tempa_int
\int_new:N \l__ufgrid_tab_cor_int
\bool_new:N \g__ufgrid_active_bool
\bool_gset_true:N \g__ufgrid_active_bool
\bool_new:N \l__ufgrid_hmode_bool %hmode (tabs)
\bool_new:N \l__ufgrid_savepos_bool %save position
\bool_new:N \l__ufgrid_insert_vskip_bool %insert vskip
\bool_new:N \l__ufgrid_autolabel_bool %numbered labels
\bool_new:N \l__ufgrid_tabfound_bool
\bool_new:N \l__ufgrid_hfill_bool
\bool_new:N \l__ufgrid_debug_tab_bool
\bool_new:N \g__ufgrid_twoside_bool
\if@twoside \bool_gset_true:N \g__ufgrid_twoside_bool \fi
\tl_new:N \l__ufgrid_setup_step_tl %step value (dim in sp)
\tl_new:N \l__ufgrid_setup_reference_tl %name of reference point
\tl_new:N \l__ufgrid_setup_offset_tl %an offset, e.g. topskip
\tl_new:N \l__ufgrid_label_tl %holds the label name
\tl_new:N \l__ufgrid_curpos_tl
\tl_new:N \g__ufgrid_prefix_vpoint_tl %prefix of v-point labels
\tl_new:N \g__ufgrid_prefix_tabpos_tl %prefix for tab positions
\tl_new:N \g__ufgrid_prefix_hpoint_tl %prefix for h-point labels
\tl_new:N \g__ufgrid_prefix_user_tl %prefix for labels provided by the user
\tl_new:N \l__ufgrid_tab_list_tl %holds the name of the current tab list
\tl_new:N \l__ufgrid_debug_tab_draw_tl %hold the draw command to debug tab positions
\tl_new:N \l__ufgrid_tmp_vskip_tl % to pass the vskip to zsavepos
\dim_new:N \l__ufgrid_debug_tab_dim
\prop_new:N \g__ufgrid_vskip_prop %will hold the vskips by label name
\cs_generate_variant:Nn \prop_gput:Nnn {Nxx}
\cs_generate_variant:Nn \prop_get:NnNTF {NxNTF}
\cs_generate_variant:Nn \prop_get:NnNF {NxNF}
% we need to store the current displacement
\zref@newprop {ufgridvskip}[0]{\int_use:N \l__ufgrid_vskip_int}
\zref@newprop*{pagecnt} [1] {\the\c@page}
\zref@addprop {savepos} {ufgridvskip}
\zref@addprop {savepos} {abspage}
\zref@addprop {savepos} {pagecnt}
\keys_define:nn { ufgrid / setup}
{
activate .bool_gset:N = \g__ufgrid_active_bool,
% step = dimension
step .code:n = { \tl_set:Nx \l__ufgrid_setup_step_tl { \dim_to_decimal_in_sp:n {#1} } },
% reference = labelname (label should be set with zsavepos)
reference .tl_set:N = \l__ufgrid_setup_reference_tl,
% offset = dimension: move down (example offset= \topskip)
offset .code:n = { \tl_set:Nx \l__ufgrid_setup_offset_tl { \dim_to_decimal_in_sp:n {#1} } },
tab-list .tl_set:N = \l__ufgrid_tab_list_tl,
settabpositions .code:n = { \__ufgrid_settabpositions:nn #1 },
prefix-vpoint .tl_gset:N = \g__ufgrid_prefix_vpoint_tl,
prefix-tabpos .tl_gset:N = \g__ufgrid_prefix_tabpos_tl,
prefix-hpoint .tl_gset:N = \g__ufgrid_prefix_hpoint_tl,
prefix-user .tl_gset:N = \g__ufgrid_prefix_user_tl,
debug-tab .bool_set:N= \l__ufgrid_debug_tab_bool,
debug-tab-len .dim_set:N = \l__ufgrid_debug_tab_dim,
debug-tab-draw .tl_set:N = \l__ufgrid_debug_tab_draw_tl,
hmode .bool_set:N= \l__ufgrid_hmode_bool,
hfill .bool_set:N= \l__ufgrid_hfill_bool,
tab .code:n =
{
\tl_if_empty:nF { #1 }
{
\tl_set:Nn \l__ufgrid_tab_list_tl {#1}
}
\bool_set_true:N \l__ufgrid_hmode_bool
},
twoside .bool_gset:N = \g__ufgrid_twoside_bool
}
\normalsize %just in case
\keys_set:nn { ufgrid / setup }
{
prefix-vpoint = ufgrid@vpoint,
prefix-tabpos = ufgrid@tabpos,
prefix-hpoint = ufgrid@hpoint,
prefix-user = ufgrid@user,
step = \baselineskip,
reference = \g__ufgrid_prefix_vpoint_tl textupperleft,
offset = \topskip,
debug-tab-len = -4cm,
debug-tab-draw= { \draw[blue,dashed] (0,1em)--++(0,\l__ufgrid_debug_tab_dim) },
hfill
}
\keys_define:nn { ufgrid / use }
{
__savepos .bool_set:N = \l__ufgrid_savepos_bool,
__insert_vskip .bool_set:N = \l__ufgrid_insert_vskip_bool,
__label .tl_set:N = \l__ufgrid_label_tl,
__autolabel .bool_set:N = \l__ufgrid_autolabel_bool,
save .meta:n = { __label=\g__ufgrid_prefix_user_tl#1, __savepos=true, __insert_vskip=false,__autolabel=false },
save .value_required:n = true,
label .meta:n = { __label=\g__ufgrid_prefix_user_tl#1, __autolabel=false },
label .value_required:n = true,
use .meta:n =
{
__label=\g__ufgrid_prefix_user_tl#1, __savepos=false, __insert_vskip=true,__autolabel=false
},
use .value_required:n = true,
strut .code:n = \__ufgrid_insert_ufgridstrut:n { #1 },
hmode .bool_set:N = \l__ufgrid_hmode_bool,
tab-list .tl_set:N = \l__ufgrid_tab_list_tl,
tab .code:n =
{
\tl_if_empty:nF { #1 }
{
\tl_set:Nn \l__ufgrid_tab_list_tl {#1}
}
\bool_set_true:N \l__ufgrid_hmode_bool
},
debug-vgrid .code:n = {\AddToShipoutPictureBG*{\AtTextUpperLeft{\showdebugpagegrid}}}
}
%%calculate the vskip to insert
%#1 = diff to a point on the grid
%#2 = currently used vskip,
%#3 = step
% all values integers =dim in sp!
\sys_if_engine_luatex:TF
{
\cs_new:Nn \__ufgrid_calculate_vskip:nnn
{ \directlua { returntogrid.ufgridvskip (#1,#2,#3) } }
}
{
\cs_new:Nn \__ufgrid_calculate_vskip:nnn
{
\int_eval:n
{
\int_mod:nn
{
#2 + #3 - \int_mod:nn { #1 }{ #3 }
}
{#3}
}
}
}
\cs_new:Nn \__ufgrid_calculate_vskip:n %#1 =labelname
{
\__ufgrid_calculate_vskip:nnn
{ %diff
\zposy{\l__ufgrid_setup_reference_tl} - \l__ufgrid_setup_offset_tl - \zposy{#1}
}
{ %current vskip
\zref@extractdefault{#1-vskip} {ufgridvskip} {0}
}
{
\l__ufgrid_setup_step_tl
}
}
\cs_new_protected:Nn \__ufgrid_savepos:n %#1 label name
{
\leavevmode\strut
\zsavepos{#1}
}
\cs_new_protected:Nn \__ufgrid_insert_vskip:n %#1 label name
{
\par
\int_compare:nT { \zposy{#1} != 0 }
{
%calculate the needed vskip base on the ypos and the old vskip
\int_set:Nn \l__ufgrid_vskip_int
{
\__ufgrid_calculate_vskip:n { #1 }
}
\zref@labelbyprops {#1-vskip}{ufgridvskip}
%insert the vskip
\vspace*{\l__ufgrid_vskip_int sp}
%\vskip \l__ufgrid_vskip_int sp\relax
%\vskip 0pt
}
}
\cs_new_protected:Nn \__ufgrid_insert_ufgridstrut:n {\rule{0pt}{\dim_eval:n { \l__ufgrid_setup_step_tl sp + \topskip }}}
%vertical version
\cs_new_protected:Nn \__ufgrid_returntogrid_v:
{
\bool_if:NT \l__ufgrid_autolabel_bool
{
\int_gincr:N \g__ufgrid_vpoint_int
\tl_set:Nn \l__ufgrid_label_tl
{
\g__ufgrid_prefix_vpoint_tl \int_use:N\g__ufgrid_vpoint_int
}
}
\bool_if:NT\l__ufgrid_insert_vskip_bool
{
\__ufgrid_insert_vskip:n { \l__ufgrid_label_tl }
}
\bool_if:NT\l__ufgrid_savepos_bool
{
\__ufgrid_savepos:n { \l__ufgrid_label_tl }
}
}
\cs_new_protected:Nn \__ufgrid_settabpositions:nn %#1 name #2 list of spaces
{
\seq_set_from_clist:Nn \l_tmpa_seq {#2}
\seq_new:c {g__ufgrid_tabpos_#1_seq}
\int_set:Nn\l__ufgrid_tempa_int {1}
\makebox[0pt][l]
{
\seq_map_inline:Nn \l_tmpa_seq
{
\zsavepos{\g__ufgrid_prefix_tabpos_tl#1\int_use:N\l__ufgrid_tempa_int}
\bool_if:NT \l__ufgrid_debug_tab_bool
{
\__ufgrid_debug_showtabs:n { #1 }
}
\hspace*{\dim_eval:n{##1}}
\int_incr:N\l__ufgrid_tempa_int
}
\zsavepos{\g__ufgrid_prefix_tabpos_tl#1\int_use:N\l__ufgrid_tempa_int}
\bool_if:NT \l__ufgrid_debug_tab_bool
{
\__ufgrid_debug_showtabs:n { #1 }
}
\int_step_inline:nnnn {1}{1}{\l__ufgrid_tempa_int}
{
\seq_gput_right:cx {g__ufgrid_tabpos_#1_seq} {\zposx{\g__ufgrid_prefix_tabpos_tl#1##1}}
}
}
}
\cs_new_protected:Nn \__ufgrid_returntogrid_h:n %#1 name
{
\seq_if_exist:cF { g__ufgrid_tabpos_#1_seq }
{
\msg_error:nnx { ufgrid } {tab-list-unknown} { #1}
}
\bool_if:NT \l__ufgrid_autolabel_bool
{
\int_gincr:N \g__ufgrid_hpoint_int
\tl_set:Nn \l__ufgrid_label_tl
{
\g__ufgrid_prefix_hpoint_tl \int_use:N\g__ufgrid_hpoint_int
}
}
\leavevmode\zsavepos{\l__ufgrid_label_tl}
\tl_set:Nx \l__ufgrid_curpos_tl
{
\zref@extractdefault {\l__ufgrid_label_tl} {posx} {-1}
}
\bool_if:NT \g__ufgrid_twoside_bool
{
\int_if_odd:nTF
{
\zref@extractdefault {\l__ufgrid_label_tl} {pagecnt} {1}
-
\zref@extractdefault {\g__ufgrid_prefix_tabpos_tl#1 1} {pagecnt} {1}
}
{
% tab setting and current pos are on different page types.
\int_if_even:nTF
{
\zref@extractdefault {\g__ufgrid_prefix_tabpos_tl#1 1} {pagecnt} {1}
}
{
\int_set:Nn \l__ufgrid_tab_cor_int {\dim_to_decimal_in_sp:n {\oddsidemargin-\evensidemargin}}
}
{
\int_set:Nn \l__ufgrid_tab_cor_int {\dim_to_decimal_in_sp:n {\evensidemargin-\oddsidemargin}}
}
}
{
\int_set:Nn \l__ufgrid_tab_cor_int {0}
}
}
\int_compare:nNnF { \l__ufgrid_curpos_tl } {=}{-1}
{
\bool_set_false:N \l__ufgrid_tabfound_bool
\int_step_inline:nn { \seq_count:c { g__ufgrid_tabpos_#1_seq }-1 }
{
\int_compare:nT
{ (\seq_item:cn { g__ufgrid_tabpos_#1_seq } { ##1 } + \l__ufgrid_tab_cor_int)
<
\l__ufgrid_curpos_tl
<
(\seq_item:cn { g__ufgrid_tabpos_#1_seq } { ##1 +1 } + \l__ufgrid_tab_cor_int)
}
{
\bool_set_true:N \l__ufgrid_tabfound_bool
\hspace*
{
\int_eval:n
{
\seq_item:cn { g__ufgrid_tabpos_#1_seq } { ##1 +1 } + \l__ufgrid_tab_cor_int
-
\l__ufgrid_curpos_tl
}sp
}
}
}
\bool_if:NT \l__ufgrid_hfill_bool
{
\int_step_inline:nn { \seq_count:c { g__ufgrid_tabpos_#1_seq }}
{
\int_compare:nT
{
\seq_item:cn { g__ufgrid_tabpos_#1_seq } { ##1 } + \l__ufgrid_tab_cor_int
=
\l__ufgrid_curpos_tl
}
{
\bool_set_true:N \l__ufgrid_tabfound_bool
}
}
\bool_if:NF \l__ufgrid_tabfound_bool {\hfill}
}
}
}
\cs_new_protected:Nn \__ufgrid_returntogrid:n
{
\group_begin:
\bool_if:NT \g__ufgrid_active_bool
{
\keys_set:nn { ufgrid / use }
{
__autolabel,__savepos=true,__insert_vskip=true,hmode=false,
#1
}
\bool_if:NTF \l__ufgrid_hmode_bool
{
\__ufgrid_returntogrid_h:n { \l__ufgrid_tab_list_tl }
}
{
\__ufgrid_returntogrid_v:
}
}
\group_end:
}
\NewDocumentCommand\returntogrid{ O {} }
{
\__ufgrid_returntogrid:n { #1 }
}
\NewDocumentCommand\returntogridsetup { m }
{
\keys_set:nn { ufgrid / setup } { #1}
}
\NewDocumentCommand \showdebugpagegrid {}
{
\cs_if_exist:NTF\tikzpicture
{
\begin{tikzpicture}[overlay]
\draw[dotted,red]
(0,0) --++ (\textwidth,0cm);
\tl_set:Nx \l_tmpa_tl {\fp_eval:n {
trunc (
(\dim_to_decimal_in_sp:n {\textheight} - \l__ufgrid_setup_offset_tl )
/
\l__ufgrid_setup_step_tl
)
}}
\foreach\x in {0,1,2,...,\l_tmpa_tl}
{
\draw[red,dashed]
(0,\fp_eval:n {-\l__ufgrid_setup_offset_tl-(\x*\l__ufgrid_setup_step_tl)}sp) --++ (\textwidth,0cm);
}
\end{tikzpicture}%
}
{
\msg_warning:nn {ufgrid} {tikz-needed}
}
}
\cs_new_protected:Nn \__ufgrid_debug_showtabs:n
{
\cs_if_exist:NTF\tikzpicture
{
\tikz[overlay]
\l__ufgrid_debug_tab_draw_tl;
}
{
\msg_warning:nn {ufgrid} {tikz-needed}
}
}
\AddToShipoutPictureBG*{\AtTextUpperLeft{\zsaveposy{\g__ufgrid_prefix_vpoint_tl textupperleft}}}
\endinput