Re: Key layout

[Daniel J S. <dan...@ie...>]

Hans-Bernhard Broeker wrote:
> Daniel J Sebald wrote:
> 
>> gnuplot> set key right outside top right
>>                                   ^
>>         warning: Multiple horizontal position settings
>>
>> where the second occurrence of the horizontal position overrides the 
>> first occurrence?  This would be setting a precedent perhaps for 
>> multiple specs for all commands?  
> 
> 
> Actually I think we already have some precedence for repeated options. 
> See set.c:set_label(), and all the TBOOLEAN flags like set_position are 
> handled: repetition of "strong" options is treated as an error:
> 
> gnuplot> set label 'text' at 1,2 at 3,4
>                                  ^
>          extraneous or contradicting arguments in label options
> 
> The difference in your current "set key" is that some options' effects 
> are "weak", i.e. they only set a default for some other choice, which is 
> expressly allowed to be overwritten by an explicit specification.

Yes, but there are a large number where an obvious conflict is present.  How about creating a special error for this?  Something that might be called as:

int_conflict_error(c_token, "label");
int_conflict_error(c_token, "key");

Dan

PS:  I forgot the revamped key documentation:

[...]
 Syntax:
       set key {on|off} {default}
               {{inside | outside} | {lmargin | rmargin | tmargin | bmargin}
                 | {at <position>}}
               {left | right | center} {top | bottom | center}
               {vertical | horizontal} {Left | Right}
               {{no}reverse} {{no}invert}
               {samplen <sample_length>} {spacing <vertical_spacing>}
               {width <width_increment>}
               {height <height_increment>}
               {{no}autotitle {columnheader}}
               {title "<text>"} {{no}enhanced}
               {{no}box { {linestyle | ls <line_style>}
                          | {linetype | lt <line_type>}
                            {linewidth | lw <line_width>}}}
       unset key
       show key

 Plots may be drawn with no visible key by requesting `set key off` or
 `unset key`.

 Elements within the key are stacked according to `vertical` or `horizontal`.
 In the case of `vertical`, the key occupies as few columns as possible.  That
 is, elements are aligned in a column until running out of vertical space at
 which point a new column is started.  In the case of `horizontal`, the key
 occupies as few rows as possible.

 By default the key is placed in the upper right inside corner of the graph.
 The keywords `left`, `right`, `top`, `bottom`, `center`, `inside`, `outside`,
 `lmargin`, `rmargin`, `tmargin`, `bmargin` (, `above`, `over`, `below` and
 `under`) may be used to automatically place the key in other positions of the
 graph.  Also an `at <position>` may be given to indicate precisely where the
 plot should be placed.  In this case, the keywords `left`, `right`, `center`,
 `bottom` and `center` serve an analogous purpose for alignment.

 To understand positioning, the best concept is to think of a region, i.e.,
 inside/outside, or one of the margins.  Along with the region, keywords
 `left/center/right` (l/c/r) and `top/center/bottom` (t/c/b) control where
 within the particular region the key should be placed.

 When in `inside` mode, the keywords `left` (l), `right` (r), `top` (t),
 `bottom` (b), and `center` (c) push the key out toward the plot boundary as
 illustrated:

      t/l   t/c   t/r

      c/l   c     c/r

      b/l   b/c   b/r


 When in `outside` mode, automatic placement is similar to the above
 illustration, but with respect to the view, rather than the graph boundary.
 That is, a border is moved inward to make room for the key outside of
 the plotting area, although this may interfere with other labels and may
 cause an error on some devices.  The particular plot border that is moved
 depends upon the position described above and the stacking direction.  For
 options centered in one of the dimensions, there is no ambiguity about which
 border to move.  For the corners, when the stack direction is `vertical`, the
 left or right border is moved inward appropriately.  When the stack direction
 is `horizontal`, the top or bottom border is moved inward appropriately.

 The margin syntax allows automatic placement of key regardless of stack
 direction.  When one of the margins `lmargin` (lm), `rmargin` (rm),
 `tmargin` (tm), and `bmargin` (bm) is combined with a single, non-conflicting
 direction keyword, the following illustrated positions may contain the key:

           l/tm  c/tm  r/tm

      t/lm                  t/rm

      c/lm                  c/rm

      b/lm                  b/rm

           l/bm  c/bm  r/bm


 Keywords `above` and `over` are synonymous with `tmargin`.  For version
 compatibility, `above` or `over` without an additional l/c/r or stack direction
 keyword uses `center` and `horizontal`.  Keywords `below` and `under` are
 synonymous with `bmargin`.  For compatibility, `below` or `under` without an
 additional l/c/r or stack  direction keyword uses `center` and `horizontal`.  A
 further compatibility issue is that `outside` appearing without an additional
 t/b/c or stack direction keyword uses `top`, `right` and `vertical` (i.e., the
 same as t/rm above).

 The <position> can be a simple x,y,z as in previous versions, but these can
 be preceded by one of five keywords (`first`, `second`, `graph`, `screen`,
 `character`) which selects the coordinate system in which the position of
 the first sample line is specified.  See `coordinates` for more details.
 The effect of `left`, `right`, `top`, `bottom`, and `center` when <position>
 is given is to align the key as though it were text positioned using the
 label command, i.e., `left` means left align with key to the right of
 <position>, etc.
[...]