sl0ppty: pick a minimise mark that fills its cell

The buttons looked unevenly spaced. They are not: the cells are mark, space,
space, mark, space, space, mark, exactly even, which is worth checking before
touching any arithmetic.

The gap was in the glyph. An en dash is a short stroke floating in a mostly
empty cell, so it donated its own whitespace to the space beside it and sat
further from the zoom button than the zoom button sat from close, which fill
theirs. A lower one-eighth block has weight comparable to the square and the
cross, and is also the conventional minimise icon and a fair description of
where the pane actually goes.

Noted in the config beside the width warning, since it is the same class of
problem: the mark is yours to choose and the two things to know about the
choice are that emoji are drawn double-width and that a light glyph will look
badly spaced next to heavy ones.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/config.h b/src/config.h
index bbd9e0c..0bbaa9e 100644
--- a/src/config.h
+++ b/src/config.h
@@ -85,6 +85,10 @@ typedef struct {
   /* Buttons in the top-right of a pane's frame: zoom, and close. Off leaves
    * the keyboard bindings alone; it is about the affordance, not the verb. */
   bool pane_buttons;
+  /* Marks of similar visual weight, so the even spacing between the buttons
+   * reads as even: a glyph that floats in a mostly-empty cell donates its own
+   * whitespace to the gap beside it and looks further away than its
+   * neighbours, which is what an en dash did here. */
   char zoom_mark[16], zoom_on_mark[16], close_mark[16], min_mark[16];
   bool bell_indicator;
   /* What to draw. A short string rather than a fixed glyph: the obvious