sl0ppty: C-a ? shows every binding you have

A prefix-key multiplexer is unusable until you know its keys, and the only
place they were written down was a config file and a README. Now they are one
keystroke away, in a pane-shaped modal floating over the layout.

It is built from CFG.binds, not from a list of what the defaults are. Rebind
something and the sheet says what you bound; unbind it (`bind "-" "none"`)
and it stops advertising it; change the prefix and the "C-a then:" line at the
top changes with it. A cheatsheet that can disagree with the keyboard is worse
than no cheatsheet, and it would disagree the first time anybody edited a
config -- so it cannot be a list.

Bindings that share an action are merged onto one row: `h ←` is one thing to
learn, not two, and the nine tab digits are `1…9` rather than nine rows.
Keys are named the way you press them -- `\` and `?` and `H`, not "backslash"
and "S-slash" and "shift+h" -- and both spellings still parse as config, so
the sheet stays copyable.

The frame is a pane's frame, corners and title and close button, because a
dialog should wear the chrome of the program it belongs to. It fills its own
background: a modal you can read a shell prompt through is one nobody trusts.
Two columns when there is room, one when there is not, split at a group
boundary so a heading never ends a column alone, and every string clipped at
the frame -- a small terminal loses words rather than its border.

Any key dismisses it, and that key does nothing else: dismissing a modal must
not also run the thing you happened to press. A click anywhere does the same
and does not reach what it landed on.

`?` is bound twice, to shift+slash and to slash, because whether it arrives
with a modifier depends on the outer terminal: as a plain byte there is no
shift to be had, and under the kitty keyboard protocol -- which our own client
asks for -- there is. Binding one of them is a binding that works on the
machine it was written on.

1 files changed, 8 insertions, 1 deletions

diff --git a/config/config.kdl b/config/config.kdl
index 3aa0e38..dd50cdd 100644
--- a/config/config.kdl
+++ b/config/config.kdl
@@ -407,7 +407,8 @@ theme {
 // Actions: split-cols split-rows close-pane focus-left focus-right focus-up
 // focus-down focus-next resize-left resize-right resize-up resize-down
 // scroll-up scroll-down scroll-page-up scroll-page-down scroll-top
-// scroll-bottom zoom minimize rerun new-tab next-tab prev-tab select-tab-1..9 finder detach quit
+// scroll-bottom zoom minimize rerun new-tab next-tab prev-tab select-tab-1..9 finder
+// help detach quit
 // literal-prefix none
 
 keys {
@@ -448,6 +449,12 @@ keys {
 
     bind "f" "finder"
 
+    // The cheatsheet, built from whatever is bound below rather than from a
+    // list of what the defaults were -- rebind something and it says so.
+    // Bound twice because a terminal may or may not tell us `?` was shifted.
+    bind "?" "help"
+    bind "/" "help"
+
     // Scrollback. The wheel does this too, unless the program in the pane
     // wants the mouse itself, or is a full-screen program with no scrollback
     // of ours to show — then the wheel means arrow keys to it.