[elpa] externals/mct 35384917af 01/23: Add prototype for continuous input

[ELPA Syncer]

branch: externals/mct
commit 35384917afe410d9ce1f6a4955957c598ed677a9
Author: Protesilaos Stavrou <info@protesilaos.com>
Commit: Protesilaos Stavrou <info@protesilaos.com>

    Add prototype for continuous input
    
    Based on the idea that is discussed in issue 25:
    <https://gitlab.com/protesilaos/mct/-/issues/25>.
    
    THIS IS HIGHLY EXPERIMENTAL.
---
 mct.el | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/mct.el b/mct.el
index ef044cbf0a..cec592cc22 100644
--- a/mct.el
+++ b/mct.el
@@ -258,6 +258,20 @@ affairs."
   :type 'boolean
   :group 'mct)
 
+;; NOTE 2022-02-22: This is highly experimental!
+(defcustom mct-continuous-self-insert nil
+  "Redirect self-insertions from the Completions to the minibuffer.
+When this variable is set to non-nil value, MCT will intercept
+any call to `self-insert-command' or single character key and
+send it to the minibuffer.
+
+This practically means that while typing in the Completions, the
+input is used to narrow the list of candidates (whereas the
+default is to let the Completions use their own keys and not try
+to send the input to the minibuffer)."
+  :type 'boolean
+  :group 'mct)
+
 ;;;; Completion metadata
 
 (defun mct--this-command ()
@@ -301,6 +315,22 @@ affairs."
 
 ;;;; Basics of intersection between minibuffer and Completions' buffer
 
+;; FIXME 2022-02-22: Silence message when key binding is undefined.
+(defun mct--redirect-self-insert (&rest _args)
+  "Redirect to the minibuffer per `mct-continuous-self-insert'."
+  (when-let* ((mct-continuous-self-insert)
+              (keys (this-single-command-keys))
+              (char (aref keys 0))
+              (mini (active-minibuffer-window)))
+    (when (and (char-or-string-p char)
+               (not (event-modifiers char)))
+      (select-window mini)
+      (insert char))))
+
+(defun mct--setup-redirect-self-insert ()
+  "Set up `mct-continuous-self-insert'."
+  (add-hook 'pre-command-hook #'mct--redirect-self-insert nil t))
+
 (define-obsolete-variable-alias
   'mct-hl-line 'mct-highlight-candidate "0.3.0")
 
@@ -1170,6 +1200,7 @@ region.")
     (mct--setup-appearance)
     (mct--setup-completion-list-keymap)
     (mct--setup-highlighting)
+    (mct--setup-redirect-self-insert)
     (mct--setup-line-numbers)
     (cursor-sensor-mode)))